Update #6853
Nothing reads the Plan 9 symbol table anymore.
The last holdout was 'go tool nm', but since being rewritten in Go
it uses the standard symbol table for the binary format
(ELF, Mach-O, PE) instead.
Removing the Plan 9 symbol table saves ~15% disk space
on most binaries.
Two supporting changes included in this CL:
debug/gosym: use Go 1.2 pclntab to synthesize func-only
symbol table when there is no Plan 9 symbol table
debug/elf, debug/macho, debug/pe: ignore final EOF from ReadAt
LGTM=r
R=r, bradfitz
CC=golang-codereviews
https://golang.org/cl/65740045
The code was returning the original value rather than the cloned value
resulting in the tests not being repeatable.
Fixes#7111.
LGTM=bradfitz
R=golang-codereviews, bradfitz
CC=golang-codereviews
https://golang.org/cl/65720045
broke 32-bit builds
««« original CL description
cmd/gc, runtime: enable precisestack by default
Precisestack makes stack collection completely precise,
in the sense that there are no "used and not set" errors
in the collection of stack frames, no times where the collector
reads a pointer from a stack word that has not actually been
initialized with a pointer (possibly a nil pointer) in that function.
The most important part is interfaces: precisestack means
that if reading an interface value, the interface value is guaranteed
to be initialized, meaning that the type word can be relied
upon to be either nil or a valid interface type word describing
the data word.
This requires additional zeroing of certain values on the stack
on entry, which right now costs about 5% overall execution
time in all.bash. That cost will come down before Go 1.3
(issue 7345).
There are at least two known garbage collector bugs right now,
issues 7343 and 7344. The first happens even without precisestack.
The second I have only seen with precisestack, but that does not
mean that precisestack is what causes it. In fact it is very difficult
to explain by what precisestack does directly. Precisestack may
be exacerbating an existing problem. Both of those issues are
marked for Go 1.3 as well.
The reasons for enabling precisestack now are to give it more
time to soak and because the copying stack work depends on it.
LGTM=r
R=r
CC=golang-codereviews, iant, khr
https://golang.org/cl/64100044
»»»
TBR=r
CC=golang-codereviews
https://golang.org/cl/65230043
Precisestack makes stack collection completely precise,
in the sense that there are no "used and not set" errors
in the collection of stack frames, no times where the collector
reads a pointer from a stack word that has not actually been
initialized with a pointer (possibly a nil pointer) in that function.
The most important part is interfaces: precisestack means
that if reading an interface value, the interface value is guaranteed
to be initialized, meaning that the type word can be relied
upon to be either nil or a valid interface type word describing
the data word.
This requires additional zeroing of certain values on the stack
on entry, which right now costs about 5% overall execution
time in all.bash. That cost will come down before Go 1.3
(issue 7345).
There are at least two known garbage collector bugs right now,
issues 7343 and 7344. The first happens even without precisestack.
The second I have only seen with precisestack, but that does not
mean that precisestack is what causes it. In fact it is very difficult
to explain by what precisestack does directly. Precisestack may
be exacerbating an existing problem. Both of those issues are
marked for Go 1.3 as well.
The reasons for enabling precisestack now are to give it more
time to soak and because the copying stack work depends on it.
LGTM=r
R=r
CC=golang-codereviews, iant, khr
https://golang.org/cl/64100044
Not recording the address being taken was causing
the liveness analysis not to preserve x in the absence
of direct references to x, which in turn was making the
net test fail with GOGC=0.
In addition to the test, this fixes a bug wherein
GOGC=0 go test -short net
crashed if liveness analysis was in use (like at tip, not like Go 1.2).
TBR=ken2
CC=golang-codereviews
https://golang.org/cl/64470043
This problem was discovered by reading the code.
I have not seen it in practice, nor do I have any ideas
on how to trigger it reliably in a test. But it's still worth
fixing.
TBR=ken2
CC=golang-codereviews
https://golang.org/cl/64370046
The VARDEF placement must be before the initialization
but after any final use. If you have something like s = ... using s ...
the rhs must be evaluated, then the VARDEF, then the lhs
assigned.
There is a large comment in pgen.c on gvardef explaining
this in more detail.
This CL also includes Ian's suggestions from earlier CLs,
namely commenting the use of mode in link.h and fixing
the precedence of the ~r check in dcl.c.
This CL enables the check that if liveness analysis decides
a variable is live on entry to the function, that variable must
be a function parameter (not a result, and not a local variable).
If this check fails, it indicates a bug in the liveness analysis or
in the generated code being analyzed.
The race detector generates invalid code for append(x, y...).
The code declares a temporary t and then uses cap(t) before
initializing t. The new liveness check catches this bug and
stops the compiler from writing out the buggy code.
Consequently, this CL disables the race detector tests in
run.bash until the race detector bug can be fixed
(golang.org/issue/7334).
Except for the race detector bug, the liveness analysis check
does not detect any problems (this CL and the previous CLs
fixed all the detected problems).
The net test still fails with GOGC=0 but the rest of the tests
now pass or time out (because GOGC=0 is so slow).
TBR=iant
CC=golang-codereviews
https://golang.org/cl/64170043
The existing tests issue4463.go and issue4654.go had failures at
typechecking and did not test walking the AST.
Fixes#7272.
LGTM=khr
R=khr, rsc, iant
CC=golang-codereviews
https://golang.org/cl/60550044
A previous CL added support for cross compiling with cgo, but
missed the GOOS check in cmd/go. Remove it.
Update #4714
LGTM=iant
R=iant
CC=golang-codereviews
https://golang.org/cl/57210046
When the liveness code doesn't know a function doesn't return
(but the generated code understands that), the liveness analysis
invents a control flow edge that is not really there, which can cause
variables to seem spuriously live. This is particularly bad when the
variables are uninitialized.
TBR=iant
CC=golang-codereviews
https://golang.org/cl/63720043
The registerization code needs the function to end in a RET,
even if that RET is actually unreachable.
The liveness code needs to avoid such unreachable RETs.
It had a special case for final RET after JMP, but no case
for final RET after UNDEF. Instead of expanding the special
cases, let fixjmp - which already knows what is and is not
reachable definitively - mark the unreachable RET so that
the liveness code can identify it.
TBR=iant
CC=golang-codereviews
https://golang.org/cl/63680043
A normal RET is treated as using the return values,
but a tail jump RET does not - it is jumping to the
function that is going to fill in the return values.
If a tail jump RET is recorded as using the return values,
since nothing initializes them they will be marked as
live on entry to the function, which is clearly wrong.
Found and tested by the new code in plive.c that looks
for variables that are incorrectly live on entry.
That code is disabled for now because there are other
cases remaining to be fixed. But once it is enabled,
test/live1.go becomes a real test of this CL.
TBR=iant
CC=golang-codereviews
https://golang.org/cl/63570045
Any initialization of a variable by a block copy or block zeroing
or by multiple assignments (componentwise copying or zeroing
of a multiword variable) needs to emit a VARDEF. These cases were not.
Fixes#7205.
TBR=iant
CC=golang-codereviews
https://golang.org/cl/63650044
The test added in CL 63630043 fails on 5g and 8g because they
were not emitting the VARDEF instruction when clearing a fat
value by clearing the components. 6g had the call in the right place.
Hooray tests.
TBR=iant
CC=golang-codereviews
https://golang.org/cl/63660043
The "fat" referred to being used for multiword values only.
We're going to use it for non-fat values sometimes too.
No change other than the renaming.
TBR=iant
CC=golang-codereviews
https://golang.org/cl/63650043
Old:
prog.go:9: invalid operation: this[i] (index of type int)
New:
prog.go:9: invalid operation: this[i] (type int does not support indexing)
LGTM=r
R=golang-codereviews, r
CC=golang-codereviews
https://golang.org/cl/52540043
Before, an unnamed return value turned into an ONAME node n with n->sym
named ~anon%d, and n->orig == n.
A blank-named return value turned into an ONAME node n with n->sym
named ~anon%d but n->orig == the original blank n. Code generation and
printing uses n->orig, so that this node formatted as _.
But some code does not use n->orig. In particular the liveness code does
not know about the n->orig convention and so mishandles blank identifiers.
It is possible to fix but seemed better to avoid the confusion entirely.
Now the first kind of node is named ~r%d and the second ~b%d; both have
n->orig == n, so that it doesn't matter whether code uses n or n->orig.
After this change the ->orig field is only used for other kinds of expressions,
not for ONAME nodes.
This requires distinguishing ~b from ~r names in a few places that care.
It fixes a liveness analysis bug without actually changing the liveness code.
TBR=ken2
CC=golang-codereviews
https://golang.org/cl/63630043
Make the loop nesting depth of &x depend on where x is declared,
not on where the &x appears. The latter is only a conservative
estimate of the former. Being more careful can avoid some
variables escaping, and it is easier to reason about.
It would have avoided issue 7313, although that was still a bug
worth fixing.
Not much effect in the tree: one variable in the whole tree
is saved from a heap allocation (something in x509 parsing).
LGTM=daniel.morsing
R=daniel.morsing
CC=golang-codereviews
https://golang.org/cl/62380043
for example, we now rewrite *_Ctype_int to *C.int.
Fixes#6781.
LGTM=iant
R=golang-codereviews, rsc, iant
CC=golang-codereviews
https://golang.org/cl/36860043
Logically, the init statement is in the enclosing scopes loopdepth, not inside the for loop.
Fixes#7313.
LGTM=rsc
R=golang-codereviews, gobot, rsc
CC=golang-codereviews
https://golang.org/cl/62430043
go/build is changed to list the .m files in a package, and match them for build constraints, adding them to a new field: Package.MFiles.
The go tool is changed to support building .m files and linking in the results during CGO and SWIG builds. This means packages that create a C interface to calls Objective-C code from go are now go-gettable without producing and distributing .syso files. This change is analogous to the one in Go 1.2 made to support C++ built code.
This change doesn't support .mm files (Objective C++).
Also added support for these MFiles to go list's -json mode.
Fixes#6536.
LGTM=iant
R=golang-codereviews, iant
CC=golang-codereviews
https://golang.org/cl/60590044
c:\src\go\pkg\obj\windows_amd64\libgc.a(lex.o): In function `catcher':
c:/src/go/src/cmd/gc/lex.c:181: undefined reference to `noted'
LGTM=0intro
R=0intro
CC=golang-codereviews
https://golang.org/cl/63270043
warning: src/cmd/gc/popt.c:700 format mismatch d VLONG, arg 4
warning: src/cmd/gc/popt.c:700 format mismatch d VLONG, arg 5
LGTM=rsc
R=rsc
CC=golang-codereviews
https://golang.org/cl/62910043
copyau1 was assuming that it could deduce the type of the
middle register p->reg from the type of the left or right
argument: in CMPF F1, F2, the p->reg==2 must be a D_FREG
because p->from is F1, and in CMP R1, R2, the p->reg==2 must
be a D_REG because p->from is R1.
This heuristic fails for CMP $0, R2, which was causing copyau1
not to recognize p->reg==2 as a reference to R2, which was
keeping it from properly renaming the register use when
substituting registers.
cmd/5c has the right approach: look at the opcode p->as to
decide the kind of register. It is unclear where 5g's copyau1
came from; perhaps it was an attempt to avoid expanding 5c's
a2type to include new instructions used only by 5g.
Copy a2type from cmd/5c, expand to include additional instructions,
and make it crash the compiler if asked about an instruction
it does not understand (avoid silent bugs in the future if new
instructions are added).
Should fix current arm build breakage.
While we're here, fix the print statements dumping the pred and
succ info in the asm listing to pass an int arg to %.4ud
(Prog.pc is a vlong now, due to the liblink merge).
