1 files changed, 151 insertions, 0 deletions
diff --git a/contrib/llvm-project/llvm/lib/CodeGen/AsmPrinter/DwarfCFIException.cpp b/contrib/llvm-project/llvm/lib/CodeGen/AsmPrinter/DwarfCFIException.cpp
new file mode 100644
index 000000000000..10c844ddb14a
--- /dev/null
+++ b/contrib/llvm-project/llvm/lib/CodeGen/AsmPrinter/DwarfCFIException.cpp
@@ -0,0 +1,151 @@
+//===-- CodeGen/AsmPrinter/DwarfException.cpp - Dwarf Exception Impl ------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains support for writing DWARF exception info into asm files.
+//
+//===----------------------------------------------------------------------===//
+
+#include "DwarfException.h"
+#include "llvm/BinaryFormat/Dwarf.h"
+#include "llvm/CodeGen/AsmPrinter.h"
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/MachineModuleInfo.h"
+#include "llvm/MC/MCAsmInfo.h"
+#include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCStreamer.h"
+#include "llvm/Target/TargetLoweringObjectFile.h"
+#include "llvm/Target/TargetMachine.h"
+#include "llvm/Target/TargetOptions.h"
+using namespace llvm;
+
+DwarfCFIException::DwarfCFIException(AsmPrinter *A) : EHStreamer(A) {}
+
+DwarfCFIException::~DwarfCFIException() = default;
+
+void DwarfCFIException::addPersonality(const GlobalValue *Personality) {
+  if (!llvm::is_contained(Personalities, Personality))
+    Personalities.push_back(Personality);
+}
+
+/// endModule - Emit all exception information that should come after the
+/// content.
+void DwarfCFIException::endModule() {
+  // SjLj uses this pass and it doesn't need this info.
+  if (!Asm->MAI->usesCFIForEH())
+    return;
+
+  const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
+
+  unsigned PerEncoding = TLOF.getPersonalityEncoding();
+
+  if ((PerEncoding & 0x80) != dwarf::DW_EH_PE_indirect)
+    return;
+
+  // Emit indirect reference table for all used personality functions
+  for (const GlobalValue *Personality : Personalities) {
+    MCSymbol *Sym = Asm->getSymbol(Personality);
+    TLOF.emitPersonalityValue(*Asm->OutStreamer, Asm->getDataLayout(), Sym);
+  }
+  Personalities.clear();
+}
+
+void DwarfCFIException::beginFunction(const MachineFunction *MF) {
+  shouldEmitPersonality = shouldEmitLSDA = false;
+  const Function &F = MF->getFunction();
+
+  // If any landing pads survive, we need an EH table.
+  bool hasLandingPads = !MF->getLandingPads().empty();
+
+  // See if we need frame move info.
+  bool shouldEmitMoves =
+      Asm->getFunctionCFISectionType(*MF) != AsmPrinter::CFISection::None;
+
+  const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
+  unsigned PerEncoding = TLOF.getPersonalityEncoding();
+  const GlobalValue *Per = nullptr;
+  if (F.hasPersonalityFn())
+    Per = dyn_cast<GlobalValue>(F.getPersonalityFn()->stripPointerCasts());
+
+  // Emit a personality function even when there are no landing pads
+  forceEmitPersonality =
+      // ...if a personality function is explicitly specified
+      F.hasPersonalityFn() &&
+      // ... and it's not known to be a noop in the absence of invokes
+      !isNoOpWithoutInvoke(classifyEHPersonality(Per)) &&
+      // ... and we're not explicitly asked not to emit it
+      F.needsUnwindTableEntry();
+
+  shouldEmitPersonality =
+      (forceEmitPersonality ||
+       (hasLandingPads && PerEncoding != dwarf::DW_EH_PE_omit)) &&
+      Per;
+
+  unsigned LSDAEncoding = TLOF.getLSDAEncoding();
+  shouldEmitLSDA = shouldEmitPersonality &&
+    LSDAEncoding != dwarf::DW_EH_PE_omit;
+
+  const MCAsmInfo &MAI = *MF->getMMI().getContext().getAsmInfo();
+  if (MAI.getExceptionHandlingType() != ExceptionHandling::None)
+    shouldEmitCFI =
+        MAI.usesCFIForEH() && (shouldEmitPersonality || shouldEmitMoves);
+  else
+    shouldEmitCFI = Asm->usesCFIWithoutEH() && shouldEmitMoves;
+}
+
+void DwarfCFIException::beginBasicBlockSection(const MachineBasicBlock &MBB) {
+  if (!shouldEmitCFI)
+    return;
+
+  if (!hasEmittedCFISections) {
+    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;
+  }
+
+  Asm->OutStreamer->emitCFIStartProc(/*IsSimple=*/false);
+
+  // Indicate personality routine, if any.
+  if (!shouldEmitPersonality)
+    return;
+
+  auto &F = MBB.getParent()->getFunction();
+  auto *P = dyn_cast<GlobalValue>(F.getPersonalityFn()->stripPointerCasts());
+  assert(P && "Expected personality function");
+  // Record the personality function.
+  addPersonality(P);
+
+  const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
+  unsigned PerEncoding = TLOF.getPersonalityEncoding();
+  const MCSymbol *Sym = TLOF.getCFIPersonalitySymbol(P, Asm->TM, MMI);
+  Asm->OutStreamer->emitCFIPersonality(Sym, PerEncoding);
+
+  // Provide LSDA information.
+  if (shouldEmitLSDA)
+    Asm->OutStreamer->emitCFILsda(Asm->getMBBExceptionSym(MBB),
+                                  TLOF.getLSDAEncoding());
+}
+
+void DwarfCFIException::endBasicBlockSection(const MachineBasicBlock &MBB) {
+  if (shouldEmitCFI)
+    Asm->OutStreamer->emitCFIEndProc();
+}
+
+/// endFunction - Gather and emit post-function exception information.
+///
+void DwarfCFIException::endFunction(const MachineFunction *MF) {
+  if (!shouldEmitPersonality)
+    return;
+
+  emitExceptionTable();
+}