Although I don't use PAX enabled ARM kernels, PAX
does have support for ARM, so we're better off add
PT_PAX_FLAGS now in case people use PAX kernels.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6453092
Fixes#3708.
The fix to allow 5{c,g,l} to compile under clang 3.1 broke cross
compilation on darwin using the Apple default compiler on 10.7.3.
This failure was introduced in 9b455eb64690.
This has been tested by cross compiling on darwin/amd64 to linux/arm using
* gcc version 4.2.1 (Based on Apple Inc. build 5658) (LLVM build 2336.1.00)
* clang version 3.1 (branches/release_31)
As well as on linux/arm using
* gcc version 4.6.3 (Ubuntu/Linaro 4.6.3-1ubuntu5)
* Ubuntu clang version 3.0-6ubuntu3 (tags/RELEASE_30/final) (based on LLVM 3.0)
* Debian clang version 3.1-4 (branches/release_31) (based on LLVM 3.1)
R=consalus, rsc
CC=golang-dev
https://golang.org/cl/6307058
On 6l and 8l, this is a real instruction, guaranteed to
cause an 'undefined instruction' exception.
On 5l, we simulate it as BL to address 0.
The plan is to use it as a signal to the linker that this
point in the instruction stream cannot be reached
(hence the changes to nofollow). This will help the
compiler explain that panicindex and friends do not
return without having to put a list of these functions
in the linker.
R=ken2
CC=golang-dev
https://golang.org/cl/6255064
16 seems pretty standard on x86 for function entry.
I don't know if ARM would benefit, so I used just 4
(single instruction alignment).
This has a minor absolute effect on the current timings.
The main hope is that it will make them more consistent from
run to run.
benchmark old ns/op new ns/op delta
BenchmarkBinaryTree17 4222117400 4140739800 -1.93%
BenchmarkFannkuch11 3462631800 3259914400 -5.85%
BenchmarkGobDecode 20887622 20620222 -1.28%
BenchmarkGobEncode 9548772 9384886 -1.72%
BenchmarkGzip 151687 150333 -0.89%
BenchmarkGunzip 8742 8741 -0.01%
BenchmarkJSONEncode 62730560 65210990 +3.95%
BenchmarkJSONDecode 252569180 249394860 -1.26%
BenchmarkMandelbrot200 5267599 5273394 +0.11%
BenchmarkRevcomp25M 980813500 996013800 +1.55%
BenchmarkTemplate 361259100 360620840 -0.18%
R=ken2
CC=golang-dev
https://golang.org/cl/6244066
Introduce a newsym() to cmd/lib.c to add a symbol but don't add
them to hash table.
Introduce a new bit flag SHIDDEN and bit mask SMASK to handle hidden
and/or local symbols in ELF symbol tables. Though we still need to order
the symbol table entries correctly.
Fix for issue 3261 comment #9.
For CL 5822049.
R=iant, rsc
CC=golang-dev
https://golang.org/cl/5823055
Some newer Linux distributions (Ubuntu ARM at least) use a new multiarch
directory organization, where dynamic linker is no longer in the hardcoded
path in our linker.
For example, Ubuntu 12.04 ARM hardfloat places its dynamic linker at
/lib/arm-linux-gnueabihf/ld-linux.so.3
Ref: http://lackof.org/taggart/hacking/multiarch/
Also, to support Debian GNU/kFreeBSD as a FreeBSD variant, we need this capability, so it's part of issue 3533.
This CL add a new pragma (#pragma dynlinker "path") to cc.
R=iant, rsc
CC=golang-dev
https://golang.org/cl/6086043
Part 1 of CL 5601044 (cgo: Linux/ARM support)
Limitation: doesn't support thumb library yet.
R=golang-dev, dave, rsc
CC=golang-dev
https://golang.org/cl/5991065
This leads to ~30kB improvement on code size for ARM machines with VFP/NEON.