TBR=ken2
CC=golang-codereviews
https://golang.org/cl/62730043
We now use the %A, %D, %P, and %R routines from liblink
across the board.
Fixes#7178.
Fixes#7055.
LGTM=iant
R=golang-codereviews, gobot, rsc, dave, iant, remyoudompheng
CC=golang-codereviews
https://golang.org/cl/49170043
Second part of the solaris/amd64 linker changes: relocation and symbol table.
LGTM=iant
R=golang-codereviews, iant
CC=golang-codereviews
https://golang.org/cl/61330043
The UNDEF instruction was listed in the instruction data as having the next instruction in the stream as its successor. This confused the optimizer into adding a load where it wasn't needed, in turn confusing the liveness analysis pass for GC bitmaps into thinking that the variable was live.
Fixes#7229.
LGTM=iant, rsc
R=golang-codereviews, bradfitz, iant, dave, rsc
CC=golang-codereviews
https://golang.org/cl/56910045
At present, when a package identifier is used outside of a selector expression, gc gives the error "use of package %S outside selector". However, in the selector expression x.f, the spec defines f as the selector. This change makes the error clearer.
Fixes#7133.
LGTM=rsc
R=golang-codereviews, rsc
CC=golang-codereviews
https://golang.org/cl/50060047
Fixes#7293.
Update #7261
The bsd ld(1) does not understand $ORIGIN and has restrictions on using -rpath when using clang(1), the default compiler on darwin.
LGTM=iant
R=iant
CC=golang-codereviews
https://golang.org/cl/58480045
Fixes#7260.
Fix three broken tests in test.bash
The test for issue 4568 was confused by go $ACTION . producing a package root of "", avoiding this mode fixes the test but weakens the test.
The test for issue 4773 was broken on linux because math/Rand would fail to resolve as a package causing the test for duplicates to be skipped.
Finally, the last breakage was a small change in the error message.
Also, add test for foldDup.
LGTM=iant
R=iant, rsc
CC=golang-codereviews
https://golang.org/cl/61070044
rsc suggested that we split the whole linker changes into three parts.
This is the first one, mostly dealing with adding Hsolaris.
LGTM=iant
R=golang-codereviews, iant, dave
CC=golang-codereviews
https://golang.org/cl/54210050
This changes makes sgen and clearfat use unaligned instructions for
the trailing bytes, like the runtime memmove does, resulting in faster
code when manipulating types whose size is not a multiple of 8.
LGTM=khr
R=khr, iant, rsc
CC=golang-codereviews
https://golang.org/cl/51740044
Introduce two new environment variables, CC_FOR_TARGET and CXX_FOR_TARGET.
CC_FOR_TARGET defaults to CC and is used when compiling for GOARCH, while
CC remains for compiling for GOHOSTARCH.
CXX_FOR_TARGET defaults to CXX and is used when compiling C++ code for
GOARCH.
CGO_ENABLED defaults to disabled when cross compiling and has to be
explicitly enabled.
Update #4714
LGTM=minux.ma, iant
R=golang-codereviews, minux.ma, iant, rsc, dominik.honnef
CC=golang-codereviews
https://golang.org/cl/57100043
CL 56120043 fixed and cleaned up TLS on ARM after introducing liblink, but
left flag_shared broken. This CL restores the (unsupported) flag_shared
behaviour by simply rewriting access to $runtime.tlsgm(SB) with
runtime.tlsgm(SB), to compensate for the extra indirection when going from
the R_ARM_TLS_LE32 relocation to the R_ARM_TLS_IE32 relocation.
Also, remove unnecessary symbol lookup left after 56120043.
LGTM=iant
R=iant, rsc
CC=golang-codereviews
https://golang.org/cl/57000043
CL 56120043 fixed TLS handling on ARM after the introduction of
liblink but left older ARM processors broken.
Before liblink, the MRC instruction was replaced with a fallback
on older ARMs. CL 56120043 removed that, because the rewrite matched
bit patterns on the AWORD pseudo-instruction and could therefore change
unrelated AWORDs that happened to match.
This CL adds an AMRC instruction to encode both MRC and MCR previously
encoded as AWORDs. Then, in liblink, the AMRC instructions are either
rewritten to AWORD, or, on goarm < 7, replaced with a branch to the
fallback.
./all.bash completes successfully on an ARMv7 with either GOARM=7 or
GOARM=5. I have verified that the fallback is indeed present in both
runtime.save_gm and runtime.load_gm when GOARM=5 but not when GOARM=7.
If all goes well, this should fix the armv5 builders.
LGTM=iant
R=iant, rsc
CC=golang-codereviews
https://golang.org/cl/55540044
Array values are comparable if values of the array element type
are comparable.
Fixes#6526.
LGTM=khr
R=rsc, bradfitz, khr
CC=golang-codereviews
https://golang.org/cl/58580043
In external link mode the linker explicitly adds the string
constant "runtime/cgo". It adds the string constant using the
same symbol name as the compiler, but a different format. The
compiler assumes that the string data immediately follows the
string header, but the linker puts the two in different
sections. The result is bad string data when the compiler
sees "runtime/cgo" used as a string constant.
The compiler assumption is in datastring in [568]g/gobj.c.
The linker layout is in addstrdata in ld/data.c. The compiler
assumption is valid for string literals. The linker is not
creating a string literal, so its assumption is also valid.
There are a few ways to avoid this problem. This patch fixes
it by only doing the fake import of runtime/cgo if necessary,
and by only creating the string symbol if necessary.
Fixes#7234.
LGTM=dvyukov
R=golang-codereviews, dvyukov, bradfitz
CC=golang-codereviews
https://golang.org/cl/58410043
The code is copied from cmd/6g.
Empirically, all branch targets are nil in this code so
something is still wrong, but at least this stops 8g -S
from crashing.
Update #7178
LGTM=dave, iant
R=iant, dave
CC=golang-codereviews
https://golang.org/cl/58400043
Under some circumstances linking a test binary with gccgo can fail, because
the installed version of the library ends up before the version built for the
test on the linker command line.
This admittedly slightly hackish fix fixes this by putting the library archives
on the linker command line in the order that a pre-order depth first traversal
of the dependencies gives them, which has the side effect of always putting the
version of the library built for the test first.
Fixes#6768
LGTM=rsc
R=golang-codereviews, minux.ma, gobot, rsc, dave
CC=golang-codereviews
https://golang.org/cl/28050043
There is more zeroing than I would like right now -
temporaries used for the new map and channel runtime
calls need to be eliminated - but it will do for now.
This CL only has an effect if you are building with
GOEXPERIMENT=precisestack ./all.bash
(or make.bash). It costs about 5% in the overall time
spent in all.bash. That number will come down before
we make it on by default, but this should be enough for
Keith to try using the precise maps for copying stacks.
amd64 only (and it's not really great generated code).
TBR=khr, iant
CC=golang-codereviews
https://golang.org/cl/56430043
The addition of TLS to ARM rewrote the MRC instruction
differently depending on whether we were using internal
or external linking mode. That's clearly not okay, since we
don't know that during compilation, which is when we now
generate the code. Also, because the change did not introduce
a real MRC instruction but instead just macro-expanded it
in the assembler, liblink is rewriting a WORD instruction that
may actually be looking for that specific constant, which would
lead to very unexpected results. It was also using one value
that happened to be 8 where a different value that also
happened to be 8 belonged. So the code was correct for those
values but not correct in general, and very confusing.
Throw it all away.
Replace with the following. There is a linker-provided symbol
runtime.tlsgm with a value (address) set to the offset from the
hardware-provided TLS base register to the g and m storage.
Any reference to that name emits an appropriate TLS relocation
to be resolved by either the internal linker or the external linker,
depending on the link mode. The relocation has exactly the
semantics of the R_ARM_TLS_LE32 relocation, which is what
the external linker provides.
This symbol is only used in two routines, runtime.load_gm and
runtime.save_gm. In both cases it is now used like this:
MRC 15, 0, R0, C13, C0, 3 // fetch TLS base pointer
MOVW $runtime·tlsgm(SB), R2
ADD R2, R0 // now R0 points at thread-local g+m storage
It is likely that this change breaks the generation of shared libraries
on ARM, because the MOVW needs to be rewritten to use the global
offset table and a different relocation type. But let's get the supported
functionality working again before we worry about unsupported
functionality.
LGTM=dave, iant
R=iant, dave
CC=golang-codereviews
https://golang.org/cl/56120043
It implements parsing of the header and symbol table for both
32-bit and 64-bit Plan 9 binaries. The nm tool was updated to
use this package.
R=rsc, aram
CC=golang-codereviews
https://golang.org/cl/49970044
Now that liblink is compiled into the compilers and assemblers,
it must not refer to the "linkmode", since that is not known until
link time. This CL makes the ARM support no longer use linkmode,
which fixes a bug with cgo binaries that contain their own TLS
variables.
The x86 code must also remove linkmode; that is issue 7164.
Fixes#6992.
R=golang-codereviews, iant
CC=golang-codereviews
https://golang.org/cl/55160043
The escape analysis works by tracing assignment paths from
variables that start with pointer type, or addresses of variables
(addresses are always pointers). It does allow non-pointers
in the path, so that in this code it sees x's value escape into y:
var x *[10]int
y := (*int)(unsafe.Pointer(uintptr(unsafe.Pointer(x))+32))
It must allow uintptr in order to see through this kind of
"pointer arithmetic".
It also traces such values if they end up as uintptrs passed to
functions. This used to be important because packages like
encoding/gob passed around uintptrs holding real pointers.
The introduction of precise collection of stacks has forced
code to be more honest about which declared stack variables
hold pointers and which do not. In particular, the garbage
collector no longer sees pointers stored in uintptr variables.
Because of this, packages like encoding/gob have been fixed.
There is not much point in the escape analysis accepting
uintptrs as holding pointers at call boundaries if the garbage
collector does not.
Excluding uintptr-valued arguments brings the escape
analysis in line with the garbage collector and has the
useful side effect of making arguments to syscall.Syscall
not appear to escape.
That is, this CL should yield the same benefits as
CL 45930043 (rolled back in CL 53870043), but it does
so by making uintptrs less special, not more.
R=golang-codereviews, iant
CC=golang-codereviews
https://golang.org/cl/53940043
Vararg C calls present a problem for the GC because the
argument types are not derivable from the signature. Remove
them by passing pointers to channel elements instead of the
channel elements directly.
R=golang-codereviews, gobot, rsc, dvyukov
CC=golang-codereviews
https://golang.org/cl/53430043
The compiler change is an ugly hack.
We can do better.
««« original CL description
syscall: mark arguments to Syscall as noescape
Heap arguments to "async" syscalls will break when/if we have moving GC anyway.
With this change is must not break until moving GC, because a user must
reference the object in Go to preserve liveness. Otherwise the code is broken already.
Reduces number of leaked params from 125 to 36 on linux.
R=golang-codereviews, mikioh.mikioh, bradfitz
CC=cshapiro, golang-codereviews, khr, rsc
https://golang.org/cl/45930043
»»»
R=golang-codereviews, r
CC=bradfitz, dvyukov, golang-codereviews
https://golang.org/cl/53870043
Heap arguments to "async" syscalls will break when/if we have moving GC anyway.
With this change is must not break until moving GC, because a user must
reference the object in Go to preserve liveness. Otherwise the code is broken already.
Reduces number of leaked params from 125 to 36 on linux.
R=golang-codereviews, mikioh.mikioh, bradfitz
CC=cshapiro, golang-codereviews, khr, rsc
https://golang.org/cl/45930043
This CL makes the bitmaps a little more precise about variables
that have their address taken but for which the address does not
escape to the heap, so that the variables are kept in the stack frame
rather than allocated on the heap.
