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-rw-r--r--lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp201
1 files changed, 142 insertions, 59 deletions
diff --git a/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp b/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp
index 418971d..679d3c4 100644
--- a/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp
+++ b/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp
@@ -13,7 +13,9 @@
//
//===----------------------------------------------------------------------===//
+#include "ARMRegisterInfo.h"
#include "ARMUnwindOp.h"
+#include "ARMUnwindOpAsm.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/Twine.h"
#include "llvm/MC/MCAsmBackend.h"
@@ -26,6 +28,7 @@
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCInst.h"
#include "llvm/MC/MCObjectStreamer.h"
+#include "llvm/MC/MCRegisterInfo.h"
#include "llvm/MC/MCSection.h"
#include "llvm/MC/MCSectionELF.h"
#include "llvm/MC/MCStreamer.h"
@@ -33,11 +36,15 @@
#include "llvm/MC/MCValue.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ELF.h"
-#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
+static std::string GetAEABIUnwindPersonalityName(unsigned Index) {
+ assert(Index < NUM_PERSONALITY_INDEX && "Invalid personality index");
+ return (Twine("__aeabi_unwind_cpp_pr") + Twine(Index)).str();
+}
+
namespace {
/// Extend the generic ELFStreamer class so that it can emit mapping symbols at
@@ -57,8 +64,9 @@ public:
ARMELFStreamer(MCContext &Context, MCAsmBackend &TAB, raw_ostream &OS,
MCCodeEmitter *Emitter, bool IsThumb)
: MCELFStreamer(SK_ARMELFStreamer, Context, TAB, OS, Emitter),
- IsThumb(IsThumb), MappingSymbolCounter(0), LastEMS(EMS_None), ExTab(0),
- FnStart(0), Personality(0), CantUnwind(false) {}
+ IsThumb(IsThumb), MappingSymbolCounter(0), LastEMS(EMS_None) {
+ Reset();
+ }
~ARMELFStreamer() {}
@@ -75,14 +83,15 @@ public:
virtual void EmitRegSave(const SmallVectorImpl<unsigned> &RegList,
bool isVector);
- virtual void ChangeSection(const MCSection *Section) {
+ virtual void ChangeSection(const MCSection *Section,
+ const MCExpr *Subsection) {
// We have to keep track of the mapping symbol state of any sections we
// use. Each one should start off as EMS_None, which is provided as the
// default constructor by DenseMap::lookup.
- LastMappingSymbols[getPreviousSection()] = LastEMS;
+ LastMappingSymbols[getPreviousSection().first] = LastEMS;
LastEMS = LastMappingSymbols.lookup(Section);
- MCELFStreamer::ChangeSection(Section);
+ MCELFStreamer::ChangeSection(Section, Subsection);
}
/// This function is the one used to emit instruction data into the ELF
@@ -175,7 +184,7 @@ private:
MCELF::SetType(SD, ELF::STT_NOTYPE);
MCELF::SetBinding(SD, ELF::STB_LOCAL);
SD.setExternal(false);
- Symbol->setSection(*getCurrentSection());
+ Symbol->setSection(*getCurrentSection().first);
const MCExpr *Value = MCSymbolRefExpr::Create(Start, getContext());
Symbol->setVariableValue(Value);
@@ -194,6 +203,8 @@ private:
void Reset();
void EmitPersonalityFixup(StringRef Name);
+ void FlushPendingOffset();
+ void FlushUnwindOpcodes(bool AllowCompactModel0);
void SwitchToEHSection(const char *Prefix, unsigned Type, unsigned Flags,
SectionKind Kind, const MCSymbol &Fn);
@@ -210,9 +221,17 @@ private:
MCSymbol *ExTab;
MCSymbol *FnStart;
const MCSymbol *Personality;
+ unsigned PersonalityIndex;
+ unsigned FPReg; // Frame pointer register
+ int64_t FPOffset; // Offset: (final frame pointer) - (initial $sp)
+ int64_t SPOffset; // Offset: (final $sp) - (initial $sp)
+ int64_t PendingOffset; // Offset: (final $sp) - (emitted $sp)
+ bool UsedFP;
bool CantUnwind;
+ SmallVector<uint8_t, 64> Opcodes;
+ UnwindOpcodeAssembler UnwindOpAsm;
};
-}
+} // end anonymous namespace
inline void ARMELFStreamer::SwitchToEHSection(const char *Prefix,
unsigned Type,
@@ -238,7 +257,7 @@ inline void ARMELFStreamer::SwitchToEHSection(const char *Prefix,
} else {
EHSection = getContext().getELFSection(EHSecName, Type, Flags, Kind);
}
- assert(EHSection);
+ assert(EHSection && "Failed to get the required EH section");
// Switch to .ARM.extab or .ARM.exidx section
SwitchSection(EHSection);
@@ -265,7 +284,16 @@ void ARMELFStreamer::Reset() {
ExTab = NULL;
FnStart = NULL;
Personality = NULL;
+ PersonalityIndex = NUM_PERSONALITY_INDEX;
+ FPReg = ARM::SP;
+ FPOffset = 0;
+ SPOffset = 0;
+ PendingOffset = 0;
+ UsedFP = false;
CantUnwind = false;
+
+ Opcodes.clear();
+ UnwindOpAsm.Reset();
}
// Add the R_ARM_NONE fixup at the same position
@@ -294,35 +322,14 @@ void ARMELFStreamer::EmitFnEnd() {
assert(FnStart && ".fnstart must preceeds .fnend");
// Emit unwind opcodes if there is no .handlerdata directive
- int PersonalityIndex = -1;
- if (!ExTab && !CantUnwind) {
- // For __aeabi_unwind_cpp_pr1, we have to emit opcodes in .ARM.extab.
