if (MAI->doesSupportDebugInformation())
DD = new DwarfDebug(this, &M);
-
+
if (MAI->doesSupportExceptionHandling())
- DE = new DwarfException(this);
+ DE = new DwarfTableException(this);
return false;
}
using namespace llvm;
DwarfException::DwarfException(AsmPrinter *A)
- : Asm(A), MMI(Asm->MMI), shouldEmitTable(false), shouldEmitMoves(false),
- shouldEmitTableModule(false), shouldEmitMovesModule(false) {}
+ : Asm(A), MMI(Asm->MMI) {}
DwarfException::~DwarfException() {}
-/// EmitCIE - Emit a Common Information Entry (CIE). This holds information that
-/// is shared among many Frame Description Entries. There is at least one CIE
-/// in every non-empty .debug_frame section.
-void DwarfException::EmitCIE(const Function *PersonalityFn, unsigned Index) {
- // Size and sign of stack growth.
- int stackGrowth = Asm->getTargetData().getPointerSize();
- if (Asm->TM.getFrameLowering()->getStackGrowthDirection() ==
- TargetFrameLowering::StackGrowsDown)
- stackGrowth *= -1;
-
- const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
-
- // Begin eh frame section.
- Asm->OutStreamer.SwitchSection(TLOF.getEHFrameSection());
-
- MCSymbol *EHFrameSym;
- if (TLOF.isFunctionEHFrameSymbolPrivate())
- EHFrameSym = Asm->GetTempSymbol("EH_frame", Index);
- else
- EHFrameSym = Asm->OutContext.GetOrCreateSymbol(Twine("EH_frame") +
- Twine(Index));
- Asm->OutStreamer.EmitLabel(EHFrameSym);
-
- Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("section_eh_frame", Index));
-
- // Define base labels.
- Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("eh_frame_common", Index));
-
- // Define the eh frame length.
- Asm->OutStreamer.AddComment("Length of Common Information Entry");
- Asm->EmitLabelDifference(Asm->GetTempSymbol("eh_frame_common_end", Index),
- Asm->GetTempSymbol("eh_frame_common_begin", Index),
- 4);
-
- // EH frame header.
- Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("eh_frame_common_begin",Index));
- Asm->OutStreamer.AddComment("CIE Identifier Tag");
- Asm->OutStreamer.EmitIntValue(0, 4/*size*/, 0/*addrspace*/);
- Asm->OutStreamer.AddComment("DW_CIE_VERSION");
- Asm->OutStreamer.EmitIntValue(dwarf::DW_CIE_VERSION, 1/*size*/, 0/*addr*/);
-
- // 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:
-
- unsigned LSDAEncoding = TLOF.getLSDAEncoding();
- unsigned FDEEncoding = TLOF.getFDEEncoding();
- unsigned PerEncoding = TLOF.getPersonalityEncoding();
-
- char Augmentation[6] = { 0 };
- unsigned AugmentationSize = 0;
- char *APtr = Augmentation + 1;
-
- if (PersonalityFn) {
- // There is a personality function.
- *APtr++ = 'P';
- AugmentationSize += 1 + Asm->GetSizeOfEncodedValue(PerEncoding);
- }
-
- if (UsesLSDA[Index]) {
- // An LSDA pointer is in the FDE augmentation.
- *APtr++ = 'L';
- ++AugmentationSize;
- }
-
- if (FDEEncoding != dwarf::DW_EH_PE_absptr) {
- // A non-default pointer encoding for the FDE.
- *APtr++ = 'R';
- ++AugmentationSize;
- }
-
- if (APtr != Augmentation + 1)
- Augmentation[0] = 'z';
-
- Asm->OutStreamer.AddComment("CIE Augmentation");
- Asm->OutStreamer.EmitBytes(StringRef(Augmentation, strlen(Augmentation)+1),0);
-
- // Round out reader.
- Asm->EmitULEB128(1, "CIE Code Alignment Factor");
- Asm->EmitSLEB128(stackGrowth, "CIE Data Alignment Factor");
- Asm->OutStreamer.AddComment("CIE Return Address Column");
-
- const TargetRegisterInfo *RI = Asm->TM.getRegisterInfo();
- const TargetFrameLowering *TFI = Asm->TM.getFrameLowering();
- Asm->EmitInt8(RI->getDwarfRegNum(RI->getRARegister(), true));
-
- if (Augmentation[0]) {
- Asm->EmitULEB128(AugmentationSize, "Augmentation Size");
-
- // If there is a personality, we need to indicate the function's location.
- if (PersonalityFn) {
- Asm->EmitEncodingByte(PerEncoding, "Personality");
- Asm->OutStreamer.AddComment("Personality");
- Asm->EmitReference(PersonalityFn, PerEncoding);
- }
- if (UsesLSDA[Index])
- Asm->EmitEncodingByte(LSDAEncoding, "LSDA");
- if (FDEEncoding != dwarf::DW_EH_PE_absptr)
- Asm->EmitEncodingByte(FDEEncoding, "FDE");
- }
-
- // Indicate locations of general callee saved registers in frame.
