Add CFI directives-based frame information emission. Not hooked yet.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123474 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 138 insertions, 0 deletions

diff --git a/lib/CodeGen/AsmPrinter/DwarfCFIException.cpp b/lib/CodeGen/AsmPrinter/DwarfCFIException.cpp
new file mode 100644
index 0000000..93c9659
--- /dev/null
+++ b/lib/CodeGen/AsmPrinter/DwarfCFIException.cpp
@@ -0,0 +1,138 @@
+//===-- CodeGen/AsmPrinter/DwarfException.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.
+//
+//===----------------------------------------------------------------------===//
+
+#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;
+
+DwarfCFIException::DwarfCFIException(AsmPrinter *A)
+  : DwarfException(A),
+    shouldEmitTable(false), shouldEmitMoves(false), shouldEmitTableModule(false)
+    {}
+
+DwarfCFIException::~DwarfCFIException() {}
+
+/// EndModule - Emit all exception information that should come after the
+/// content.
+void DwarfCFIException::EndModule() {
+  if (Asm->MAI->getExceptionHandlingType() != ExceptionHandling::Dwarf)
+    return;
+
+  if (!shouldEmitTableModule)
+    return;
+
+  const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
+  unsigned PerEncoding = TLOF.getPersonalityEncoding();
+
+  // Begin eh frame section.
+  Asm->OutStreamer.SwitchSection(TLOF.getEHFrameSection());
+
+  // Emit references to all used personality functions
+  const std::vector<const Function*> &Personalities = MMI->getPersonalities();
+  for (size_t i = 0, e = Personalities.size(); i != e; ++i) {
+    Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("personality", i));
+    Asm->EmitReference(Personalities[i], PerEncoding);
+  }
+}
+
+/// BeginFunction - Gather pre-function exception information. Assumes it's
+/// being emitted immediately after the function entry point.
+void DwarfCFIException::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;
+
+  if (shouldEmitMoves) {
+    const TargetFrameLowering *TFL = Asm->TM.getFrameLowering();
+    Asm->OutStreamer.EmitCFIStartProc();
+
+    // Indicate locations of general callee saved registers in frame.
+    std::vector<MachineMove> Moves;
+    TFL->getInitialFrameState(Moves);
+    Asm->EmitCFIFrameMoves(Moves);
+    Asm->EmitCFIFrameMoves(MMI->getFrameMoves());
+  }
+
+  if (!shouldEmitTable)
+    return;
+
+  const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
+
+  // Provide LSDA information.
+  unsigned LSDAEncoding = TLOF.getLSDAEncoding();
+  if (LSDAEncoding != dwarf::DW_EH_PE_omit)
+    Asm->OutStreamer.EmitCFILsda(Asm->GetTempSymbol("exception",
+                                                    Asm->getFunctionNumber()),
+                                 LSDAEncoding);
+
+  // Indicate personality routine, if any.
+  unsigned PerEncoding = TLOF.getPersonalityEncoding();
+  if (PerEncoding != dwarf::DW_EH_PE_omit &&
+      MMI->getPersonalities()[MMI->getPersonalityIndex()])
+    Asm->OutStreamer.EmitCFIPersonality(Asm->GetTempSymbol("personality",
+                                                    MMI->getPersonalityIndex()),
+                                        PerEncoding);
+}
+
+/// EndFunction - Gather and emit post-function exception information.
+///
+void DwarfCFIException::EndFunction() {
+  if (!shouldEmitMoves && !shouldEmitTable) return;
+
+  if (shouldEmitMoves)
+    Asm->OutStreamer.EmitCFIEndProc();
+
+  Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("eh_func_end",
+                                                Asm->getFunctionNumber()));
+
+  // Map all labels and get rid of any dead landing pads.
+  MMI->TidyLandingPads();
+
+  if (shouldEmitTable)
+    EmitExceptionTable();
+}