cgo: use slash-free relative paths for .so references

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

diff --git a/src/Make.pkg b/src/Make.pkg
index 8f444be1236c512b47283408dc4dc04b9829064a..39c19611e327685ecf281ac1d8ee1a18df0d1c1b 100644 (file)
--- a/src/Make.pkg
+++ b/src/Make.pkg
@@ -31,11 +31,12 @@ INSTALLFILES+=$(pkgdir)/$(TARG).a
 # The rest of the cgo rules are below, but these variable updates
 # must be done here so they apply to the main rules.
 ifdef CGOFILES
+CGOTARG=cgo_$(subst /,_,$(TARG))
 GOFILES+=$(patsubst %.go,%.cgo1.go,$(CGOFILES))
 GOFILES+=_cgo_gotypes.go
 OFILES+=_cgo_defun.$O
 GCC_OFILES=$(patsubst %.go,%.cgo2.o,$(CGOFILES))
-INSTALLFILES+=$(pkgdir)/$(TARG).so
+INSTALLFILES+=$(pkgdir)/$(CGOTARG).so
 endif
 
 PREREQ+=$(patsubst %,%.make,$(DEPS))
@@ -146,7 +147,7 @@ _cgo_defun.$O: _cgo_defun.c
 _cgo_.so: $(GCC_OFILES) $(CGO_DEPS)
        gcc $(_CGO_CFLAGS_$(GOARCH)) -o $@ $(GCC_OFILES) $(CGO_LDFLAGS)  $(_CGO_LDFLAGS_$(GOOS))
 
-$(pkgdir)/$(TARG).so: _cgo_.so
+$(pkgdir)/$(CGOTARG).so: _cgo_.so
        @test -d $(QUOTED_GOROOT)/pkg && mkdir -p $(pkgdir)/$(dir)
        cp _cgo_.so "$@"
 

diff --git a/src/cmd/5l/obj.c b/src/cmd/5l/obj.c
index 1d09f286a5a0735facaee8a79ab77b11e0cfb51e..e3597e0404044f1a39daebb523915af933692c00 100644 (file)
--- a/src/cmd/5l/obj.c
+++ b/src/cmd/5l/obj.c
@@ -146,6 +146,8 @@ main(int argc, char *argv[])
                usage();
 
        libinit();
+       if(rpath == nil)
+               rpath = smprint("%s/pkg/%s_%s", goroot, goos, goarch);
 
        if(!debug['9'] && !debug['U'] && !debug['B'])
                debug[DEFAULT] = 1;

diff --git a/src/cmd/6l/obj.c b/src/cmd/6l/obj.c
index 6a0d49f13510df2de440203ed96450fceb857943..5a4b6a3fc0c5b8519fbe64d81cdffa41c63c6afd 100644 (file)
--- a/src/cmd/6l/obj.c
+++ b/src/cmd/6l/obj.c
@@ -138,6 +138,8 @@ main(int argc, char *argv[])
                usage();
 
        libinit();
+       if(rpath == nil)
+               rpath = smprint("%s/pkg/%s_%s", goroot, goos, goarch);
 
        if(HEADTYPE == -1) {
                HEADTYPE = 2;

diff --git a/src/cmd/8l/obj.c b/src/cmd/8l/obj.c
index 304187649f4efedad758664d0513de0003993cbc..1a3ecec1d8c0a4313127cdf9255be4a985100e2b 100644 (file)
--- a/src/cmd/8l/obj.c
+++ b/src/cmd/8l/obj.c
@@ -175,6 +175,8 @@ main(int argc, char *argv[])
        }
 
        libinit();
+       if(rpath == nil)
+               rpath = smprint("%s/pkg/%s_%s", goroot, goos, goarch);
 
        switch(HEADTYPE) {
        default:

diff --git a/src/cmd/cgo/out.go b/src/cmd/cgo/out.go
index e58923ab2a1968f716647b9f2cc991f711f0de2f..7cdf483f0eb91df601b71189e52ee3976a7c8480 100644 (file)
--- a/src/cmd/cgo/out.go
+++ b/src/cmd/cgo/out.go
@@ -21,6 +21,13 @@ func creat(name string) *os.File {
        return f
 }
 
+func slashToUnderscore(c int) int {
+       if c == '/' {
+               c = '_'
+       }
+       return c
+}
+
 // writeDefs creates output files to be compiled by 6g, 6c, and gcc.
 // (The comments here say 6g and 6c but the code applies to the 8 and 5 tools too.)
 func (p *Prog) writeDefs() {
@@ -30,6 +37,15 @@ func (p *Prog) writeDefs() {
                path = pkgroot + "/" + path
        }
 
