[ORC] Re-apply r322913 with a fix for a read-after-free error.
ExternalSymbolMap now stores the string key (rather than using a StringRef),
as the object file backing the key may be removed at any time.
llvm-svn: 323001
diff --git a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp
index 3a025f4..7d5d2e3 100644
--- a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp
+++ b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp
@@ -202,7 +202,33 @@
ObjSectionToIDMap LocalSections;
// Common symbols requiring allocation, with their sizes and alignments
- CommonSymbolList CommonSymbols;
+ CommonSymbolList CommonSymbolsToAllocate;
+
+ uint64_t CommonSize = 0;
+ uint32_t CommonAlign = 0;
+
+ // First, collect all weak and common symbols. We need to know if stronger
+ // definitions occur elsewhere.
+ JITSymbolResolver::LookupFlagsResult SymbolFlags;
+ {
+ JITSymbolResolver::SymbolNameSet Symbols;
+ for (auto &Sym : Obj.symbols()) {
+ uint32_t Flags = Sym.getFlags();
+ if ((Flags & SymbolRef::SF_Common) || (Flags & SymbolRef::SF_Weak)) {
+ // Get symbol name.
+ StringRef Name;
+ if (auto NameOrErr = Sym.getName())
+ Symbols.insert(*NameOrErr);
+ else
+ return NameOrErr.takeError();
+ }
+ }
+
+ if (auto FlagsResultOrErr = Resolver.lookupFlags(Symbols))
+ SymbolFlags = std::move(*FlagsResultOrErr);
+ else
+ return FlagsResultOrErr.takeError();
+ }
// Parse symbols
DEBUG(dbgs() << "Parse symbols:\n");
@@ -214,102 +240,108 @@
if (Flags & SymbolRef::SF_Undefined)
continue;
- if (Flags & SymbolRef::SF_Common)
- CommonSymbols.push_back(*I);
- else {
+ // Get the symbol type.
+ object::SymbolRef::Type SymType;
+ if (auto SymTypeOrErr = I->getType())
+ SymType = *SymTypeOrErr;
+ else
+ return SymTypeOrErr.takeError();
- // Get the symbol type.
- object::SymbolRef::Type SymType;
- if (auto SymTypeOrErr = I->getType())
- SymType = *SymTypeOrErr;
+ // Get symbol name.
+ StringRef Name;
+ if (auto NameOrErr = I->getName())
+ Name = *NameOrErr;
+ else
+ return NameOrErr.takeError();
+
+ // Compute JIT symbol flags.
+ JITSymbolFlags JITSymFlags = getJITSymbolFlags(*I);
+
+ // If this is a weak definition, check to see if there's a strong one.
+ // If there is, skip this symbol (we won't be providing it: the strong
+ // definition will). If there's no strong definition, make this definition
+ // strong.
+ if (JITSymFlags.isWeak() || JITSymFlags.isCommon()) {
+ // First check whether there's already a definition in this instance.
+ // FIXME: Override existing weak definitions with strong ones.
+ if (GlobalSymbolTable.count(Name))
+ continue;
+
+ // Then check whether we found flags for an existing symbol during the
+ // flags lookup earlier.
+ auto FlagsI = SymbolFlags.find(Name);
+ if (FlagsI == SymbolFlags.end() ||
+ (JITSymFlags.isWeak() && !FlagsI->second.isStrong()) ||
+ (JITSymFlags.isCommon() && FlagsI->second.isCommon())) {
+ if (JITSymFlags.isWeak())
+ JITSymFlags &= ~JITSymbolFlags::Weak;
+ if (JITSymFlags.isCommon()) {
+ JITSymFlags &= ~JITSymbolFlags::Common;
+ uint32_t Align = I->getAlignment();
+ uint64_t Size = I->getCommonSize();
+ if (!CommonAlign)
+ CommonAlign = Align;
+ CommonSize += alignTo(CommonSize, Align) + Size;
+ CommonSymbolsToAllocate.push_back(*I);
+ }
+ } else
+ continue;
+ }
+
+ if (Flags & SymbolRef::SF_Absolute &&
+ SymType != object::SymbolRef::ST_File) {
+ uint64_t Addr = 0;
+ if (auto AddrOrErr = I->getAddress())
+ Addr = *AddrOrErr;
else
- return SymTypeOrErr.takeError();
+ return AddrOrErr.takeError();
- // Get symbol name.
