[release-branch.go1.14] cmd/go: don't lookup the path for CC when invoking cgo
Previously, if CC was a path without separators (like gcc or clang),
we'd look it up in PATH in cmd/go using internal/execabs.LookPath,
then pass the resolved path to cgo in CC.
This caused a regression: if the directory in PATH containing CC has a
space, cgo splits it and interprets it as multiple arguments.
With this change, cmd/go no longer resolves CC before invoking
cgo. cgo does the path lookup on each invocation. This reverts the
security fix CL 284780, but that was redundant with the addition of
internal/execabs (CL 955304), which still protects us.
NOTE: This CL includes a related test fix from CL 286292.
Fixes #43859
Change-Id: I65d91a1e303856df8653881eb6e2e75a3bf95c49
Reviewed-on: https://go-review.googlesource.com/c/go/+/285873
Trust: Jay Conrod <jayconrod@google.com>
Run-TryBot: Jay Conrod <jayconrod@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
(cherry picked from commit a2cef9b544708ecae983ed8836ee2425a28aab68)
Reviewed-on: https://go-review.googlesource.com/c/go/+/285952
diff --git a/src/cmd/go/internal/work/action.go b/src/cmd/go/internal/work/action.go
index 8256681..e3cb87f 100644
--- a/src/cmd/go/internal/work/action.go
+++ b/src/cmd/go/internal/work/action.go
@@ -56,9 +56,6 @@
id sync.Mutex
toolIDCache map[string]string // tool name -> tool ID
buildIDCache map[string]string // file name -> build ID
-
- cgoEnvOnce sync.Once
- cgoEnvCache []string
}
// NOTE: Much of Action would not need to be exported if not for test.
diff --git a/src/cmd/go/internal/work/exec.go b/src/cmd/go/internal/work/exec.go
index 8230d85..1c50f47 100644
--- a/src/cmd/go/internal/work/exec.go
+++ b/src/cmd/go/internal/work/exec.go
@@ -1076,7 +1076,10 @@
}
// TODO(rsc): Why do we pass $GCCGO to go vet?
- env := b.cgoEnv()
+ env := b.cCompilerEnv()
+ if cfg.BuildToolchainName == "gccgo" {
+ env = append(env, "GCCGO="+BuildToolchain.compiler())
+ }
p := a.Package
tool := VetTool
@@ -1980,24 +1983,6 @@
return []string{"TERM=dumb"}
}
-// cgoEnv returns environment variables to set when running cgo.
-// Some of these pass through to cgo running the C compiler,
-// so it includes cCompilerEnv.
-func (b *Builder) cgoEnv() []string {
- b.cgoEnvOnce.Do(func() {
- cc, err := exec.LookPath(b.ccExe()[0])
- if err != nil || filepath.Base(cc) == cc { // reject relative path
- cc = "/missing-cc"
- }
- gccgo := GccgoBin
- if filepath.Base(gccgo) == gccgo { // reject relative path
- gccgo = "/missing-gccgo"
- }
- b.cgoEnvCache = append(b.cCompilerEnv(), "CC="+cc, "GCCGO="+gccgo)
- })
- return b.cgoEnvCache
-}
-
// mkdir makes the named directory.
func (b *Builder) Mkdir(dir string) error {
// Make Mkdir(a.Objdir) a no-op instead of an error when a.Objdir == "".
@@ -2543,7 +2528,7 @@
// along to the host linker. At this point in the code, cgoLDFLAGS
// consists of the original $CGO_LDFLAGS (unchecked) and all the
// flags put together from source code (checked).