The code before this CL handled these variables by treating every
return statement as using every such variable and depending on
liveness analysis to essentially treat the variable as live during the
entire function. That approach has false positives and (worse) false
negatives. That is, it's both sloppy and buggy:
func f(b1, b2 bool) { // x live here! (sloppy)
if b2 {
print(0) // x live here! (sloppy)
return
}
var z **int
x := new(int)
*x = 42
z = &x
print(**z) // x live here (conservative)
if b2 {
print(1) // x live here (conservative)
return
}
for {
print(**z) // x not live here (buggy)
}
}
The first two liveness annotations (marked sloppy) are clearly
wrong: x cannot be live if it has not yet been declared.
The last liveness annotation (marked buggy) is also wrong:
x is live here as *z, but because there is no return statement
reachable from this point in the code, the analysis treats x as dead.
This CL changes the liveness calculation to mark such variables
live exactly at points in the code reachable from the variable
declaration. This keeps the conservative decisions but fixes
the sloppy and buggy ones.
The CL also detects ambiguously live variables, those that are
being marked live but may not actually have been initialized,
such as in this example:
func f(b1 bool) {
var z **int
if b1 {
x := new(int)
*x = 42
z = &x
} else {
y := new(int)
*y = 54
z = &y
}
print(**z) // x, y live here (conservative)
}
Since the print statement is reachable from the declaration of x,
x must conservatively be marked live. The same goes for y.
Although both x and y are marked live at the print statement,
clearly only one of them has been initialized. They are both
"ambiguously live".
These ambiguously live variables cause problems for garbage
collection: the collector cannot ignore them but also cannot
depend on them to be initialized to valid pointer values.
Ambiguously live variables do not come up too often in real code,
but recent changes to the way map and interface runtime functions
are invoked has created a large number of ambiguously live
compiler-generated temporary variables. The next CL will adjust
the analysis to understand these temporaries better, to make
ambiguously live variables fairly rare.
Once ambiguously live variables are rare enough, another CL will
introduce code at the beginning of a function to zero those
slots on the stack. At that point the garbage collector and the
stack copying routines will be able to depend on the guarantee that
if a slot is marked as live in a liveness bitmap, it is initialized.
R=khr
CC=golang-codereviews, iant
https://golang.org/cl/51810043
Replace the pack command, a C program, with a clean reimplementation in Go.
It does not need to reproduce the full feature set and it is no longer used by
the build chain, but has a role in looking inside archives created by the build
chain directly.
Since it's not in C, it is no longer build by dist, so remove it from cmd/dist and
make it a "tool" in cmd/go terminology.
Fixes#2705
R=rsc, dave, minux.ma, josharian
CC=golang-codereviews
https://golang.org/cl/52310044
Map iteration previously started from a random bucket, but walked each
bucket from the beginning. Now, iteration always starts from the first
bucket and walks each bucket starting at a random offset. For
performance, the random offset is selected at the start of iteration
and reused for each bucket.
Iteration over a map with 8 or fewer elements--a single bucket--will
now be non-deterministic. There will now be only 8 different possible
map iterations.
Significant benchmark changes, on my OS X laptop (rough but consistent):
benchmark old ns/op new ns/op delta
BenchmarkMapIter 128 121 -5.47%
BenchmarkMapIterEmpty 4.26 4.45 +4.46%
BenchmarkNewEmptyMap 114 111 -2.63%
Fixes#6719.
R=khr, bradfitz
CC=golang-codereviews
https://golang.org/cl/47370043
Having these flags misleads people into thinking they're acceptable
for code that "must be gofmt'd".
If an organization wishes to use gofmt internally with
different settings, they can fork gofmt trivially. But "gofmt"
as used by the community with open source Go code should not
support these old knobs.
Also removes the -comments flag.
Fixes#7101
R=r, gri
CC=golang-codereviews
https://golang.org/cl/52170043
For historical reasons, temp was returning a copy
of the created Node*, not the original Node*.
This meant that if analysis recorded information in the
returned node (for example, n->addrtaken = 1), the
analysis would not show up on the original Node*, the
one kept in fn->dcl and consulted during liveness
bitmap creation.
Correct this, and watch for it when setting addrtaken.
Fixes#7083.
R=khr, dave, minux.ma
CC=golang-codereviews
https://golang.org/cl/51010045
The golden file for link.hello.darwin.amd64
was a little ahead of the checked-in code.
R=iant
TBR=iant
CC=golang-codereviews
https://golang.org/cl/51870043
Related changes included in this CL:
- Add explicit start symbol to Prog.
- Add omitRuntime bool to Prog.
- Introduce p.Packages[""] to hold automatic symbols
- Add SymOrder to Prog to preserve symbol order.
- Add layout test (and fix bug that was putting everything in text section).
R=iant
CC=golang-codereviews
https://golang.org/cl/51260045
The hex dumps will diff better, and I hope they will avoid
a repeat of http://bugs.debian.org/716853.
The CL will probably show the testdata diffs as "binary",
but in fact the binary versions are being replaced by
textual hex dumps (output of hexdump -C).
R=iant
CC=golang-codereviews
https://golang.org/cl/51000044
Nodes of goto statements were corrupted when written
to export data.
Fixes#7023.
R=rsc, dave, minux.ma
CC=golang-codereviews
https://golang.org/cl/46190043
Everything was doing this already with #defines.
Do it right.
R=golang-codereviews, jsing, 0intro, iant
CC=golang-codereviews
https://golang.org/cl/49090043
When printing the size, we often want to sort on that key.
Because it's used when looking for large things, make the
sort go from largest to smallest.
Perfect recreation of CL 45150044, which was lost to some blunder.
R=golang-codereviews, gobot, rsc
CC=golang-codereviews
https://golang.org/cl/48500044
When recompiling a package whose basename is the name of a standard
package for testing with gccgo, a .o file with the basename of the
package being tested was being placed in the _test/ directory where the
compilation of the test binary then found it when looking for the
standard library package.
This change puts the object files in a separate directory.
Fixes#6793
R=golang-codereviews, dave, gobot, rsc, iant
CC=golang-codereviews
https://golang.org/cl/27650045
This change adds solaris to the list of supported operating
systems and allows cmd/dist to be built on Solaris.
This CL has to come first because we want the tools to ignore
solaris-specific files until the whole port is integrated.
R=golang-codereviews, jsing, rsc, minux.ma
CC=golang-codereviews
https://golang.org/cl/35900045
[]byte("string") was simplifying to
[]byte{0: 0x73, 1: 0x74, 2: 0x72, 3: 0x69, 4: 0x6e, 5: 0x67},
but that latter form takes up much more memory in the compiler.
Preserve the string form and recognize it to turn global variables
initialized this way into linker-initialized data.
Reduces the compiler memory footprint for a large []byte initialized
this way from approximately 10 kB/B to under 100 B/B.
See also issue 6643.
R=golang-codereviews, r, iant, oleku.konko, dave, gobot, bradfitz
CC=golang-codereviews
https://golang.org/cl/15930045
This change fixes a serious performance regression
with reflect.Value growing to 4 words instead of 3.
The json benchmark was ~50% slower, with this change
it is ~5% slower (and the binary is 0.5% larger).
Longer term, we probably need to rethink our copy
generation. Using REP is really expensive time-wise.
But inlining the copy grows the binary.
R=golang-codereviews, r
CC=golang-codereviews
https://golang.org/cl/44990043
As much as 7x speedup on some programs, cuts all.bash time by 20%.
Change splicebefore function from O(n) to O(1).
The approach was suggested by Carl during the code's review
but apparently did not make it into the tree.
It makes a huge difference on huge programs.
Make twobitwalktype1 slightly faster by using & instead of %.
Really it needs to be cached; left a note to that effect.
(Not a complete fix, hence the ½.)
big.go (output of test/chan/select5.go)
47.53u 0.50s 48.14r before this CL
7.09u 0.47s 7.59r with splicebefore change (6.7x speedup)
6.15u 0.42s 6.59r with twobitwalktype1 change (1.15x speedup; total 7.7x)
slow.go (variant of program in go.text, by mpvl)
77.75u 2.11s 80.03r before this CL
24.40u 1.97s 26.44r with splicebefore change (3.2x speedup)
18.12u 2.19s 20.38r with twobitwalktype1 change (1.35x speedup; total 4.3x)
test/run
150.63u 49.57s 81.08r before this CL
88.01u 45.60s 46.65r after this CL (1.7x speedup)
all.bash
369.70u 115.64s 256.21r before this CL
298.52u 110.35s 214.67r after this CL (1.24x speedup)
The test programs are at
https://rsc.googlecode.com/hg/testdata/big.go (36k lines, 276kB)
https://rsc.googlecode.com/hg/testdata/slow.go (7k lines, 352kB)
R=golang-codereviews, gobot, r
CC=cshapiro, golang-codereviews
https://golang.org/cl/43210045
Eventually we will want to bypass DATA for everything,
but the relocations are not standardized well enough across
architectures to make that possible.
This did not help as much as I expected, but it is definitely better.
It shaves maybe 1-2% off all.bash depending on how much you
trust the timings of a single run:
Before: 241.139r 362.702u 112.967s
After: 234.339r 359.623u 111.045s
R=golang-codereviews, gobot, r, iant
CC=golang-codereviews
https://golang.org/cl/44650043
These no longer work; removing them makes other refactoring easier.
The code for pack P being deleted in this CL does not work either.
I created issue 6989 to track restoring this functionality (probably not
until pack is written in Go).
R=golang-codereviews, bradfitz
CC=golang-codereviews
https://golang.org/cl/44300043
The code is all about tags, and the cmd/go documentation
said to look in the go/build documentation for information
about tags, but the documentation said nothing about tags,
only build constraints. Make things clearer.
R=golang-dev, adg, rsc
CC=golang-dev
https://golang.org/cl/44100043
Make hostobj work on OpenBSD 5.3/5.4/-current - these have PIE
enabled by default and linking fails since the Go linker generates
objects that are neither PIC nor PIE.
Fixes#5067
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/7572049
warning: src/cmd/6g/reg.c:671 format mismatch d VLONG, arg 4
warning: src/cmd/gc/pgen.c:230 set and not used: oldstksize
warning: src/cmd/gc/plive.c:877 format mismatch lx UVLONG, arg 2
warning: src/cmd/gc/walk.c:2878 set and not used: cbv
warning: src/cmd/gc/walk.c:2885 set and not used: hbv
warning: src/cmd/ld/data.c:198 format mismatch s IND FUNC(IND CHAR) INT, arg 2
warning: src/cmd/ld/data.c:230 format mismatch s IND FUNC(IND CHAR) INT, arg 2
warning: src/cmd/ld/dwarf.c:1517 set and not used: pc
warning: src/cmd/ld/elf.c:1507 format mismatch d VLONG, arg 2
warning: src/cmd/ld/ldmacho.c:509 set and not used: dsymtab
R=golang-dev, gobot, rsc
CC=golang-dev
https://golang.org/cl/36740045
warning: src/libmach/sym.c:1861 non-interruptable temporary
warning: src/cmd/8l/../ld/pcln.c:29 set and not used: p
R=golang-dev, gobot, rsc
CC=golang-dev
https://golang.org/cl/40500043
All packages now use the -pack option to the compiler.
For a pure Go package, that's enough.
For a package with additional C and assembly files, the extra
archive entries can be added directly (by concatenation)
instead of by invoking go tool pack.
These changes make it possible to rewrite cmd/pack in Go.
R=iant, r
CC=golang-dev
https://golang.org/cl/42910043
All packages now use the -pack option to the compiler.
