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
The static func named thread in issue5337.go's C snippet
conflicts with the static func named thread in issue3350.go's C snippet.
I don't know why (they're both static) but I also don't care,
because -linkmode=internal only needs to be able to handle
the cgo in the standard library, and it does.
Change the test to avoid this problem.
Fixes build (after run.bash is fixed to detect the breakage).
R=minux.ma
TBR=minux.ma
CC=golang-dev
https://golang.org/cl/11201043
Add gostartcall and gostartcallfn.
The old gogocall = gostartcall + gogo.
The old gogocallfn = gostartcallfn + gogo.
R=dvyukov, minux.ma
CC=golang-dev
https://golang.org/cl/10036044
runtime.setmg() calls another function (cgo_save_gm), so it must save
LR onto stack.
Re-enabled TestCthread test in misc/cgo/test.
Fixes#4863.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/9019043
This change removes processing of #cgo directives from cmd/cgo,
pushing the onus back on cmd/go to pass all necessary flags.
Fixes#5224. See comments for rationale.
R=golang-dev, iant, r
CC=golang-dev
https://golang.org/cl/8610044
Some variables declared in C could end up as undefined symbols
in the final binary and have null address.
Fixes#5114.
Fixes#5227.
R=golang-dev, iant, ajstarks, dave, r
CC=golang-dev
https://golang.org/cl/8602044
This CL was written by rsc. I just tweaked 8l.
This CL adds TLS relocation to the ELF .o file we write during external linking,
so that the host linker (gcc) can decide the final location of m and g.
Similar relocations are not necessary on OS X because we use an alternate
program start-time mechanism to acquire thread-local storage.
Similar relocations are not necessary on ARM or Plan 9 or Windows
because external linking mode is not yet supported on those systems.
On almost all ELF systems, the references we use are like %fs:-0x4 or %gs:-0x4,
which we write in 6a/8a as -0x4(FS) or -0x4(GS). On Linux/ELF, however,
Xen's lack of support for this mode forced us long ago to use a two-instruction
sequence: first we load %gs:0x0 into a register r, and then we use -0x4(r).
(The ELF program loader arranges that %gs:0x0 contains a regular pointer to
that same memory location.) In order to relocate those -0x4(r) references,
the linker must know where they are. This CL adds the equivalent notation
-0x4(r)(GS*1) for this purpose: it assembles to the same encoding as -0x4(r)
but the (GS*1) indicates to the linker that this is one of those thread-local
references that needs relocation.
Thanks to Elias Naur for reminding me about this missing piece and
also for writing the test.
R=r
CC=golang-dev
https://golang.org/cl/7891047
The arm gentraceback mishandled frame linkage values pointing
to the assembly return function. This function is special as
its frame size is zero and it contains only one instruction.
These conditions would preserve the frame pointer and result
in an off by one error when unwinding the caller.
Fixes#5124
R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/8023043
The ARM implementation of runtime.cgocallback_gofunc diverged
from the calling convention by leaving a word of garbage at
the top of the stack and storing the return PC above the
locals. This change stores the return PC at the top of the
stack and removes the save area above the locals.
Update #5124
This CL fixes first part of the ARM issues and added the unwind test.
R=golang-dev, bradfitz, minux.ma, cshapiro, rsc
CC=golang-dev
https://golang.org/cl/7728045
This works with at least one version of clang
that existed at one moment in time.
No guarantees about clangs past or future.
To try:
CC=clang all.bash
It does not work with the Xcode clang,
because that clang fails at printing a useful answer
to:
clang -print-libgcc-file-name
The clang that works prints a full path name for
that command, not just "libgcc.a".
Fixes#4713.
R=iant, minux.ma
CC=golang-dev
https://golang.org/cl/7323068
* Separate internal and external LockOSThread, for cgo safety.
* Show goroutine that made faulting cgo call.
* Never start a panic due to a signal caused by a cgo call.
Fixes#3774.
Fixes#3775.
Fixes#3797.
R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/7228081
Enable cgo on OpenBSD.
The OpenBSD ld.so(1) does not currently support PT_TLS sections. Work
around this by fixing up the TCB that has been provided by librthread
and reallocating a TCB with additional space for TLS. Also provide a
wrapper for pthread_create, allowing zeroed TLS to be allocated for
threads created externally to Go.
Joint work with Shenghou Ma (minux).
Requires change 6846064.
Fixes#3205.
R=golang-dev, minux.ma, iant, rsc, iant
CC=golang-dev
https://golang.org/cl/6853059
compiler_rt introduces a weak and hidden symbol compilerrt_abort_impl
into our pre-linked _all.o object, we have to handle it.
Fixes#4273.
R=iant, rsc, r
CC=golang-dev
https://golang.org/cl/6783050
In a few places, the existing cgo tests assume that a
Go int is the same as a C int. Making int 64 bits wide
on 64-bit platforms violates this assumption.
Change that code to assume that Go int32 and C int
are the same instead. That's still not great, but it's better,
and I am unaware of any systems we run on where it is not true.
Update #2188.
R=iant, r
CC=golang-dev
https://golang.org/cl/6552064
Always process the DWARF info, even when the const value is determined
using the debug data block. This ensures that the injected enum is
removed and future loads of the same constant do not trigger
inconsistent definitions.
Add tests for issues 2470 and 4054.
Fixes#4054.
R=golang-dev, fullung, dave, rsc, minux.ma
CC=golang-dev
https://golang.org/cl/6501101
use a function to get stdout and stderr, instead of depending
on a specific libc implementation.
also make test/run.go replace \r\n by \n before comparing
output.
Fixes#2121.
Part of issue 1741.
R=alex.brainman, rsc, r, remyoudompheng
CC=golang-dev
https://golang.org/cl/5847068
Fixes#4008.
Run a background goroutine that wastes CPU to trick the
power management into raising the CPU frequency which,
by side effect, makes sleep more accurate on arm.
=== RUN TestParallelSleep
--- PASS: TestParallelSleep (1.30 seconds)
_cgo_gotypes.go:772: sleep(1) slept for 1.000458s
R=minux.ma, r
CC=golang-dev
https://golang.org/cl/6498060
This CL adds a step to the build procedure for cgo programs. It uses 'ld -r'
to combine all gcc compiled object file and generate a relocatable object file
for our ld. Additionally, this linking step will combine some static linking
gcc library into the relocatable object file, so that we can use libgcc,
libmingwex and libmingw32 without problem.
Fixes#3261.
Fixes#1741.
Added a testcase for linking in libgcc.
TODO:
1. still need to fix the INDIRECT_SYMBOL_LOCAL problem on Darwin/386.
2. still need to enable the libgcc test on Linux/ARM, because 5l can't deal
with thumb libgcc.
Tested on Darwin/amd64, Darwin/386, FreeBSD/amd64, FreeBSD/386, Linux/amd64,
Linux/386, Linux/ARM, Windows/amd64, Windows/386
R=iant, rsc, bradfitz, coldredlemur
CC=golang-dev
https://golang.org/cl/5822049
