llvm-mc/Mach-O: Don't put assembler temporary labels in the symbol table.

 - I moved section creation back into AsmParser. I think policy decisions like
   this should be pushed higher, not lower, when possible (in addition the
   assembler has flags which change this behavior, for example).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@80162 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/llvm/MC/MCContext.h b/include/llvm/MC/MCContext.h
index 28436f052d9b1527c8d51989e92bab357db30ce8..9e0662071cb7d3745f8ac859f260a9a6b9096fdb 100644 (file)
--- a/include/llvm/MC/MCContext.h
+++ b/include/llvm/MC/MCContext.h
@@ -57,6 +57,8 @@ namespace llvm {
     /// reference and return it.
     ///
     /// @param Name - The symbol name, which must be unique across all symbols.
+    /// @param IsTemporary - Whether this symbol is an assembler temporary,
+    /// which should not survive into the symbol table for the translation unit.
     MCSymbol *GetOrCreateSymbol(const StringRef &Name);
     
     /// CreateTemporarySymbol - Create a new temporary symbol with the specified

diff --git a/include/llvm/MC/MCSymbol.h b/include/llvm/MC/MCSymbol.h
index 37a2755328f02eafcd8cab9721f729e36c591d06..631fa12f3f325aa3b6f6847d1a52d9ade90680bc 100644 (file)
--- a/include/llvm/MC/MCSymbol.h
+++ b/include/llvm/MC/MCSymbol.h
@@ -63,6 +63,11 @@ namespace llvm {
     /// @name Symbol Type
     /// @{
 
+    /// isTemporary - Check if this is an assembler temporary symbol.
+    bool isTemporary() const {
+      return IsTemporary;
+    }
+
     /// isDefined - Check if this symbol is defined (i.e., it has an address).
     ///
     /// Defined symbols are either absolute or in some section.

diff --git a/lib/MC/MCAssembler.cpp b/lib/MC/MCAssembler.cpp
index 9efdfe359bbdbfd24ea32073e5bd21351210822c..9388df8df61de1b8eb3c9d3e9d2ef46248770f02 100644 (file)
--- a/lib/MC/MCAssembler.cpp
+++ b/lib/MC/MCAssembler.cpp
@@ -557,6 +557,10 @@ public:
            ie = Asm.symbol_end(); it != ie; ++it) {
       MCSymbol &Symbol = it->getSymbol();
 
+      // Ignore assembler temporaries.
+      if (it->getSymbol().isTemporary())
+        continue;
+
       if (!it->isExternal() && !Symbol.isUndefined())
         continue;
 
@@ -589,6 +593,10 @@ public:
            ie = Asm.symbol_end(); it != ie; ++it) {
       MCSymbol &Symbol = it->getSymbol();
 
+      // Ignore assembler temporaries.
+      if (it->getSymbol().isTemporary())
+        continue;
+
       if (it->isExternal() || Symbol.isUndefined())
         continue;
 

diff --git a/lib/MC/MCContext.cpp b/lib/MC/MCContext.cpp
index 5a3e7f661ec8e694090d9e02a43931255d5d354b..f36564a6afaebee11da17dcbecaac41066a9ad40 100644 (file)
--- a/lib/MC/MCContext.cpp
+++ b/lib/MC/MCContext.cpp
@@ -38,7 +38,6 @@ MCSymbol *MCContext::GetOrCreateSymbol(const StringRef &Name) {
   return Entry = new (*this) MCSymbol(Name, false);
 }
 
-
 MCSymbol *MCContext::CreateTemporarySymbol(const StringRef &Name) {
   // If unnamed, just create a symbol.
   if (Name.empty())

diff --git a/test/MC/MachO/symbols-1.s b/test/MC/MachO/symbols-1.s
index 2cf1311eb32f4f750d995d0b7595f9ab106cc480..4c72fb3e7c2d5bb0d9b1eb16f39d7af7d799b072 100644 (file)
--- a/test/MC/MachO/symbols-1.s
+++ b/test/MC/MachO/symbols-1.s
@@ -13,8 +13,9 @@ sym_local_C:
 sym_globl_def_A: 
 sym_globl_def_B: 
 sym_globl_def_C: 
+Lsym_asm_temp:
         .long 0
-
+        
 // CHECK: ('cputype', 7)
 // CHECK: ('cpusubtype', 3)
 // CHECK: ('filetype', 1)

diff --git a/tools/llvm-mc/AsmParser.cpp b/tools/llvm-mc/AsmParser.cpp
index 24c830127ac368f89146e94217a24f6ec2bc3902..467f8095e3d363b29698bf9e386f89384ee0022a 100644 (file)
--- a/tools/llvm-mc/AsmParser.cpp
+++ b/tools/llvm-mc/AsmParser.cpp
@@ -129,6 +129,17 @@ bool AsmParser::ParseParenExpr(AsmExpr *&Res) {
   return false;
 }
 