For a pure Go package, that's enough.
For a package with additional C and assembly files, the extra
archive entries can be added directly (by concatenation)
instead of by invoking go tool pack.
These changes make it possible to rewrite cmd/pack in Go.
R=iant, r
CC=golang-dev
https://golang.org/cl/42890043
The -pack flag causes 5g, 6g, 8g to write a Go archive directly,
instead of requiring the use of 'go tool pack' to convert the .5/.6/.8
to .a format.
Writing directly avoids the copy and also avoids having the
export data stored twice in the archive (once in __.PKGDEF,
once in .5/.6/.8).
A separate CL will enable the use of this flag by cmd/go.
Other build systems that do not know about -pack will be unaffected.
The changes to cmd/ld handle a minor simplification to the format:
an unused section is removed.
R=iant, r
CC=golang-dev
https://golang.org/cl/42880043
This particular test would never pass unless you had GOROOT set in your
environment. This changes makes the test use the baked-in GOROOT, as it
does with GOOS and GOARCH.
R=golang-dev, dave, iant
CC=golang-dev
https://golang.org/cl/43080043
The immediate goal is to support the new object file format,
which libmach (nm's support library) does not understand.
Rather than add code to libmach or reengineer liblink to
support this new use, just write it in Go.
The C version of nm reads the Plan 9 symbol table stored in
Go binaries, now otherwise unused.
This reimplementation uses the standard symbol table for
the corresponding file format instead, bringing us one step
closer to removing the Plan 9 symbol table from Go binaries.
Tell cmd/dist not to build cmd/nm anymore.
Tell cmd/go to install cmd/nm in the tool directory.
R=golang-dev, r, iant, alex.brainman
CC=golang-dev
https://golang.org/cl/40600043
- new object file reader/writer (liblink/objfile.c)
- remove old object file writing routines
- add pcdata iterator
- remove all trace of "line number stack" and "path fragments" from
object files, linker (!!!)
- dwarf now writes a single "compilation unit" instead of one per package
This CL disables the check for chains of no-split functions that
could overflow the stack red zone. A future CL will attack the problem
of reenabling that check (issue 6931).
This CL is just the liblink and cmd/ld changes.
There are minor associated adjustments in CL 37030045.
Each depends on the other.
R=golang-dev, dave, iant
CC=golang-dev
https://golang.org/cl/39680043
- add buffered stdout to all tools and provide to link ctxt.
- avoid extra \n before ! in .6 files written by assemblers
(makes them match the C compilers).
- use linkwriteobj instead of linkouthist+linkwritefuncs.
- in assemblers and C compilers, record pc explicitly in Prog,
for use by liblink.
- in C compilers, preserve jump target links.
- in Go compilers (gsubr.c) attach gotype directly to
corresponding LSym* instead of rederiving from instruction stream.
- in Go compilers, emit just one definition for runtime.zerovalue
from each compilation.
This CL consists entirely of small adjustments.
The heavy lifting is in CL 39680043.
Each depends on the other.
R=golang-dev, dave, iant
CC=golang-dev
https://golang.org/cl/37030045
When I renamed LAddr back to Addr (before sending the
original linker CLs), I missed the .y files in my global substitute.
Since the .y files are only processed when running make in
one of those directories (not during all.bash), they were
behind the generated files.
R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/40770044
warning: src/cmd/8c/list.c:124 format mismatch d VLONG, arg 3
warning: src/cmd/8c/list.c:134 format mismatch d VLONG, arg 3
warning: src/cmd/8c/list.c:142 format mismatch d VLONG, arg 3
warning: src/cmd/8c/list.c:152 format mismatch d VLONG, arg 3
warning: src/cmd/8c/list.c:156 format mismatch d VLONG, arg 4
warning: src/cmd/8c/list.c:160 format mismatch d VLONG, arg 4
warning: src/cmd/8c/list.c:165 format mismatch d VLONG, arg 4
warning: src/cmd/8c/list.c:167 format mismatch d VLONG, arg 3
warning: src/cmd/8c/list.c:172 format mismatch d VLONG, arg 4
warning: src/cmd/8c/list.c:174 format mismatch d VLONG, arg 3
warning: src/cmd/8c/list.c:178 format mismatch d VLONG, arg 3
warning: src/cmd/8c/list.c:184 format mismatch d VLONG, arg 3
warning: src/cmd/8g/list.c:91 format mismatch d VLONG, arg 4
warning: src/cmd/8g/list.c:100 format mismatch d VLONG, arg 4
warning: src/cmd/8g/list.c:114 format mismatch d VLONG, arg 5
warning: src/cmd/8g/list.c:118 format mismatch d VLONG, arg 5
warning: src/cmd/8g/list.c:122 format mismatch d VLONG, arg 5
warning: src/cmd/8g/list.c:126 format mismatch d VLONG, arg 5
warning: src/cmd/8g/list.c:136 format mismatch d VLONG, arg 4
warning: src/cmd/8l/list.c:107 format mismatch d VLONG, arg 4
warning: src/cmd/8l/list.c:125 format mismatch ux VLONG, arg 4
warning: src/cmd/8l/list.c:128 format mismatch ux VLONG, arg 4
warning: src/cmd/8l/list.c:130 format mismatch d VLONG, arg 4
warning: src/cmd/8l/list.c:134 format mismatch d VLONG, arg 5
warning: src/cmd/8l/list.c:138 format mismatch d VLONG, arg 6
warning: src/cmd/8l/list.c:143 format mismatch d VLONG, arg 5
warning: src/cmd/8l/list.c:148 format mismatch d VLONG, arg 5
warning: src/cmd/8l/list.c:150 format mismatch d VLONG, arg 4
warning: src/cmd/8l/list.c:154 format mismatch d VLONG, arg 4
warning: src/cmd/8l/list.c:158 format mismatch d VLONG, arg 4
warning: src/cmd/8l/obj.c:132 format mismatch ux VLONG, arg 2
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/39710043
The funcdata symbol incorrectly named the dead value map the
dead pointer map. The dead value map identifies all dead
values, including pointers and non-pointers, in a stack frame.
The purpose of this map is to allow the runtime to poison
locations of dead data to catch lost invariants.
R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/38670043
That option turns off word wrapping of individual
error messages generated by clang. The wrapping
makes the errors harder to read and conflicts with the
idea of a terminal window that can be resized.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/35810043
Preparation for golang.org/s/go13linker work.
This CL does not build by itself. It depends on 35740044
and 35790044 and will be submitted at the same time.
R=iant
CC=golang-dev
https://golang.org/cl/34590045
Preparation for golang.org/s/go13linker work.
This CL does not build by itself. It depends on 35740044
and 35790044 and will be submitted at the same time.
R=iant
CC=golang-dev
https://golang.org/cl/34580044
Preparation for golang.org/s/go13linker work.
This CL does not build by itself. It depends on 35740044
and 35790044 and will be submitted at the same time.
R=iant
CC=golang-dev
https://golang.org/cl/35830043
There is an enormous amount of code moving around in this CL,
but the code is the same, and it is invoked in the same ways.
This CL is preparation for the new linker structure, not the new
structure itself.
The new library's definition is in include/link.h.
The main change is the use of a Link structure to hold all the
linker-relevant state, replacing the smattering of global variables.
The Link structure should both make it clearer which state must
be carried around and make it possible to parallelize more easily
later.
The main body of the linker has moved into the architecture-independent
cmd/ld directory. That includes the list of known header types, so the
distinction between Hplan9x32 and Hplan9x64 is removed (no other
header type distinguished 32- and 64-bit formats), and code for unused
formats such as ipaq kernels has been deleted.
The code being deleted from 5l, 6l, and 8l reappears in liblink or in ld.
Because multiple files are being merged in the liblink directory,
it is not possible to show the diffs nicely in hg.
The Prog and Addr structures have been unified into an
architecture-independent form and moved to link.h, where they will
be shared by all tools: the assemblers, the compilers, and the linkers.
The unification makes it possible to write architecture-independent
traversal of Prog lists, among other benefits.
The Sym structures cannot be unified: they are too fundamentally
different between the linker and the compilers. Instead, liblink defines
an LSym - a linker Sym - to be used in the Prog and Addr structures,
and the linker now refers exclusively to LSyms. The compilers will
keep using their own syms but will fill out the corresponding LSyms in
the Prog and Addr structures.
Although code from 5l, 6l, and 8l is now in a single library, the
code has been arranged so that only one architecture needs to
be linked into a particular program: 5l will not contain the code
needed for x86 instruction layout, for example.
The object file writing code in liblink/obj.c is from cmd/gc/obj.c.
Preparation for golang.org/s/go13linker work.
This CL does not build by itself. It depends on 35740044
and will be submitted at the same time.
R=iant
CC=golang-dev
https://golang.org/cl/35790044
In addition to adding the library, change the way the anames array is created.
Previously, it was written to src/cmd/6l/enam.c (and similarly for 5l and 8l)
and each of the other tools (6g, 6c, 6a) compiled the 6l/enam.c file in addition
to their own sources.
Now that there is a library shared by all these programs, move the anames
array into that library. To eliminate name conflicts, name the array after
the architecture letter: anames5, anames6, anames8.
First step to linker cleanup (golang.org/s/go13linker).
This CL does not build by itself. It depends on the CLs introducing
liblink and changing commands to use it.
R=iant
CC=golang-dev
https://golang.org/cl/35740044
We are not clearing dead values in the garbage collector so it
is not worth the RSS cost to materialize the data and write it
out to the binary.
R=golang-dev, iant, cshapiro
CC=golang-dev
https://golang.org/cl/38650043
This change allows the garbage collector to examine stack
slots that are determined as live and containing a pointer
value by the garbage collector. This results in a mean
reduction of 65% in the number of stack slots scanned during
an invocation of "GOGC=1 all.bash".
Unfortunately, this does not yet allow garbage collection to
be precise for the stack slots computed as live. Pointers
confound the determination of what definitions reach a given
instruction. In general, this problem is not solvable without
runtime cost but some advanced cooperation from the compiler
might mitigate common cases.
R=golang-dev, rsc, cshapiro
CC=golang-dev
https://golang.org/cl/14430048
Pass as a slice of strings instead. For 2-5 strings, implement
dedicated routines so no slices are needed.
static call counts in the go binary:
2 strings: 342 occurrences
3 strings: 98
4 strings: 30
5 strings: 13
6+ strings: 14
Why? C varags, bad for stack scanning and copying.
R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/36380043
This change is part of the plan to get rid of all vararg C calls
which are a pain for getting exact stack scanning.
We allocate a chunk of zero memory to return a pointer to when a
map access doesn't find the key. This is simpler than returning nil
and fixing things up in the caller. Linker magic allocates a single
zero memory area that is shared by all (non-reflect-generated) map
types.
Passing things by reference gets rid of some copies, so it speeds
up code with big keys/values.
benchmark old ns/op new ns/op delta
BenchmarkBigKeyMap 34 31 -8.48%
BenchmarkBigValMap 37 30 -18.62%
BenchmarkSmallKeyMap 26 23 -11.28%
R=golang-dev, dvyukov, khr, rsc
CC=golang-dev
https://golang.org/cl/14794043
Clang does not record the "size" field for pointer types,
so we must insert the size ourselves. We were already
doing this, but only for the case of pointer types.
For an array of pointer types, the setting of the size for
the nested pointer type was happening after the computation
of the size of the array type, meaning that the array type
was always computed as 0 bytes. Delay the size computation.
This bug happens on all Clang systems, not just FreeBSD.
Our test checked that cgo wrote something, not that it was correct.
FreeBSD's default clang rejects array[0] as a C struct field,
so it noticed the incorrect sizes. But the sizes were incorrect
everywhere.
