[llvm] 63cfab4 - [NFC] Refactor how CFI section types are represented in AsmPrinter
via llvm-commits
llvm-commits at lists.llvm.org
Tue Apr 27 20:34:30 PDT 2021
Author: RamNalamothu
Date: 2021-04-28T09:04:04+05:30
New Revision: 63cfab4f40390bf10a313039adf0b955db9706b9
URL: https://github.com/llvm/llvm-project/commit/63cfab4f40390bf10a313039adf0b955db9706b9
DIFF: https://github.com/llvm/llvm-project/commit/63cfab4f40390bf10a313039adf0b955db9706b9.diff
LOG: [NFC] Refactor how CFI section types are represented in AsmPrinter
In terms of readability, the `enum CFIMoveType` didn't better document what it
intends to convey i.e. the type of CFI section that gets emitted.
Reviewed By: dblaikie, MaskRay
Differential Revision: https://reviews.llvm.org/D76519
Added:
Modified:
llvm/include/llvm/CodeGen/AsmPrinter.h
llvm/lib/CodeGen/AsmPrinter/ARMException.cpp
llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
llvm/lib/CodeGen/AsmPrinter/DwarfCFIException.cpp
llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
Removed:
################################################################################
diff --git a/llvm/include/llvm/CodeGen/AsmPrinter.h b/llvm/include/llvm/CodeGen/AsmPrinter.h
index 52b5ecd1a3bbf..2c65a344e3848 100644
--- a/llvm/include/llvm/CodeGen/AsmPrinter.h
+++ b/llvm/include/llvm/CodeGen/AsmPrinter.h
@@ -157,6 +157,13 @@ class AsmPrinter : public MachineFunctionPass {
TimerGroupDescription(TimerGroupDescription) {}
};
+ // Flags representing which CFI section is required for a function/module.
+ enum class CFISection : unsigned {
+ None = 0, ///< Do not emit either .eh_frame or .debug_frame
+ EH = 1, ///< Emit .eh_frame
+ Debug = 2 ///< Emit .debug_frame
+ };
+
private:
MCSymbol *CurrentFnEnd = nullptr;
@@ -199,8 +206,8 @@ class AsmPrinter : public MachineFunctionPass {
/// context.
PseudoProbeHandler *PP = nullptr;
- /// If the current module uses dwarf CFI annotations strictly for debugging.
- bool isCFIMoveForDebugging = false;
+ /// CFISection type the module needs i.e. either .eh_frame or .debug_frame.
+ CFISection ModuleCFISection = CFISection::None;
protected:
explicit AsmPrinter(TargetMachine &TM, std::unique_ptr<MCStreamer> Streamer);
@@ -357,12 +364,14 @@ class AsmPrinter : public MachineFunctionPass {
void emitRemarksSection(remarks::RemarkStreamer &RS);
- enum CFIMoveType { CFI_M_None, CFI_M_EH, CFI_M_Debug };
- CFIMoveType needsCFIMoves() const;
+ /// Get the CFISection type for a function.
+ CFISection getFunctionCFISectionType(const Function &F) const;
+
+ /// Get the CFISection type for a function.
+ CFISection getFunctionCFISectionType(const MachineFunction &MF) const;
- /// Returns false if needsCFIMoves() == CFI_M_EH for any function
- /// in the module.
- bool needsOnlyDebugCFIMoves() const { return isCFIMoveForDebugging; }
+ /// Get the CFISection type for the module.
+ CFISection getModuleCFISectionType() const { return ModuleCFISection; }
bool needsSEHMoves();
diff --git a/llvm/lib/CodeGen/AsmPrinter/ARMException.cpp b/llvm/lib/CodeGen/AsmPrinter/ARMException.cpp
index b634b24377fe4..db4215e92d44f 100644
--- a/llvm/lib/CodeGen/AsmPrinter/ARMException.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/ARMException.cpp
@@ -39,13 +39,13 @@ void ARMException::beginFunction(const MachineFunction *MF) {
if (Asm->MAI->getExceptionHandlingType() == ExceptionHandling::ARM)
getTargetStreamer().emitFnStart();
// See if we need call frame info.
- AsmPrinter::CFIMoveType MoveType = Asm->needsCFIMoves();
- assert(MoveType != AsmPrinter::CFI_M_EH &&
+ AsmPrinter::CFISection CFISecType = Asm->getFunctionCFISectionType(*MF);
+ assert(CFISecType != AsmPrinter::CFISection::EH &&
"non-EH CFI not yet supported in prologue with EHABI lowering");
- if (MoveType == AsmPrinter::CFI_M_Debug) {
+ if (CFISecType == AsmPrinter::CFISection::Debug) {
if (!hasEmittedCFISections) {
- if (Asm->needsOnlyDebugCFIMoves())
+ if (Asm->getModuleCFISectionType() == AsmPrinter::CFISection::Debug)
Asm->OutStreamer->emitCFISections(false, true);
hasEmittedCFISections = true;
}
diff --git a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index 0f7616f51c006..0c5126da5b84a 100644
--- a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -354,21 +354,18 @@ bool AsmPrinter::doInitialization(Module &M) {
case ExceptionHandling::SjLj:
case ExceptionHandling::DwarfCFI:
case ExceptionHandling::ARM:
- isCFIMoveForDebugging = true;
- if (MAI->getExceptionHandlingType() != ExceptionHandling::DwarfCFI)
- break;
for (auto &F : M.getFunctionList()) {
- // If the module contains any function with unwind data,
- // .eh_frame has to be emitted.