- std::vector<MachineMove> Moves;
- TFI->getInitialFrameState(Moves);
- Asm->EmitFrameMoves(Moves, 0, true);
-
- // On Darwin the linker honors the alignment of eh_frame, which means it must
- // be 8-byte on 64-bit targets to match what gcc does. Otherwise you get
- // holes which confuse readers of eh_frame.
- Asm->EmitAlignment(Asm->getTargetData().getPointerSize() == 4 ? 2 : 3);
- Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("eh_frame_common_end", Index));
-}
-
-/// EmitFDE - Emit the Frame Description Entry (FDE) for the function.
-void DwarfException::EmitFDE(const FunctionEHFrameInfo &EHFrameInfo) {
- assert(!EHFrameInfo.function->hasAvailableExternallyLinkage() &&
- "Should not emit 'available externally' functions at all");
-
- const Function *TheFunc = EHFrameInfo.function;
- const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
-
- 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.
- if (!TheFunc->hasLocalLinkage() && TLOF.isFunctionEHSymbolGlobal())
- Asm->OutStreamer.EmitSymbolAttribute(EHFrameInfo.FunctionEHSym,MCSA_Global);
-
- // If corresponding function is weak definition, this should be too.
- if (TheFunc->isWeakForLinker() && Asm->MAI->getWeakDefDirective())
- Asm->OutStreamer.EmitSymbolAttribute(EHFrameInfo.FunctionEHSym,
- MCSA_WeakDefinition);
-
- // If corresponding function is hidden, this should be too.
- if (TheFunc->hasHiddenVisibility())
- if (MCSymbolAttr HiddenAttr = Asm->MAI->getHiddenVisibilityAttr())
- Asm->OutStreamer.EmitSymbolAttribute(EHFrameInfo.FunctionEHSym,
- HiddenAttr);
-
- // If there are no calls then you can't unwind. This may mean we can omit the
- // EH Frame, but some environments do not handle weak absolute symbols. If
- // UnwindTablesMandatory is set we cannot do this optimization; the unwind
- // info is to be available for non-EH uses.
- if (!EHFrameInfo.adjustsStack && !UnwindTablesMandatory &&
- (!TheFunc->isWeakForLinker() ||
- !Asm->MAI->getWeakDefDirective() ||
- TLOF.getSupportsWeakOmittedEHFrame())) {
- Asm->OutStreamer.EmitAssignment(EHFrameInfo.FunctionEHSym,
- MCConstantExpr::Create(0, Asm->OutContext));
- // This name has no connection to the function, so it might get
- // dead-stripped when the function is not, erroneously. Prohibit
- // dead-stripping unconditionally.
- if (Asm->MAI->hasNoDeadStrip())
- Asm->OutStreamer.EmitSymbolAttribute(EHFrameInfo.FunctionEHSym,
- MCSA_NoDeadStrip);
- } else {
- Asm->OutStreamer.EmitLabel(EHFrameInfo.FunctionEHSym);
-
- // EH frame header.
- Asm->OutStreamer.AddComment("Length of Frame Information Entry");
- Asm->EmitLabelDifference(
- Asm->GetTempSymbol("eh_frame_end", EHFrameInfo.Number),
- Asm->GetTempSymbol("eh_frame_begin", EHFrameInfo.Number), 4);
-
- Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("eh_frame_begin",
- EHFrameInfo.Number));
-
- Asm->OutStreamer.AddComment("FDE CIE offset");
- Asm->EmitLabelDifference(
- Asm->GetTempSymbol("eh_frame_begin", EHFrameInfo.Number),
- Asm->GetTempSymbol("eh_frame_common",
- EHFrameInfo.PersonalityIndex), 4);
-
- MCSymbol *EHFuncBeginSym =
- Asm->GetTempSymbol("eh_func_begin", EHFrameInfo.Number);
-
- Asm->OutStreamer.AddComment("FDE initial location");
- Asm->EmitReference(EHFuncBeginSym, FDEEncoding);
-
- Asm->OutStreamer.AddComment("FDE address range");
- Asm->EmitLabelDifference(Asm->GetTempSymbol("eh_func_end",
- EHFrameInfo.Number),
- EHFuncBeginSym,
- Asm->GetSizeOfEncodedValue(FDEEncoding));
-
- // 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 = Asm->GetSizeOfEncodedValue(LSDAEncoding);
-
- Asm->EmitULEB128(Size, "Augmentation size");
- Asm->OutStreamer.AddComment("Language Specific Data Area");
- if (EHFrameInfo.hasLandingPads)
- Asm->EmitReference(Asm->GetTempSymbol("exception", EHFrameInfo.Number),
- LSDAEncoding);
- else
- Asm->OutStreamer.EmitIntValue(0, Size/*size*/, 0/*addrspace*/);
-
- } else {
- Asm->EmitULEB128(0, "Augmentation size");
- }
-
- // Indicate locations of function specific callee saved registers in frame.
