Revert "cmd/go: support cgo files in overlays"

This reverts CL 267197.

Reason for revert: tests failing on windows-amd64-longtest builder (https://build.golang.org/log/83afde1aac3ea49debddb8996d089a741c3b1cf1).

Change-Id: I0d7c706144e34b1715316ca2ee9662c901b7f8f5
Reviewed-on: https://go-review.googlesource.com/c/go/+/267357
Trust: Bryan C. Mills <[email protected]>
Run-TryBot: Bryan C. Mills <[email protected]>
Reviewed-by: Dmitri Shuralyov <[email protected]>
TryBot-Result: Go Bot <[email protected]>

Author: Bryan C. Mills

src/cmd/go/internal/work/exec.go

@@ -8,7 +8,6 @@ package work
 
 import (
 	"bytes"
-	"cmd/go/internal/fsys"
 	"context"
 	"encoding/json"
 	"errors"
@@ -2243,6 +2242,8 @@ func (b *Builder) ccompile(a *Action, p *load.Package, outfile string, flags []s
 	// when -trimpath is enabled.
 	if b.gccSupportsFlag(compiler, "-fdebug-prefix-map=a=b") {
 		if cfg.BuildTrimpath {
+			// TODO(#39958): handle overlays
+
 			// Keep in sync with Action.trimpath.
 			// The trimmed paths are a little different, but we need to trim in the
 			// same situations.
@@ -2312,8 +2313,7 @@ func (b *Builder) gccld(a *Action, p *load.Package, objdir, outfile string, flag
 
 	cmdargs := []interface{}{cmd, "-o", outfile, objs, flags}
 	dir := p.Dir
-	out, err := b.runOut(a, base.Cwd, b.cCompilerEnv(), cmdargs...)
-
+	out, err := b.runOut(a, dir, b.cCompilerEnv(), cmdargs...)
 	if len(out) > 0 {
 		// Filter out useless linker warnings caused by bugs outside Go.
 		// See also cmd/link/internal/ld's hostlink method.
@@ -2641,8 +2641,7 @@ func (b *Builder) cgo(a *Action, cgoExe, objdir string, pcCFLAGS, pcLDFLAGS, cgo
 		cgoLDFLAGS = append([]string{"-fsanitize=memory"}, cgoLDFLAGS...)
 	}
 
-	// Allows including _cgo_export.h, as well as the user's .h files,
-	// from .[ch] files in the package.
+	// Allows including _cgo_export.h from .[ch] files in the package.
 	cgoCPPFLAGS = append(cgoCPPFLAGS, "-I", objdir)
 
 	// cgo
@@ -2655,8 +2654,6 @@ func (b *Builder) cgo(a *Action, cgoExe, objdir string, pcCFLAGS, pcLDFLAGS, cgo
 		cfiles = append(cfiles, f+".cgo2.c")
 	}
 
-	hfiles := append([]string{}, p.HFiles...)
-
 	// TODO: make cgo not depend on $GOARCH?
 
 	cgoflags := []string{}
@@ -2701,38 +2698,7 @@ func (b *Builder) cgo(a *Action, cgoExe, objdir string, pcCFLAGS, pcLDFLAGS, cgo
 		cgoflags = append(cgoflags, "-exportheader="+objdir+"_cgo_install.h")
 	}
 
-	execdir := p.Dir
-
-	// If any of the Cgo, C, or H files are overlaid, copy them all to
-	// objdir to ensure that they refer to the right header files.
-	// TODO(#39958): Ideally, we'd always do this, but this could
-	// subtly break some cgo files that include .h files across directory
-	// boundaries, even though they shouldn't.
-	hasOverlay := false
-	cgoFileLists := [][]string{cgofiles, gccfiles, gxxfiles, mfiles, ffiles, hfiles}
-OverlayLoop:
-	for _, fs := range cgoFileLists {
-		for _, f := range fs {
-			if _, ok := fsys.OverlayPath(mkAbs(p.Dir, f)); ok {
-				hasOverlay = true
-				break OverlayLoop
-			}
-		}
-	}
-	if hasOverlay {
-		execdir = objdir
-		for _, fs := range cgoFileLists {
-			for i := range fs {
-				opath, _ := fsys.OverlayPath(mkAbs(p.Dir, fs[i]))
-				fs[i] = objdir + filepath.Base(fs[i])
-				if err := b.copyFile(fs[i], opath, 0666, false); err != nil {
-					return nil, nil, err
-				}
-			}
-		}
-	}
-
-	if err := b.run(a, execdir, p.ImportPath, cgoenv, cfg.BuildToolexec, cgoExe, "-objdir", objdir, "-importpath", p.ImportPath, cgoflags, "--", cgoCPPFLAGS, cgoCFLAGS, cgofiles); err != nil {
+	if err := b.run(a, p.Dir, p.ImportPath, cgoenv, cfg.BuildToolexec, cgoExe, "-objdir", objdir, "-importpath", p.ImportPath, cgoflags, "--", cgoCPPFLAGS, cgoCFLAGS, cgofiles); err != nil {
 		return nil, nil, err
 	}
 	outGo = append(outGo, gofiles...)
@@ -2826,7 +2792,7 @@ func (b *Builder) dynimport(a *Action, p *load.Package, objdir, importGo, cgoExe
 		return err
 	}
 
