The second part of support for generating dwarf for assembly source f…

…iles. This

generates the dwarf Compile Unit DIE and a dwarf subprogram DIE for each
non-temporary label.

The next part will be to get the clang driver to enable this when assembling
a .s file.  rdar://9275556


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146262 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/MC/MCContext.h

@@ -108,6 +108,16 @@ namespace llvm {
     /// The default initial text section that we generate dwarf debugging line
     /// info for when generating dwarf assembly source files.
     const MCSection *GenDwarfSection;
+    /// Symbols created for the start and end of this section.
+    MCSymbol *GenDwarfSectionStartSym, *GenDwarfSectionEndSym;
+
+    /// The information gathered from labels that will have dwarf subprogram
+    /// entries when generating dwarf assembly source files.
+    std::vector<const MCGenDwarfSubprogramEntry *> MCGenDwarfSubprogramEntries;
+
+    /// The string to embed in the debug information for the compile unit, if
+    /// non-empty.
+    StringRef DwarfDebugFlags;
 
     /// Honor temporary labels, this is useful for debugging semantic
     /// differences between temporary and non-temporary labels (primarily on
@@ -269,6 +279,24 @@ namespace llvm {
     unsigned nextGenDwarfFileNumber() { return ++GenDwarfFileNumber; }
     const MCSection *getGenDwarfSection() { return GenDwarfSection; }
     void setGenDwarfSection(const MCSection *Sec) { GenDwarfSection = Sec; }
+    MCSymbol *getGenDwarfSectionStartSym() { return GenDwarfSectionStartSym; }
+    void setGenDwarfSectionStartSym(MCSymbol *Sym) {
+      GenDwarfSectionStartSym = Sym;
+    }
+    MCSymbol *getGenDwarfSectionEndSym() { return GenDwarfSectionEndSym; }
+    void setGenDwarfSectionEndSym(MCSymbol *Sym) {
+      GenDwarfSectionEndSym = Sym;
+    }
+    const std::vector<const MCGenDwarfSubprogramEntry *>
+      &getMCGenDwarfSubprogramEntries() const {
+      return MCGenDwarfSubprogramEntries;
+    }
+    void addMCGenDwarfSubprogramEntry(const MCGenDwarfSubprogramEntry *E) {
+      MCGenDwarfSubprogramEntries.push_back(E);
+    }
+
+    void setDwarfDebugFlags(StringRef S) { DwarfDebugFlags = S; }
+    StringRef getDwarfDebugFlags() { return DwarfDebugFlags; }
 
     /// @}
 

include/llvm/MC/MCDwarf.h

@@ -31,6 +31,8 @@ namespace llvm {
   class MCSymbol;
   class MCObjectStreamer;
   class raw_ostream;
+  class SourceMgr;
+  class SMLoc;
 
   /// MCDwarfFile - Instances of this class represent the name of the dwarf
   /// .file directive and its associated dwarf file number in the MC file,
@@ -227,6 +229,46 @@ namespace llvm {
                       int64_t LineDelta, uint64_t AddrDelta);
   };
 
+  class MCGenDwarfInfo {
+  public:
+    //
+    // When generating dwarf for assembly source files this emits the Dwarf
+    // sections.
+    //
+    static void Emit(MCStreamer *MCOS);
+  };
+
+  // When generating dwarf for assembly source files this is the info that is
+  // needed to be gathered for each symbol that will have a dwarf2_subprogram.
+  class MCGenDwarfSubprogramEntry {
+  private:
+    // Name of the symbol without a leading underbar, if any.
+    StringRef Name;
+    // The dwarf file number this symbol is in.
+    unsigned FileNumber;
+    // The line number this symbol is at.
+    unsigned LineNumber;
+    // The low_pc for the dwarf2_subprogram is taken from this symbol.  The
+    // high_pc is taken from the next symbol's value or the end of the section
+    // for the last symbol
+    MCSymbol *Label;
+
+  public:
+    MCGenDwarfSubprogramEntry(StringRef name, unsigned fileNumber,
+                              unsigned lineNumber, MCSymbol *label) :
+      Name(name), FileNumber(fileNumber), LineNumber(lineNumber), Label(label){}
+
+    StringRef getName() const { return Name; }
+    unsigned getFileNumber() const { return FileNumber; }
+    unsigned getLineNumber() const { return LineNumber; }
+    MCSymbol *getLabel() const { return Label; }
+
+    // This is called when label is created when we are generating dwarf for
+    // assembly source files.
+    static void Make(MCSymbol *Symbol, MCStreamer *MCOS, SourceMgr &SrcMgr,
+                     SMLoc &Loc);
+  };
+
   class MCCFIInstruction {
   public:
     enum OpType { SameValue, Remember, Restore, Move, RelMove };

include/llvm/Support/Dwarf.h

@@ -526,6 +526,7 @@ enum dwarf_constants {
   DW_LANG_D = 0x0013,
   DW_LANG_Python = 0x0014,
   DW_LANG_lo_user = 0x8000,
+  DW_LANG_Mips_Assembler = 0x8001,
   DW_LANG_hi_user = 0xffff,
 
   // Identifier case codes

lib/MC/MCAsmStreamer.cpp

@@ -1284,6 +1284,10 @@ void MCAsmStreamer::Finish() {
   if (getContext().hasDwarfFiles() && !UseLoc)
     MCDwarfFileTable::Emit(this);
 
+  // If we are generating dwarf for assembly source files dump out the sections.
+  if (getContext().getGenDwarfForAssembly())
+    MCGenDwarfInfo::Emit(this);
+
   if (!UseCFI)
     EmitFrames(false);
 }