- Asm->EmitFrameMoves(EHFrameInfo.Moves, EHFuncBeginSym, true);
-
- // On Darwin the linker honors the alignment of eh_frame, which means it
- // must be 8-byte on 64-bit targets to match what gcc does. Otherwise you
- // get holes which confuse readers of eh_frame.
- Asm->EmitAlignment(Asm->getTargetData().getPointerSize() == 4 ? 2 : 3);
- Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("eh_frame_end",
- EHFrameInfo.Number));
-
- // If the function is marked used, this table should be also. We cannot
- // make the mark unconditional in this case, since retaining the table also
- // retains the function in this case, and there is code around that depends
- // on unused functions (calling undefined externals) being dead-stripped to
- // link correctly. Yes, there really is.
- if (MMI->isUsedFunction(EHFrameInfo.function))
- if (Asm->MAI->hasNoDeadStrip())
- Asm->OutStreamer.EmitSymbolAttribute(EHFrameInfo.FunctionEHSym,
- MCSA_NoDeadStrip);
- }
- Asm->OutStreamer.AddBlankLine();
-}
-
/// SharedTypeIds - How many leading type ids two landing pads have in common.
unsigned DwarfException::SharedTypeIds(const LandingPadInfo *L,
const LandingPadInfo *R) {
const MachineOperand &MO = MI->getOperand(I);
if (!MO.isGlobal()) continue;
-
+
const Function *F = dyn_cast<Function>(MO.getGlobal());
if (F == 0) continue;
// Be conservative. If we have more than one function operand for this
// call, then we can't make the assumption that it's the callee and
// not a parameter to the call.
- //
+ //
// FIXME: Determine if there's a way to say that `F' is the callee or
// parameter.
MarkedNoUnwind = false;
// Call sites.
bool IsSJLJ = Asm->MAI->getExceptionHandlingType() == ExceptionHandling::SjLj;
bool HaveTTData = IsSJLJ ? (!TypeInfos.empty() || !FilterIds.empty()) : true;
-
+
unsigned CallSiteTableLength;
if (IsSJLJ)
CallSiteTableLength = 0;
unsigned SiteStartSize = 4; // dwarf::DW_EH_PE_udata4
unsigned SiteLengthSize = 4; // dwarf::DW_EH_PE_udata4
unsigned LandingPadSize = 4; // dwarf::DW_EH_PE_udata4
- CallSiteTableLength =
+ CallSiteTableLength =
CallSites.size() * (SiteStartSize + SiteLengthSize + LandingPadSize);
}
// mode, this reference will require a relocation by the dynamic linker.
//
// Because of this, we have a couple of options:
- //
+ //
// 1) If we are in -static mode, we can always use an absolute reference
// from the LSDA, because the static linker will resolve it.
- //
+ //
// 2) Otherwise, if the LSDA section is writable, we can output the direct
// reference to the typeinfo and allow the dynamic linker to relocate
// it. Since it is in a writable section, the dynamic linker won't
// have a problem.
- //
+ //
// 3) Finally, if we're in PIC mode and the LDSA section isn't writable,
// we need to use some form of indirection. For example, on Darwin,
// we can output a statically-relocatable reference to a dyld stub. The
Asm->EmitAlignment(2);
// Emit the LSDA.
- MCSymbol *GCCETSym =
+ MCSymbol *GCCETSym =
Asm->OutContext.GetOrCreateSymbol(Twine("GCC_except_table")+
Twine(Asm->getFunctionNumber()));
Asm->OutStreamer.EmitLabel(GCCETSym);
for (SmallVectorImpl<CallSiteEntry>::const_iterator
I = CallSites.begin(), E = CallSites.end(); I != E; ++I) {
const CallSiteEntry &S = *I;
-
+
MCSymbol *EHFuncBeginSym =
Asm->GetTempSymbol("eh_func_begin", Asm->getFunctionNumber());
-
+
MCSymbol *BeginLabel = S.BeginLabel;
if (BeginLabel == 0)
BeginLabel = EHFuncBeginSym;
MCSymbol *EndLabel = S.EndLabel;
if (EndLabel == 0)
EndLabel = Asm->GetTempSymbol("eh_func_end", Asm->getFunctionNumber());
-
+
// Offset of the call site relative to the previous call site, counted in
// number of 16-byte bundles. The first call site is counted relative to
// the start of the procedure fragment.
