Preliminary patch to improve dwarf EH generation - Hooks to return Personality / FDE / LSDA / TType encoding depending on target / options (e.g. code model / relocation model) - MCIzation of Dwarf EH printer to use encoding information - Stub generation for ELF target (needed for indirect references) - Some other small changes here and there
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96285 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/TargetLoweringObjectFile.cpp b/lib/Target/TargetLoweringObjectFile.cpp
index a231ebc..88a978a 100644
--- a/lib/Target/TargetLoweringObjectFile.cpp
+++ b/lib/Target/TargetLoweringObjectFile.cpp
@@ -17,6 +17,7 @@
#include "llvm/DerivedTypes.h"
#include "llvm/Function.h"
#include "llvm/GlobalVariable.h"
+#include "llvm/CodeGen/MachineModuleInfoImpls.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCSectionMachO.h"
@@ -26,6 +27,7 @@
#include "llvm/Target/TargetData.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetOptions.h"
+#include "llvm/Support/Dwarf.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/ADT/SmallString.h"
@@ -289,32 +291,56 @@
}
/// getSymbolForDwarfGlobalReference - Return an MCExpr to use for a
-/// pc-relative reference to the specified global variable from exception
-/// handling information. In addition to the symbol, this returns
-/// by-reference:
-///
-/// IsIndirect - True if the returned symbol is actually a stub that contains
-/// the address of the symbol, false if the symbol is the global itself.
-///
-/// IsPCRel - True if the symbol reference is already pc-relative, false if
-/// the caller needs to subtract off the address of the reference from the
-/// symbol.
-///
+/// reference to the specified global variable from exception
+/// handling information.
const MCExpr *TargetLoweringObjectFile::
getSymbolForDwarfGlobalReference(const GlobalValue *GV, Mangler *Mang,
- MachineModuleInfo *MMI,
- bool &IsIndirect, bool &IsPCRel) const {
- // The generic implementation of this just returns a direct reference to the
- // symbol.
- IsIndirect = false;
- IsPCRel = false;
-
+ MachineModuleInfo *MMI, unsigned Encoding) const {
// FIXME: Use GetGlobalValueSymbol.
SmallString<128> Name;
Mang->getNameWithPrefix(Name, GV, false);
- return MCSymbolRefExpr::Create(Name.str(), getContext());
+ const MCSymbol *Sym = getContext().GetOrCreateSymbol(Name.str());
+
+ return getSymbolForDwarfReference(Sym, MMI, Encoding);
}
+const MCExpr *TargetLoweringObjectFile::
+getSymbolForDwarfReference(const MCSymbol *Sym, MachineModuleInfo *MMI,
+ unsigned Encoding) const {
+ const MCExpr *Res = MCSymbolRefExpr::Create(Sym, getContext());
+
+ switch (Encoding & 0xF0) {
+ default:
+ llvm_report_error("Do not support this DWARF encoding yet!");
+ break;
+ case dwarf::DW_EH_PE_absptr:
+ // Do nothing special
+ break;
+ case dwarf::DW_EH_PE_pcrel:
+ // FIXME: PCSymbol
+ const MCExpr *PC = MCSymbolRefExpr::Create(".", getContext());
+ Res = MCBinaryExpr::CreateSub(Res, PC, getContext());
+ break;
+ }
+
+ return Res;
+}
+
+unsigned TargetLoweringObjectFile::getPersonalityEncoding() const {
+ return dwarf::DW_EH_PE_absptr;
+}
+
+unsigned TargetLoweringObjectFile::getLSDAEncoding() const {
+ return dwarf::DW_EH_PE_absptr;
+}
+
+unsigned TargetLoweringObjectFile::getFDEEncoding() const {
+ return dwarf::DW_EH_PE_absptr;
+}
+
+unsigned TargetLoweringObjectFile::getTTypeEncoding() const {
+ return dwarf::DW_EH_PE_absptr;
+}
//===----------------------------------------------------------------------===//
// ELF
@@ -671,6 +697,35 @@
return DataRelROSection;
}
+const MCExpr *TargetLoweringObjectFileELF::
+getSymbolForDwarfGlobalReference(const GlobalValue *GV, Mangler *Mang,
+ MachineModuleInfo *MMI, unsigned Encoding) const {
+
+ if (Encoding & dwarf::DW_EH_PE_indirect) {
+ MachineModuleInfoELF &ELFMMI = MMI->getObjFileInfo<MachineModuleInfoELF>();
+
+ SmallString<128> Name;
+ Mang->getNameWithPrefix(Name, GV, true);
+
+ // Add information about the stub reference to ELFMMI so that the stub
+ // gets emitted by the asmprinter.
+ MCSymbol *Sym = getContext().GetOrCreateSymbol(Name.str());
+ MCSymbol *&StubSym = ELFMMI.getGVStubEntry(Sym);
+ if (StubSym == 0) {
+ Name.clear();
+ Mang->getNameWithPrefix(Name, GV, false);
+ StubSym = getContext().GetOrCreateSymbol(Name.str());
+ }
+
+ return TargetLoweringObjectFile::
+ getSymbolForDwarfReference(Sym, MMI,
+ Encoding & ~dwarf::DW_EH_PE_indirect);
+ }
+
+ return TargetLoweringObjectFile::
+ getSymbolForDwarfGlobalReference(GV, Mang, MMI, Encoding);
+}
+
//===----------------------------------------------------------------------===//
// MachO
//===----------------------------------------------------------------------===//
@@ -987,16 +1042,22 @@
const MCExpr *TargetLoweringObjectFileMachO::
getSymbolForDwarfGlobalReference(const GlobalValue *GV, Mangler *Mang,
- MachineModuleInfo *MMI,
- bool &IsIndirect, bool &IsPCRel) const {
+ MachineModuleInfo *MMI, unsigned Encoding) const {
// The mach-o version of this method defaults to returning a stub reference.
- IsIndirect = true;
- IsPCRel = false;
-
- SmallString<128> Name;
- Mang->getNameWithPrefix(Name, GV, true);
- Name += "$non_lazy_ptr";
- return MCSymbolRefExpr::Create(Name.str(), getContext());
+
+ if (Encoding & dwarf::DW_EH_PE_indirect) {
+ SmallString<128> Name;
+ Mang->getNameWithPrefix(Name, GV, true);
+ Name += "$non_lazy_ptr";
+ MCSymbol *Sym = getContext().GetOrCreateSymbol(Name.str());
+
+ return TargetLoweringObjectFile::
+ getSymbolForDwarfReference(Sym, MMI,
+ Encoding & ~dwarf::DW_EH_PE_indirect);
+ }
+
+ return TargetLoweringObjectFile::
+ getSymbolForDwarfGlobalReference(GV, Mang, MMI, Encoding);
}