Example: go test -c math
GOARM=5 GOARM=6
Old: 1884200 1839144
New: 1884165 1805245
-: 35 33899
R=rsc, bradfitz, dave, kai.backman
CC=golang-dev
https://golang.org/cl/5975060
Using reg as the flag word was unfortunate, since the
default value is not 0 but NREG (==16), which happens
to be the bit NOPTR now. Clear it.
If I say this will fix the build, it won't.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/5690072
dodata will convert to SNOPTRDATA if appropriate.
Should fix arm build (hope springs eternal).
TBR=golang-dev
CC=golang-dev
https://golang.org/cl/5687074
cc: add #pragma textflag to set it
runtime: mark mheap to go into noptr-bss.
remove special case in garbage collector
Remove the ARM from.flag field created by CL 5687044.
The DUPOK flag was already in p->reg, so keep using that.
Otherwise test/nilptr.go creates a very large binary.
Should fix the arm build.
Diagnosed by minux.ma; replacement for CL 5690044.
R=golang-dev, minux.ma, r
CC=golang-dev
https://golang.org/cl/5686060
ARM doesn't have the concept of scale, so I renamed the field
Addr.scale to Addr.flag to better reflect its true meaning.
R=rsc
CC=golang-dev
https://golang.org/cl/5687044
The garbage collector can avoid scanning this section, with
reduces collection time as well as the number of false positives.
Helps a little bit with issue 909, but certainly does not solve it.
R=ken2
CC=golang-dev
https://golang.org/cl/5671099
As a convenience to people working on the tools,
leave Makefiles that invoke the go dist tool appropriately.
They are not used during the build.
R=golang-dev, bradfitz, n13m3y3r, gustavo
CC=golang-dev
https://golang.org/cl/5636050
5l -v is for benchmarking various parts of the loader, but this code in
obj.c will clutter the output. I only comment them out, because this is
on par with 8l/6l.
R=golang-dev
CC=golang-dev
https://golang.org/cl/5600046
Also delete gotest, since it's messy to fix and slated for deletion anyway.
A couple of things outside src can't be tested any more. "go test" will be
fixed and these tests will be re-enabled. They're noisy for now.
Fixes#284.
R=rsc
CC=golang-dev
https://golang.org/cl/5598049
To allow these types as map keys, we must fill in
equal and hash functions in their algorithm tables.
Structs or arrays that are "just memory", like [2]int,
can and do continue to use the AMEM algorithm.
Structs or arrays that contain special values like
strings or interface values use generated functions
for both equal and hash.
The runtime helper func runtime.equal(t, x, y) bool handles
the general equality case for x == y and calls out to
the equal implementation in the algorithm table.
For short values (<= 4 struct fields or array elements),
the sequence of elementwise comparisons is inlined
instead of calling runtime.equal.
R=ken, mpimenov
CC=golang-dev
https://golang.org/cl/5451105
If the length of the interpreter string
pushes us over the ELFRESERVE limit, the
resulting error message will be comical.
I was doing some ELF tinkering with a
modified version of 8l when I hit this.
To be clear, the stock linkers wouldn't
hit this without adding about forty more
section headers. We're safe for now. ;)
Also, remove a redundant call to cflush.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/5268044
This requires making the .dynamic section writable, as the
dynamic linker will change the value of the DT_DEBUG tag at
runtime. The DT_DEBUG tag is used by gdb to find all loaded
shared libraries.
R=rsc
CC=golang-dev
https://golang.org/cl/5189044
The dynamic ELF sections were pointing to the proper data,
but that data was already owned by the rodata and text sections.
Some ELF references explicitly prohibit multiple sections from
owning the same data, and strip behaves accordingly.
The data for these sections was moved out and their ranges are
now owned by their respective sections. This change makes strip
happy both with and without -s being provided at link time.
A test was added in debug/elf to ensure there are no regressions
on this area in the future.
Fixes#1242.
Fixes#2022.
NOTE: Tested on Linux amd64/386/arm only.
R=rsc
CC=golang-dev
https://golang.org/cl/4808043
Reduces number of write+seek's from 88516 to 2080
when linking godoc with 6l.