+       // The path for the shared object is slash-free so that ELF loaders
+       // will treat it as a relative path.  We rewrite slashes to underscores.
+       sopath := "cgo_" + strings.Map(slashToUnderscore, p.PackagePath)
+       soprefix := ""
+       if os.Getenv("GOOS") == "darwin" {
+               // OS X requires its own prefix for a relative path
+               soprefix = "@rpath/"
+       }
+
        fgo2 := creat("_cgo_gotypes.go")
        fc := creat("_cgo_defun.c")
 
@@ -48,10 +64,10 @@ func (p *Prog) writeDefs() {
        }
        fmt.Fprintf(fgo2, "type _C_void [0]byte\n")
 
-       fmt.Fprintf(fc, cProlog, pkgroot, pkgroot, pkgroot, pkgroot, pkgroot)
+       fmt.Fprintf(fc, cProlog, soprefix, soprefix, soprefix, soprefix, soprefix)
 
        for name, def := range p.Vardef {
-               fmt.Fprintf(fc, "#pragma dynimport ·_C_%s %s \"%s.so\"\n", name, name, path)
+               fmt.Fprintf(fc, "#pragma dynimport ·_C_%s %s \"%s%s.so\"\n", name, name, soprefix, sopath)
                fmt.Fprintf(fgo2, "var _C_%s ", name)
                printer.Fprint(fgo2, &ast.StarExpr{X: def.Go})
                fmt.Fprintf(fgo2, "\n")
@@ -130,7 +146,7 @@ func (p *Prog) writeDefs() {
 
                // C wrapper calls into gcc, passing a pointer to the argument frame.
                // Also emit #pragma to get a pointer to the gcc wrapper.
-               fmt.Fprintf(fc, "#pragma dynimport _cgo_%s _cgo_%s \"%s.so\"\n", name, name, path)
+               fmt.Fprintf(fc, "#pragma dynimport _cgo_%s _cgo_%s \"%s%s.so\"\n", name, name, soprefix, sopath)
                fmt.Fprintf(fc, "void (*_cgo_%s)(void*);\n", name)
                fmt.Fprintf(fc, "\n")
                fmt.Fprintf(fc, "void\n")
@@ -564,11 +580,11 @@ const cProlog = `
 #include "runtime.h"
 #include "cgocall.h"
 
-#pragma dynimport initcgo initcgo "%s/libcgo.so"
-#pragma dynimport libcgo_thread_start libcgo_thread_start "%s/libcgo.so"
-#pragma dynimport libcgo_set_scheduler libcgo_set_scheduler "%s/libcgo.so"
-#pragma dynimport _cgo_malloc _cgo_malloc "%s/libcgo.so"
-#pragma dynimport _cgo_free _cgo_free "%s/libcgo.so"
+#pragma dynimport initcgo initcgo "%slibcgo.so"
+#pragma dynimport libcgo_thread_start libcgo_thread_start "%slibcgo.so"
+#pragma dynimport libcgo_set_scheduler libcgo_set_scheduler "%slibcgo.so"
+#pragma dynimport _cgo_malloc _cgo_malloc "%slibcgo.so"
+#pragma dynimport _cgo_free _cgo_free "%slibcgo.so"
 
 void
 ·_C_GoString(int8 *p, String s)

diff --git a/src/cmd/ld/macho.c b/src/cmd/ld/macho.c
index 3e33fe494e683e1e4bcbb45162a58130fa2197ee..24400cf14c248127c98057d6216ce4f739806736 100644 (file)
--- a/src/cmd/ld/macho.c
+++ b/src/cmd/ld/macho.c
@@ -441,6 +441,7 @@ asmbmacho(vlong symdatva, vlong symo)
        vlong v, w;
        vlong va;
        int a, i, ptrsize;
+       char *pkgroot;
        MachoHdr *mh;
        MachoSect *msect;
        MachoSeg *ms;
@@ -584,6 +585,12 @@ asmbmacho(vlong symdatva, vlong symo)
                ml->data[0] = 12;       /* offset to string */
                strcpy((char*)&ml->data[1], "/usr/lib/dyld");
 
+               if(ndylib > 0) {        /* add reference to where .so files are installed */
+                       pkgroot = smprint("%s/pkg/%s_%s", goroot, goos, goarch);
+                       ml = newMachoLoad(0x80000000 | 0x1c, 1+(strlen(pkgroot)+1+7)/8*2);      /* LC_RPATH */
+                       ml->data[0] = 12;       /* offset of string from beginning of load */
+                       strcpy((char*)&ml->data[1], pkgroot);
+               }
                for(i=0; i<ndylib; i++) {
                        ml = newMachoLoad(12, 4+(strlen(dylib[i])+1+7)/8*2);    /* LC_LOAD_DYLIB */
                        ml->data[0] = 24;       /* offset of string from beginning of load */