compiler_wrapper: handle split "-Wl,-z,defs"

During the libxcrypt build, both "-Wl,-z,defs" and its
split equivalent "-Wl,-z -Wl,defs" are used which create
problems because only the unified version is supported.

This adds support for filtering the flags seprately
and two tests to verify the functionality.

BUG=b:187795307
TEST=Local builds with cross-*/libxcrypt; CQ.

Change-Id: If48499f5c8e552e28c7cefd2d959e40f4757a88f
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/toolchain-utils/+/3641843
Tested-by: Adrian Ratiu <adrian.ratiu@collabora.corp-partner.google.com>
Reviewed-by: Manoj Gupta <manojgupta@chromium.org>
Reviewed-by: George Burgess <gbiv@chromium.org>
Commit-Queue: Manoj Gupta <manojgupta@chromium.org>
Tested-by: Manoj Gupta <manojgupta@chromium.org>

3 files changed, 37 insertions, 0 deletions

diff --git a/compiler_wrapper/command.go b/compiler_wrapper/command.go
index 253251ab..e186623a 100644
--- a/compiler_wrapper/command.go
+++ b/compiler_wrapper/command.go
@@ -265,6 +265,21 @@ func (builder *commandBuilder) transformArgs(transform func(arg builderArg) stri
 	builder.args = newArgs
 }
 
+// Allows to filter arg pairs, useful for eg when having adjacent unsupported args
+// like "-Wl,-z -Wl,defs"
+func (builder *commandBuilder) filterArgPairs(keepPair func(arg1, arg2 builderArg) bool) {
+	newArgs := builder.args[:0]
+	for i := 0; i < len(builder.args); i++ {
+		if i == len(builder.args)-1 || keepPair(builder.args[i], builder.args[i+1]) {
+			newArgs = append(newArgs, builder.args[i])
+		} else {
+			// skip builder.args[i]) as well as next item
+			i++
+		}
+	}
+	builder.args = newArgs
+}
+
 func (builder *commandBuilder) updateEnv(updates ...string) {
 	builder.envUpdates = append(builder.envUpdates, updates...)
 }
diff --git a/compiler_wrapper/sanitizer_flags.go b/compiler_wrapper/sanitizer_flags.go
index 5d517e49..b9eb0558 100644
--- a/compiler_wrapper/sanitizer_flags.go
+++ b/compiler_wrapper/sanitizer_flags.go
@@ -37,5 +37,9 @@ func processSanitizerFlags(builder *commandBuilder) {
 			}
 			return arg.value
 		})
+
+		builder.filterArgPairs(func(arg1, arg2 builderArg) bool {
+			return !(arg1.value == "-Wl,-z" && arg2.value == "-Wl,defs")
+		})
 	}
 }
diff --git a/compiler_wrapper/sanitizer_flags_test.go b/compiler_wrapper/sanitizer_flags_test.go
index 8b22a05e..17c41438 100644
--- a/compiler_wrapper/sanitizer_flags_test.go
+++ b/compiler_wrapper/sanitizer_flags_test.go
@@ -23,6 +23,15 @@ func TestFilterUnsupportedSanitizerFlagsIfSanitizeGiven(t *testing.T) {
 		}
 
 		cmd = ctx.must(callCompiler(ctx, ctx.cfg,
+			ctx.newCommand(gccX86_64, "-fsanitize=kernel-address", "-Wl,-z -Wl,defs", mainCc)))
+		if err := verifyArgCount(cmd, 0, "-Wl,-z"); err != nil {
+			t.Error(err)
+		}
+		if err := verifyArgCount(cmd, 0, "-Wl,defs"); err != nil {
+			t.Error(err)
+		}
+
+		cmd = ctx.must(callCompiler(ctx, ctx.cfg,
 			ctx.newCommand(gccX86_64, "-fsanitize=kernel-address", "-D_FORTIFY_SOURCE=1", mainCc)))
 		if err := verifyArgCount(cmd, 0, "-D_FORTIFY_SOURCE=1"); err != nil {
 			t.Error(err)
@@ -75,6 +84,15 @@ func TestKeepSanitizerFlagsIfNoSanitizeGiven(t *testing.T) {
 		}
 
 		cmd = ctx.must(callCompiler(ctx, ctx.cfg,
+			ctx.newCommand(gccX86_64, "-Wl,-z -Wl,defs", mainCc)))
+		if err := verifyArgCount(cmd, 1, "-Wl,-z"); err != nil {
+			t.Error(err)
+		}
+		if err := verifyArgCount(cmd, 1, "-Wl,defs"); err != nil {
+			t.Error(err)
+		}
+
+		cmd = ctx.must(callCompiler(ctx, ctx.cfg,
 			ctx.newCommand(gccX86_64, "-D_FORTIFY_SOURCE=1", mainCc)))
 		if err := verifyArgCount(cmd, 1, "-D_FORTIFY_SOURCE=1"); err != nil {
 			t.Error(err)