LowerTypeTests: Propagate symver directives
Summary:
This change fixes https://crbug.com/834474, a build failure caused by
LowerTypeTests not preserving .symver symbol versioning directives for
exported functions. Emit symver information to ThinLTO summary data and
then propagate symver directives for exported functions to the merged
module.
Emitting symver information to the summaries increases the size of
intermediate build artifacts for a Chromium build by less than 0.2%.
Reviewers: pcc
Reviewed By: pcc
Subscribers: tejohnson, mehdi_amini, eraman, llvm-commits, eugenis, kcc
Differential Revision: https://reviews.llvm.org/D45798
llvm-svn: 330387
diff --git a/llvm/lib/Object/ModuleSymbolTable.cpp b/llvm/lib/Object/ModuleSymbolTable.cpp
index f0d70ae..b353ef3 100644
--- a/llvm/lib/Object/ModuleSymbolTable.cpp
+++ b/llvm/lib/Object/ModuleSymbolTable.cpp
@@ -68,9 +68,9 @@
});
}
-void ModuleSymbolTable::CollectAsmSymbols(
- const Module &M,
- function_ref<void(StringRef, BasicSymbolRef::Flags)> AsmSymbol) {
+static void
+initializeRecordStreamer(const Module &M,
+ function_ref<void(RecordStreamer &)> Init) {
StringRef InlineAsm = M.getModuleInlineAsm();
if (InlineAsm.empty())
return;
@@ -119,36 +119,53 @@
if (Parser->Run(false))
return;
- Streamer.flushSymverDirectives();
+ Init(Streamer);
+}
- for (auto &KV : Streamer) {
- StringRef Key = KV.first();
- RecordStreamer::State Value = KV.second;
- // FIXME: For now we just assume that all asm symbols are executable.
- uint32_t Res = BasicSymbolRef::SF_Executable;
- switch (Value) {
- case RecordStreamer::NeverSeen:
- llvm_unreachable("NeverSeen should have been replaced earlier");
- case RecordStreamer::DefinedGlobal:
- Res |= BasicSymbolRef::SF_Global;
- break;
- case RecordStreamer::Defined:
- break;
- case RecordStreamer::Global:
- case RecordStreamer::Used:
- Res |= BasicSymbolRef::SF_Undefined;
- Res |= BasicSymbolRef::SF_Global;
- break;
- case RecordStreamer::DefinedWeak:
- Res |= BasicSymbolRef::SF_Weak;
- Res |= BasicSymbolRef::SF_Global;
- break;
- case RecordStreamer::UndefinedWeak:
- Res |= BasicSymbolRef::SF_Weak;
- Res |= BasicSymbolRef::SF_Undefined;
+void ModuleSymbolTable::CollectAsmSymbols(
+ const Module &M,
+ function_ref<void(StringRef, BasicSymbolRef::Flags)> AsmSymbol) {
+ initializeRecordStreamer(M, [&](RecordStreamer &Streamer) {
+ Streamer.flushSymverDirectives();
+
+ for (auto &KV : Streamer) {
+ StringRef Key = KV.first();
+ RecordStreamer::State Value = KV.second;
+ // FIXME: For now we just assume that all asm symbols are executable.
+ uint32_t Res = BasicSymbolRef::SF_Executable;
+ switch (Value) {
+ case RecordStreamer::NeverSeen:
+ llvm_unreachable("NeverSeen should have been replaced earlier");
+ case RecordStreamer::DefinedGlobal:
+ Res |= BasicSymbolRef::SF_Global;
+ break;
+ case RecordStreamer::Defined:
+ break;
+ case RecordStreamer::Global:
+ case RecordStreamer::Used:
+ Res |= BasicSymbolRef::SF_Undefined;
+ Res |= BasicSymbolRef::SF_Global;
+ break;
+ case RecordStreamer::DefinedWeak:
+ Res |= BasicSymbolRef::SF_Weak;
+ Res |= BasicSymbolRef::SF_Global;
+ break;
+ case RecordStreamer::UndefinedWeak:
+ Res |= BasicSymbolRef::SF_Weak;
+ Res |= BasicSymbolRef::SF_Undefined;
+ }
+ AsmSymbol(Key, BasicSymbolRef::Flags(Res));
}
- AsmSymbol(Key, BasicSymbolRef::Flags(Res));
- }
+ });
+}
+
+void ModuleSymbolTable::CollectAsmSymvers(
+ const Module &M, function_ref<void(StringRef, StringRef)> AsmSymver) {
+ initializeRecordStreamer(M, [&](RecordStreamer &Streamer) {
+ for (auto &KV : Streamer.symverAliases())
+ for (auto &Alias : KV.second)
+ AsmSymver(KV.first->getName(), Alias);
+ });
}
void ModuleSymbolTable::printSymbolName(raw_ostream &OS, Symbol S) const {
diff --git a/llvm/lib/Object/RecordStreamer.cpp b/llvm/lib/Object/RecordStreamer.cpp
index 21577bb..f49c823 100644
--- a/llvm/lib/Object/RecordStreamer.cpp
+++ b/llvm/lib/Object/RecordStreamer.cpp
@@ -128,6 +128,11 @@
SymverAliasMap[Aliasee].push_back(AliasName);
}
+iterator_range<RecordStreamer::const_symver_iterator>
+RecordStreamer::symverAliases() {
+ return {SymverAliasMap.begin(), SymverAliasMap.end()};
+}
+
void RecordStreamer::flushSymverDirectives() {
// Mapping from mangled name to GV.
StringMap<const GlobalValue *> MangledNameMap;
diff --git a/llvm/lib/Object/RecordStreamer.h b/llvm/lib/Object/RecordStreamer.h
index 60b2d3e..13eac02 100644
--- a/llvm/lib/Object/RecordStreamer.h
+++ b/llvm/lib/Object/RecordStreamer.h
@@ -47,10 +47,6 @@
public:
RecordStreamer(MCContext &Context, const Module &M);
- using const_iterator = StringMap<State>::const_iterator;
-
- const_iterator begin();
- const_iterator end();
void EmitInstruction(const MCInst &Inst, const MCSubtargetInfo &STI,
bool) override;
void EmitLabel(MCSymbol *Symbol, SMLoc Loc = SMLoc()) override;
@@ -63,9 +59,19 @@
/// Record .symver aliases for later processing.
void emitELFSymverDirective(StringRef AliasName,
const MCSymbol *Aliasee) override;
+
// Emit ELF .symver aliases and ensure they have the same binding as the
// defined symbol they alias with.
void flushSymverDirectives();
+
+ // Symbols iterators
+ using const_iterator = StringMap<State>::const_iterator;
+ const_iterator begin();
+ const_iterator end();
+
+ // SymverAliasMap iterators
+ using const_symver_iterator = decltype(SymverAliasMap)::const_iterator;
+ iterator_range<const_symver_iterator> symverAliases();
};
} // end namespace llvm