Asm->OutStreamer.AddComment("Region start");
Asm->EmitLabelDifference(BeginLabel, EHFuncBeginSym, 4);
-
+
Asm->OutStreamer.AddComment("Region length");
Asm->EmitLabelDifference(EndLabel, BeginLabel, 4);
Asm->OutStreamer.AddComment("-- Action Record Table --");
Asm->OutStreamer.AddBlankLine();
}
-
+
for (SmallVectorImpl<ActionEntry>::const_iterator
I = Actions.begin(), E = Actions.end(); I != E; ++I) {
const ActionEntry &Action = *I;
/// EndModule - Emit all exception information that should come after the
/// content.
void DwarfException::EndModule() {
- if (Asm->MAI->getExceptionHandlingType() != ExceptionHandling::Dwarf)
- return;
-
- if (!shouldEmitMovesModule && !shouldEmitTableModule)
- return;
-
- const std::vector<const Function*> &Personalities = MMI->getPersonalities();
-
- for (unsigned I = 0, E = Personalities.size(); I < E; ++I)
- EmitCIE(Personalities[I], I);
-
- for (std::vector<FunctionEHFrameInfo>::iterator
- I = EHFrames.begin(), E = EHFrames.end(); I != E; ++I)
- EmitFDE(*I);
+ assert(0 && "Should be implemented");
}
/// BeginFunction - Gather pre-function exception information. Assumes it's
/// being emitted immediately after the function entry point.
void DwarfException::BeginFunction(const MachineFunction *MF) {
- shouldEmitTable = shouldEmitMoves = false;
-
- // If any landing pads survive, we need an EH table.
- shouldEmitTable = !MMI->getLandingPads().empty();
-
- // See if we need frame move info.
- shouldEmitMoves =
- !Asm->MF->getFunction()->doesNotThrow() || UnwindTablesMandatory;
-
- if (shouldEmitMoves || shouldEmitTable)
- // Assumes in correct section after the entry point.
- Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("eh_func_begin",
- Asm->getFunctionNumber()));
-
- shouldEmitTableModule |= shouldEmitTable;
- shouldEmitMovesModule |= shouldEmitMoves;
+ assert(0 && "Should be implemented");
}
/// EndFunction - Gather and emit post-function exception information.
///
void DwarfException::EndFunction() {
- if (!shouldEmitMoves && !shouldEmitTable) return;
-
- Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("eh_func_end",
- Asm->getFunctionNumber()));
-
- // Record if this personality index uses a landing pad.
- bool HasLandingPad = !MMI->getLandingPads().empty();
- UsesLSDA[MMI->getPersonalityIndex()] |= HasLandingPad;
-
- // Map all labels and get rid of any dead landing pads.
- MMI->TidyLandingPads();
-
- if (HasLandingPad)
- EmitExceptionTable();
-
- const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
- MCSymbol *FunctionEHSym =
- Asm->GetSymbolWithGlobalValueBase(Asm->MF->getFunction(), ".eh",
- TLOF.isFunctionEHFrameSymbolPrivate());
-
- // Save EH frame information
- EHFrames.
- push_back(FunctionEHFrameInfo(FunctionEHSym,
- Asm->getFunctionNumber(),
- MMI->getPersonalityIndex(),
- Asm->MF->getFrameInfo()->adjustsStack(),
- !MMI->getLandingPads().empty(),
- MMI->getFrameMoves(),
- Asm->MF->getFunction()));
+ assert(0 && "Should be implemented");
}
/// DwarfException - Emits Dwarf exception handling directives.
///
class DwarfException {
+protected:
/// Asm - Target of Dwarf emission.
AsmPrinter *Asm;
/// MMI - Collected machine module information.
MachineModuleInfo *MMI;
- struct FunctionEHFrameInfo {
- MCSymbol *FunctionEHSym; // L_foo.eh
- unsigned Number;
- unsigned PersonalityIndex;
- bool adjustsStack;
- bool hasLandingPads;
- std::vector<MachineMove> Moves;
- const Function *function;
-
- FunctionEHFrameInfo(MCSymbol *EHSym, unsigned Num, unsigned P,
- bool hC, bool hL,
- const std::vector<MachineMove> &M,
- const Function *f):
- FunctionEHSym(EHSym), Number(Num), PersonalityIndex(P),
- adjustsStack(hC), hasLandingPads(hL), Moves(M), function (f) { }
- };
-
- std::vector<FunctionEHFrameInfo> EHFrames;
-
- /// UsesLSDA - Indicates whether an FDE that uses the CIE at the given index
- /// uses an LSDA. If so, then we need to encode that information in the CIE's
- /// augmentation.
- DenseMap<unsigned, bool> UsesLSDA;
-
- /// shouldEmitTable - Per-function flag to indicate if EH tables should
- /// be emitted.
- bool shouldEmitTable;
-
- /// shouldEmitMoves - Per-function flag to indicate if frame moves info
- /// should be emitted.
- bool shouldEmitMoves;
-
- /// shouldEmitTableModule - Per-module flag to indicate if EH tables
- /// should be emitted.
- bool shouldEmitTableModule;
-
- /// shouldEmitFrameModule - Per-module flag to indicate if frame moves
- /// should be emitted.
