Move .ident handling to MCStreamer.

No functionality change, but exposes the API so that codegen can use it too.

Patch by Katya Romanova.

llvm-svn: 192757

llvm/include/llvm/MC/MCAsmInfo.h

@@ -271,6 +271,10 @@ namespace llvm {
     /// .file directive, this is true for ELF targets.
     bool HasSingleParameterDotFile;          // Defaults to true.
 
+    /// hasIdentDirective - True if the target has a .ident directive, this is
+    /// true for ELF targets.
+    bool HasIdentDirective;                  // Defaults to false.
+
     /// HasNoDeadStrip - True if this target supports the MachO .no_dead_strip
     /// directive.
     bool HasNoDeadStrip;                     // Defaults to false.
@@ -523,6 +527,7 @@ namespace llvm {
     }
     bool hasDotTypeDotSizeDirective() const {return HasDotTypeDotSizeDirective;}
     bool hasSingleParameterDotFile() const { return HasSingleParameterDotFile; }
+    bool hasIdentDirective() const { return HasIdentDirective; }
     bool hasNoDeadStrip() const { return HasNoDeadStrip; }
     bool hasSymbolResolver() const { return HasSymbolResolver; }
     const char *getWeakRefDirective() const { return WeakRefDirective; }

llvm/include/llvm/MC/MCELFStreamer.h

@@ -31,13 +31,14 @@ class MCELFStreamer : public MCObjectStreamer {
 public:
   MCELFStreamer(MCContext &Context, MCTargetStreamer *TargetStreamer,
                 MCAsmBackend &TAB, raw_ostream &OS, MCCodeEmitter *Emitter)
-      : MCObjectStreamer(Context, TargetStreamer, TAB, OS, Emitter) {}
+      : MCObjectStreamer(Context, TargetStreamer, TAB, OS, Emitter), 
+                         SeenIdent(false) {}
 
   MCELFStreamer(MCContext &Context, MCTargetStreamer *TargetStreamer,
                 MCAsmBackend &TAB, raw_ostream &OS, MCCodeEmitter *Emitter,
                 MCAssembler *Assembler)
-      : MCObjectStreamer(Context, TargetStreamer, TAB, OS, Emitter, Assembler) {
-  }
+      : MCObjectStreamer(Context, TargetStreamer, TAB, OS, Emitter, Assembler), 
+                         SeenIdent(false) {}
 
   virtual ~MCELFStreamer();
 
@@ -77,6 +78,8 @@ public:
 
   virtual void EmitFileDirective(StringRef Filename);
 
+  virtual void EmitIdent(StringRef IdentString);
+
   virtual void EmitValueToAlignment(unsigned, int64_t, unsigned, unsigned);
 
   virtual void Flush();
@@ -93,6 +96,8 @@ private:
 
   void fixSymbolsInTLSFixups(const MCExpr *expr);
 
+  bool SeenIdent;
+
   struct LocalCommon {
     MCSymbolData *SD;
     uint64_t Size;

llvm/include/llvm/MC/MCStreamer.h

@@ -571,6 +571,10 @@ public:
   /// implement the '.file "foo.c"' assembler directive.
   virtual void EmitFileDirective(StringRef Filename) = 0;
 
+  /// Emit the "identifiers" directive.  This implements the
+  /// '.ident "version foo"' assembler directive.
+  virtual void EmitIdent(StringRef IdentString) {}
+
   /// EmitDwarfFileDirective - Associate a filename with a specified logical
   /// file number.  This implements the DWARF2 '.file 4 "foo.c"' assembler
   /// directive.

llvm/lib/MC/MCAsmInfo.cpp

@@ -76,6 +76,7 @@ MCAsmInfo::MCAsmInfo() {
   LCOMMDirectiveAlignmentType = LCOMM::NoAlignment;
   HasDotTypeDotSizeDirective = true;
   HasSingleParameterDotFile = true;
+  HasIdentDirective = false;
   HasNoDeadStrip = false;
   HasSymbolResolver = false;
   WeakRefDirective = 0;

llvm/lib/MC/MCAsmStreamer.cpp

@@ -213,6 +213,7 @@ public:
                                      unsigned Isa, unsigned Discriminator,
                                      StringRef FileName);
 
+  virtual void EmitIdent(StringRef IdentString);
   virtual void EmitCFISections(bool EH, bool Debug);
   virtual void EmitCFIDefCfa(int64_t Register, int64_t Offset);
   virtual void EmitCFIDefCfaOffset(int64_t Offset);
@@ -880,6 +881,13 @@ void MCAsmStreamer::EmitDwarfLocDirective(unsigned FileNo, unsigned Line,
   EmitEOL();
 }
 
+void MCAsmStreamer::EmitIdent(StringRef IdentString) {
+  assert(MAI->hasIdentDirective() && ".ident directive not supported");
+  OS << "\t.ident\t";
+  PrintQuotedString(IdentString, OS);
+  EmitEOL();
+}
+
 void MCAsmStreamer::EmitCFISections(bool EH, bool Debug) {
   MCStreamer::EmitCFISections(EH, Debug);
 

llvm/lib/MC/MCELFStreamer.cpp

@@ -329,7 +329,22 @@ void MCELFStreamer::EmitFileDirective(StringRef Filename) {
   SD.setFlags(ELF_STT_File | ELF_STB_Local | ELF_STV_Default);
 }
 
