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/CodeGen/AsmPrinter/DwarfException.cpp b/lib/CodeGen/AsmPrinter/DwarfException.cpp
index 22b1b1c..e3f06a3 100644
--- a/lib/CodeGen/AsmPrinter/DwarfException.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfException.cpp
@@ -50,26 +50,6 @@
delete ExceptionTimer;
}
-/// SizeOfEncodedValue - Return the size of the encoding in bytes.
-unsigned DwarfException::SizeOfEncodedValue(unsigned Encoding) {
- if (Encoding == dwarf::DW_EH_PE_omit)
- return 0;
-
- switch (Encoding & 0x07) {
- case dwarf::DW_EH_PE_absptr:
- return TD->getPointerSize();
- case dwarf::DW_EH_PE_udata2:
- return 2;
- case dwarf::DW_EH_PE_udata4:
- return 4;
- case dwarf::DW_EH_PE_udata8:
- return 8;
- }
-
- assert(0 && "Invalid encoded value.");
- return 0;
-}
-
/// CreateLabelDiff - Emit a label and subtract it from the expression we
/// already have. This is equivalent to emitting "foo - .", but we have to emit
/// the label for "." directly.
@@ -100,7 +80,7 @@
TD->getPointerSize() : -TD->getPointerSize();
const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
-
+
// Begin eh frame section.
Asm->OutStreamer.SwitchSection(TLOF.getEHFrameSection());
@@ -128,30 +108,16 @@
// The personality presence indicates that language specific information will
// show up in the eh frame. Find out how we are supposed to lower the
// personality function reference:
- const MCExpr *PersonalityRef = 0;
- bool IsPersonalityIndirect = false, IsPersonalityPCRel = false;
- if (PersonalityFn) {
- // FIXME: HANDLE STATIC CODEGEN MODEL HERE.
-
- // In non-static mode, ask the object file how to represent this reference.
- PersonalityRef =
- TLOF.getSymbolForDwarfGlobalReference(PersonalityFn, Asm->Mang,
- Asm->MMI,
- IsPersonalityIndirect,
- IsPersonalityPCRel);
- }
-
- unsigned PerEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
- if (IsPersonalityIndirect)
- PerEncoding |= dwarf::DW_EH_PE_indirect;
- unsigned LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
- unsigned FDEEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
+
+ unsigned LSDAEncoding = TLOF.getLSDAEncoding();
+ unsigned FDEEncoding = TLOF.getFDEEncoding();
+ unsigned PerEncoding = TLOF.getPersonalityEncoding();
char Augmentation[6] = { 0 };
unsigned AugmentationSize = 0;
char *APtr = Augmentation + 1;
- if (PersonalityRef) {
+ if (PersonalityFn) {
// There is a personality function.
*APtr++ = 'P';
AugmentationSize += 1 + SizeOfEncodedValue(PerEncoding);
@@ -182,19 +148,16 @@
EOL("CIE Return Address Column");
EmitULEB128(AugmentationSize, "Augmentation Size");
- EmitEncodingByte(PerEncoding, "Personality");
// If there is a personality, we need to indicate the function's location.
- if (PersonalityRef) {
- if (!IsPersonalityPCRel)
- PersonalityRef = CreateLabelDiff(PersonalityRef, "personalityref_addr",
- Index);
-
- O << MAI->getData32bitsDirective() << *PersonalityRef;
+ if (PersonalityFn) {
+ EmitEncodingByte(PerEncoding, "Personality");
+ EmitReference(PersonalityFn, PerEncoding);
EOL("Personality");
-
- EmitEncodingByte(LSDAEncoding, "LSDA");
- EmitEncodingByte(FDEEncoding, "FDE");
+ if (UsesLSDA[Index])
+ EmitEncodingByte(LSDAEncoding, "LSDA");
+ if (FDEEncoding != dwarf::DW_EH_PE_absptr)
+ EmitEncodingByte(FDEEncoding, "FDE");
}
// Indicate locations of general callee saved registers in frame.
@@ -216,8 +179,12 @@
"Should not emit 'available externally' functions at all");
const Function *TheFunc = EHFrameInfo.function;
+ const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
- Asm->OutStreamer.SwitchSection(Asm->getObjFileLowering().getEHFrameSection());
+ unsigned LSDAEncoding = TLOF.getLSDAEncoding();
+ unsigned FDEEncoding = TLOF.getFDEEncoding();
+
+ Asm->OutStreamer.SwitchSection(TLOF.getEHFrameSection());
// Externally visible entry into the functions eh frame info. If the
// corresponding function is static, this should not be externally visible.