Thanks to Alex Brainman for pointing out the
many small writes.
R=golang-dev, r, alex.brainman, robert.hencke
CC=golang-dev
https://golang.org/cl/4743043
Per the TIS ELF spec, if a PHDR entry is present in the
program header table, it must be part of the memory image of
the program. Failure to do this makes elflint complain, and
causes some tools that manipulate ELF to crash.
R=iant, rsc
CC=dave, golang-dev
https://golang.org/cl/4650067
The gosymtab and gopclntab sections were pointing to the proper
data, but that data was already owned by the rodata section.
Some ELF references explicitly prohibit multiple sections from
owning the same data, and strip behaves accordingly.
The data for these sections was moved to after rodata, and the
gosymtab and gopclntab sections now own their respective ranges.
This change makes strip happy both with and without -s being
provided at link time. Note that it won't remove these sections
because they are still allocated, and that's by design since
they are necessary at runtime for generating proper backtraces
and similar introspection operations.
Unlike the previous behavior, -s will now maintain zero-sized
gosymtab and gopclntab sections. This makes the implementation
slightly cleaner.
Fixes#1242.
NOTE: Tested on Linux amd64/386/arm only.
R=ality, rsc
CC=golang-dev
https://golang.org/cl/4639077
Thumb code and ARM pre-V4 code is unused,
unmaintained, and almost certainly wrong by now.
Every time I try to change 5l I have to sort out
what's dead code and what's not.
30% of lines of code in this directory deleted.
R=ken2
CC=golang-dev
https://golang.org/cl/4601049
5a: add SQRTF and SQRTD
5l: add ASQRTF and ASQRTD
Use ARMv7 VFP VSQRT instruction to speed up math.Sqrt
R=rsc, dave, m
CC=golang-dev
https://golang.org/cl/4551082
I started looking at this code because the nm in GNU
binutils was ignoring the first symbol in the .symtab
section. Apparently, the System V ABI reserves the
first entry and requires all fields inside to be set
to zero.
The list of changes is as follows:
· reserve the first symbol entry (as noted above)
· fix the section indices for .data and .bss symbols
· factor out common code for Elf32 and Elf64
· remove the special case for elfsymo in [568]l/asm.c:/^asmb
· add the "etext" symbol in 6l
· add static symbols
R=rsc
CC=golang-dev
https://golang.org/cl/4524075
The ld time was dominated by symbol table processing, so
* increase hash table size
* emit fewer symbols in gc (just 1 per string, 1 per type)
* add read-only lookup to avoid creating spurious symbols
* add linked list to speed whole-table traversals
Breaks dwarf generator (no idea why), so disable dwarf.
Reduces time for 6l to link godoc by 25%.
R=ken2
CC=golang-dev
https://golang.org/cl/4383047
Much of the bulk of Go binaries is the symbol tables,
which give a name to every C string, Go string,
and reflection type symbol. These names are not worth
much other than seeing what's where in a binary.
This CL deletes all those names from the symbol table,
instead aggregating the symbols into contiguous blocks
and giving them the names "string.*", "go.string.*", and "type.*".
Before:
$ 6nm $(which godoc.old) | sort | grep ' string\.' | tail -10
59eda4 D string."aa87ca22be8b05378eb1c71...
59ee08 D string."b3312fa7e23ee7e4988e056...
59ee6c D string."func(*token.FileSet, st...
59eed0 D string."func(io.Writer, []uint8...
59ef34 D string."func(*tls.Config, *tls....
59ef98 D string."func(*bool, **template....
59effc D string."method(p *printer.print...
59f060 D string."method(S *scanner.Scann...
59f12c D string."func(*struct { begin in...
59f194 D string."method(ka *tls.ecdheRSA...
$
After:
$ 6nm $(which godoc) | sort | grep ' string\.' | tail -10
5e6a30 D string.*
$
Those names in the "Before" are truncated for the CL.
In the real binary they are the complete string, up to
a certain length, or else a unique identifier.
