Applied some recommend changes from sabre. The dominate one beginning "let the

pass manager do it's thing."  Fixes crash when compiling -g files and suppresses
dwarf statements if no debug info is present.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@25100 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/DwarfWriter.cpp

@@ -11,32 +11,35 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "llvm/CodeGen/DwarfWriter.h"
 
 #include "llvm/CodeGen/AsmPrinter.h"
-#include "llvm/CodeGen/DwarfWriter.h"
+#include "llvm/CodeGen/MachineDebugInfo.h"
 #include "llvm/Support/CommandLine.h"
 
+#include <iostream>
 
-namespace llvm {
+using namespace llvm;
 
 static cl::opt<bool>
 DwarfVerbose("dwarf-verbose", cl::Hidden,
                                 cl::desc("Add comments to dwarf directives."));
 
 /// EmitULEB128Bytes - Emit an assembler byte data directive to compose an
-/// unsigned leb128 value.
+/// unsigned leb128 value.  Comment is added to the end of the directive if
+/// DwarfVerbose is true (should not contain any newlines.)
 ///
-void DwarfWriter::EmitULEB128Bytes(unsigned Value, std::string Comment) {
+void DwarfWriter::EmitULEB128Bytes(unsigned Value, const char *Comment) const {
   if (hasLEB128) {
     O << "\t.uleb128\t"
       << Value;
   } else {
-    O << Asm->getData8bitsDirective();
+    O << Asm->Data8bitsDirective;
     EmitULEB128(Value);
   }
   if (DwarfVerbose) {
     O << "\t"
-      << Asm->getCommentString()
+      << Asm->CommentString
       << " "
       << Comment
       << " "
@@ -46,19 +49,20 @@ void DwarfWriter::EmitULEB128Bytes(unsigned Value, std::string Comment) {
 }
 
 /// EmitSLEB128Bytes - Emit an assembler byte data directive to compose a
-/// signed leb128 value.
+/// signed leb128 value.  Comment is added to the end of the directive if
+/// DwarfVerbose is true (should not contain any newlines.)
 ///
-void DwarfWriter::EmitSLEB128Bytes(int Value, std::string Comment) {
+void DwarfWriter::EmitSLEB128Bytes(int Value, const char *Comment) const {
   if (hasLEB128) {
     O << "\t.sleb128\t"
       << Value;
   } else {
-    O << Asm->getData8bitsDirective();
+    O << Asm->Data8bitsDirective;
     EmitSLEB128(Value);
   }
   if (DwarfVerbose) {
     O << "\t"
-      << Asm->getCommentString()
+      << Asm->CommentString
       << " "
       << Comment
       << " "
@@ -67,13 +71,75 @@ void DwarfWriter::EmitSLEB128Bytes(int Value, std::string Comment) {
   O << "\n";
 }
 
-/// BeginModule - Emit all dwarf sections that should come prior to the content.
+/// EmitHex - Emit a hexidecimal string to the output stream.
 ///
-void DwarfWriter::BeginModule() {
-  if (!DebugInfo.hasInfo()) return;
-  EmitComment("Dwarf Begin Module");
+void DwarfWriter::EmitHex(unsigned Value) const {
+  O << "0x"
+    << std::hex
+    << Value
+    << std::dec;
+}
+
+/// EmitComment - Emit a simple string comment.
+///
+void DwarfWriter::EmitComment(const char *Comment) const {
+  O << "\t"
+    << Asm->CommentString
+    << " "
+    << Comment
+    << "\n";
+}
+
+/// EmitULEB128 - Emit a series of hexidecimal values (separated by commas)
+/// representing an unsigned leb128 value.
+///
+void DwarfWriter::EmitULEB128(unsigned Value) const {
+  do {
+    unsigned Byte = Value & 0x7f;
+    Value >>= 7;
+    if (Value) Byte |= 0x80;
+    EmitHex(Byte);
+    if (Value) O << ", ";
+  } while (Value);
+}
+
+/// EmitSLEB128 - Emit a series of hexidecimal values (separated by commas)
+/// representing a signed leb128 value.
+///
+void DwarfWriter::EmitSLEB128(int Value) const {
+  int Sign = Value >> (8 * sizeof(Value) - 1);
+  bool IsMore;
   
-  // define base addresses for dwarf sections
+  do {
+    unsigned Byte = Value & 0x7f;
+    Value >>= 7;
+    IsMore = Value != Sign || ((Byte ^ Sign) & 0x40) != 0;
+    if (IsMore) Byte |= 0x80;
+    EmitHex(Byte);
+    if (IsMore) O << ", ";
+  } while (IsMore);
+}
+
+/// EmitLabelName - Emit label name for internal use by dwarf.
+///
+void DwarfWriter::EmitLabelName(const char *Tag, int Num) const {
+  O << Asm->PrivateGlobalPrefix
+    << "debug_"
+    << Tag
+    << Num;
+}
+
+/// EmitLabel - Emit location label for internal use by dwarf.
+///
+void DwarfWriter::EmitLabel(const char *Tag, int Num) const {
+  EmitLabelName(Tag, Num);
+  O << ":\n";
+}
+
+/// EmitInitial -Emit initial dwarf declarations.
+///
+void DwarfWriter::EmitInitial() const {
+  // Dwarf section's base addresses.
   Asm->SwitchSection(DwarfAbbrevSection, 0);
   EmitLabel("abbrev", 0);
   Asm->SwitchSection(DwarfInfoSection, 0);
@@ -82,33 +148,51 @@ void DwarfWriter::BeginModule() {
   EmitLabel("line", 0);
 }
 
+/// ShouldEmitDwarf - Determine if dwarf declarations should be made.
+///
+bool DwarfWriter::ShouldEmitDwarf() {
+  // Check if debug info is present.
+  if (!DebugInfo || !DebugInfo->hasInfo()) return false;
+  
+  // Make sure initial declarations are made.
+  if (!didInitial) {
+    EmitInitial();
+    didInitial = true;
+  }
+  
+  // Okay to emit.
+  return true;
+}
+
+/// BeginModule - Emit all dwarf sections that should come prior to the content.
+///
+void DwarfWriter::BeginModule() {
+  if (!ShouldEmitDwarf()) return;
+  EmitComment("Dwarf Begin Module");
+}
+
 /// EndModule - Emit all dwarf sections that should come after the content.
 ///
 void DwarfWriter::EndModule() {
-  if (!DebugInfo.hasInfo()) return;
+  if (!ShouldEmitDwarf()) return;
   EmitComment("Dwarf End Module");
   // Print out dwarf file info
-  std::vector<std::string> Sources = DebugInfo.getSourceFiles();
+  std::vector<std::string> Sources = DebugInfo->getSourceFiles();
   for (unsigned i = 0, N = Sources.size(); i < N; i++) {
     O << "\t; .file\t" << (i + 1) << "," << "\"" << Sources[i]  << "\"" << "\n";
   }
 }
 
-
 /// BeginFunction - Emit pre-function debug information.
 ///
 void DwarfWriter::BeginFunction() {
-  if (!DebugInfo.hasInfo()) return;
+  if (!ShouldEmitDwarf()) return;
   EmitComment("Dwarf Begin Function");
 }
 
 /// EndFunction - Emit post-function debug information.
 ///
 void DwarfWriter::EndFunction() {
-  if (!DebugInfo.hasInfo()) return;
+  if (!ShouldEmitDwarf()) return;
   EmitComment("Dwarf End Function");
 }
-
-
-} // End llvm namespace
-