- // Ignore functions that won't get emitted.
- if (!F.isDeclarationForLinker() && F.needsUnwindTableEntry()) {
- isCFIMoveForDebugging = false;
+ if (getFunctionCFISectionType(F) != CFISection::None)
+ ModuleCFISection = getFunctionCFISectionType(F);
+ // If any function needsUnwindTableEntry(), it needs .eh_frame and hence
+ // the module needs .eh_frame. If we have found that case, we are done.
+ if (ModuleCFISection == CFISection::EH)
break;
- }
}
+ assert(MAI->getExceptionHandlingType() == ExceptionHandling::DwarfCFI ||
+ ModuleCFISection != CFISection::EH);
break;
default:
- isCFIMoveForDebugging = false;
break;
}
@@ -1040,15 +1037,25 @@ static bool emitDebugLabelComment(const MachineInstr *MI, AsmPrinter &AP) {
return true;
}
-AsmPrinter::CFIMoveType AsmPrinter::needsCFIMoves() const {
+AsmPrinter::CFISection
+AsmPrinter::getFunctionCFISectionType(const Function &F) const {
+ // Ignore functions that won't get emitted.
+ if (F.isDeclarationForLinker())
+ return CFISection::None;
+
if (MAI->getExceptionHandlingType() == ExceptionHandling::DwarfCFI &&
- MF->getFunction().needsUnwindTableEntry())
- return CFI_M_EH;
+ F.needsUnwindTableEntry())
+ return CFISection::EH;
- if (MMI->hasDebugInfo() || MF->getTarget().Options.ForceDwarfFrameSection)
- return CFI_M_Debug;
+ if (MMI->hasDebugInfo() || TM.Options.ForceDwarfFrameSection)
+ return CFISection::Debug;
+
+ return CFISection::None;
+}
- return CFI_M_None;
+AsmPrinter::CFISection
+AsmPrinter::getFunctionCFISectionType(const MachineFunction &MF) const {
+ return getFunctionCFISectionType(MF.getFunction());
}
bool AsmPrinter::needsSEHMoves() {
@@ -1061,7 +1068,7 @@ void AsmPrinter::emitCFIInstruction(const MachineInstr &MI) {
ExceptionHandlingType != ExceptionHandling::ARM)
return;
- if (needsCFIMoves() == CFI_M_None)
+ if (getFunctionCFISectionType(*MF) == CFISection::None)
return;
// If there is no "real" instruction following this CFI instruction, skip
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfCFIException.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfCFIException.cpp
index 4b08e7d284686..ae1c80141ff91 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfCFIException.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfCFIException.cpp
@@ -93,9 +93,8 @@ void DwarfCFIException::beginFunction(const MachineFunction *MF) {
bool hasLandingPads = !MF->getLandingPads().empty();
// See if we need frame move info.
- AsmPrinter::CFIMoveType MoveType = Asm->needsCFIMoves();
-
- bool shouldEmitMoves = MoveType != AsmPrinter::CFI_M_None;
+ bool shouldEmitMoves =
+ Asm->getFunctionCFISectionType(*MF) != AsmPrinter::CFISection::None;
const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
unsigned PerEncoding = TLOF.getPersonalityEncoding();
@@ -132,10 +131,14 @@ void DwarfCFIException::beginFragment(const MachineBasicBlock *MBB,
return;
if (!hasEmittedCFISections) {
- if (Asm->needsOnlyDebugCFIMoves())
- Asm->OutStreamer->emitCFISections(false, true);
- else if (Asm->TM.Options.ForceDwarfFrameSection)
- Asm->OutStreamer->emitCFISections(true, true);
+ AsmPrinter::CFISection CFISecType = Asm->getModuleCFISectionType();
+ // If we don't say anything it implies `.cfi_sections .eh_frame`, so we
+ // chose not to be verbose in that case. And with `ForceDwarfFrameSection`,
+ // we should always emit .debug_frame.
+ if (CFISecType == AsmPrinter::CFISection::Debug ||
+ Asm->TM.Options.ForceDwarfFrameSection)
+ Asm->OutStreamer->emitCFISections(
+ CFISecType == AsmPrinter::CFISection::EH, true);
hasEmittedCFISections = true;
}
diff --git a/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp b/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
index 3373e6c91b7fd..b7b5bf33b9e67 100644
--- a/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
+++ b/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
@@ -1229,7 +1229,7 @@ void AArch64AsmPrinter::emitInstruction(const MachineInstr *MI) {
ExceptionHandlingType != ExceptionHandling::ARM)
return;
- if (needsCFIMoves() == CFI_M_None)
+ if (getFunctionCFISectionType(*MF) == CFISection::None)
return;
OutStreamer->emitCFIBKeyFrame();
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