@@ -255,7 +222,8 @@
// EH frame header.
EmitDifference("eh_frame_end", EHFrameInfo.Number,
- "eh_frame_begin", EHFrameInfo.Number, true);
+ "eh_frame_begin", EHFrameInfo.Number,
+ true);
EOL("Length of Frame Information Entry");
EmitLabel("eh_frame_begin", EHFrameInfo.Number);
@@ -266,33 +234,23 @@
EOL("FDE CIE offset");
- EmitReference("eh_func_begin", EHFrameInfo.Number, true, true);
+ EmitReference("eh_func_begin", EHFrameInfo.Number, FDEEncoding);
EOL("FDE initial location");
EmitDifference("eh_func_end", EHFrameInfo.Number,
- "eh_func_begin", EHFrameInfo.Number, true);
+ "eh_func_begin", EHFrameInfo.Number,
+ SizeOfEncodedValue(FDEEncoding) == 4);
EOL("FDE address range");
// If there is a personality and landing pads then point to the language
// specific data area in the exception table.
if (MMI->getPersonalities()[0] != NULL) {
+ unsigned Size = SizeOfEncodedValue(LSDAEncoding);
- if (Asm->TM.getLSDAEncoding() != DwarfLSDAEncoding::EightByte) {
- EmitULEB128(4, "Augmentation size");
-
- if (EHFrameInfo.hasLandingPads)
- EmitReference("exception", EHFrameInfo.Number, true, true);
- else
- Asm->OutStreamer.EmitIntValue(0, 4/*size*/, 0/*addrspace*/);
- } else {
- EmitULEB128(TD->getPointerSize(), "Augmentation size");
-
- if (EHFrameInfo.hasLandingPads) {
- EmitReference("exception", EHFrameInfo.Number, true, false);
- } else {
- Asm->OutStreamer.EmitIntValue(0, TD->getPointerSize(),
- 0/*addrspace*/);
- }
- }
+ EmitULEB128(Size, "Augmentation size");
+ if (EHFrameInfo.hasLandingPads)
+ EmitReference("exception", EHFrameInfo.Number, LSDAEncoding);
+ else
+ Asm->OutStreamer.EmitIntValue(0, Size/*size*/, 0/*addrspace*/);
EOL("Language Specific Data Area");
} else {
@@ -694,13 +652,13 @@
// Type infos.
const MCSection *LSDASection = Asm->getObjFileLowering().getLSDASection();
- unsigned TTypeFormat;
+ unsigned TTypeEncoding;
unsigned TypeFormatSize;
if (!HaveTTData) {
// For SjLj exceptions, if there is no TypeInfo, then we just explicitly say
// that we're omitting that bit.
- TTypeFormat = dwarf::DW_EH_PE_omit;
+ TTypeEncoding = dwarf::DW_EH_PE_omit;
TypeFormatSize = SizeOfEncodedValue(dwarf::DW_EH_PE_absptr);
} else {
// Okay, we have actual filters or typeinfos to emit. As such, we need to
@@ -730,14 +688,8 @@
// somewhere. This predicate should be moved to a shared location that is
// in target-independent code.
//
- if (LSDASection->getKind().isWriteable() ||
- Asm->TM.getRelocationModel() == Reloc::Static)
- TTypeFormat = dwarf::DW_EH_PE_absptr;
- else
- TTypeFormat = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
- dwarf::DW_EH_PE_sdata4;
-
- TypeFormatSize = SizeOfEncodedValue(TTypeFormat);
+ TTypeEncoding = Asm->getObjFileLowering().getTTypeEncoding();
+ TypeFormatSize = SizeOfEncodedValue(TTypeEncoding);
}
// Begin the exception table.
@@ -788,7 +740,7 @@
// Emit the header.
EmitEncodingByte(dwarf::DW_EH_PE_omit, "@LPStart");
- EmitEncodingByte(TTypeFormat, "@TType");
+ EmitEncodingByte(TTypeEncoding, "@TType");
if (HaveTTData)
EmitULEB128(TyOffset, "@TType base offset");
@@ -911,12 +863,12 @@
for (std::vector<GlobalVariable *>::const_reverse_iterator
I = TypeInfos.rbegin(), E = TypeInfos.rend(); I != E; ++I) {
const GlobalVariable *GV = *I;
- PrintRelDirective();
if (GV) {
- O << *Asm->GetGlobalValueSymbol(GV);
+ EmitReference(GV, TTypeEncoding);
EOL("TypeInfo");
} else {
+ PrintRelDirective();
O << "0x0";
EOL("");
}