+MCSymbol *AsmParser::CreateSymbol(StringRef Name) {
+  if (MCSymbol *S = Ctx.LookupSymbol(Name))
+    return S;
+
+  // If the label starts with L it is an assembler temporary label.
+  if (Name.startswith("L"))
+    return Ctx.CreateTemporarySymbol(Name);
+
+  return Ctx.CreateSymbol(Name);
+}
+
 /// ParsePrimaryExpr - Parse a primary expression and return it.
 ///  primaryexpr ::= (parenexpr
 ///  primaryexpr ::= symbol
@@ -148,7 +159,7 @@ bool AsmParser::ParsePrimaryExpr(AsmExpr *&Res) {
   case AsmToken::Identifier: {
     // This is a label, this should be parsed as part of an expression, to
     // handle things like LFOO+4.
-    MCSymbol *Sym = Ctx.GetOrCreateSymbol(Lexer.getTok().getIdentifier());
+    MCSymbol *Sym = CreateSymbol(Lexer.getTok().getIdentifier());
     
     Res = new AsmSymbolRefExpr(Sym);
     Lexer.Lex(); // Eat identifier.
@@ -371,13 +382,11 @@ bool AsmParser::ParseStatement() {
     // FIXME: Diagnostics. Note the location of the definition as a label.
     // FIXME: This doesn't diagnose assignment to a symbol which has been
     // implicitly marked as external.
-    MCSymbol *Sym = Ctx.GetOrCreateSymbol(IDVal);
+    MCSymbol *Sym = CreateSymbol(IDVal);
     if (!Sym->isUndefined())
       return Error(IDLoc, "invalid symbol redefinition");
     
-    // Since we saw a label, create a symbol and emit it.
-    // FIXME: If the label starts with L it is an assembler temporary label.
-    // Why does the client of this api need to know this?
+    // Emit the label.
     Out.EmitLabel(Sym);
    
     return ParseStatement();
@@ -683,7 +692,7 @@ bool AsmParser::ParseAssignment(const StringRef &Name, bool IsDotSet) {
   // FIXME: Diagnostics. Note the location of the definition as a label.
   // FIXME: Handle '.'.
   // FIXME: Diagnose assignment to protected identifier (e.g., register name).
-  MCSymbol *Sym = Ctx.GetOrCreateSymbol(Name);
+  MCSymbol *Sym = CreateSymbol(Name);
   if (!Sym->isUndefined() && !Sym->isAbsolute())
     return Error(EqualLoc, "symbol has already been defined");
 
@@ -1110,7 +1119,7 @@ bool AsmParser::ParseDirectiveSymbolAttribute(MCStreamer::SymbolAttr Attr) {
       if (ParseIdentifier(Name))
         return TokError("expected identifier in directive");
       
-      MCSymbol *Sym = Ctx.GetOrCreateSymbol(Name);
+      MCSymbol *Sym = CreateSymbol(Name);
 
       Out.EmitSymbolAttribute(Sym, Attr);
 
@@ -1135,7 +1144,7 @@ bool AsmParser::ParseDirectiveDarwinSymbolDesc() {
     return TokError("expected identifier in directive");
   
   // Handle the identifier as the key symbol.
-  MCSymbol *Sym = Ctx.GetOrCreateSymbol(Name);
+  MCSymbol *Sym = CreateSymbol(Name);
 
   if (Lexer.isNot(AsmToken::Comma))
     return TokError("unexpected token in '.desc' directive");
@@ -1166,7 +1175,7 @@ bool AsmParser::ParseDirectiveComm(bool IsLocal) {
     return TokError("expected identifier in directive");
   
   // Handle the identifier as the key symbol.
-  MCSymbol *Sym = Ctx.GetOrCreateSymbol(Name);
+  MCSymbol *Sym = CreateSymbol(Name);
 
   if (Lexer.isNot(AsmToken::Comma))
     return TokError("unexpected token in directive");
@@ -1258,7 +1267,7 @@ bool AsmParser::ParseDirectiveDarwinZerofill() {
   
   // handle the identifier as the key symbol.
   SMLoc IDLoc = Lexer.getLoc();
-  MCSymbol *Sym = Ctx.GetOrCreateSymbol(Lexer.getTok().getString());
+  MCSymbol *Sym = CreateSymbol(Lexer.getTok().getString());
   Lexer.Lex();
 
   if (Lexer.isNot(AsmToken::Comma))
@@ -1363,7 +1372,7 @@ bool AsmParser::ParseDirectiveDarwinLsym() {
     return TokError("expected identifier in directive");
   
   // Handle the identifier as the key symbol.
-  MCSymbol *Sym = Ctx.GetOrCreateSymbol(Name);
+  MCSymbol *Sym = CreateSymbol(Name);
 
   if (Lexer.isNot(AsmToken::Comma))
     return TokError("unexpected token in '.lsym' directive");

diff --git a/tools/llvm-mc/AsmParser.h b/tools/llvm-mc/AsmParser.h
index c4e505f14eb68211dae1cf897d83c034384e5acf..21a7f46c70f032cd0a2f6acbb066455c8385e678 100644 (file)
--- a/tools/llvm-mc/AsmParser.h
+++ b/tools/llvm-mc/AsmParser.h
@@ -69,6 +69,8 @@ public:
   /// }
 
 private:
+  MCSymbol *CreateSymbol(StringRef Name);
+
   bool ParseStatement();
 
   bool TokError(const char *Msg);