- bool shouldEmitMovesModule;
-
- /// EmitCIE - Emit a Common Information Entry (CIE). This holds information
- /// that is shared among many Frame Description Entries. There is at least
- /// one CIE in every non-empty .debug_frame section.
- void EmitCIE(const Function *Personality, unsigned Index);
-
- /// EmitFDE - Emit the Frame Description Entry (FDE) for the function.
- void EmitFDE(const FunctionEHFrameInfo &EHFrameInfo);
-
/// EmitExceptionTable - Emit landing pads and actions.
///
/// The general organization of the table is complex, but the basic concepts
// Main entry points.
//
DwarfException(AsmPrinter *A);
- ~DwarfException();
+ virtual ~DwarfException();
+
+ /// EndModule - Emit all exception information that should come after the
+ /// content.
+ virtual void EndModule();
+
+ /// BeginFunction - Gather pre-function exception information. Assumes being
+ /// emitted immediately after the function entry point.
+ virtual void BeginFunction(const MachineFunction *MF);
+
+ /// EndFunction - Gather and emit post-function exception information.
+ virtual void EndFunction();
+};
+
+class DwarfTableException : public DwarfException {
+ /// shouldEmitTable - Per-function flag to indicate if EH tables should
+ /// be emitted.
+ bool shouldEmitTable;
+
+ /// shouldEmitMoves - Per-function flag to indicate if frame moves info
+ /// should be emitted.
+ bool shouldEmitMoves;
+
+ /// shouldEmitTableModule - Per-module flag to indicate if EH tables
+ /// should be emitted.
+ bool shouldEmitTableModule;
+
+ /// shouldEmitMovesModule - Per-module flag to indicate if frame moves
+ /// should be emitted.
+ bool shouldEmitMovesModule;
+
+ struct FunctionEHFrameInfo {
+ MCSymbol *FunctionEHSym; // L_foo.eh
+ unsigned Number;
+ unsigned PersonalityIndex;
+ bool adjustsStack;
+ bool hasLandingPads;
+ std::vector<MachineMove> Moves;
+ const Function *function;
+
+ FunctionEHFrameInfo(MCSymbol *EHSym, unsigned Num, unsigned P,
+ bool hC, bool hL,
+ const std::vector<MachineMove> &M,
+ const Function *f):
+ FunctionEHSym(EHSym), Number(Num), PersonalityIndex(P),
+ adjustsStack(hC), hasLandingPads(hL), Moves(M), function (f) { }
+ };
+
+ std::vector<FunctionEHFrameInfo> EHFrames;
+
+ /// UsesLSDA - Indicates whether an FDE that uses the CIE at the given index
+ /// uses an LSDA. If so, then we need to encode that information in the CIE's
+ /// augmentation.
+ DenseMap<unsigned, bool> UsesLSDA;
+
+ /// EmitCIE - Emit a Common Information Entry (CIE). This holds information
+ /// that is shared among many Frame Description Entries. There is at least
+ /// one CIE in every non-empty .debug_frame section.
+ void EmitCIE(const Function *Personality, unsigned Index);
+
+ /// EmitFDE - Emit the Frame Description Entry (FDE) for the function.
+ void EmitFDE(const FunctionEHFrameInfo &EHFrameInfo);
+public:
+ //===--------------------------------------------------------------------===//
+ // Main entry points.
+ //
+ DwarfTableException(AsmPrinter *A);
+ virtual ~DwarfTableException();
/// EndModule - Emit all exception information that should come after the
/// content.
- void EndModule();
+ virtual void EndModule();
/// BeginFunction - Gather pre-function exception information. Assumes being
/// emitted immediately after the function entry point.
- void BeginFunction(const MachineFunction *MF);
+ virtual void BeginFunction(const MachineFunction *MF);
/// EndFunction - Gather and emit post-function exception information.
- void EndFunction();
+ virtual void EndFunction();
};
} // End of namespace llvm
--- /dev/null
+//===-- CodeGen/AsmPrinter/DwarfTableException.cpp - Dwarf Exception Impl --==//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains support for writing DWARF exception info into asm files.
+// The implementation emits all the necessary tables "by hands".
