From 9091ce77930923dacf82e0f72eac466e915c490c Mon Sep 17 00:00:00 2001 From: Clement Date: Tue, 19 Feb 2019 14:48:00 -0600 Subject: [PATCH 15/24] cmd, runtime: fix C trampolines on aix/ppc64 --- src/cmd/go/internal/work/exec.go | 21 +++++++++++++++++++++ src/cmd/link/internal/ld/lib.go | 28 ++++++++++++++++++++++++++++ src/cmd/link/internal/ld/pcln.go | 2 +- src/cmd/link/internal/ld/xcoff.go | 6 +++--- src/runtime/asm_ppc64x.s | 6 ++++++ src/runtime/cgo/callbacks.go | 5 +++++ src/runtime/cgo/gcc_aix_ppc64.S | 4 ++-- src/runtime/cgo/gcc_aix_ppc64.c | 22 ++++++++++++++++++++++ 8 files changed, 88 insertions(+), 6 deletions(-) create mode 100644 src/runtime/cgo/gcc_aix_ppc64.c diff --git a/src/cmd/go/internal/work/exec.go b/src/cmd/go/internal/work/exec.go index 07b21aaf4f..57f6ffbb4e 100644 --- a/src/cmd/go/internal/work/exec.go +++ b/src/cmd/go/internal/work/exec.go @@ -2162,11 +2162,32 @@ func (b *Builder) gccld(p *load.Package, objdir, outfile string, flags []string, // Filter out useless linker warnings caused by bugs outside Go. // See also cmd/link/internal/ld's hostlink method. var save [][]byte + var skipLines int for _, line := range bytes.SplitAfter(out, []byte("\n")) { // golang.org/issue/26073 - Apple Xcode bug if bytes.Contains(line, []byte("ld: warning: text-based stub file")) { continue } + + if skipLines > 0 { + skipLines-- + continue + } + + // Remove duplicate main symbol with runtime/cgo on AIX. + // With runtime/cgo, two main are available: + // One is generated by cgo tool with {return 0;}. + // The other one is the main calling runtime.rt0_go + // in runtime/cgo. + // The second can't be used by cgo programs because + // runtime.rt0_go is unknown to them. + // Therefore, we let ld remove this main version + // and used the cgo generated one. + if p.ImportPath == "runtime/cgo" && bytes.Contains(line, []byte("ld: 0711-224 WARNING: Duplicate symbol: .main")) { + skipLines = 1 + continue + } + save = append(save, line) } out = bytes.Join(save, nil) diff --git a/src/cmd/link/internal/ld/lib.go b/src/cmd/link/internal/ld/lib.go index 19d04461c3..3f610ae4a1 100644 --- a/src/cmd/link/internal/ld/lib.go +++ b/src/cmd/link/internal/ld/lib.go @@ -1286,6 +1286,34 @@ func (ctxt *Link) hostlink() { argv = append(argv, filepath.Join(*flagTmpdir, "go.o")) argv = append(argv, hostobjCopy()...) + if ctxt.HeadType == objabi.Haix { + // We want to have C files after Go files to remove + // trampolines csects made by ld. + argv = append(argv, "-nostartfiles") + argv = append(argv, "/lib/crt0_64.o") + + // Get gcc starting files. + var target, version string + out, err := exec.Command("gcc", "-v").CombinedOutput() + if err != nil { + Exitf("running gcc failed: %v\n%s", err, out) + } + + for _, line := range bytes.SplitAfter(out, []byte("\n")) { + if bytes.Contains(line, []byte("Target:")) { + targetbyte := bytes.Split(line, []byte(" "))[1] + target = string(bytes.Trim(targetbyte, "\n")) + } + if bytes.Contains(line, []byte("gcc version")) { + version = string(bytes.Split(line, []byte(" "))[2]) + } + } + + dir := "/opt/freeware/lib/gcc/" + target + "/" + version + + argv = append(argv, dir+"/pthread/ppc64/crtcxa.o") + argv = append(argv, dir+"/pthread/ppc64/crtdbase.o") + } if ctxt.linkShared { seenDirs := make(map[string]bool) diff --git a/src/cmd/link/internal/ld/pcln.go b/src/cmd/link/internal/ld/pcln.go index e4db834622..1d4315590c 100644 --- a/src/cmd/link/internal/ld/pcln.go +++ b/src/cmd/link/internal/ld/pcln.go @@ -164,7 +164,7 @@ func renumberfiles(ctxt *Link, files []*sym.Symbol, d *sym.Pcdata) { // onlycsymbol reports whether this is a symbol that is referenced by C code. func onlycsymbol(s *sym.Symbol) bool { switch s.Name { - case "_cgo_topofstack", "_cgo_panic", "crosscall2": + case "_cgo_topofstack", "__cgo_topofstack", "_cgo_panic", "crosscall2": return true } if strings.HasPrefix(s.Name, "_cgoexp_") { diff --git a/src/cmd/link/internal/ld/xcoff.go b/src/cmd/link/internal/ld/xcoff.go index ca95d5945e..4276fbe5d4 100644 --- a/src/cmd/link/internal/ld/xcoff.go +++ b/src/cmd/link/internal/ld/xcoff.go @@ -1224,9 +1224,9 @@ func (ctxt *Link) doxcoff() { } if ctxt.LinkMode == LinkExternal { - // Change main name to match __start code. - main := ctxt.Syms.ROLookup("_main", 0) - main.Name = ".main" + // Change rt0_go name to match name in runtime/cgo:main(). + rt0 := ctxt.Syms.ROLookup("runtime.rt0_go", 0) + ctxt.Syms.Rename(rt0.Name, "runtime_rt0_go", 0, ctxt.Reachparent) for _, s := range ctxt.Syms.Allsym { if !s.Attr.CgoExport() { diff --git a/src/runtime/asm_ppc64x.s b/src/runtime/asm_ppc64x.s index 9539423d4b..76af1e0a2b 100644 --- a/src/runtime/asm_ppc64x.s +++ b/src/runtime/asm_ppc64x.s @@ -854,7 +854,13 @@ TEXT runtime·return0(SB), NOSPLIT, $0 // Called from cgo wrappers, this function returns g->m->curg.stack.hi. // Must obey the gcc calling convention. +#ifdef GOOS_aix +// On AIX, _cgo_topofstack is defined in runtime/cgo, because it must +// be a longcall in order to prevent trampolines from ld. +TEXT __cgo_topofstack(SB),NOSPLIT|NOFRAME,$0 +#else TEXT _cgo_topofstack(SB),NOSPLIT|NOFRAME,$0 +#endif // g (R30) and R31 are callee-save in the C ABI, so save them MOVD g, R4 MOVD R31, R5 diff --git a/src/runtime/cgo/callbacks.go b/src/runtime/cgo/callbacks.go index 14a218ec92..64ab24abce 100644 --- a/src/runtime/cgo/callbacks.go +++ b/src/runtime/cgo/callbacks.go @@ -109,3 +109,8 @@ var _cgo_yield unsafe.Pointer //go:cgo_export_static _cgo_topofstack //go:cgo_export_dynamic _cgo_topofstack + +// This is specific to AIX (see gcc_aix_ppc64.c). +// It will be removed for others OSes. +//go:cgo_export_static __cgo_topofstack +//go:cgo_export_static runtime.rt0_go diff --git a/src/runtime/cgo/gcc_aix_ppc64.S b/src/runtime/cgo/gcc_aix_ppc64.S index ea1e4ceaaa..af0addc3fd 100644 --- a/src/runtime/cgo/gcc_aix_ppc64.S +++ b/src/runtime/cgo/gcc_aix_ppc64.S @@ -31,8 +31,8 @@ crosscall_ppc64: stdu 1, -296(1) // Set up Go ABI constant registers - bl ._cgo_reginit - nop + // Must match _cgo_reginit in runtime package. + xor 0, 0, 0 // Restore g pointer (r30 in Go ABI, which may have been clobbered by C) mr 30, 4 diff --git a/src/runtime/cgo/gcc_aix_ppc64.c b/src/runtime/cgo/gcc_aix_ppc64.c new file mode 100644 index 0000000000..bcb615d4b6 --- /dev/null +++ b/src/runtime/cgo/gcc_aix_ppc64.c @@ -0,0 +1,22 @@ +// Copyright 2018 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// +build aix +// +build ppc64 ppc64le + +/* + * On AIX, call to _cgo_topofstack and main are forced to be a longcall. + * Without it, ld might add trampolines in the middle of .text section + * to reach these functions which are normally declared in runtime package. + */ +extern int __attribute__((longcall)) __cgo_topofstack(void); +extern int __attribute__((longcall)) runtime_rt0_go(int argc, char **argv); + +int _cgo_topofstack(void) { + return __cgo_topofstack(); +} + +int main(int argc, char **argv){ + return runtime_rt0_go(argc, argv); +} -- 2.15.1