The same applies to the type and go.string symbols.
Removing the names cuts godoc by more than half:
-rwxr-xr-x 1 rsc rsc 9153405 2011-03-07 23:19 godoc.old
-rwxr-xr-x 1 rsc rsc 4290071 2011-03-07 23:19 godoc
For what it's worth, only 80% of what's left gets loaded
into memory; the other 20% is dwarf debugging information
only ever accessed by gdb:
-rwxr-xr-x 1 rsc rsc 3397787 2011-03-07 23:19 godoc.nodwarf
R=r, cw
CC=golang-dev
https://golang.org/cl/4245072
A reference to the address of weak.foo resolves at link time
to the address of the symbol foo if foo would end up in the
binary anyway, or to zero if foo would not be in the binary.
For example:
int xxx = 1;
int yyy = 2;
int weak·xxx;
int weak·yyy;
void main·main(void) {
runtime·printf("%p %p %p\n", &xxx, &weak·xxx, &weak·yyy);
}
prints the same non-nil address twice, then 0 (because yyy is not
referenced so it was dropped from the binary).
This will be used by the reflection tables.
R=iant
CC=golang-dev
https://golang.org/cl/4223044
Fix problems found.
On amd64, various library routines had bigger
stack frames than expected, because large function
calls had been added.
runtime.assertI2T: nosplit stack overflow
120 assumed on entry to runtime.assertI2T
8 after runtime.assertI2T uses 112
0 on entry to runtime.newTypeAssertionError
-8 on entry to runtime.morestack01
runtime.assertE2E: nosplit stack overflow
120 assumed on entry to runtime.assertE2E
16 after runtime.assertE2E uses 104
8 on entry to runtime.panic
0 on entry to runtime.morestack16
-8 after runtime.morestack16 uses 8
runtime.assertE2T: nosplit stack overflow
120 assumed on entry to runtime.assertE2T
16 after runtime.assertE2T uses 104
8 on entry to runtime.panic
0 on entry to runtime.morestack16
-8 after runtime.morestack16 uses 8
runtime.newselect: nosplit stack overflow
120 assumed on entry to runtime.newselect
56 after runtime.newselect uses 64
48 on entry to runtime.printf
8 after runtime.printf uses 40
0 on entry to vprintf
-8 on entry to runtime.morestack16
runtime.selectdefault: nosplit stack overflow
120 assumed on entry to runtime.selectdefault
56 after runtime.selectdefault uses 64
48 on entry to runtime.printf
8 after runtime.printf uses 40
0 on entry to vprintf
-8 on entry to runtime.morestack16
runtime.selectgo: nosplit stack overflow
120 assumed on entry to runtime.selectgo
0 after runtime.selectgo uses 120
-8 on entry to runtime.gosched
On arm, 5c was tagging functions NOSPLIT that should
not have been, like the recursive function printpanics:
printpanics: nosplit stack overflow
124 assumed on entry to printpanics
112 after printpanics uses 12
108 on entry to printpanics
96 after printpanics uses 12
92 on entry to printpanics
80 after printpanics uses 12
76 on entry to printpanics
64 after printpanics uses 12
60 on entry to printpanics
48 after printpanics uses 12
44 on entry to printpanics
32 after printpanics uses 12
28 on entry to printpanics
16 after printpanics uses 12
12 on entry to printpanics
0 after printpanics uses 12
-4 on entry to printpanics
R=r, r2
CC=golang-dev
https://golang.org/cl/4188061
Shame on me: I fixed the same bug in 6l in 8691fcc6a66e
(https://golang.org/cl/2609041) and neglected
to look at 5l and 8l to see if they were affected.
On the positive side, the check I added in that CL is the
one that detected this bug.
Fixes#1457.
R=ken2
CC=golang-dev
https://golang.org/cl/3981052
The fault was lucky: when it wasn't faulting it was silently
copying a word from some other block and later putting
that same word back. If some other goroutine had changed
that word of memory in the interim, too bad.
