Fix addrsig warnings
ld -r reorders symbols and invalidates the .llvm_addrsig section, which
then causes warnings if the resulting object is used with ld --icf=safe.
The warning is especially common when building with musl, as the
clang_rt.crt* objects have .llvm_addrsig sections, are linked into
libc_musl_crt* using ld -r, and are then linked into every other binary
and shared library with --icf=safe.
Strip the .llvm_addrsig section after ld -r to prevent the warnings.
Test: m USE_HOST_MUSL=true host-native -k
Change-Id: Ia52a4756b9ebbb62115898d0de9f8641e6fea705
diff --git a/cc/builder.go b/cc/builder.go
index fef00d4..f5e0dcc 100644
--- a/cc/builder.go
+++ b/cc/builder.go
@@ -125,6 +125,14 @@
},
"objcopyCmd", "prefix")
+ // Rule to run objcopy --remove-section=.llvm_addrsig on a partially linked object
+ noAddrSig = pctx.AndroidStaticRule("noAddrSig",
+ blueprint.RuleParams{
+ Command: "rm -f ${out} && $objcopyCmd --remove-section=.llvm_addrsig ${in} ${out}",
+ CommandDeps: []string{"$objcopyCmd"},
+ },
+ "objcopyCmd")
+
_ = pctx.SourcePathVariable("stripPath", "build/soong/scripts/strip.sh")
_ = pctx.SourcePathVariable("xzCmd", "prebuilts/build-tools/${config.HostPrebuiltTag}/bin/xz")
_ = pctx.SourcePathVariable("createMiniDebugInfo", "prebuilts/build-tools/${config.HostPrebuiltTag}/bin/create_minidebuginfo")
@@ -1008,6 +1016,21 @@
})
}
+// Generate a rule for running objcopy --remove-section=.llvm_addrsig on a partially linked object
+func transformObjectNoAddrSig(ctx android.ModuleContext, inputFile android.Path, outputFile android.WritablePath) {
+ objcopyCmd := "${config.ClangBin}/llvm-objcopy"
+
+ ctx.Build(pctx, android.BuildParams{
+ Rule: noAddrSig,
+ Description: "remove addrsig " + outputFile.Base(),
+ Output: outputFile,
+ Input: inputFile,
+ Args: map[string]string{
+ "objcopyCmd": objcopyCmd,
+ },
+ })
+}
+
// Registers a build statement to invoke `strip` (to discard symbols and data from object files).
func transformStrip(ctx android.ModuleContext, inputFile android.Path,
outputFile android.WritablePath, flags StripFlags) {
diff --git a/cc/object.go b/cc/object.go
index d65cdea..4ddce99 100644
--- a/cc/object.go
+++ b/cc/object.go
@@ -309,6 +309,8 @@
})
}
} else {
+ outputAddrSig := android.PathForModuleOut(ctx, "addrsig", outputName)
+
if String(object.Properties.Prefix_symbols) != "" {
input := android.PathForModuleOut(ctx, "unprefixed", outputName)
transformBinaryPrefixSymbols(ctx, String(object.Properties.Prefix_symbols), input,
@@ -316,7 +318,12 @@
output = input
}
- transformObjsToObj(ctx, objs.objFiles, builderFlags, output, flags.LdFlagsDeps)
+ transformObjsToObj(ctx, objs.objFiles, builderFlags, outputAddrSig, flags.LdFlagsDeps)
+
+ // ld -r reorders symbols and invalidates the .llvm_addrsig section, which then causes warnings
+ // if the resulting object is used with ld --icf=safe. Strip the .llvm_addrsig section to
+ // prevent the warnings.
+ transformObjectNoAddrSig(ctx, outputAddrSig, output)
}
ctx.CheckbuildFile(outputFile)
diff --git a/java/app_test.go b/java/app_test.go
index 561be68..02a9eac 100644
--- a/java/app_test.go
+++ b/java/app_test.go
@@ -443,9 +443,9 @@
inputs := ctx.ModuleForTests("libjni", "android_arm64_armv8-a_sdk_shared").Description("link").Implicits
var crtbeginFound, crtendFound bool
expectedCrtBegin := ctx.ModuleForTests("crtbegin_so",
- "android_arm64_armv8-a_sdk_29").Rule("partialLd").Output
+ "android_arm64_armv8-a_sdk_29").Rule("noAddrSig").Output
expectedCrtEnd := ctx.ModuleForTests("crtend_so",
- "android_arm64_armv8-a_sdk_29").Rule("partialLd").Output
+ "android_arm64_armv8-a_sdk_29").Rule("noAddrSig").Output
implicits := []string{}
for _, input := range inputs {
implicits = append(implicits, input.String())