[lld] r239005 - COFF: /include'd symbols must be preserved.
Rui Ueyama
ruiu at google.com
Wed Jun 3 19:12:16 PDT 2015
Author: ruiu
Date: Wed Jun 3 21:12:16 2015
New Revision: 239005
URL: http://llvm.org/viewvc/llvm-project?rev=239005&view=rev
Log:
COFF: /include'd symbols must be preserved.
Not only entry point symbol but also symbols specified by /include
option must be preserved, as they will never be dead-stripped.
http://reviews.llvm.org/D10220
Modified:
lld/trunk/COFF/Config.h
lld/trunk/COFF/Driver.cpp
lld/trunk/COFF/SymbolTable.cpp
lld/trunk/COFF/Writer.cpp
lld/trunk/COFF/Writer.h
lld/trunk/test/COFF/lto.ll
Modified: lld/trunk/COFF/Config.h
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/COFF/Config.h?rev=239005&r1=239004&r2=239005&view=diff
==============================================================================
--- lld/trunk/COFF/Config.h (original)
+++ lld/trunk/COFF/Config.h Wed Jun 3 21:12:16 2015
@@ -27,7 +27,10 @@ public:
llvm::COFF::MachineTypes MachineType = llvm::COFF::IMAGE_FILE_MACHINE_AMD64;
bool Verbose = false;
WindowsSubsystem Subsystem = llvm::COFF::IMAGE_SUBSYSTEM_UNKNOWN;
- std::string EntryName;
+ StringRef EntryName;
+
+ // Symbols in this set are considered as live by the garbage collector.
+ std::set<StringRef> GCRoots;
std::set<StringRef> NoDefaultLibs;
bool NoDefaultLibAll = false;
Modified: lld/trunk/COFF/Driver.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/COFF/Driver.cpp?rev=239005&r1=239004&r2=239005&view=diff
==============================================================================
--- lld/trunk/COFF/Driver.cpp (original)
+++ lld/trunk/COFF/Driver.cpp Wed Jun 3 21:12:16 2015
@@ -312,8 +312,11 @@ bool LinkerDriver::link(int Argc, const
// Add undefined symbols given via the command line.
// (/include is equivalent to Unix linker's -u option.)
- for (auto *Arg : Args->filtered(OPT_incl))
- Symtab.addUndefined(Arg->getValue());
+ for (auto *Arg : Args->filtered(OPT_incl)) {
+ StringRef Sym = Arg->getValue();
+ Symtab.addUndefined(Sym);
+ Config->GCRoots.insert(Sym);
+ }
// Parse all input files and put all symbols to the symbol table.
// The symbol table will take care of name resolution.
@@ -362,11 +365,14 @@ bool LinkerDriver::link(int Argc, const
}
Config->EntryName = EntryOrErr.get();
}
+ Config->GCRoots.insert(Config->EntryName);
// Make sure we have resolved all symbols.
if (Symtab.reportRemainingUndefines())
return false;
+ // Do LTO by compiling bitcode input files to a native COFF file
+ // then link that file.
if (auto EC = Symtab.addCombinedLTOObject()) {
llvm::errs() << EC.message() << "\n";
return false;
Modified: lld/trunk/COFF/SymbolTable.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/COFF/SymbolTable.cpp?rev=239005&r1=239004&r2=239005&view=diff
==============================================================================
--- lld/trunk/COFF/SymbolTable.cpp (original)
+++ lld/trunk/COFF/SymbolTable.cpp Wed Jun 3 21:12:16 2015
@@ -227,20 +227,17 @@ std::error_code SymbolTable::addCombined
return std::error_code();
llvm::LTOCodeGenerator CG;
- std::set<DefinedBitcode *> PreservedBitcodeSymbols;
// All symbols referenced by non-bitcode objects must be preserved.
for (std::unique_ptr<ObjectFile> &File : ObjectFiles)
for (SymbolBody *Body : File->getSymbols())
if (auto *S = dyn_cast<DefinedBitcode>(Body->getReplacement()))
- PreservedBitcodeSymbols.insert(S);
+ CG.addMustPreserveSymbol(S->getName());
- // Likewise for the linker-generated reference to the entry point.
- if (auto *S = dyn_cast<DefinedBitcode>(Symtab[Config->EntryName]->Body))
- PreservedBitcodeSymbols.insert(S);
-
- for (DefinedBitcode *S : PreservedBitcodeSymbols)
- CG.addMustPreserveSymbol(S->getName());
+ // Likewise for other symbols that must be preserved.
