tequilaOS/platform_build_soong
2
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

Fix addrsig warnings

Browse source 
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
This commit is contained in:
Colin Cross 2022-12-06 14:50:08 -08:00
parent 748fd189b5
commit dea1d03975
3 changed files with 33 additions and 3 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

23
cc/builder.go
View file

@ -125,6 +125,14 @@ var (
},
"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 @@ func transformBinaryPrefixSymbols(ctx android.ModuleContext, prefix string, inpu
})
}
// 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) {

9
cc/object.go
View file

@ -309,6 +309,8 @@ func (object *objectLinker) link(ctx ModuleContext,
})
}
} 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 @@ func (object *objectLinker) link(ctx ModuleContext,
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)

4
java/app_test.go
View file

@ -443,9 +443,9 @@ func TestUpdatableApps_JniLibShouldBeBuiltAgainstMinSdkVersion(t *testing.T) {
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())