Update testcdefs to check the output has the right semantics.
Fixes#6292.
R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/22840043
Two bugs:
1. The first iteration of the traceback always uses LR when provided,
which it is (only) during a profiling signal, but in fact LR is correct
only if the stack frame has not been allocated yet. Otherwise an
intervening call may have changed LR, and the saved copy in the stack
frame should be used. Fix in traceback_arm.c.
2. The division runtime call adds 8 bytes to the stack. In order to
keep the traceback routines happy, it must copy the saved LR into
the new 0(SP). Change
SUB $8, SP
into
MOVW 0(SP), R11 // r11 is temporary, for use by linker
MOVW.W R11, -8(SP)
to update SP and 0(SP) atomically, so that the traceback always
sees a saved LR at 0(SP).
Fixes#6681.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/19910044
The CL causes misc/cgo/test to fail randomly.
I suspect that the problem is the use of a division instruction
in usleep, which can be called while trying to acquire an m
and therefore cannot store the denominator in m.
The solution to that would be to rewrite the code to use a
magic multiply instead of a divide, but now we're getting
pretty far off the original code.
Go back to the original in preparation for a different,
less efficient but simpler fix.
««« original CL description
cmd/5l, runtime: make ARM integer division profiler-friendly
The implementation of division constructed non-standard
stack frames that could not be handled by the traceback
routines.
CL 13239052 left the frames non-standard but fixed them
for the specific case of a divide-by-zero panic.
A profiling signal can arrive at any time, so that fix
is not sufficient.
Change the division to store the extra argument in the M struct
instead of in a new stack slot. That keeps the frames bog standard
at all times.
Also fix a related bug in the traceback code: when starting
a traceback, the LR register should be ignored if the current
function has already allocated its stack frame and saved the
original LR on the stack. The stack copy should be used, as the
LR register may have been modified.
Combined, these make the torture test from issue 6681 pass.
Fixes#6681.
R=golang-dev, r, josharian
CC=golang-dev
https://golang.org/cl/19810043
»»»
TBR=r
CC=golang-dev
https://golang.org/cl/20350043
The implementation of division constructed non-standard
stack frames that could not be handled by the traceback
routines.
CL 13239052 left the frames non-standard but fixed them
for the specific case of a divide-by-zero panic.
A profiling signal can arrive at any time, so that fix
is not sufficient.
Change the division to store the extra argument in the M struct
instead of in a new stack slot. That keeps the frames bog standard
at all times.
Also fix a related bug in the traceback code: when starting
a traceback, the LR register should be ignored if the current
function has already allocated its stack frame and saved the
original LR on the stack. The stack copy should be used, as the
LR register may have been modified.
Combined, these make the torture test from issue 6681 pass.
Fixes#6681.
R=golang-dev, r, josharian
CC=golang-dev
https://golang.org/cl/19810043
The current Windows build breakage appears to be because
the Windows code should be looking for __cgodebug_data
not ___cgodebug_data. Dodge the question everywhere by
accepting both.
R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/19780043
This flag was added in January 2010, in CL 181102, to fix issue 497.
(Numbers were just shorter back then.) The fix was for OS X machines
and the llvm-gcc frontend.
In July 2011 we had to change the way we get enum values, because
there were no flags available to force Xcode's llvm-gcc to include the
enum names and values in DWARF debug output.
We now use clang, not llvm-gcc, on OS X machines.
Earlier versions of clang printed a warning about not knowing the flag.
Newer versions of clang now make that an error.
That is:
- The flag was added for OS X machines.
- The flag is no longer necessary on OS X machines.
- The flag now breaks some OS X machines.
Remove it.
I have run the original program from issue 497 successfully
without the flag on both OS X and Linux machines.
Fixes#6678.
R=golang-dev, minux.ma
CC=golang-dev
https://golang.org/cl/18850043
The old approach to determining whether "name" was a type, constant,
or expression was to compile the C program
name;
and scan the errors and warnings generated by the compiler.
This requires looking for specific substrings in the errors and warnings,
which ties the implementation to specific compiler versions.
As compilers change their errors or drop warnings, cgo breaks.
This happens slowly but it does happen.
Clang in particular (now required on OS X) has a significant churn rate.
The new approach compiles a slightly more complex program
that is either valid C or not valid C depending on what kind of
thing "name" is. It uses only the presence or absence of an error
message on a particular line, not the error text itself. The program is:
// error if and only if name is undeclared
void f1(void) { typeof(name) *x; }
// error if and only if name is not a type
void f2(void) { name *x; }
// error if and only if name is not an integer constant
void f3(void) { enum { x = (name)*1 }; }
I had not been planning to do this until Go 1.3, because it is a
non-trivial change, but it fixes a real Xcode 5 problem in Go 1.2,
and the new code is easier to understand than the old code.
It should be significantly more robust.
Fixes#6596.
Fixes#6612.
R=golang-dev, r, james, iant
CC=golang-dev
https://golang.org/cl/15070043
The preamble may want to #define some special symbols
and then #include <sys/types.h> itself. The builtin prolog
also #includes <sys/types.h>, which would break such a
preamble (because the second #include will be a no-op).
The use of sys/types.h in the builtin prolog is new since Go 1.1,
so this should preserve the semantics of more existing cgo
code than we would otherwise.
It also fixes src/pkg/syscall/mkall.sh's use of go tool cgo -godefs
on some Linux systems.
Thanks to fullung@ for identifying the problem.
Fixes#6558.
R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/14684044
Ensure that clang always exits with a non-zero status by
giving it something that it always warns about (the statement "1;").
Fixes#6128.
R=golang-dev, iant, minux.ma
CC=golang-dev
https://golang.org/cl/14702043
make use of $USER or %USERNAME% to determine the current user.
Fixes#6578.
R=golang-dev, bradfitz, alex.brainman
CC=golang-dev
https://golang.org/cl/14649043
Also add the action's object directory to the list of
directories we use to find SWIG shared libraries.
Fixes#6521.
R=golang-dev, minux.ma
CC=golang-dev
https://golang.org/cl/14369043
Instead of adding an -march=armv5t flag to the gcc command
line, the same effect is obtained with an ".arch armv5t"
pseudo op in the assembly file that uses armv5t instructions.
R=golang-dev, iant, dave
CC=golang-dev
https://golang.org/cl/14511044
Add the -installsuffix flag to gc and {5,6,8}l, which overrides -race
for the suffix if both are supplied.
Pass this flag from the go tool for build and install.
R=rsc
CC=golang-dev
https://golang.org/cl/14246044
Added a new $GO_DISTFLAGS to make.bash, and while we're here,
added mention $CXX in make.bash (CL 13704044).
Fixes#6448.
Update #3564
We can pass GO_DISTFLAGS=-s from misc/dist to make.bash so that
it will build a statically linked toolchain.
(Note: OS X doesn't have the concept of static linking, so don't
pass GO_DISTFLAGS=-s for OS X builds)
R=adg, rsc, iant
CC=golang-dev
https://golang.org/cl/13887043
Currently, the directories generaed by includeArgs can have the "_race"
suffix added if invoked with -race flag, but ignores -installsuffix if
set.
R=adg, rsc
CC=golang-dev
https://golang.org/cl/14174043
Use the symbol prefixes with the prologue functions when using
gccgo.
Use an & when referring to a function declared as a variable.
Fix the malloc prologue function.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/13878043
The line number alone does not help when the line is
case '~', '*', '(', ')', '[', ']', '{', '}', '?', ':', ';', ',', '*', '%', '^', '!', '=', '<', '>', '+', '-', '&', '|':
R=ken2
CC=golang-dev
https://golang.org/cl/13431046
Keeping pointers from the pre-walk phase confuses
the race detection instrumentation.
Fixes#6418.
R=golang-dev, dvyukov, r
CC=golang-dev
https://golang.org/cl/13368057
This is a framework for docs on the subject more than it is
actual docs.
The section header in go/doc.go just says "C", not "C/C++,"
because otherwise godoc doesn't recognize the line as a
section header.
Fixes#5473.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/13280050
This eliminates ~75% of the nil checks being emitted,
on all architectures. We can do better, but we need
a bit more general support from the compiler, and
I don't want to do that so close to Go 1.2.
What's here is simple but effective and safe.
A few small code generation cleanups were required
to make the analysis consistent on all systems about
which nil checks are omitted, at least in the test.
Fixes#6019.
R=ken2
CC=golang-dev
https://golang.org/cl/13334052
In particular document that the Go tool will look for certain
file extensions and compile with them with either the C or the
C++ compiler.
Fixes#6393.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/13733043
Hide container symbols like text and etext so that
the individual pieces inside are shown instead.
For example, if text and main.init have the same
address, it was a toss-up which name was printed.
R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/13722046
The code for call site-specific pointer bitmaps was not ready in time,
but the zeroing required without it is too expensive to use by default.
We will have to wait for precise collection of stack frames until Go 1.3.
The precise collection can be re-enabled by
GOEXPERIMENT=precisestack ./all.bash
but that will not be the default for a Go 1.2 build.
Fixes#6087.
R=golang-dev, jeremyjackins, dan.kortschak, r
CC=golang-dev
https://golang.org/cl/13677045
Because we can, and because it otherwise might crash
the program if we think we're out of memory.
Fixes#6390.
R=golang-dev, iant, minux.ma
CC=golang-dev
https://golang.org/cl/13345048
Fake types describing the internal structure of hashmaps are
generated for use by precise GC.
Generating hash and eq functions for these fake types slows down
the build and wastes space: the go tool binary size is 13MB
instead of 12MB, and the package size on amd64 is 48.7MB instead
of 45.3MB.
R=golang-dev, daniel.morsing, r, khr, rsc, iant
CC=golang-dev
https://golang.org/cl/13698043
This reverts CL 13261048. I have just learned that these are
no longer supported on code.google.com (that is, it is impossible
to create them), so there is little reason to add support in
Go 1.2.
Update #5408
R=golang-dev, dave, r
CC=golang-dev
https://golang.org/cl/13317046
Bug #1:
Issue 5406 identified an interesting case:
defer iface.M()
may end up calling a wrapper that copies an indirect receiver
from the iface value and then calls the real M method. That's
two calls down, not just one, and so recover() == nil always
in the real M method, even during a panic.
[For the purposes of this entire discussion, a wrapper's
implementation is a function containing an ordinary call, not
the optimized tail call form that is somtimes possible. The
tail call does not create a second frame, so it is already
handled correctly.]
Fix this bug by introducing g->panicwrap, which counts the
number of bytes on current stack segment that are due to
wrapper calls that should not count against the recover
check. All wrapper functions must now adjust g->panicwrap up
on entry and back down on exit. This adds slightly to their
expense; on the x86 it is a single instruction at entry and
exit; on the ARM it is three. However, the alternative is to
make a call to recover depend on being able to walk the stack,
which I very much want to avoid. We have enough problems
walking the stack for garbage collection and profiling.
Also, if performance is critical in a specific case, it is already
faster to use a pointer receiver and avoid this kind of wrapper
entirely.
Bug #2:
The old code, which did not consider the possibility of two
calls, already contained a check to see if the call had split
its stack and so the panic-created segment was one behind the
current segment. In the wrapper case, both of the two calls
might split their stacks, so the panic-created segment can be
two behind the current segment.
Fix this by propagating the Stktop.panic flag forward during
stack splits instead of looking backward during recover.
Fixes#5406.
R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/13367052
Pull the stack split generation into its own function.
This will make an upcoming change to fix recover
easier to digest.
R=ken2
CC=golang-dev
https://golang.org/cl/13611044
There is a cleaner, simpler way.