+ for (StringRef Name : Config->GCRoots)
+ if (isa<DefinedBitcode>(Symtab[Name]->Body))
+ CG.addMustPreserveSymbol(Name);
CG.setModule(BitcodeFiles[0]->releaseModule());
for (unsigned I = 1, E = BitcodeFiles.size(); I != E; ++I)
Modified: lld/trunk/COFF/Writer.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/COFF/Writer.cpp?rev=239005&r1=239004&r2=239005&view=diff
==============================================================================
--- lld/trunk/COFF/Writer.cpp (original)
+++ lld/trunk/COFF/Writer.cpp Wed Jun 3 21:12:16 2015
@@ -87,8 +87,8 @@ void OutputSection::writeHeader(uint8_t
}
void Writer::markLive() {
- Entry = cast<Defined>(Symtab->find(Config->EntryName));
- Entry->markLive();
+ for (StringRef Name : Config->GCRoots)
+ cast<Defined>(Symtab->find(Name))->markLive();
for (Chunk *C : Symtab->getChunks())
if (C->isRoot())
C->markLive();
@@ -291,6 +291,7 @@ void Writer::writeHeader() {
PE->Subsystem = Config->Subsystem;
PE->SizeOfImage = SizeOfImage;
PE->SizeOfHeaders = SizeOfHeaders;
+ Defined *Entry = cast<Defined>(Symtab->find(Config->EntryName));
PE->AddressOfEntryPoint = Entry->getRVA();
PE->SizeOfStackReserve = Config->StackReserve;
PE->SizeOfStackCommit = Config->StackCommit;
Modified: lld/trunk/COFF/Writer.h
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/COFF/Writer.h?rev=239005&r1=239004&r2=239005&view=diff
==============================================================================
--- lld/trunk/COFF/Writer.h (original)
+++ lld/trunk/COFF/Writer.h Wed Jun 3 21:12:16 2015
@@ -98,7 +98,6 @@ private:
uint32_t ImportDirectoryTableSize = 0;
uint32_t ImportAddressTableSize = 0;
- Defined *Entry;
uint64_t FileSize;
uint64_t SizeOfImage;
uint64_t SizeOfHeaders;
Modified: lld/trunk/test/COFF/lto.ll
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/COFF/lto.ll?rev=239005&r1=239004&r2=239005&view=diff
==============================================================================
--- lld/trunk/test/COFF/lto.ll (original)
+++ lld/trunk/test/COFF/lto.ll Wed Jun 3 21:12:16 2015
@@ -8,10 +8,10 @@
; RUN: rm -f %T/foo.lib
; RUN: llvm-ar cru %T/foo.lib %T/foo.obj
-; RUN: lld -flavor link2 /out:%T/main.exe /entry:main /subsystem:console %T/main.lto.obj %T/foo.lto.obj
+; RUN: lld -flavor link2 /out:%T/main.exe /entry:main /include:f2 /subsystem:console %T/main.lto.obj %T/foo.lto.obj
; RUN: llvm-readobj -file-headers %T/main.exe | FileCheck -check-prefix=HEADERS-11 %s
; RUN: llvm-objdump -d %T/main.exe | FileCheck -check-prefix=TEXT-11 %s
-; RUN: lld -flavor link2 /out:%T/main.exe /entry:main /subsystem:console %T/main.lto.obj %T/foo.lto.lib
+; RUN: lld -flavor link2 /out:%T/main.exe /entry:main /include:f2 /subsystem:console %T/main.lto.obj %T/foo.lto.lib
; RUN: llvm-readobj -file-headers %T/main.exe | FileCheck -check-prefix=HEADERS-11 %s
; RUN: llvm-objdump -d %T/main.exe | FileCheck -check-prefix=TEXT-11 %s
@@ -34,6 +34,21 @@
; TEXT-11-NEXT: .text:
; TEXT-11-NEXT: xorl %eax, %eax
; TEXT-11-NEXT: retq
+; TEXT-11-NEXT: int3
+; TEXT-11-NEXT: int3
+; TEXT-11-NEXT: int3
+; TEXT-11-NEXT: int3
+; TEXT-11-NEXT: int3
+; TEXT-11-NEXT: int3
+; TEXT-11-NEXT: int3
+; TEXT-11-NEXT: int3
+; TEXT-11-NEXT: int3
+; TEXT-11-NEXT: int3
+; TEXT-11-NEXT: int3
+; TEXT-11-NEXT: int3
+; TEXT-11-NEXT: int3
+; TEXT-11-NEXT: movl $2, %eax
+; TEXT-11-NEXT: retq
; HEADERS-01: AddressOfEntryPoint: 0x1000
; TEXT-01: Disassembly of section .text:
@@ -79,3 +94,13 @@ define i32 @main() {
}
declare void @foo()
+
+$f1 = comdat any
+define i32 @f1() comdat($f1) {
+ ret i32 1
+}
+
+$f2 = comdat any
+define i32 @f2() comdat($f2) {
+ ret i32 2
+}
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