#define DEBUG_TYPE "asm-printer"
#include "llvm/CodeGen/AsmPrinter.h"
+#include "llvm/CodeGen/MachineLocation.h"
#include "llvm/MC/MCAsmInfo.h"
+#include "llvm/MC/MCSection.h"
#include "llvm/MC/MCStreamer.h"
+#include "llvm/MC/MCSymbol.h"
+#include "llvm/Target/TargetData.h"
+#include "llvm/Target/TargetFrameInfo.h"
+#include "llvm/Target/TargetLoweringObjectFile.h"
+#include "llvm/Target/TargetMachine.h"
+#include "llvm/Target/TargetRegisterInfo.h"
#include "llvm/ADT/Twine.h"
#include "llvm/Support/Dwarf.h"
using namespace llvm;
+//===----------------------------------------------------------------------===//
+// Dwarf Emission Helper Routines
+//===----------------------------------------------------------------------===//
+
/// EmitSLEB128 - emit the specified signed leb128 value.
void AsmPrinter::EmitSLEB128(int Value, const char *Desc) const {
if (isVerbose() && Desc)
OutStreamer.AddComment(Desc);
- if (MAI->hasLEB128()) {
+ if (MAI->hasLEB128() && OutStreamer.hasRawTextSupport()) {
// FIXME: MCize.
OutStreamer.EmitRawText("\t.sleb128\t" + Twine(Value));
return;
if (isVerbose() && Desc)
OutStreamer.AddComment(Desc);
- if (MAI->hasLEB128() && PadTo == 0) {
+ if (MAI->hasLEB128() && PadTo == 0 && OutStreamer.hasRawTextSupport()) {
// FIXME: MCize.
OutStreamer.EmitRawText("\t.uleb128\t" + Twine(Value));
return;
OutStreamer.EmitIntValue(Val, 1, 0/*addrspace*/);
}
+static const char *DecodeDWARFEncoding(unsigned Encoding) {
+ switch (Encoding) {
+ case dwarf::DW_EH_PE_absptr: return "absptr";
+ case dwarf::DW_EH_PE_omit: return "omit";
+ case dwarf::DW_EH_PE_pcrel: return "pcrel";
+ case dwarf::DW_EH_PE_udata4: return "udata4";
+ case dwarf::DW_EH_PE_udata8: return "udata8";
+ case dwarf::DW_EH_PE_sdata4: return "sdata4";
+ case dwarf::DW_EH_PE_sdata8: return "sdata8";
+ case dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata4: return "pcrel udata4";
+ case dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4: return "pcrel sdata4";
+ case dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8: return "pcrel udata8";
+ case dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata8: return "pcrel sdata8";
+ case dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |dwarf::DW_EH_PE_udata4:
+ return "indirect pcrel udata4";
+ case dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |dwarf::DW_EH_PE_sdata4:
+ return "indirect pcrel sdata4";
+ case dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |dwarf::DW_EH_PE_udata8:
+ return "indirect pcrel udata8";
+ case dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |dwarf::DW_EH_PE_sdata8:
+ return "indirect pcrel sdata8";
+ }
+
+ return "<unknown encoding>";
+}
+
+
+/// EmitEncodingByte - Emit a .byte 42 directive that corresponds to an
+/// encoding. If verbose assembly output is enabled, we output comments
+/// describing the encoding. Desc is an optional string saying what the
+/// encoding is specifying (e.g. "LSDA").
+void AsmPrinter::EmitEncodingByte(unsigned Val, const char *Desc) const {
+ if (isVerbose()) {
+ if (Desc != 0)
+ OutStreamer.AddComment(Twine(Desc)+" Encoding = " +
+ Twine(DecodeDWARFEncoding(Val)));
+ else
+ OutStreamer.AddComment(Twine("Encoding = ") +
+ DecodeDWARFEncoding(Val));
+ }
+
+ OutStreamer.EmitIntValue(Val, 1, 0/*addrspace*/);
+}
+
+/// GetSizeOfEncodedValue - Return the size of the encoding in bytes.
+unsigned AsmPrinter::GetSizeOfEncodedValue(unsigned Encoding) const {
+ if (Encoding == dwarf::DW_EH_PE_omit)
+ return 0;
+
+ switch (Encoding & 0x07) {
+ default: assert(0 && "Invalid encoded value.");
+ case dwarf::DW_EH_PE_absptr: return TM.getTargetData()->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;
+ }
+}
+
+void AsmPrinter::EmitReference(const MCSymbol *Sym, unsigned Encoding) const {
+ const TargetLoweringObjectFile &TLOF = getObjFileLowering();
+
+ const MCExpr *Exp =
+ TLOF.getExprForDwarfReference(Sym, Mang, MMI, Encoding, OutStreamer);
+ OutStreamer.EmitValue(Exp, GetSizeOfEncodedValue(Encoding), /*addrspace*/0);
+}
+
+void AsmPrinter::EmitReference(const GlobalValue *GV, unsigned Encoding)const{
+ const TargetLoweringObjectFile &TLOF = getObjFileLowering();
+
+ const MCExpr *Exp =
+ TLOF.getExprForDwarfGlobalReference(GV, Mang, MMI, Encoding, OutStreamer);
+ OutStreamer.EmitValue(Exp, GetSizeOfEncodedValue(Encoding), /*addrspace*/0);
+}
+
+/// EmitSectionOffset - Emit the 4-byte offset of Label from the start of its
+/// section. This can be done with a special directive if the target supports
+/// it (e.g. cygwin) or by emitting it as an offset from a label at the start
+/// of the section.