- SwitchToExTabSection(*FnStart);
-
- // Create .ARM.extab label for offset in .ARM.exidx
- ExTab = getContext().CreateTempSymbol();
- EmitLabel(ExTab);
-
- PersonalityIndex = 1;
-
- uint32_t Entry = 0;
- uint32_t NumExtraEntryWords = 0;
- Entry |= NumExtraEntryWords << 24;
- Entry |= (EHT_COMPACT | PersonalityIndex) << 16;
-
- // TODO: This should be generated according to .save, .vsave, .setfp
- // directives. Currently, we are simply generating FINISH opcode.
- Entry |= UNWIND_OPCODE_FINISH << 8;
- Entry |= UNWIND_OPCODE_FINISH;
-
- EmitIntValue(Entry, 4, 0);
- }
+ if (!ExTab && !CantUnwind)
+ FlushUnwindOpcodes(true);
// Emit the exception index table entry
SwitchToExIdxSection(*FnStart);
- if (PersonalityIndex == 1)
- EmitPersonalityFixup("__aeabi_unwind_cpp_pr1");
+ if (PersonalityIndex < NUM_PERSONALITY_INDEX)
+ EmitPersonalityFixup(GetAEABIUnwindPersonalityName(PersonalityIndex));
const MCSymbolRefExpr *FnStartRef =
MCSymbolRefExpr::Create(FnStart,
@@ -333,14 +340,28 @@ void ARMELFStreamer::EmitFnEnd() {
if (CantUnwind) {
EmitIntValue(EXIDX_CANTUNWIND, 4, 0);
- } else {
+ } else if (ExTab) {
+ // Emit a reference to the unwind opcodes in the ".ARM.extab" section.
const MCSymbolRefExpr *ExTabEntryRef =
MCSymbolRefExpr::Create(ExTab,
MCSymbolRefExpr::VK_ARM_PREL31,
getContext());
EmitValue(ExTabEntryRef, 4, 0);
+ } else {
+ // For the __aeabi_unwind_cpp_pr0, we have to emit the unwind opcodes in
+ // the second word of exception index table entry. The size of the unwind
+ // opcodes should always be 4 bytes.
+ assert(PersonalityIndex == AEABI_UNWIND_CPP_PR0 &&
+ "Compact model must use __aeabi_cpp_unwind_pr0 as personality");
+ assert(Opcodes.size() == 4u &&
+ "Unwind opcode size for __aeabi_cpp_unwind_pr0 must be equal to 4");
+ EmitBytes(StringRef(reinterpret_cast<const char*>(Opcodes.data()),
+ Opcodes.size()), 0);
}
+ // Switch to the section containing FnStart
+ SwitchSection(&FnStart->getSection());
+
// Clean exception handling frame information
Reset();
}
@@ -349,7 +370,34 @@ void ARMELFStreamer::EmitCantUnwind() {
CantUnwind = true;
}
-void ARMELFStreamer::EmitHandlerData() {
+void ARMELFStreamer::FlushPendingOffset() {
+ if (PendingOffset != 0) {
+ UnwindOpAsm.EmitSPOffset(-PendingOffset);
+ PendingOffset = 0;
+ }
+}
+
+void ARMELFStreamer::FlushUnwindOpcodes(bool AllowCompactModel0) {
+ // Emit the unwind opcode to restore $sp.
+ if (UsedFP) {
+ const MCRegisterInfo &MRI = getContext().getRegisterInfo();
+ int64_t LastRegSaveSPOffset = SPOffset - PendingOffset;
+ UnwindOpAsm.EmitSPOffset(LastRegSaveSPOffset - FPOffset);
+ UnwindOpAsm.EmitSetSP(MRI.getEncodingValue(FPReg));
+ } else {
+ FlushPendingOffset();
+ }
+
+ // Finalize the unwind opcode sequence
+ UnwindOpAsm.Finalize(PersonalityIndex, Opcodes);
+
+ // For compact model 0, we have to emit the unwind opcodes in the .ARM.exidx
+ // section. Thus, we don't have to create an entry in the .ARM.extab
+ // section.