-	linkobj := str.StringList(ofile, outObj, mkAbsFiles(p.Dir, p.SysoFiles))
+	linkobj := str.StringList(ofile, outObj, p.SysoFiles)
 	dynobj := objdir + "_cgo_.o"
 
 	// we need to use -pie for Linux/ARM to get accurate imported sym
@@ -2851,7 +2817,7 @@ func (b *Builder) dynimport(a *Action, p *load.Package, objdir, importGo, cgoExe
 	if p.Standard && p.ImportPath == "runtime/cgo" {
 		cgoflags = []string{"-dynlinker"} // record path to dynamic linker
 	}
-	return b.run(a, base.Cwd, p.ImportPath, b.cCompilerEnv(), cfg.BuildToolexec, cgoExe, "-dynpackage", p.Name, "-dynimport", dynobj, "-dynout", importGo, cgoflags)
+	return b.run(a, p.Dir, p.ImportPath, b.cCompilerEnv(), cfg.BuildToolexec, cgoExe, "-dynpackage", p.Name, "-dynimport", dynobj, "-dynout", importGo, cgoflags)
 }
 
 // Run SWIG on all SWIG input files.

src/cmd/go/internal/work/gc.go

@@ -262,7 +262,7 @@ func (a *Action) trimpath() string {
 	if len(objdir) > 1 && objdir[len(objdir)-1] == filepath.Separator {
 		objdir = objdir[:len(objdir)-1]
 	}
-	rewrite := ""
+	rewrite := objdir + "=>"
 
 	rewriteDir := a.Package.Dir
 	if cfg.BuildTrimpath {
@@ -271,7 +271,7 @@ func (a *Action) trimpath() string {
 		} else {
 			rewriteDir = a.Package.ImportPath
 		}
-		rewrite += a.Package.Dir + "=>" + rewriteDir + ";"
+		rewrite += ";" + a.Package.Dir + "=>" + rewriteDir
 	}
 
 	// Add rewrites for overlays. The 'from' and 'to' paths in overlays don't need to have
@@ -280,14 +280,11 @@ func (a *Action) trimpath() string {
 	if fsys.OverlayFile != "" {
 		for _, filename := range a.Package.AllFiles() {
 			overlayPath, ok := fsys.OverlayPath(filepath.Join(a.Package.Dir, filename))
-			rewrite += filepath.Join(objdir, filename) + "=>" + filepath.Join(rewriteDir, filename) + ";"
 			if !ok {
 				continue
 			}
-			rewrite += overlayPath + "=>" + filepath.Join(rewriteDir, filename) + ";"
+			rewrite += ";" + overlayPath + "=>" + filepath.Join(rewriteDir, filename)
 		}
-	} else {
-		rewrite += objdir + "=>"
 	}
 
 	return rewrite

src/cmd/go/testdata/script/build_overlay.txt

@@ -1,11 +1,9 @@
 [short] skip
 
 # Test building in overlays.
-# TODO(#39958): add a test case where the destination file in the replace map
+# TODO(matloob): add a test case where the destination file in the replace map
 #   isn't a go file. Either completely exclude that case in fs.IsDirWithGoFiles
 #   if the compiler doesn't allow it, or test that it works all the way.
-# TODO(#39958): add a test that both gc and gccgo assembly files can include .h
-#   files.
 
 # The main package (m) is contained in an overlay. It imports m/dir2 which has one
 # file in an overlay and one file outside the overlay, which in turn imports m/dir,
@@ -31,18 +29,6 @@ exec ./print_trimpath_two_files$GOEXE
 stdout $WORK[/\\]gopath[/\\]src[/\\]m[/\\]printpath[/\\]main.go
 stdout $WORK[/\\]gopath[/\\]src[/\\]m[/\\]printpath[/\\]other.go
 
-go build -overlay overlay.json -o main_cgo_replace$GOEXE ./cgo_hello_replace
-exec ./main_cgo_replace$GOEXE
-stdout '^hello cgo$'
-
-go build -overlay overlay.json -o main_cgo_quote$GOEXE ./cgo_hello_quote
-exec ./main_cgo_quote$GOEXE
-stdout '^hello cgo$'
-
-go build -overlay overlay.json -o main_cgo_angle$GOEXE ./cgo_hello_angle
-exec ./main_cgo_angle$GOEXE
-stdout '^hello cgo$'
-
 # Run same tests but with gccgo.
 env GO111MODULE=off
 [!exec:gccgo] stop
@@ -60,19 +46,6 @@ go build -compiler=gccgo -overlay overlay.json -o print_trimpath_gccgo$GOEXE -tr
 exec ./print_trimpath_gccgo$GOEXE
 stdout ^\.[/\\]printpath[/\\]main.go
 
