re PR go/77857 (gccgo: vendoring doesn't work in gcc 6/7)

	PR go/77857
    cmd/go: generate vendor paths for -I arg on compile

    This change generates the vendor path to be used with -I
    on a gccgo compile to find imports from the vendor directories.

    Fixes golang/go#15628

    Reviewed-on: https://go-review.googlesource.com/39590

From-SVN: r246864

diff --git a/libgo/go/cmd/go/build.go b/libgo/go/cmd/go/build.go
index a8f90344c30ab4c2e1b649cc9bbc935cf68d90c4..f2d11f43f19aab525b0d47d09b15ba35bc1550fd 100644 (file)
--- a/libgo/go/cmd/go/build.go
+++ b/libgo/go/cmd/go/build.go
@@ -2398,14 +2398,6 @@ func (gcToolchain) gc(b *builder, p *Package, archive, obj string, asmhdr bool,
                }
        }
 
-       for _, path := range p.Imports {
-               if i := strings.LastIndex(path, "/vendor/"); i >= 0 {
-                       gcargs = append(gcargs, "-importmap", path[i+len("/vendor/"):]+"="+path)
-               } else if strings.HasPrefix(path, "vendor/") {
-                       gcargs = append(gcargs, "-importmap", path[len("vendor/"):]+"="+path)
-               }
-       }
-
        args := []interface{}{buildToolExec, tool("compile"), "-o", ofile, "-trimpath", b.work, buildGcflags, gcargs, "-D", p.localPrefix, importArgs}
        if ofile == archive {
                args = append(args, "-pack")
@@ -2706,6 +2698,55 @@ func (tools gccgoToolchain) gc(b *builder, p *Package, archive, obj string, asmh
        if p.localPrefix != "" {
                gcargs = append(gcargs, "-fgo-relative-import-path="+p.localPrefix)
        }
+       savedirs := []string{}
+       for _, incdir := range importArgs {
+               if incdir != "-I" {
+                       savedirs = append(savedirs, incdir)
+               }
+       }
+
+       for _, path := range p.Imports {
+               // If this is a new vendor path, add it to the list of importArgs
+               if i := strings.LastIndex(path, "/vendor"); i >= 0 {
+                       for _, dir := range savedirs {
+                               // Check if the vendor path is already included in dir
+                               if strings.HasSuffix(dir, path[:i+len("/vendor")]) {
+                                       continue
+                               }
+                               // Make sure this vendor path is not already in the list for importArgs
+                               vendorPath := dir + "/" + path[:i+len("/vendor")]
+                               for _, imp := range importArgs {
+                                       if imp == "-I" {
+                                               continue
+                                       }
+                                       // This vendorPath is already in the list
+                                       if imp == vendorPath {
+                                               goto nextSuffixPath
+                                       }
+                               }
+                               // New vendorPath not yet in the importArgs list, so add it
+                               importArgs = append(importArgs, "-I", vendorPath)
+                       nextSuffixPath:
+                       }
+               } else if strings.HasPrefix(path, "vendor/") {
+                       for _, dir := range savedirs {
+                               // Make sure this vendor path is not already in the list for importArgs
+                               vendorPath := dir + "/" + path[len("/vendor"):]
+                               for _, imp := range importArgs {
+                                       if imp == "-I" {
+                                               continue
+                                       }
+                                       if imp == vendorPath {
+                                               goto nextPrefixPath
+                                       }
+                               }
+                               // This vendor path is needed and not already in the list, so add it
+                               importArgs = append(importArgs, "-I", vendorPath)
+                       nextPrefixPath:
+                       }
+               }
+       }
+
        args := stringList(tools.compiler(), importArgs, "-c", gcargs, "-o", ofile, buildGccgoflags)
        for _, f := range gofiles {
                args = append(args, mkAbs(p.Dir, f))