+//
+//===----------------------------------------------------------------------===//
+
+#include "DwarfException.h"
+#include "llvm/Module.h"
+#include "llvm/CodeGen/AsmPrinter.h"
+#include "llvm/CodeGen/MachineModuleInfo.h"
+#include "llvm/CodeGen/MachineFrameInfo.h"
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/MachineLocation.h"
+#include "llvm/MC/MCAsmInfo.h"
+#include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCExpr.h"
+#include "llvm/MC/MCSection.h"
+#include "llvm/MC/MCStreamer.h"
+#include "llvm/MC/MCSymbol.h"
+#include "llvm/Target/Mangler.h"
+#include "llvm/Target/TargetData.h"
+#include "llvm/Target/TargetFrameLowering.h"
+#include "llvm/Target/TargetLoweringObjectFile.h"
+#include "llvm/Target/TargetMachine.h"
+#include "llvm/Target/TargetOptions.h"
+#include "llvm/Target/TargetRegisterInfo.h"
+#include "llvm/Support/Dwarf.h"
+#include "llvm/Support/FormattedStream.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/ADT/StringExtras.h"
+#include "llvm/ADT/Twine.h"
+using namespace llvm;
+
+DwarfTableException::DwarfTableException(AsmPrinter *A)
+ : DwarfException(A),
+ shouldEmitTable(false), shouldEmitMoves(false),
+ shouldEmitTableModule(false), shouldEmitMovesModule(false) {}
+
+DwarfTableException::~DwarfTableException() {}
+
+/// EmitCIE - Emit a Common Information Entry (CIE). This holds information that
+/// is shared among many Frame Description Entries. There is at least one CIE
+/// in every non-empty .debug_frame section.
+void DwarfTableException::EmitCIE(const Function *PersonalityFn, unsigned Index) {
+ // Size and sign of stack growth.
+ int stackGrowth = Asm->getTargetData().getPointerSize();
+ if (Asm->TM.getFrameLowering()->getStackGrowthDirection() ==
+ TargetFrameLowering::StackGrowsDown)
+ stackGrowth *= -1;
+
+ const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
+
+ // Begin eh frame section.
+ Asm->OutStreamer.SwitchSection(TLOF.getEHFrameSection());
+
+ MCSymbol *EHFrameSym;
+ if (TLOF.isFunctionEHFrameSymbolPrivate())
+ EHFrameSym = Asm->GetTempSymbol("EH_frame", Index);
+ else
+ EHFrameSym = Asm->OutContext.GetOrCreateSymbol(Twine("EH_frame") +
+ Twine(Index));
+ Asm->OutStreamer.EmitLabel(EHFrameSym);
+
+ Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("section_eh_frame", Index));
+
+ // Define base labels.
+ Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("eh_frame_common", Index));
+
+ // Define the eh frame length.
+ Asm->OutStreamer.AddComment("Length of Common Information Entry");
+ Asm->EmitLabelDifference(Asm->GetTempSymbol("eh_frame_common_end", Index),
+ Asm->GetTempSymbol("eh_frame_common_begin", Index),
+ 4);
+
+ // EH frame header.
+ Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("eh_frame_common_begin",Index));
+ Asm->OutStreamer.AddComment("CIE Identifier Tag");
+ Asm->OutStreamer.EmitIntValue(0, 4/*size*/, 0/*addrspace*/);
+ Asm->OutStreamer.AddComment("DW_CIE_VERSION");
+ Asm->OutStreamer.EmitIntValue(dwarf::DW_CIE_VERSION, 1/*size*/, 0/*addr*/);
+
+ // 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:
+
+ unsigned LSDAEncoding = TLOF.getLSDAEncoding();
+ unsigned FDEEncoding = TLOF.getFDEEncoding();
+ unsigned PerEncoding = TLOF.getPersonalityEncoding();
+
+ char Augmentation[6] = { 0 };
+ unsigned AugmentationSize = 0;
+ char *APtr = Augmentation + 1;
+
+ if (PersonalityFn) {
+ // There is a personality function.
+ *APtr++ = 'P';
+ AugmentationSize += 1 + Asm->GetSizeOfEncodedValue(PerEncoding);
+ }
+
+ if (UsesLSDA[Index]) {
+ // An LSDA pointer is in the FDE augmentation.
+ *APtr++ = 'L';
+ ++AugmentationSize;
+ }
+
+ if (FDEEncoding != dwarf::DW_EH_PE_absptr) {
+ // A non-default pointer encoding for the FDE.
+ *APtr++ = 'R';
+ ++AugmentationSize;
+ }
+
+ if (APtr != Augmentation + 1)
+ Augmentation[0] = 'z';
+
+ Asm->OutStreamer.AddComment("CIE Augmentation");
+ Asm->OutStreamer.EmitBytes(StringRef(Augmentation, strlen(Augmentation)+1),0);
+
+ // Round out reader.
+ Asm->EmitULEB128(1, "CIE Code Alignment Factor");
+ Asm->EmitSLEB128(stackGrowth, "CIE Data Alignment Factor");
+ Asm->OutStreamer.AddComment("CIE Return Address Column");
+
+ const TargetRegisterInfo *RI = Asm->TM.getRegisterInfo();
+ const TargetFrameLowering *TFI = Asm->TM.getFrameLowering();
+ Asm->EmitInt8(RI->getDwarfRegNum(RI->getRARegister(), true));
+
+ if (Augmentation[0]) {
+ Asm->EmitULEB128(AugmentationSize, "Augmentation Size");
+
+ // If there is a personality, we need to indicate the function's location.