- StringRef Name;
- if (auto NameOrErr = I->getName())
- Name = *NameOrErr;
+ unsigned SectionID = AbsoluteSymbolSection;
+
+ DEBUG(dbgs() << "\tType: " << SymType << " (absolute) Name: " << Name
+ << " SID: " << SectionID
+ << " Offset: " << format("%p", (uintptr_t)Addr)
+ << " flags: " << Flags << "\n");
+ GlobalSymbolTable[Name] = SymbolTableEntry(SectionID, Addr, JITSymFlags);
+ } else if (SymType == object::SymbolRef::ST_Function ||
+ SymType == object::SymbolRef::ST_Data ||
+ SymType == object::SymbolRef::ST_Unknown ||
+ SymType == object::SymbolRef::ST_Other) {
+
+ section_iterator SI = Obj.section_end();
+ if (auto SIOrErr = I->getSection())
+ SI = *SIOrErr;
else
- return NameOrErr.takeError();
+ return SIOrErr.takeError();
- // Compute JIT symbol flags.
- JITSymbolFlags JITSymFlags = getJITSymbolFlags(*I);
+ if (SI == Obj.section_end())
+ continue;
- // If this is a weak definition, check to see if there's a strong one.
- // If there is, skip this symbol (we won't be providing it: the strong
- // definition will). If there's no strong definition, make this definition
- // strong.
- if (JITSymFlags.isWeak()) {
- // First check whether there's already a definition in this instance.
- // FIXME: Override existing weak definitions with strong ones.
- if (GlobalSymbolTable.count(Name))
- continue;
- // Then check the symbol resolver to see if there's a definition
- // elsewhere in this logical dylib.
- if (auto Sym = Resolver.findSymbolInLogicalDylib(Name)) {
- if (Sym.getFlags().isStrong())
- continue;
- } else if (auto Err = Sym.takeError())
- return std::move(Err);
- // else
- JITSymFlags &= ~JITSymbolFlags::Weak;
- }
+ // Get symbol offset.
+ uint64_t SectOffset;
+ if (auto Err = getOffset(*I, *SI, SectOffset))
+ return std::move(Err);
- if (Flags & SymbolRef::SF_Absolute &&
- SymType != object::SymbolRef::ST_File) {
- uint64_t Addr = 0;
- if (auto AddrOrErr = I->getAddress())
- Addr = *AddrOrErr;
- else
- return AddrOrErr.takeError();
+ bool IsCode = SI->isText();
+ unsigned SectionID;
+ if (auto SectionIDOrErr =
+ findOrEmitSection(Obj, *SI, IsCode, LocalSections))
+ SectionID = *SectionIDOrErr;
+ else
+ return SectionIDOrErr.takeError();
- unsigned SectionID = AbsoluteSymbolSection;
-
- DEBUG(dbgs() << "\tType: " << SymType << " (absolute) Name: " << Name
- << " SID: " << SectionID << " Offset: "
- << format("%p", (uintptr_t)Addr)
- << " flags: " << Flags << "\n");
- GlobalSymbolTable[Name] =
- SymbolTableEntry(SectionID, Addr, JITSymFlags);
- } else if (SymType == object::SymbolRef::ST_Function ||
- SymType == object::SymbolRef::ST_Data ||
- SymType == object::SymbolRef::ST_Unknown ||
- SymType == object::SymbolRef::ST_Other) {
-
- section_iterator SI = Obj.section_end();
- if (auto SIOrErr = I->getSection())
- SI = *SIOrErr;
- else
- return SIOrErr.takeError();
-
- if (SI == Obj.section_end())
- continue;
-
- // Get symbol offset.
- uint64_t SectOffset;
- if (auto Err = getOffset(*I, *SI, SectOffset))
- return std::move(Err);
-
- bool IsCode = SI->isText();
- unsigned SectionID;
- if (auto SectionIDOrErr = findOrEmitSection(Obj, *SI, IsCode,
- LocalSections))
- SectionID = *SectionIDOrErr;
- else
- return SectionIDOrErr.takeError();
-
- DEBUG(dbgs() << "\tType: " << SymType << " Name: " << Name
- << " SID: " << SectionID << " Offset: "
- << format("%p", (uintptr_t)SectOffset)
- << " flags: " << Flags << "\n");
- GlobalSymbolTable[Name] =
+ DEBUG(dbgs() << "\tType: " << SymType << " Name: " << Name
+ << " SID: " << SectionID
+ << " Offset: " << format("%p", (uintptr_t)SectOffset)
+ << " flags: " << Flags << "\n");
+ GlobalSymbolTable[Name] =
SymbolTableEntry(SectionID, SectOffset, JITSymFlags);
- }
}
}
// Allocate common symbols
- if (auto Err = emitCommonSymbols(Obj, CommonSymbols))
+ if (auto Err = emitCommonSymbols(Obj, CommonSymbolsToAllocate, CommonSize,
+ CommonAlign))
return std::move(Err);
// Parse and process relocations
@@ -621,45 +653,12 @@
}
Error RuntimeDyldImpl::emitCommonSymbols(const ObjectFile &Obj,
- CommonSymbolList &CommonSymbols) {
- if (CommonSymbols.empty())
+ CommonSymbolList &SymbolsToAllocate,
+ uint64_t CommonSize,
+ uint32_t CommonAlign) {
+ if (SymbolsToAllocate.empty())
return Error::success();
- uint64_t CommonSize = 0;
- uint32_t CommonAlign = CommonSymbols.begin()->getAlignment();
- CommonSymbolList SymbolsToAllocate;
-
- DEBUG(dbgs() << "Processing common symbols...\n");
-
- for (const auto &Sym : CommonSymbols) {
- StringRef Name;
- if (auto NameOrErr = Sym.getName())
- Name = *NameOrErr;
- else
- return NameOrErr.takeError();
-
- // Skip common symbols already elsewhere.