««« original CL description
cmd/5g, cmd/6g, cmd/8g: faster compilation
Replace linked list walk with memset.
This reduces CPU time taken by 'go install -a std' by ~10%.
Before:
real user sys
0m23.561s 0m16.625s 0m5.848s
0m23.766s 0m16.624s 0m5.846s
0m23.742s 0m16.621s 0m5.868s
after:
0m22.714s 0m14.858s 0m6.138s
0m22.644s 0m14.875s 0m6.120s
0m22.604s 0m14.854s 0m6.081s
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/13084043
»»»
TBR=dvyukov
CC=golang-dev
https://golang.org/cl/13352049
Asking about runtime/cgo when CgoEnabled=false now correctly
returns an error from build.Import (specifically, NoGoError), because
there are no buildable Go files in that directory.
The API tool was depending on it returning a package with no Go
files instead. Correct that assumption.
Fixes all.bash on local machines.
(Dashboard appears not to be running the api tool at all.)
Update #6124
TBR=golang-dev
CC=golang-dev
https://golang.org/cl/13385046
It was never going to last.
««« original CL description
cmd/api: break the builds
There is some question about whether the api tool is
running on Windows (see issue 6124), and now I'm
starting to question whether it runs on any of the builders,
since both darwin/amd64 and linux/amd64 are crashing for me
in the api tool due to a recent cgo-related change, and yet
the dashboard is happy.
If the dashboard is still happy after this CL, we have a problem.
Update #6124
TBR=golang-dev
CC=golang-dev
https://golang.org/cl/13632053
»»»
TBR=golang-dev
CC=golang-dev
https://golang.org/cl/13474045
There is some question about whether the api tool is
running on Windows (see issue 6124), and now I'm
starting to question whether it runs on any of the builders,
since both darwin/amd64 and linux/amd64 are crashing for me
in the api tool due to a recent cgo-related change, and yet
the dashboard is happy.
If the dashboard is still happy after this CL, we have a problem.
Update #6124
TBR=golang-dev
CC=golang-dev
https://golang.org/cl/13632053
The old test for "no Go files" was p.Name == "", meaning we never
saw a Go package statement. That test fails if there are cgo files
that we parsed (and recorded the package name) but then chose
not to use (because cgo is not available).
Test the actual file lists instead.
Fixes#6078.
R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/13661043
The units example is nice but is covered by the Lucent
license, which may be a concern for some people making a
commercial source code distribution of Go.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/13283045
This allows us to make two changes:
1. Force the argument type to be size_t, even on broken
systems that declare malloc to take a ulong.
2. Call runtime.throw if malloc fails.
(That is, the program crashes; it does not panic.)
Fixes#3403.
Fixes#5926.
R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/13413047
For example, if the pattern is m... there is
no need to look in directories not beginning with m.
Fixes#5214.
R=golang-dev, adg
CC=golang-dev
https://golang.org/cl/13253049
The scan starts at the directory we care about and works
backward to the GOPATH root. The error should say the
original directory name, not the name of the GOPATH root.
Fixes#6175.
R=golang-dev, minux.ma
CC=golang-dev
https://golang.org/cl/13366050
The entry for LEAL/LEAQ in these optabs was listed as having
two data bytes in the y array. In fact they had and expect no data
bytes. However, the general loop expects to be able to look at at
least one data byte, to make sure it is not 0x0f. So give them each
a single data byte set to 0 (not 0x0f).
Since the MOV instructions have the largest optab cases, this
requires growing the size of the data array.
Clang found this bug because the general o->op[z] == 0x0f
test was using z == 22, which was out of bounds.
In practice the next byte in memory was probably not 0x0f
so it wasn't truly broken. But might as well be clean.
Update #5764
R=ken2
CC=golang-dev
https://golang.org/cl/13241050
For example, if an x_test.go file contains a syntax error,
b.test fails with an error message. But it wasn't printing
the same FAIL line that a build failure later would print.
This makes all the test failures that happen (once we
decide to start running tests) consistently say FAIL.
Fixes#4701.
R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/13431044
A package main binary (that is, a command) being installed
does not mean we can skip the build of the package archive
during a test.
Fixes#3417.
R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/13462046
Remove test of whether SWIG shared library is older than
sources--should be covered by test of package file anyhow.
Fixes#5739.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/13352046
This will bring in the C++ standard library without requiring
any special #cgo LDFLAGS options.
When using gccgo, just add -lstdc++ to link line; this should
do no harm if it is not needed.
No tests, since we don't want to assume a C++ compiler.
Update #5629
R=golang-dev, minux.ma, rsc
CC=golang-dev
https://golang.org/cl/13394045
If you thought gcc -ansi -pedantic was pedantic, just wait
until you meet clang -fsanitize=undefined.
I think this addresses all the reported "errors", but we'll
need another run to be sure.
all.bash still passes.
Update #5764
Dave, can you please try again?
R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/13334049
Cannot happen when using the go command, but help
people running commands by hand or with other tools.
Fixes#5888.
R=ken2
CC=golang-dev
https://golang.org/cl/13324048
* Sort imports by import path, then import name, then comment. Currently, gofmt sorts only by import path.
* If two imports have the same import path and import name, and one of them has no comment, remove the import with no comment. (See the discussion at issue 4414.)
Based on @rsc's https://golang.org/cl/7231070/Fixes#4414.
R=gri, rsc
CC=golang-dev
https://golang.org/cl/12837044
This message was helpful for pre-Go 1 users updating to Go 1.
That time is past. Now the message is confusing because it
depends on knowing what pre-Go 1 looked like.
Update #4697.
R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/13335051
cmd/cc: bv.c imports libc.h twice
When using the Plan 9 compiler, the invocation
#include <../ld/textflag.h>
works for the toolchain, but not for the MACH library.
Module cmd/cc/bv.c includes libc.h and "cc.h", which in
turn also includes libc.h. In the Plan 9 context, this
causes a number of duplicate definitions.
R=golang-dev, rsc, r
CC=golang-dev
https://golang.org/cl/13303047
This should have been part of revision 16731:cdedb129e020, but
I missed it. This fixes printing local variables when doing
an external link.
No test because we aren't doing any debug info testing yet.
Fixes#5719.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/13464046
Also introduce BGET2/4, BPUT2/4 as they are widely used.
Slightly improve BGETC/BPUTC implementation.
This gives ~5% CPU time improvement on go install -a -p1 std.
Before:
real user sys
0m23.561s 0m16.625s 0m5.848s
0m23.766s 0m16.624s 0m5.846s
0m23.742s 0m16.621s 0m5.868s
after:
0m22.999s 0m15.841s 0m5.889s
0m22.845s 0m15.808s 0m5.850s
0m22.889s 0m15.832s 0m5.848s
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/12745047
#pragma textflag and #pragma dataflag directives.
Update dataflag directives to use symbols instead of integer constants.
R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/13310043
Types in function scope can have methods on them if they embed another type, but we didn't make the name unique, meaning that 2 identically named types in different functions would conflict with eachother.
Fixes#6269.
R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/13326045
These instructions are emitted when GO386=387 or the target
i386 CPU does not have SSE2 capabilities.
Fixes#6215.
R=golang-dev, remyoudompheng
CC=golang-dev
https://golang.org/cl/12812045
The compiler computes initialization order by finding
a spanning tree between a package's global variables.
But it does so by walking both variables and functions
and stops detecting cycles between variables when they
mix with a cycle of mutually recursive functions.
Fixes#4847.
R=golang-dev, daniel.morsing, rsc
CC=golang-dev
https://golang.org/cl/9663047
Causes the package dependencies to include those for race detection.
Fixes#5653.
R=golang-dev, dave, bradfitz
CC=golang-dev
https://golang.org/cl/13236045
OS X in particular deletes tmp files (but not directories)
pretty reliably.
Ask hg whether the go.tools directory in tmp is good before
using it.
Fixes issue Rob and others were reporting, which I just hit
myself now.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/13084049
This was breaking people setting GOARCH=386 before running
all.bash on amd64 machines.
cmd/go puts different architecture binaries where "go tool"
can't find them.
R=golang-dev, r, khr
CC=golang-dev
https://golang.org/cl/13139044
slice type to an array type, the haspointer-ness may change.
Before this change, we'd sometimes get types like [1]int marked
as having pointers.
R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/13189044
Update the original change but do not read interface types in
the arguments area. Once the arguments area is zeroed as the
locals area is we can safely read interface type values there
too.
««« original CL description
undo CL 12785045 / 71ce80dc4195
This has broken the 32-bit builds.
««« original CL description
cmd/gc, runtime: use type information to scan interface values
R=golang-dev, rsc, dvyukov
CC=golang-dev
https://golang.org/cl/12785045
»»»
R=khr, golang-dev, khr
CC=golang-dev
https://golang.org/cl/13010045
»»»
R=khr, khr
CC=golang-dev
https://golang.org/cl/13073045
Replace linked list walk with memset.
This reduces CPU time taken by 'go install -a std' by ~10%.
Before:
real user sys
0m23.561s 0m16.625s 0m5.848s
0m23.766s 0m16.624s 0m5.846s
0m23.742s 0m16.621s 0m5.868s
after:
0m22.714s 0m14.858s 0m6.138s
0m22.644s 0m14.875s 0m6.120s
0m22.604s 0m14.854s 0m6.081s
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/13084043
This has broken the 32-bit builds.
««« original CL description
cmd/gc, runtime: use type information to scan interface values
R=golang-dev, rsc, dvyukov
CC=golang-dev
https://golang.org/cl/12785045
»»»
R=khr, golang-dev, khr
CC=golang-dev
https://golang.org/cl/13010045
Before this CL, the import stack was a) not printed and b) overwritten later
in the build, destroying the information about the cycle. This CL fixes both.
I made time depend on os (os already depends on time) and with this CL the error is:
/Users/r/go/src/pkg/fmt/print.go:10:2: import cycle not allowed
package code.google.com/p/XXX/YYY:
imports fmt
imports os
imports time
imports os
Doesn't give line numbers for the actual imports, as requested in the bug, but
I don't believe that's important.
Fixes#4292.
R=golang-dev, adg
CC=golang-dev
https://golang.org/cl/13100043
Given
if (i == 0)
x++
The old message was
x.go:6: syntax error: unexpected semicolon or newline before {
Now we see
x.go:6: syntax error: missing { after if clause
Fixes#5687
R=golang-dev, adg
CC=golang-dev
https://golang.org/cl/12822045
This might fix the mkdtemp problem on the darwin builders if they
have TMPDIR set to a path ending in a slash; at worse this will
result in cleaner path names.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/13097043
The Darwin builders are all failing here but strerror doesn't provide context.
R=golang-dev, bradfitz, adg
CC=golang-dev
https://golang.org/cl/13095043
When the new call site-specific frame bitmaps are available,
we can cut the zeroing to just those values that need it due
to scope escaping.
R=cshapiro, cshapiro
CC=golang-dev
https://golang.org/cl/13045043
When the packages the tested package depends on don't build,
we weren't getting out early. Added a simple check for a successful
build to an existing early out.
There may be other ways that double compilation arises, but
this fixes the one listed in the issue.
Fixes#5679
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/13036043
It's next to useless and confusing as well. Let's make godoc better instead.
Fixes#4849.
R=golang-dev, dsymonds, adg, rogpeppe, rsc
CC=golang-dev
https://golang.org/cl/12974043
See golang.org/s/go12nil.
This CL is about getting all the right checks inserted.
A followup CL will add an optimization pass to
remove redundant checks.
R=ken2
CC=golang-dev
https://golang.org/cl/12970043
Was checking for nil map; must check for empty map instead.