+ if (PersonalityFn) {
+ Asm->EmitEncodingByte(PerEncoding, "Personality");
+ Asm->OutStreamer.AddComment("Personality");
+ Asm->EmitReference(PersonalityFn, PerEncoding);
+ }
+ if (UsesLSDA[Index])
+ Asm->EmitEncodingByte(LSDAEncoding, "LSDA");
+ if (FDEEncoding != dwarf::DW_EH_PE_absptr)
+ Asm->EmitEncodingByte(FDEEncoding, "FDE");
+ }
+
+ // Indicate locations of general callee saved registers in frame.
+ std::vector<MachineMove> Moves;
+ TFI->getInitialFrameState(Moves);
+ Asm->EmitFrameMoves(Moves, 0, true);
+
+ // On Darwin the linker honors the alignment of eh_frame, which means it must
+ // be 8-byte on 64-bit targets to match what gcc does. Otherwise you get
+ // holes which confuse readers of eh_frame.
+ Asm->EmitAlignment(Asm->getTargetData().getPointerSize() == 4 ? 2 : 3);
+ Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("eh_frame_common_end", Index));
+}
+
+/// EmitFDE - Emit the Frame Description Entry (FDE) for the function.
+void DwarfTableException::EmitFDE(const FunctionEHFrameInfo &EHFrameInfo) {
+ assert(!EHFrameInfo.function->hasAvailableExternallyLinkage() &&
+ "Should not emit 'available externally' functions at all");
+
+ const Function *TheFunc = EHFrameInfo.function;
+ const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
+
+ 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.
+ if (!TheFunc->hasLocalLinkage() && TLOF.isFunctionEHSymbolGlobal())
+ Asm->OutStreamer.EmitSymbolAttribute(EHFrameInfo.FunctionEHSym,MCSA_Global);
+
+ // If corresponding function is weak definition, this should be too.
+ if (TheFunc->isWeakForLinker() && Asm->MAI->getWeakDefDirective())
+ Asm->OutStreamer.EmitSymbolAttribute(EHFrameInfo.FunctionEHSym,
+ MCSA_WeakDefinition);
+
+ // If corresponding function is hidden, this should be too.
+ if (TheFunc->hasHiddenVisibility())
+ if (MCSymbolAttr HiddenAttr = Asm->MAI->getHiddenVisibilityAttr())
+ Asm->OutStreamer.EmitSymbolAttribute(EHFrameInfo.FunctionEHSym,
+ HiddenAttr);
+
+ // If there are no calls then you can't unwind. This may mean we can omit the
+ // EH Frame, but some environments do not handle weak absolute symbols. If
+ // UnwindTablesMandatory is set we cannot do this optimization; the unwind
+ // info is to be available for non-EH uses.
+ if (!EHFrameInfo.adjustsStack && !UnwindTablesMandatory &&
+ (!TheFunc->isWeakForLinker() ||
+ !Asm->MAI->getWeakDefDirective() ||
+ TLOF.getSupportsWeakOmittedEHFrame())) {
+ Asm->OutStreamer.EmitAssignment(EHFrameInfo.FunctionEHSym,
+ MCConstantExpr::Create(0, Asm->OutContext));
+ // This name has no connection to the function, so it might get
+ // dead-stripped when the function is not, erroneously. Prohibit
+ // dead-stripping unconditionally.
+ if (Asm->MAI->hasNoDeadStrip())
+ Asm->OutStreamer.EmitSymbolAttribute(EHFrameInfo.FunctionEHSym,
+ MCSA_NoDeadStrip);
+ } else {
+ Asm->OutStreamer.EmitLabel(EHFrameInfo.FunctionEHSym);
+
+ // EH frame header.
+ Asm->OutStreamer.AddComment("Length of Frame Information Entry");
+ Asm->EmitLabelDifference(
+ Asm->GetTempSymbol("eh_frame_end", EHFrameInfo.Number),
+ Asm->GetTempSymbol("eh_frame_begin", EHFrameInfo.Number), 4);
+
+ Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("eh_frame_begin",
+ EHFrameInfo.Number));
+
+ Asm->OutStreamer.AddComment("FDE CIE offset");
+ Asm->EmitLabelDifference(
+ Asm->GetTempSymbol("eh_frame_begin", EHFrameInfo.Number),
+ Asm->GetTempSymbol("eh_frame_common",
+ EHFrameInfo.PersonalityIndex), 4);
+
+ MCSymbol *EHFuncBeginSym =
+ Asm->GetTempSymbol("eh_func_begin", EHFrameInfo.Number);
+
+ Asm->OutStreamer.AddComment("FDE initial location");
+ Asm->EmitReference(EHFuncBeginSym, FDEEncoding);
+
+ Asm->OutStreamer.AddComment("FDE address range");
+ Asm->EmitLabelDifference(Asm->GetTempSymbol("eh_func_end",
+ EHFrameInfo.Number),
+ EHFuncBeginSym,
+ Asm->GetSizeOfEncodedValue(FDEEncoding));
+
+ // 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 = Asm->GetSizeOfEncodedValue(LSDAEncoding);
+
+ Asm->EmitULEB128(Size, "Augmentation size");
+ Asm->OutStreamer.AddComment("Language Specific Data Area");
+ if (EHFrameInfo.hasLandingPads)
+ Asm->EmitReference(Asm->GetTempSymbol("exception", EHFrameInfo.Number),
+ LSDAEncoding);
+ else
+ Asm->OutStreamer.EmitIntValue(0, Size/*size*/, 0/*addrspace*/);
+
+ } else {
+ Asm->EmitULEB128(0, "Augmentation size");
+ }
+
+ // Indicate locations of function specific callee saved registers in frame.