- cgoenv := b.cgoEnv()
+ cgoenv := b.cCompilerEnv()
if len(cgoLDFLAGS) > 0 {
flags := make([]string, len(cgoLDFLAGS))
for i, f := range cgoLDFLAGS {
@@ -2764,7 +2749,7 @@
if p.Standard && p.ImportPath == "runtime/cgo" {
cgoflags = []string{"-dynlinker"} // record path to dynamic linker
}
- return b.run(a, p.Dir, p.ImportPath, b.cgoEnv(), cfg.BuildToolexec, cgoExe, "-dynpackage", p.Name, "-dynimport", dynobj, "-dynout", importGo, cgoflags)
+ return b.run(a, p.Dir, p.ImportPath, b.cCompilerEnv(), cfg.BuildToolexec, cgoExe, "-dynpackage", p.Name, "-dynimport", dynobj, "-dynout", importGo, cgoflags)
}
// Run SWIG on all SWIG input files.
diff --git a/src/cmd/go/testdata/script/cgo_path.txt b/src/cmd/go/testdata/script/cgo_path.txt
index e4d07de..548a65f 100644
--- a/src/cmd/go/testdata/script/cgo_path.txt
+++ b/src/cmd/go/testdata/script/cgo_path.txt
@@ -1,12 +1,20 @@
[!cgo] skip
+# Set CC explicitly to something that requires a PATH lookup.
+# Normally, the default is gcc or clang, but if CC was set during make.bash,
+# that becomes the default.
+[exec:clang] env CC=clang
+[exec:gcc] env CC=gcc
+[!exec:clang] [!exec:gcc] skip 'Unknown C compiler'
+
env GOCACHE=$WORK/gocache # Looking for compile flags, so need a clean cache.
[!windows] env PATH=.:$PATH
-[!windows] chmod 0777 p/gcc p/clang
+[!windows] chmod 0755 p/gcc p/clang
[!windows] exists p/gcc p/clang
[windows] exists p/gcc.bat p/clang.bat
! exists p/bug.txt
-go build -x
+! go build -x
+stderr '^cgo: exec (clang|gcc): (clang|gcc) resolves to executable in current directory \(.[/\\](clang|gcc)(.bat)?\)$'
! exists p/bug.txt
-- go.mod --
diff --git a/src/cmd/go/testdata/script/cgo_path_space.txt b/src/cmd/go/testdata/script/cgo_path_space.txt
new file mode 100644
index 0000000..3ae8dce
--- /dev/null
+++ b/src/cmd/go/testdata/script/cgo_path_space.txt
@@ -0,0 +1,52 @@
+# Check that if the PATH directory containing the C compiler has a space,
+# we can still use that compiler with cgo.
+# Verifies #43808.
+[!cgo] skip
+
+# Set CC explicitly to something that requires a PATH lookup.
+# Normally, the default is gcc or clang, but if CC was set during make.bash,
+# that becomes the default.
+[exec:clang] env CC=clang
+[exec:gcc] env CC=gcc
+[!exec:clang] [!exec:gcc] skip 'Unknown C compiler'
+
+[!windows] chmod 0755 $WORK/'program files'/clang
+[!windows] chmod 0755 $WORK/'program files'/gcc
+[!windows] env PATH=$WORK/'program files':$PATH
+[windows] env PATH=$WORK\'program files';%PATH%
+
+! exists $WORK/log.txt
+! go build -x
+exists $WORK/log.txt
+rm $WORK/log.txt
+
+# TODO(#41400, #43078): when CC is set explicitly, it should be allowed to
+# contain spaces separating arguments, and it should be possible to quote
+# arguments with spaces (including the path), as in CGO_CFLAGS and other
+# variables. For now, this doesn't work.
+[!windows] env CC=$WORK/'program files'/gcc
+[windows] env CC=$WORK\'program files'\gcc.bat
+! go build -x
+! exists $WORK/log.txt
+
+-- go.mod --
+module m
+
+-- m.go --
+package m
+
+// #define X 1
+import "C"
+
+-- $WORK/program files/gcc --
+#!/bin/sh
+
+echo ok >$WORK/log.txt
+-- $WORK/program files/clang --
+#!/bin/sh
+
+echo ok >$WORK/log.txt
+-- $WORK/program files/gcc.bat --
+echo ok >%WORK%\log.txt
+-- $WORK/program files/clang.bat --
+echo ok >%WORK%\log.txt