The ARM code was inconsistent about whether the
"argument frame" included the saved LR. Including it made
some things more regular but mostly just caused confusion
in the places where the regularity broke. Now the rule
reflects reality: argp is always a pointer to arguments,
never a saved link register.
Renamed struct fields to make meaning clearer.
Running ARM in QEMU, package time's gotest:
* before: 27/58 failed
* after: 0/50
R=r, r2
CC=golang-dev
https://golang.org/cl/3993041
The recent linker changes broke NaCl support
a month ago, and there are no known users of it.
The NaCl code can always be recovered from the
repository history.
R=adg, r
CC=golang-dev
https://golang.org/cl/3671042
Sub-symbols are laid out inside a larger symbol
but can be addressed directly.
Use to make Mach-O pointer array not a special case.
Will use later to describe ELF sections.
Glimpses of the beginning of ELF loading.
R=ken2
CC=golang-dev
https://golang.org/cl/2623043
Load the entire archive file instead.
Reduces I/O by avoiding additional passes
through libraries to resolve symbols.
Go packages always need all the files anyway
(most often, all 1 of them).
R=ken2
CC=golang-dev
https://golang.org/cl/2613042
That is, move the pc/ln table and the symbol table
into the read-only data segment. This eliminates
the need for a special load command to map the
symbol table into memory, which makes the
information available on systems that couldn't handle
the magic load to 0x99000000, like NaCl and ARM QEMU
and Linux without config_highmem=y. It also
eliminates an #ifdef and some clumsy code to
find the symbol table on Windows.
The bad news is that the binary appears to be bigger
than it used to be. This is not actually the case, though:
the same amount of data is being mapped into memory
as before, and the tables are still read-only, so they're
still shared across multiple instances of the binary as
they were before. The difference is just that the tables
aren't squirreled away in some section that "size" doesn't
know to look at.
This is a checkpoint.
It probably breaks Windows and breaks NaCl more
than it used to be broken, but those will be fixed.
The logic involving -s needs to be revisited too.
Fixes#871.
R=ken2
CC=golang-dev
https://golang.org/cl/2587041
Because the SB is only good for 8k and Go programs
tend to have much more data than that, SB doesn't
save very much. A fmt.Printf-based hello world program
has 360 kB text segment. Removing SB makes the text
500 bytes (0.14%) longer.
R=ken2, r2, ken3
CC=golang-dev
https://golang.org/cl/2487042
Also change the span-dependent jump algorithm
to use fewer iterations:
* resolve forward jumps at their targets (comefrom list)
* mark jumps as small or big and only do small->big
* record whether a jump failed to be encodable
These changes mean that a function with only small
jumps can be laid out in a single iteration, and the
vast majority of functions take just two iterations.
I was seeing a maximum of 5 iterations before; the
max now is 3 and there are fewer that get even that far.
R=ken2
CC=golang-dev
https://golang.org/cl/2537041
Using explicit relocations internally, we can
represent the data for a particular symbol as
an initialized block of memory instead of a
linked list of ADATA instructions. The real
goal here is to be able to hand off some of the
relocations to the dynamic linker when interacting
with system libraries, but a pleasant side effect is
that the memory image is much more compact
than the ADATA list, so the linkers use less memory.
R=ken2
CC=golang-dev
https://golang.org/cl/2512041
The Plan 9 tools assume that long is 32 bits.
We converted all instances of long to int32 when
importing the code but missed the print formats.
Because int32 is always int on the compilers we use,
it is never correct to use %lux, %ld, etc. Convert to %ux, %d, etc.
(It matters because on 64-bit gcc, long is 64 bits,
so we were printing 32-bit quantities with 64-bit formats.)
R=ken2
CC=golang-dev
https://golang.org/cl/2491041
* Maintain Sym* list for text with individual
prog lists instead of using one huge list and
overloading p->pcond.
* Comment what each file is for.
* Move some output code from span.c to asm.c.
* Move profiling into prof.c, symbol table into symtab.c.
* Move mkfwd to ld/lib.c.
* Throw away dhog dynamic loading code.