- if (GlobalSymbolTable.count(Name)) {
- DEBUG(dbgs() << "\tSkipping already emitted common symbol '" << Name
- << "'\n");
- continue;
- }
-
- if (auto Sym = Resolver.findSymbolInLogicalDylib(Name)) {
- if (!Sym.getFlags().isCommon()) {
- DEBUG(dbgs() << "\tSkipping common symbol '" << Name
- << "' in favor of stronger definition.\n");
- continue;
- }
- }
- uint32_t Align = Sym.getAlignment();
- uint64_t Size = Sym.getCommonSize();
-
- CommonSize = alignTo(CommonSize, Align) + Size;
-
- SymbolsToAllocate.push_back(Sym);
- }
-
// Allocate memory for the section
unsigned SectionID = Sections.size();
uint8_t *Addr = MemMgr.allocateDataSection(CommonSize, CommonAlign, SectionID,
@@ -997,7 +996,40 @@
}
Error RuntimeDyldImpl::resolveExternalSymbols() {
+ StringMap<JITEvaluatedSymbol> ExternalSymbolMap;
+
+ // Resolution can trigger emission of more symbols, so iterate until
+ // we've resolved *everything*.
+ {
+ JITSymbolResolver::SymbolNameSet ResolvedSymbols;
+
+ while (true) {
+ JITSymbolResolver::SymbolNameSet NewSymbols;
+
+ for (auto &RelocKV : ExternalSymbolRelocations) {
+ StringRef Name = RelocKV.first();
+ if (!Name.empty() && !GlobalSymbolTable.count(Name) &&
+ !ResolvedSymbols.count(Name))
+ NewSymbols.insert(Name);
+ }
+
+ if (NewSymbols.empty())
+ break;
+
+ auto NewResolverResults = Resolver.lookup(NewSymbols);
+ if (!NewResolverResults)
+ return NewResolverResults.takeError();
+
+ for (auto &RRKV : *NewResolverResults) {
+ assert(!ResolvedSymbols.count(RRKV.first) && "Redundant resolution?");
+ ExternalSymbolMap.insert(RRKV);
+ ResolvedSymbols.insert(RRKV.first);
+ }
+ }
+ }
+
while (!ExternalSymbolRelocations.empty()) {
+
StringMap<RelocationList>::iterator i = ExternalSymbolRelocations.begin();
StringRef Name = i->first();
@@ -1012,29 +1044,10 @@
JITSymbolFlags Flags;
RTDyldSymbolTable::const_iterator Loc = GlobalSymbolTable.find(Name);
if (Loc == GlobalSymbolTable.end()) {
- // This is an external symbol, try to get its address from the symbol
- // resolver.
- // First search for the symbol in this logical dylib.
- if (auto Sym = Resolver.findSymbolInLogicalDylib(Name.data())) {
- if (auto AddrOrErr = Sym.getAddress()) {
- Addr = *AddrOrErr;
- Flags = Sym.getFlags();
- } else
- return AddrOrErr.takeError();
- } else if (auto Err = Sym.takeError())
- return Err;
-
- // If that fails, try searching for an external symbol.
- if (!Addr) {
- if (auto Sym = Resolver.findSymbol(Name.data())) {
- if (auto AddrOrErr = Sym.getAddress()) {
- Addr = *AddrOrErr;
- Flags = Sym.getFlags();
- } else
- return AddrOrErr.takeError();
- } else if (auto Err = Sym.takeError())
- return Err;
- }
+ auto RRI = ExternalSymbolMap.find(Name);
+ assert(RRI != ExternalSymbolMap.end() && "No result for symbol");
+ Addr = RRI->second.getAddress();
+ Flags = RRI->second.getFlags();
// The call to getSymbolAddress may have caused additional modules to
// be loaded, which may have added new entries to the
// ExternalSymbolRelocations map. Consquently, we need to update our
@@ -1095,6 +1108,7 @@
void RuntimeDyld::MemoryManager::anchor() {}
void JITSymbolResolver::anchor() {}
+void LegacyJITSymbolResolver::anchor() {}
RuntimeDyld::RuntimeDyld(RuntimeDyld::MemoryManager &MemMgr,
JITSymbolResolver &Resolver)