-
-go build -compiler=gccgo  -overlay overlay.json -o main_cgo_replace_gccgo$GOEXE ./cgo_hello_replace
-exec ./main_cgo_replace_gccgo$GOEXE
-stdout '^hello cgo$'
-
-go build -compiler=gccgo  -overlay overlay.json -o main_cgo_quote_gccgo$GOEXE ./cgo_hello_quote
-exec ./main_cgo_quote_gccgo$GOEXE
-stdout '^hello cgo$'
-
-go build -compiler=gccgo  -overlay overlay.json -o main_cgo_angle_gccgo$GOEXE ./cgo_hello_angle
-exec ./main_cgo_angle_gccgo$GOEXE
-stdout '^hello cgo$'
-
 -- m/go.mod --
 // TODO(matloob): how do overlays work with go.mod (especially if mod=readonly)
 module m
@@ -98,32 +71,9 @@ the actual code is in the overlay
 		"dir/g.go": "overlay/dir_g.go",
 		"dir2/i.go": "overlay/dir2_i.go",
 		"printpath/main.go": "overlay/printpath.go",
-		"printpath/other.go": "overlay2/printpath2.go",
-		"cgo_hello_replace/cgo_header.h": "overlay/cgo_head.h",
-		"cgo_hello_quote/cgo_hello.go": "overlay/cgo_hello_quote.go",
-		"cgo_hello_quote/cgo_header.h": "overlay/cgo_head.h",
-		"cgo_hello_angle/cgo_hello.go": "overlay/cgo_hello_angle.go",
-		"cgo_hello_angle/cgo_header.h": "overlay/cgo_head.h"
+		"printpath/other.go": "overlay2/printpath2.go"
 	}
 }
--- m/cgo_hello_replace/cgo_hello_replace.go --
-package main
-
-// #include "cgo_header.h"
-import "C"
-
-func main() {
-	C.say_hello()
-}
--- m/cgo_hello_replace/cgo_header.h --
- // Test that this header is replaced with one that has the proper declaration.
-void say_goodbye();
-
--- m/cgo_hello_replace/goodbye.c --
-#include <stdio.h>
-
-void say_hello() { puts("hello cgo\n"); fflush(stdout); }
-
 -- m/overlay/f.go --
 package main
 
@@ -178,32 +128,3 @@ import "m/dir"
 func printMessage() {
 	dir.PrintMessage()
 }
--- m/overlay/cgo_hello_quote.go --
-package main
-
-// #include "cgo_header.h"
-import "C"
-
-func main() {
-	C.say_hello()
-}
--- m/overlay/cgo_hello_angle.go --
-package main
-
-// #include <cgo_header.h>
-import "C"
-
-func main() {
-	C.say_hello()
-}
--- m/overlay/cgo_head.h --
-void say_hello();
--- m/cgo_hello_quote/hello.c --
-#include <stdio.h>
-
-void say_hello() { puts("hello cgo\n"); fflush(stdout); }
--- m/cgo_hello_angle/hello.c --
-#include <stdio.h>
-
-void say_hello() { puts("hello cgo\n"); fflush(stdout); }
-

src/cmd/go/testdata/script/build_trimpath_cgo.txt

@@ -20,38 +20,10 @@ go build -trimpath -o hello.exe .
 go run ./list-dwarf hello.exe
 ! stdout gopath/src
 
-
-# Do the above, with the cgo (but not .c) sources in an overlay
-# Check that the source path appears when -trimpath is not used.
-mkdir $WORK/overlay
-cp hello.go $WORK/overlay/hello.go
-mkdir hello_overlay
-cp hello.c hello_overlay/hello.c
-go build -overlay overlay.json -o hello_overlay.exe ./hello_overlay
-grep -q gopath[/\\]src hello_overlay.exe
-! grep -q $WORK[/\\]overlay hello_overlay.exe
-go run ./list-dwarf hello_overlay.exe
-stdout gopath[/\\]src
-! stdout $WORK[/\\]overlay
-
-# Check that the source path does not appear when -trimpath is used.
-go build -overlay overlay.json -trimpath -o hello_overlay.exe ./hello_overlay
-! grep -q gopath[/\\]src hello_overlay.exe
-! grep -q $WORK[/\\]overlay hello_overlay.exe
-go run ./list-dwarf hello_overlay.exe
-! stdout gopath/src
-! stdout $WORK[/\\]overlay
-
 -- go.mod --
 module m
 
 go 1.14
--- overlay.json --
-{
-	"Replace": {
-		"hello_overlay/hello.go": "../../overlay/hello.go"
-	}
-}
 -- hello.c --
 #include <stdio.h>