* Throw away Alef become.
* Fix printing of WORD instructions in 5l -a.
Goal here is to be able to handle each piece of text or data
as a separate piece, both to make it easier to load the
occasional .o file and also to make it possible to split the
work across multiple threads.
R=ken2, r, ken3
CC=golang-dev
https://golang.org/cl/2335043
This is entirely adding and removing tabs.
It looks weird but will make the diffs for the
next change easier to read.
R=ken2
CC=golang-dev
https://golang.org/cl/2490041
The Makefile and cgo now rewrite / to _ when creating the path.
The .so for gosqlite.googlecode.com/hg/sqlite is named
cgo_gosqlite.googlecode.com_hg_sqlite.so, and then 6l and 8l
both include a default rpath of $GOROOT/pkg/$GOOS_$GOARCH.
This should make it easier to move binaries from one system
to another.
Fixes#857.
R=iant, r
CC=golang-dev
https://golang.org/cl/1700048
This avoids a crash when using cgo where glibc's malloc thinks
that it can use some of the memory following the symbol table.
This fails because the symbol table is mapped read-only, which
affects the whole page.
R=rsc
CC=golang-dev
https://golang.org/cl/1616042
* correct symbol table size
* do not reorder functions in output
* traceback
* signal handling
* use same code for go + defer
* handle leaf functions in symbol table
R=kaib, dpx
CC=golang-dev
https://golang.org/cl/884041
trivial stuff
lex.c: these prototypes are in a.h
asm.c: unused variables
arm-pass.txt deal w/ sieve.go rename and addition of sieve2.go
R=kaib, rsc
CC=golang-dev
https://golang.org/cl/244041
This permits more flexibility with cgo and swig in cases where
the program is run on a machine other than the one on which it
is built. Rather than storing the absolute path to the shared
library in the DT_NEEDED entry, we can store just the name,
and let the dynamic linker find it using DT_RUNPATH or the
LD_LIBRARY_PATH environment variable.
R=rsc
CC=golang-dev
https://golang.org/cl/223068
eliminates spurious multiple initialization errors.
give more information in the multiple init errors that remain.
Fixes#87.
R=r
CC=golang-dev
https://golang.org/cl/194052
5g/6g/8g: add import statements to export metadata, mapping package path to package name.
recognize "" as the path of the package in export metadata.
use "" as the path of the package in object symbol names.
5c/6c/8c, 5a/6a/8a: rewrite leading . to "". so that ·Sin means Sin in this package.
5l/6l/8l: rewrite "" in symbol names as object files are read.
gotest: handle new symbol names.
gopack: handle new import lines in export metadata.
Collectively, these changes eliminate the assumption of a global
name space in the object file formats. Higher level pieces such as
reflect and the computation of type hashes still depend on the
assumption; we're not done yet.
R=ken2, r, ken3
CC=golang-dev
https://golang.org/cl/186263
* switch to real dot (.) instead of center dot (·) everywhere in object files.
before it was half and half depending on where in the name it appeared.
* in 6c/6a/etc identifiers, · can still be used but turns into . immediately.
* in export metadata, replace package identifiers with quoted strings
(still package names, not paths).
R=ken2, r
CC=golang-dev
https://golang.org/cl/190076
the bash scripts and makefiles for building go didn't take into account
the fact $GOROOT / $GOBIN could both be directories containing whitespaces,
and was not possible to build it in such a situation.
this commit adjusts the various makefiles/scripts to make it aware of that
possibility, and now it builds successfully when using a path with whitespaces
as well.
Fixes#115.
R=rsc, dsymonds1
https://golang.org/cl/157067
now that all arguments are passed on the stack.
go/test: passes 89% (310/345)
R=rsc
APPROVED=rsc
DELTA=33 (13 added, 14 deleted, 6 changed)
OCL=36009
CL=36022
because they are in package runtime.
another step to enforcing package boundaries.
R=r
DELTA=732 (114 added, 93 deleted, 525 changed)
OCL=35811
CL=35824