+ Asm->EmitFrameMoves(EHFrameInfo.Moves, EHFuncBeginSym, true);
+
+ // On Darwin the linker honors the alignment of eh_frame, which means it
+ // must be 8-byte on 64-bit targets to match what gcc does. Otherwise you
+ // get holes which confuse readers of eh_frame.
+ Asm->EmitAlignment(Asm->getTargetData().getPointerSize() == 4 ? 2 : 3);
+ Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("eh_frame_end",
+ EHFrameInfo.Number));
+
+ // If the function is marked used, this table should be also. We cannot
+ // make the mark unconditional in this case, since retaining the table also
+ // retains the function in this case, and there is code around that depends
+ // on unused functions (calling undefined externals) being dead-stripped to
+ // link correctly. Yes, there really is.
+ if (MMI->isUsedFunction(EHFrameInfo.function))
+ if (Asm->MAI->hasNoDeadStrip())
+ Asm->OutStreamer.EmitSymbolAttribute(EHFrameInfo.FunctionEHSym,
+ MCSA_NoDeadStrip);
+ }
+ Asm->OutStreamer.AddBlankLine();
+}
+
+/// EndModule - Emit all exception information that should come after the
+/// content.
+void DwarfTableException::EndModule() {
+ if (Asm->MAI->getExceptionHandlingType() != ExceptionHandling::Dwarf)
+ return;
+
+ if (!shouldEmitMovesModule && !shouldEmitTableModule)
+ return;
+
+ const std::vector<const Function*> &Personalities = MMI->getPersonalities();
+
+ for (unsigned I = 0, E = Personalities.size(); I < E; ++I)
+ EmitCIE(Personalities[I], I);
+
+ for (std::vector<FunctionEHFrameInfo>::iterator
+ I = EHFrames.begin(), E = EHFrames.end(); I != E; ++I)
+ EmitFDE(*I);
+}
+
+/// BeginFunction - Gather pre-function exception information. Assumes it's
+/// being emitted immediately after the function entry point.
+void DwarfTableException::BeginFunction(const MachineFunction *MF) {
+ shouldEmitTable = shouldEmitMoves = false;
+
+ // If any landing pads survive, we need an EH table.
+ shouldEmitTable = !MMI->getLandingPads().empty();
+
+ // See if we need frame move info.
+ shouldEmitMoves =
+ !Asm->MF->getFunction()->doesNotThrow() || UnwindTablesMandatory;
+
+ if (shouldEmitMoves || shouldEmitTable)
+ // Assumes in correct section after the entry point.
+ Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("eh_func_begin",
+ Asm->getFunctionNumber()));
+
+ shouldEmitTableModule |= shouldEmitTable;
+ shouldEmitMovesModule |= shouldEmitMoves;
+}
+
+/// EndFunction - Gather and emit post-function exception information.
+///
+void DwarfTableException::EndFunction() {
+ if (!shouldEmitMoves && !shouldEmitTable) return;
+
+ Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("eh_func_end",
+ Asm->getFunctionNumber()));
+
+ // Record if this personality index uses a landing pad.
+ bool HasLandingPad = !MMI->getLandingPads().empty();
+ UsesLSDA[MMI->getPersonalityIndex()] |= HasLandingPad;
+
+ // Map all labels and get rid of any dead landing pads.
+ MMI->TidyLandingPads();
+
+ if (HasLandingPad)
+ EmitExceptionTable();
+
+ const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
+ MCSymbol *FunctionEHSym =
+ Asm->GetSymbolWithGlobalValueBase(Asm->MF->getFunction(), ".eh",
+ TLOF.isFunctionEHFrameSymbolPrivate());
+
+ // Save EH frame information
+ EHFrames.
+ push_back(FunctionEHFrameInfo(FunctionEHSym,
+ Asm->getFunctionNumber(),
+ MMI->getPersonalityIndex(),
+ Asm->MF->getFrameInfo()->adjustsStack(),
+ !MMI->getLandingPads().empty(),
+ MMI->getFrameMoves(),
+ Asm->MF->getFunction()));
+}
projects / oota-llvm.git / commitdiff