+///
+/// SectionLabel is a temporary label emitted at the start of the section that
+/// Label lives in.
+void AsmPrinter::EmitSectionOffset(const MCSymbol *Label,
+ const MCSymbol *SectionLabel) const {
+ // On COFF targets, we have to emit the special .secrel32 directive.
+ if (const char *SecOffDir = MAI->getDwarfSectionOffsetDirective()) {
+ // FIXME: MCize.
+ OutStreamer.EmitRawText(SecOffDir + Twine(Label->getName()));
+ return;
+ }
+
+ // Get the section that we're referring to, based on SectionLabel.
+ const MCSection &Section = SectionLabel->getSection();
+
+ // If Label has already been emitted, verify that it is in the same section as
+ // section label for sanity.
+ assert((!Label->isInSection() || &Label->getSection() == &Section) &&
+ "Section offset using wrong section base for label");
+
+ // If the section in question will end up with an address of 0 anyway, we can
+ // just emit an absolute reference to save a relocation.
+ if (Section.isBaseAddressKnownZero()) {
+ OutStreamer.EmitSymbolValue(Label, 4, 0/*AddrSpace*/);
+ return;
+ }
+
+ // Otherwise, emit it as a label difference from the start of the section.
+ EmitLabelDifference(Label, SectionLabel, 4);
+}
+
+//===----------------------------------------------------------------------===//
+// Dwarf Lowering Routines
+//===----------------------------------------------------------------------===//
+
+
+/// EmitFrameMoves - Emit frame instructions to describe the layout of the
+/// frame.
+void AsmPrinter::EmitFrameMoves(const std::vector<MachineMove> &Moves,
+ MCSymbol *BaseLabel, bool isEH) const {
+ const TargetRegisterInfo *RI = TM.getRegisterInfo();
+
+ int stackGrowth = TM.getTargetData()->getPointerSize();
+ if (TM.getFrameInfo()->getStackGrowthDirection() !=
+ TargetFrameInfo::StackGrowsUp)
+ stackGrowth *= -1;
+
+ for (unsigned i = 0, N = Moves.size(); i < N; ++i) {
+ const MachineMove &Move = Moves[i];
+ MCSymbol *Label = Move.getLabel();
+ // Throw out move if the label is invalid.
+ if (Label && !Label->isDefined()) continue; // Not emitted, in dead code.
+
+ const MachineLocation &Dst = Move.getDestination();
+ const MachineLocation &Src = Move.getSource();
+
+ // Advance row if new location.
+ if (BaseLabel && Label) {
+ MCSymbol *ThisSym = Label;
+ if (ThisSym != BaseLabel) {
+ EmitCFAByte(dwarf::DW_CFA_advance_loc4);
+ EmitLabelDifference(ThisSym, BaseLabel, 4);
+ BaseLabel = ThisSym;
+ }
+ }
+
+ // If advancing cfa.
+ if (Dst.isReg() && Dst.getReg() == MachineLocation::VirtualFP) {
+ assert(!Src.isReg() && "Machine move not supported yet.");
+
+ if (Src.getReg() == MachineLocation::VirtualFP) {
+ EmitCFAByte(dwarf::DW_CFA_def_cfa_offset);
+ } else {
+ EmitCFAByte(dwarf::DW_CFA_def_cfa);
+ EmitULEB128(RI->getDwarfRegNum(Src.getReg(), isEH), "Register");
+ }
+
+ EmitULEB128(-Src.getOffset(), "Offset");
+ continue;
+ }
+
+ if (Src.isReg() && Src.getReg() == MachineLocation::VirtualFP) {
+ assert(Dst.isReg() && "Machine move not supported yet.");
+ EmitCFAByte(dwarf::DW_CFA_def_cfa_register);
+ EmitULEB128(RI->getDwarfRegNum(Dst.getReg(), isEH), "Register");
+ continue;
+ }
+
+ unsigned Reg = RI->getDwarfRegNum(Src.getReg(), isEH);
+ int Offset = Dst.getOffset() / stackGrowth;
+
+ if (Offset < 0) {
+ EmitCFAByte(dwarf::DW_CFA_offset_extended_sf);
+ EmitULEB128(Reg, "Reg");
+ EmitSLEB128(Offset, "Offset");
+ } else if (Reg < 64) {
+ EmitCFAByte(dwarf::DW_CFA_offset + Reg);
+ EmitULEB128(Offset, "Offset");
+ } else {
+ EmitCFAByte(dwarf::DW_CFA_offset_extended);
+ EmitULEB128(Reg, "Reg");
+ EmitULEB128(Offset, "Offset");
+ }
+ }
+}
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