Fixes#6065
Before:
go test -cover
# testmain
/var/folders/00/013l0000h01000cxqpysvccm0004fc/T/go-build233480051/_/Users/r/issue/_test/_testmain.go:11: imported and not used: "_/Users/r/issue"
FAIL _/Users/r/issue [build failed]
Now:
go test -cover
testing: warning: no tests to run
PASS
coverage: 0.0% of statements
ok _/Users/r/issue 0.021s
R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/12916043
The baseline architecture had been left to the GCC configured
default which can be more accomodating than the rest of the Go
toolchain. This prevented instructions used by the 5g compiler,
like BLX, from being used in GCC compiled assembler code.
R=golang-dev, dave, rsc, elias.naur, cshapiro
CC=golang-dev
https://golang.org/cl/12954043
The shared library changes broke the windows build because __attribute__ ((visibility ("hidden"))) is not supported in windows gcc. This change removes the attribute, as it is only needed when building shared libraries.
R=rsc
CC=golang-dev
https://golang.org/cl/12829044
This CL is an aggregate of 10271047, 10499043, 9733044. Descriptions of each follow:
10499043
runtime,cmd/ld: Merge TLS symbols and teach 5l about ARM TLS
This CL prepares for external linking support to ARM.
The pseudo-symbols runtime.g and runtime.m are merged into a single
runtime.tlsgm symbol. When external linking, the offset of a thread local
variable is stored at a memory location instead of being embedded into a offset
of a ldr instruction. With a single runtime.tlsgm symbol for both g and m, only
one such offset is needed.
The larger part of this CL moves TLS code from gcc compiled to internally
compiled. The TLS code now uses the modern MRC instruction, and 5l is taught
about TLS fallbacks in case the instruction is not available or appropriate.
10271047
This CL adds support for -linkmode external to 5l.
For 5l itself, use addrel to allow for D_CALL relocations to be handled by the
host linker. Of the cases listed in rsc's comment in issue 4069, only case 5 and
63 needed an update. One of the TODO: addrel cases was since replaced, and the
rest of the cases are either covered by indirection through addpool (cases with
LTO or LFROM flags) or stubs (case 74). The addpool cases are covered because
addpool emits AWORD instructions, which in turn are handled by case 11.
In the runtime, change the argv argument in the rt0* functions slightly to be a
pointer to the argv list, instead of relying on a particular location of argv.
9733044
The -shared flag to 6l outputs a shared library, implemented in Go
and callable from non-Go programs such as C.
The main part of this CL change the thread local storage model.
Go uses the fastest and least general mode, local exec. TLS data in shared
libraries normally requires at least the local dynamic mode, however, this CL
instead opts for using the initial exec mode. Initial exec mode is faster than
local dynamic mode and can be used in linux since the linker has reserved a
limited amount of TLS space for performance sensitive TLS code.
Initial exec mode requires an extra load from the GOT table to determine the
TLS offset. This penalty will not be paid if ld is not in -shared mode, since
TLS accesses will be reduced to local exec.
The elf sections .init_array and .rela.init_array are added to register the Go
runtime entry with cgo at library load time.
The "hidden" attribute is added to Cgo functions called from Go, since Go
does not generate call through the GOT table, and adding non-GOT relocations for
a global function is not supported by gcc. Cgo symbols don't need to be global
and avoiding the GOT table is also faster.
The changes to 8l are only removes code relevant to the old -shared mode where
internal linking was used.
This CL only address the low level linker work. It can be submitted by itself,
but to be useful, the runtime changes in CL 9738047 is also needed.
Design discussion at
https://groups.google.com/forum/?fromgroups#!topic/golang-nuts/zmjXkGrEx6QFixes#5590.
R=rsc
CC=golang-dev
https://golang.org/cl/12871044
mkvar was taking care of the "LeftAddr" case,
effectively hiding it from the temp-merging optimization.
Move it into prog.c.
R=ken2
CC=golang-dev
https://golang.org/cl/12884045
Before,
go test -bench .
would just dump the long generic "go help" message. Confusing and
unhelpful. Now the message is short and on point and also reminds the
user about the oft-forgotten "go help testflag".
% go test -bench
go test: missing argument for flag bench
run "go help test" or "go help testflag" for more information
%
R=rsc
CC=golang-dev
https://golang.org/cl/12662046
* Add a new kind of Name, "fpvar" which stands for function pointer variable
* When walking the AST, find functions used as expressions and create a new Name object for them
* Track functions which are only used in expr contexts, and avoid generating bridge code for them
R=golang-dev, minux.ma, fullung, rsc, iant
CC=golang-dev
https://golang.org/cl/9835047
The compilers assume they can generate temporary variables
as needed to preserve the right semantics or simplify code
generation and the back end will still generate good code.
This turns out not to be true. The back ends will only
track the first 128 variables per function and give up
on the remainder. That needs to be fixed too, in a later CL.
This CL merges temporary variables with equal types and
non-overlapping lifetimes using the greedy algorithm in
Poletto and Sarkar, "Linear Scan Register Allocation",
ACM TOPLAS 1999.
The result can be striking in the right functions.
Top 20 frame size changes in a 6g godoc binary by bytes saved:
5464 1984 (-3480, -63.7%) go/build.(*Context).Import
4456 1824 (-2632, -59.1%) go/printer.(*printer).expr1
2560 80 (-2480, -96.9%) time.nextStdChunk
3496 1608 (-1888, -54.0%) go/printer.(*printer).stmt
1896 272 (-1624, -85.7%) net/http.init
2688 1400 (-1288, -47.9%) fmt.(*pp).printReflectValue
2800 1512 (-1288, -46.0%) main.main
3296 2016 (-1280, -38.8%) crypto/tls.(*Conn).clientHandshake
1664 488 (-1176, -70.7%) time.loadZoneZip
1760 608 (-1152, -65.5%) time.parse
4104 3072 (-1032, -25.1%) runtime/pprof.writeHeap
1680 712 ( -968, -57.6%) go/ast.Walk
2488 1560 ( -928, -37.3%) crypto/x509.parseCertificate
1128 392 ( -736, -65.2%) math/big.nat.divLarge
1528 864 ( -664, -43.5%) go/printer.(*printer).fieldList
1360 712 ( -648, -47.6%) regexp/syntax.(*parser).factor
2104 1528 ( -576, -27.4%) encoding/asn1.parseField
1064 504 ( -560, -52.6%) encoding/xml.(*Decoder).text
584 48 ( -536, -91.8%) html.init
1400 864 ( -536, -38.3%) go/doc.playExample
In the same godoc build, cuts the number of functions with
too many vars from 83 to 32.
R=ken2
CC=golang-dev
https://golang.org/cl/12829043
If the hg checkout of go.tools fails, check for Internet
connectivity before failing.
R=golang-dev, shivakumar.gn
CC=golang-dev
https://golang.org/cl/12814043
Now there's only one copy of the flow graph construction
and dominator computation, and different optimizations
can attach different annotations to the instructions.
R=ken2
CC=golang-dev
https://golang.org/cl/12797045
Code in gc/popt.c is compiled as part of 5g, 6g, and 8g,
meaning it can use arch-specific headers but there's
just one copy of the code.
This is the same arrangement we use for the portable
code generation logic in gc/pgen.c.
Move fixjmp and noreturn there to get the ball rolling.
R=ken2
CC=golang-dev
https://golang.org/cl/12789043
Add new proginfo function that returns information about a
Prog*. The information includes various instruction
description bits as well as a list of required registers set
and used and indexing registers used.
Convert the large instruction switches to use proginfo.
This information was formerly duplicated in multiple
optimization passes, inconsistently. For example, the
information about which registers an instruction requires
appeared three times for most instructions.
Most of the switches were incomplete or incorrect in some way.
For example, the switch in copyu did not list cases for INCB,
JPS, MOVAPD, MOVBWSX, MOVBWZX, PCDATA, POPQ, PUSHQ, STD,
TESTB, TESTQ, and XCHGL. Those were all falling into the
"unknown instruction" default case and stopping the rewrite,
perhaps unnecessarily. Similarly, the switch in needc only
listed a handful of the instructions that use or set the carry bit.
We still need to decide whether to use proginfo to generalize
a few of the remaining smaller switches in peep.c.
If this goes well, we'll make similar changes in 8g and 5g.
R=ken2
CC=golang-dev
https://golang.org/cl/12637051
On entry to a function, zero the results and zero the pointer
section of the local variables.
This is an intermediate step on the way to precise collection
of Go frames.
This can incur a significant (up to 30%) slowdown, but it also ensures
that the garbage collector never looks at a word in a Go frame
and sees a stale pointer value that could cause a space leak.
(C frames and assembly frames are still possibly problematic.)
This CL is required to start making collection of interface values
as precise as collection of pointer values are today.
Since we have to dereference the interface type to understand
whether the value is a pointer, it is critical that the type field be
initialized.
A future CL by Carl will make the garbage collection pointer
bitmaps context-sensitive. At that point it will be possible to
remove most of the zeroing. The only values that will still need
zeroing are values whose addresses escape the block scoping
of the function but do not escape to the heap.
benchmark old ns/op new ns/op delta
BenchmarkBinaryTree17 4420289180 4331060459 -2.02%
BenchmarkFannkuch11 3442469663 3277706251 -4.79%
BenchmarkFmtFprintfEmpty 100 142 +42.00%
BenchmarkFmtFprintfString 262 310 +18.32%
BenchmarkFmtFprintfInt 213 281 +31.92%
BenchmarkFmtFprintfIntInt 355 431 +21.41%
BenchmarkFmtFprintfPrefixedInt 321 383 +19.31%
BenchmarkFmtFprintfFloat 444 533 +20.05%
BenchmarkFmtManyArgs 1380 1559 +12.97%
BenchmarkGobDecode 10240054 11794915 +15.18%
BenchmarkGobEncode 17350274 19970478 +15.10%
BenchmarkGzip 455179460 460699139 +1.21%
BenchmarkGunzip 114271814 119291574 +4.39%
BenchmarkHTTPClientServer 89051 89894 +0.95%
BenchmarkJSONEncode 40486799 52691558 +30.15%
BenchmarkJSONDecode 94193361 112428781 +19.36%
BenchmarkMandelbrot200 4747060 4748043 +0.02%
BenchmarkGoParse 6363798 6675098 +4.89%
BenchmarkRegexpMatchEasy0_32 129 171 +32.56%
BenchmarkRegexpMatchEasy0_1K 365 395 +8.22%
BenchmarkRegexpMatchEasy1_32 106 152 +43.40%
BenchmarkRegexpMatchEasy1_1K 952 1245 +30.78%
BenchmarkRegexpMatchMedium_32 198 283 +42.93%
BenchmarkRegexpMatchMedium_1K 79006 101097 +27.96%
BenchmarkRegexpMatchHard_32 3478 5115 +47.07%
BenchmarkRegexpMatchHard_1K 110245 163582 +48.38%
BenchmarkRevcomp 777384355 793270857 +2.04%
BenchmarkTemplate 136713089 157093609 +14.91%
BenchmarkTimeParse 1511 1761 +16.55%
BenchmarkTimeFormat 535 850 +58.88%
benchmark old MB/s new MB/s speedup
BenchmarkGobDecode 74.95 65.07 0.87x
BenchmarkGobEncode 44.24 38.43 0.87x
BenchmarkGzip 42.63 42.12 0.99x
BenchmarkGunzip 169.81 162.67 0.96x
BenchmarkJSONEncode 47.93 36.83 0.77x
BenchmarkJSONDecode 20.60 17.26 0.84x
BenchmarkGoParse 9.10 8.68 0.95x
BenchmarkRegexpMatchEasy0_32 247.24 186.31 0.75x
BenchmarkRegexpMatchEasy0_1K 2799.20 2591.93 0.93x
BenchmarkRegexpMatchEasy1_32 299.31 210.44 0.70x
BenchmarkRegexpMatchEasy1_1K 1074.71 822.45 0.77x
BenchmarkRegexpMatchMedium_32 5.04 3.53 0.70x
BenchmarkRegexpMatchMedium_1K 12.96 10.13 0.78x
BenchmarkRegexpMatchHard_32 9.20 6.26 0.68x
BenchmarkRegexpMatchHard_1K 9.29 6.26 0.67x
BenchmarkRevcomp 326.95 320.40 0.98x
BenchmarkTemplate 14.19 12.35 0.87x
R=cshapiro
CC=golang-dev
https://golang.org/cl/12616045
Prior to this change, pointer maps encoded the disposition of
a word using a single bit. A zero signaled a non-pointer
value and a one signaled a pointer value. Interface values,
which are a effectively a union type, were conservatively
labeled as a pointer.
