/usr/src/gcc-5/debian/patches/pr66904.diff is in gcc-5-source 5.3.1-14ubuntu2.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 | # DP: PR go/66904, pass linker flags from "#cgo pkg-config:" directives.
commit 6209b6e6b849b6d913be74253e0e972de01d4785
Author: Michael Hudson-Doyle <michael.hudson@canonical.com>
Date: Thu Jan 21 14:53:55 2016 +1300
cmd/go: fix "#cgo pkg-config:" comments with gccgo
DO NOT SUBMIT
This is too late for Go 1.6 but we'd like to get a fix into Ubuntu (as a distro
patch) so a review would be appreciated.
The unique difficulty of #cgo pkg-config is that the linker flags are recorded
when the package is compiled but (obviously) must be used when the package is
linked into an executable -- so the flags need to be stored on disk somewhere.
As it happens cgo already writes out a _cgo_flags file: nothing uses it
currently, but this change adds it to the lib$pkg.a file when compiling a
package, reads it out when linking (and passes a version of the .a file with
_cgo_flags stripped out of it to the linker). It's all fairly ugly but it works
and I can't really think of any way of reducing the essential level of
ugliness.
Fixes #11739
Change-Id: I35621878014e1e107eda77a5b0b23d0240ec5750
--- a/src/libgo/go/cmd/go/build.go
+++ a/src/libgo/go/cmd/go/build.go
@@ -887,6 +887,9 @@ func (b *builder) build(a *action) (err error) {
if err != nil {
return err
}
+ if _, ok := buildToolchain.(gccgoToolchain); ok {
+ cgoObjects = append(cgoObjects, filepath.Join(a.objdir, "_cgo_flags"))
+ }
cgoObjects = append(cgoObjects, outObj...)
gofiles = append(gofiles, outGo...)
}
@@ -1928,6 +1931,57 @@ func (tools gccgoToolchain) ld(b *builder, p *Package, out string, allactions []
cxx := len(p.CXXFiles) > 0
objc := len(p.MFiles) > 0
+ readCgoFlags := func(flagsFile string) error {
+ flags, err := ioutil.ReadFile(flagsFile)
+ if err != nil {
+ return err
+ }
+ for _, line := range strings.Split(string(flags), "\n") {
+ if strings.HasPrefix(line, "_CGO_LDFLAGS=") {
+ cgoldflags = append(cgoldflags, strings.Fields(line[13:])...)
+ }
+ }
+ return nil
+ }
+
+ readAndRemoveCgoFlags := func(archive string) (string, error) {
+ newa, err := ioutil.TempFile(b.work, filepath.Base(archive))
+ if err != nil {
+ return "", err
+ }
+ olda, err := os.Open(archive)
+ if err != nil {
+ return "", err
+ }
+ _, err = io.Copy(newa, olda)
+ if err != nil {
+ return "", err
+ }
+ err = olda.Close()
+ if err != nil {
+ return "", err
+ }
+ err = newa.Close()
+ if err != nil {
+ return "", err
+ }
+
+ newarchive := newa.Name()
+ err = b.run(b.work, p.ImportPath, nil, "ar", "x", newarchive, "_cgo_flags")
+ if err != nil {
+ return "", err
+ }
+ err = b.run(".", p.ImportPath, nil, "ar", "d", newarchive, "_cgo_flags")
+ if err != nil {
+ return "", err
+ }
+ err = readCgoFlags(filepath.Join(b.work, "_cgo_flags"))
+ if err != nil {
+ return "", err
+ }
+ return newarchive, nil
+ }
+
// Prefer the output of an install action to the output of a build action,
// because the install action will delete the output of the build action.
// Iterate over the list backward (reverse dependency order) so that we
@@ -1937,16 +1991,24 @@ func (tools gccgoToolchain) ld(b *builder, p *Package, out string, allactions []
if !a.p.Standard {
if a.p != nil && !apackagesSeen[a.p] {
apackagesSeen[a.p] = true
+ target := a.target
+ if len(a.p.CgoFiles) > 0 {
+ var err error
+ target, err = readAndRemoveCgoFlags(target)
+ if err != nil {
+ return err
+ }
+ }
if a.p.fake && a.p.external {
// external _tests, if present must come before
// internal _tests. Store these on a seperate list
// and place them at the head after this loop.
- xfiles = append(xfiles, a.target)
+ xfiles = append(xfiles, target)
} else if a.p.fake {
// move _test files to the top of the link order
- afiles = append([]string{a.target}, afiles...)
+ afiles = append([]string{target}, afiles...)
} else {
- afiles = append(afiles, a.target)
+ afiles = append(afiles, target)
}
}
}
@@ -1970,6 +2032,15 @@ func (tools gccgoToolchain) ld(b *builder, p *Package, out string, allactions []
}
}
}
+
+ for i, o := range ofiles {
+ if filepath.Base(o) == "_cgo_flags" {
+ readCgoFlags(o)
+ ofiles = append(ofiles[:i], ofiles[i+1:]...)
+ break
+ }
+ }
+
ldflags = append(ldflags, afiles...)
ldflags = append(ldflags, cgoldflags...)
ldflags = append(ldflags, envList("CGO_LDFLAGS", "")...)
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