+ if (AllowCompactModel0 && PersonalityIndex == AEABI_UNWIND_CPP_PR0)
+ return;
+
+ // Switch to .ARM.extab section.
SwitchToExTabSection(*FnStart);
// Create .ARM.extab label for offset in .ARM.exidx
@@ -357,47 +405,82 @@ void ARMELFStreamer::EmitHandlerData() {
ExTab = getContext().CreateTempSymbol();
EmitLabel(ExTab);
- // Emit Personality
- assert(Personality && ".personality directive must preceed .handlerdata");
-
- const MCSymbolRefExpr *PersonalityRef =
- MCSymbolRefExpr::Create(Personality,
- MCSymbolRefExpr::VK_ARM_PREL31,
- getContext());
+ // Emit personality
+ if (Personality) {
+ const MCSymbolRefExpr *PersonalityRef =
+ MCSymbolRefExpr::Create(Personality,
+ MCSymbolRefExpr::VK_ARM_PREL31,
+ getContext());
- EmitValue(PersonalityRef, 4, 0);
+ EmitValue(PersonalityRef, 4, 0);
+ }
// Emit unwind opcodes
- uint32_t Entry = 0;
- uint32_t NumExtraEntryWords = 0;
-
- // TODO: This should be generated according to .save, .vsave, .setfp
- // directives. Currently, we are simply generating FINISH opcode.
- Entry |= NumExtraEntryWords << 24;
- Entry |= UNWIND_OPCODE_FINISH << 16;
- Entry |= UNWIND_OPCODE_FINISH << 8;
- Entry |= UNWIND_OPCODE_FINISH;
+ EmitBytes(StringRef(reinterpret_cast<const char *>(Opcodes.data()),
+ Opcodes.size()), 0);
+}
- EmitIntValue(Entry, 4, 0);
+void ARMELFStreamer::EmitHandlerData() {
+ FlushUnwindOpcodes(false);
}
void ARMELFStreamer::EmitPersonality(const MCSymbol *Per) {
Personality = Per;
+ UnwindOpAsm.setPersonality(Per);
}
-void ARMELFStreamer::EmitSetFP(unsigned NewFpReg,
- unsigned NewSpReg,
+void ARMELFStreamer::EmitSetFP(unsigned NewFPReg,
+ unsigned NewSPReg,
int64_t Offset) {
- // TODO: Not implemented
+ assert((NewSPReg == ARM::SP || NewSPReg == FPReg) &&
+ "the operand of .setfp directive should be either $sp or $fp");
+
+ UsedFP = true;
+ FPReg = NewFPReg;
+
+ if (NewSPReg == ARM::SP)
+ FPOffset = SPOffset + Offset;
+ else
+ FPOffset += Offset;
}
void ARMELFStreamer::EmitPad(int64_t Offset) {
- // TODO: Not implemented
+ // Track the change of the $sp offset
+ SPOffset -= Offset;
+
+ // To squash multiple .pad directives, we should delay the unwind opcode
+ // until the .save, .vsave, .handlerdata, or .fnend directives.
+ PendingOffset -= Offset;
}
void ARMELFStreamer::EmitRegSave(const SmallVectorImpl<unsigned> &RegList,
bool IsVector) {
- // TODO: Not implemented
+ // Collect the registers in the register list
+ unsigned Count = 0;
+ uint32_t Mask = 0;
+ const MCRegisterInfo &MRI = getContext().getRegisterInfo();
+ for (size_t i = 0; i < RegList.size(); ++i) {
+ unsigned Reg = MRI.getEncodingValue(RegList[i]);
+ assert(Reg < (IsVector ? 32U : 16U) && "Register out of range");
+ unsigned Bit = (1u << Reg);
+ if ((Mask & Bit) == 0) {
+ Mask |= Bit;
+ ++Count;
+ }
+ }
+
+ // Track the change the $sp offset: For the .save directive, the
+ // corresponding push instruction will decrease the $sp by (4 * Count).
+ // For the .vsave directive, the corresponding vpush instruction will
+ // decrease $sp by (8 * Count).
+ SPOffset -= Count * (IsVector ? 8 : 4);
+
+ // Emit the opcode
+ FlushPendingOffset();
+ if (IsVector)
+ UnwindOpAsm.EmitVFPRegSave(Mask);
+ else
+ UnwindOpAsm.EmitRegSave(Mask);
}
namespace llvm {
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