This change widens the logical element size of the pointer map
to two bits per word. As before, zero signals a non-pointer
value and one signals a pointer value. Additionally, a two
signals an iface pointer and a three signals an eface pointer.
Following other changes to the runtime, values two and three
will allow a type information to drive interpretation of the
subsequent word so only those interface values containing a
pointer value will be scanned.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/12689046
On my Mac, cuts the API checks from 15 seconds to 6 seconds.
Also clean up some tag confusion: go run list-of-files ignores tags.
R=bradfitz, gri
CC=golang-dev
https://golang.org/cl/12699048
This change makes the way cc constructs pointer maps closer to
what gc does and is being done in preparation for changes to
the internal content of the pointer map such as a change to
distinguish interface pointers from ordinary pointers.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/12692043
g% 6c ~/x.c
/Users/rsc/x.c:1 duplicate types given: STRUCT s and VOID
/Users/rsc/x.c:1 no return at end of function: f
g%
Fixes#6083.
R=ken2
CC=golang-dev
https://golang.org/cl/12691043
MOVBS and MOVHS are defined as duplicates of MOVB and MOVH,
and perform sign-extension moving.
No change is made to code generation.
Update #1837
R=rsc, bradfitz
CC=golang-dev
https://golang.org/cl/12682043
- adjusted test files so that they actually type-check
- adjusted go1.txt, go1.1.txt, next.txt
- to run, provide build tag: api_tool
Fixes#4538.
R=bradfitz
CC=golang-dev
https://golang.org/cl/12300043
I moved the pointer block from one end of the frame
to the other toward the end of working on the last CL,
and of course that made the optimization no longer work.
Now it works again:
0030 (bug361.go:12) DATA gclocals·0+0(SB)/4,$4
0030 (bug361.go:12) DATA gclocals·0+4(SB)/4,$3
0030 (bug361.go:12) GLOBL gclocals·0+0(SB),8,$8
Fixes arm build (this time for sure!).
TBR=golang-dev
CC=cshapiro, golang-dev, iant
https://golang.org/cl/12627044
Sort non-pointer-containing data to the low end of the
stack frame, and make the bitmaps only cover the
pointer-containing top end.
Generates significantly less garbage collection bitmap
for programs with large byte buffers on the stack.
Only 2% shorter for godoc, but 99.99998% shorter
in some test cases.
Fixes arm build.
TBR=golang-dev
CC=cshapiro, golang-dev, iant
https://golang.org/cl/12541047
Individual variables bigger than 10 MB are now
moved to the heap, as if they had escaped on
their own.
This avoids ridiculous stacks for programs that
do things like
x := [1<<30]byte{}
... use x ...
If 10 MB is too small, we can raise the limit.
Fixes#6077.
R=ken2
CC=golang-dev
https://golang.org/cl/12650045
In prep for Robert's forthcoming cmd/api rewrite which
depends on the go.tools subrepo, we'll need to be more
careful about how and when we run cmd/api.
Rather than implement this policy in both run.bash and
run.bat, this change moves the policy and mechanism into
cmd/api/run.go, which will then evolve.
The plan is in a TODO in run.go.
R=golang-dev, gri
CC=golang-dev
https://golang.org/cl/12482044
Previously, all word aligned locations in the local variables
area were scanned as conservative roots. With this change, a
bitmap is generated describing the locations of pointer values
in local variables.
With this change the argument bitmap information has been
changed to only store information about arguments. The locals
member, has been removed. In its place, the bitmap data for
local variables is now used to store the size of locals. If
the size is negative, the magnitude indicates the size of the
local variables area.
R=rsc
CC=golang-dev
https://golang.org/cl/12328044
We can then include this file in assembly to replace
cryptic constants like "7" with meaningful constants
like "(NOPROF|DUPOK|NOSPLIT)".
Converting just pkg/runtime/asm*.s for now. Dropping NOPROF
and DUPOK from lots of places where they aren't needed.
More .s files to come in a subsequent changelist.
A nonzero number in the textflag field now means
"has not been converted yet".
R=golang-dev, daniel.morsing, rsc, khr
CC=golang-dev
https://golang.org/cl/12568043
For normal slices a[i:j] we're generating 3 bounds
checks: j<={len(string),cap(slice)}, j<=j (!), and i<=j.
Somehow snuck in as part of the [i:j:k] implementation
where the second check does something.
Remove the second check when we don't need it.
R=rsc, r
CC=golang-dev
https://golang.org/cl/12311046
Also, add a meaningful error message when an encoding which
can't be parsed is found.
Fixes#5801.
R=golang-dev, bradfitz, rsc
CC=golang-dev
https://golang.org/cl/12343043
Fixes#5822.
Will no doubt cause other problems, but Apple has forced our hand.
R=golang-dev, bradfitz, khr
CC=golang-dev
https://golang.org/cl/12350044
Also move chatty recent additions to -v -v.
For what it's worth:
$ go build -o /dev/null -ldflags -v cmd/go
...
0.87 pclntab=1110836 bytes, funcdata total 69700 bytes
...
$
This broke the ELF builds last time because I tried to dedup
the funcdata in case the same funcdata was pointed at by
multiple functions. That doesn't currently happen, so I've
removed that test.
If we start doing bitmap coalescing we'll need to figure out
how to measure the size more carefully, but I think at that
point the bitmaps will be an extra indirection away from the
funcdata anyway, so the dedup I used before wouldn't help.
R=ken2
CC=golang-dev
https://golang.org/cl/12269043
This is required to properly unwind reflect.methodValueCall/makeFuncStub.
Fixes#5954.
Stats for 'go install std':
61849 total INSTCALL
24655 currently have ArgSize metadata
27278 have ArgSize metadata with this change
godoc size before: 11351888, after: 11364288
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/12163043
There is a chance that the SIGQUIT will make the test process
dump its stacks as part of exiting, which would be nice for
finding out what it is doing.
Right now the builders are occasionally timing out running
the runtime test. I hope this will give us some information
about the state of the runtime.
R=golang-dev, dave
CC=golang-dev
https://golang.org/cl/12041051
Don't require a full-scale callback for calls to the special
prologue functions.
Always use a simple wrapper function for C functions, so that
we can handle static functions defined in the import "C"
comment.
Disable a test that relies on gc-specific function names.
Fixes#5905.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/11406047
Backends do not exactly expect receiving binary operators with
constant operands or use workarounds to move them to
register/stack in order to handle them.
Fixes#5841.
R=golang-dev, daniel.morsing, rsc
CC=golang-dev
https://golang.org/cl/11107044
The problem is that the cdecl() function in cmd/cgo/godefs.go isn't
properly translating the Go array type to a C array type when an
asterisk follows the [] in the array type declaration (it is perfectly
legal to put the asterisk on either side of the [] in go syntax,
depending on how you set up your pointers).
That said, the cdefs tool is only designed to translate from Go types
generated using the cgo *godefs* tool -- where the godefs tool is
designed to translate gcc-style C types into Go types. In essence, the
cdefs tool translates from gcc-style C types to Go types (via the godefs
tool), then back to kenc-style C types. Because of this, cdefs does not
need to know how to translate arbitraty Go types into C, just the ones
produced by godefs.
The problem is that during this translation process, the logic is
slightly wrong when going from (e.g.):
char *array[10];
to:
array [10]*int8;
back to:
int8 *array[10];
In the current implementation of cdecl(), the translation from the Go
type declaration back to the kenc-style declaration looks for Go
types of the form:
name *[]type;
rather than the actual generated Go type declaration of:
name []*type;
Both are valid Go syntax, with slightly different semantics, but the
latter is the only one that can ever be generated by the godefs tools.
(The semantics of the former are not directly expressible in a
single C statement -- you would have to have to first typedef the array
type, then declare a pointer to that typedef'd type in a separate
statement).
This commit changes the logic of cdecl() to look properly for, and
translate, Go type declarations of the form:
name []*type;
Additionally, the original implementation only allowed for a single
asterisk and a single sized aray (i.e. only a single level of pointer
indirection, and only one set of []) on the type, whereas the patched
version allows for an arbitrary number of both.
Tests are included in misc/cgo/testcdefs and the all.bash script has been
updated to account for these.
R=golang-dev, bradfitz, dave, iant
CC=golang-dev
https://golang.org/cl/11377043
Phrases like "returns whether or not the image is opaque" could be
describing what the function does (it always returns, regardless of
the opacity) or what it returns (a boolean indicating the opacity).
Even when the "or not" is missing, the phrasing is bizarre.
Go with "reports whether", which is still clunky but at least makes
it clear we're talking about the return value.
These were edited by hand. A few were cleaned up in other ways.
R=golang-dev, dsymonds
CC=golang-dev
https://golang.org/cl/11699043
src/cmd/ld/lib.c:1379 set and not used: p
src/cmd/ld/lib.c:1426 format mismatch 6llux INT, arg 3
src/cmd/ld/lib.c:1437 format mismatch 6llux INT, arg 3
src/cmd/ld/lib.c:1456 format mismatch 6llux INT, arg 3
src/cmd/ld/lib.c:1477 format mismatch 6llux INT, arg 3
src/cmd/ld/lib.c:1459 set and not used: started
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/11615044
This does not change the default compiler on OS X to clang.
It appears that for now we can keep using gcc as long as we
enable a few more warning settings that are on-by-default
elsewhere.
R=golang-dev, bradfitz, dave
CC=golang-dev
https://golang.org/cl/11610044
This CL introduces a FUNCDATA number for runtime-specific
garbage collection metadata, changes the C and Go compilers
to emit that metadata, and changes the runtime to expect it.
The old pseudo-instructions that carried this information
are gone, as is the linker code to process them.
R=golang-dev, dvyukov, cshapiro
CC=golang-dev
https://golang.org/cl/11406044
So far no checked-in assembly needs these,
but it matches having them for M and G.
I needed these for some manual testing.
R=golang-dev, dvyukov
CC=golang-dev
https://golang.org/cl/11595043
whose argument size is unknown (C vararg functions, and
assembly code without an explicit specification).
We used to use 0 to mean "unknown" and 1 to mean "zero".
Now we use ArgsSizeUnknown (0x80000000) to mean "unknown".
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/11590043
This should fix the Windows build, or at least
what's breaking it at the moment.
Fixes#5904.
TBR=golang-dev
CC=golang-dev
https://golang.org/cl/11519044
clearfat (used to zero initialize structures) will use AX for x86 block ops. If we write to AX while calculating the dest pointer, we will fill the structure with incorrect values.
Since 64-bit arithmetic uses AX to synthesize a 64-bit register, getting an adress by indexing with 64-bit ops can clobber the register.
Fixes#5820.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/11383043