-void  MCELFStreamer::fixSymbolsInTLSFixups(const MCExpr *expr) {
+void MCELFStreamer::EmitIdent(StringRef IdentString) {
+  const MCSection *Comment = getAssembler().getContext().getELFSection(
+      ".comment", ELF::SHT_PROGBITS, ELF::SHF_MERGE | ELF::SHF_STRINGS,
+      SectionKind::getReadOnly(), 1, "");
+  PushSection();
+  SwitchSection(Comment);
+  if (!SeenIdent) {
+    EmitIntValue(0, 1);
+    SeenIdent = true;
+  }
+  EmitBytes(IdentString);
+  EmitIntValue(0, 1);
+  PopSection();
+}
+
+void MCELFStreamer::fixSymbolsInTLSFixups(const MCExpr *expr) {
   switch (expr->getKind()) {
   case MCExpr::Target:
     cast<MCTargetExpr>(expr)->fixELFSymbolsInTLSFixups(getAssembler());

llvm/lib/MC/MCMachOStreamer.cpp

@@ -82,7 +82,11 @@ public:
     // FIXME: Just ignore the .file; it isn't important enough to fail the
     // entire assembly.
 
-    //report_fatal_error("unsupported directive: '.file'");
+    // report_fatal_error("unsupported directive: '.file'");
+  }
+
+  virtual void EmitIdent(StringRef IdentString) {
+    llvm_unreachable("macho doesn't support this directive");
   }
 
   virtual void FinishImpl();

llvm/lib/MC/MCParser/ELFAsmParser.cpp

@@ -31,14 +31,11 @@ class ELFAsmParser : public MCAsmParserExtension {
     getParser().addDirectiveHandler(Directive, Handler);
   }
 
-  bool ParseSectionSwitch(StringRef Section, unsigned Type,
-                          unsigned Flags, SectionKind Kind);
-  bool SeenIdent;
+  bool ParseSectionSwitch(StringRef Section, unsigned Type, unsigned Flags,
+                          SectionKind Kind);
 
 public:
-  ELFAsmParser() : SeenIdent(false) {
-    BracketExpressionsSupported = true;
-  }
+  ELFAsmParser() { BracketExpressionsSupported = true; }
 
   virtual void Initialize(MCAsmParser &Parser) {
     // Call the base implementation.
@@ -579,22 +576,7 @@ bool ELFAsmParser::ParseDirectiveIdent(StringRef, SMLoc) {
 
   Lex();
 
-  const MCSection *Comment =
-    getContext().getELFSection(".comment", ELF::SHT_PROGBITS,
-                               ELF::SHF_MERGE |
-                               ELF::SHF_STRINGS,
-                               SectionKind::getReadOnly(),
-                               1, "");
-
-  getStreamer().PushSection();
-  getStreamer().SwitchSection(Comment);
-  if (!SeenIdent) {
-    getStreamer().EmitIntValue(0, 1);
-    SeenIdent = true;
-  }
-  getStreamer().EmitBytes(Data);
-  getStreamer().EmitIntValue(0, 1);
-  getStreamer().PopSection();
+  getStreamer().EmitIdent(Data);
   return false;
 }
 

llvm/lib/MC/MCPureStreamer.cpp

@@ -94,6 +94,9 @@ public:
   virtual void EmitFileDirective(StringRef Filename) {
     report_fatal_error("unsupported directive in pure streamer");
   }
+  virtual void EmitIdent(StringRef IdentString) {
+    report_fatal_error("unsupported directive in pure streamer");
+  }
   virtual bool EmitDwarfFileDirective(unsigned FileNo, StringRef Directory,
                                       StringRef Filename, unsigned CUID = 0) {
     report_fatal_error("unsupported directive in pure streamer");

llvm/lib/MC/WinCOFFStreamer.cpp

@@ -72,6 +72,7 @@ public:
   virtual void EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
                               uint64_t Size, unsigned ByteAlignment);
   virtual void EmitFileDirective(StringRef Filename);
+  virtual void EmitIdent(StringRef IdentString);
   virtual void EmitWin64EHHandlerData();
   virtual void FinishImpl();
 
@@ -306,6 +307,11 @@ void WinCOFFStreamer::EmitFileDirective(StringRef Filename) {
   // info will be a much large effort.
 }
 
+// TODO: Implement this if you want to emit .comment section in COFF obj files.
+void WinCOFFStreamer::EmitIdent(StringRef IdentString) {
+  llvm_unreachable("unsupported directive");
+}
+
 void WinCOFFStreamer::EmitWin64EHHandlerData() {
   MCStreamer::EmitWin64EHHandlerData();
 

llvm/lib/Target/X86/MCTargetDesc/X86MCAsmInfo.cpp

@@ -91,6 +91,7 @@ X86ELFMCAsmInfo::X86ELFMCAsmInfo(const Triple &T) {
 
   PrivateGlobalPrefix = ".L";
   WeakRefDirective = "\t.weak\t";
+  HasIdentDirective = true;
 
   // Set up DWARF directives
   HasLEB128 = true;  // Target asm supports leb128 directives (little-endian)