MC: Parse .set and assignments.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74208 91177308-0d34-0410-b5e6-96231b3b80d8

test/MC/AsmParser/assignment.s

@@ -0,0 +1,7 @@
+# RUN: llvm-mc %s > %t
+
+# RUN: grep -A 2 TEST0 %t > %t2
+# RUN: grep "a = 0" %t2
+TEST0:  
+        a = 0
+        

test/MC/AsmParser/directive_set.s

@@ -0,0 +1,7 @@
+# RUN: llvm-mc %s > %t
+
+# RUN: grep -A 2 TEST0 %t > %t2
+# RUN: grep ".set a, 0" %t2
+TEST0:  
+        .set a, 0
+        

tools/llvm-mc/AsmLexer.cpp

@@ -262,6 +262,7 @@ asmtok::TokKind AsmLexer::LexToken() {
   case '*': return asmtok::Star;
   case ',': return asmtok::Comma;
   case '$': return asmtok::Dollar;
+  case '=': return asmtok::Equal;
   case '|': return asmtok::Pipe;
   case '^': return asmtok::Caret;
   case '&': return asmtok::Amp;

tools/llvm-mc/AsmLexer.h

@@ -42,7 +42,7 @@ namespace asmtok {
     Plus, Minus, Tilde,
     Slash,    // '/'
     LParen, RParen,
-    Star, Comma, Dollar,
+    Star, Comma, Dollar, Equal,
     
     Pipe, Caret, Amp, Exclaim,
     Percent, LessLess, GreaterGreater

tools/llvm-mc/AsmParser.cpp

@@ -182,7 +182,8 @@ bool AsmParser::ParseStatement() {
   const char *IDVal = Lexer.getCurStrVal();
   
   // Consume the identifier, see what is after it.
-  if (Lexer.Lex() == asmtok::Colon) {
+  switch (Lexer.Lex()) {
+  case asmtok::Colon:
     // identifier ':'   -> Label.
     Lexer.Lex();
     
@@ -192,6 +193,15 @@ bool AsmParser::ParseStatement() {
     Out.EmitLabel(Ctx.GetOrCreateSymbol(IDVal));
     
     return ParseStatement();
+
+  case asmtok::Equal:
+    // identifier '=' ... -> assignment statement
+    Lexer.Lex();
+
+    return ParseAssignment(IDVal, false);
+
+  default: // Normal instruction or directive.
+    break;
   }
   
   // Otherwise, we have a normal instruction or directive.  
@@ -209,7 +219,8 @@ bool AsmParser::ParseStatement() {
     if (!strcmp(IDVal, ".static_const"))
       return ParseDirectiveSectionSwitch("__TEXT,__static_const");
     if (!strcmp(IDVal, ".cstring"))
-      return ParseDirectiveSectionSwitch("__TEXT,__cstring","cstring_literals");
+      return ParseDirectiveSectionSwitch("__TEXT,__cstring", 
+                                         "cstring_literals");
     if (!strcmp(IDVal, ".literal4"))
       return ParseDirectiveSectionSwitch("__TEXT,__literal4", "4byte_literals");
     if (!strcmp(IDVal, ".literal8"))
@@ -291,6 +302,10 @@ bool AsmParser::ParseStatement() {
     if (!strcmp(IDVal, ".objc_selector_strs"))
       return ParseDirectiveSectionSwitch("__OBJC,__selector_strs");
     
+    // Assembler features
+    if (!strcmp(IDVal, ".set"))
+      return ParseDirectiveSet();
+
     // Data directives
 
     if (!strcmp(IDVal, ".ascii"))
@@ -336,6 +351,40 @@ bool AsmParser::ParseStatement() {
   return false;
 }
 
+bool AsmParser::ParseAssignment(const char *Name, bool IsDotSet) {
+  int64_t Value;
+  if (ParseExpression(Value))
+    return true;
+  
+  if (Lexer.isNot(asmtok::EndOfStatement))
+    return TokError("unexpected token in assignment");
+
+  // Eat the end of statement marker.
+  Lexer.Lex();
+
+  // Get the symbol for this name.
+  // FIXME: Handle '.'.
+  MCSymbol *Sym = Ctx.GetOrCreateSymbol(Name);
+  Out.EmitAssignment(Sym, MCValue::get(Value), IsDotSet);
+
+  return false;
+}
+
+/// ParseDirectiveSet:
+///   ::= .set identifier ',' expression
+bool AsmParser::ParseDirectiveSet() {
+  if (Lexer.isNot(asmtok::Identifier))
+    return TokError("expected identifier after '.set' directive");
+
+  const char *Name = Lexer.getCurStrVal();
+  
+  if (Lexer.Lex() != asmtok::Comma)
+    return TokError("unexpected token in '.set'");
+  Lexer.Lex();
+
+  return ParseAssignment(Name, true);
+}
+
 /// ParseDirectiveSection:
 ///   ::= .section identifier (',' identifier)*
 /// FIXME: This should actually parse out the segment, section, attributes and

tools/llvm-mc/AsmParser.h

@@ -43,6 +43,7 @@ private:
   
   void EatToEndOfStatement();
   
+  bool ParseAssignment(const char *Name, bool IsDotSet);
   bool ParseExpression(int64_t &Res);
   bool ParsePrimaryExpr(int64_t &Res);
   bool ParseBinOpRHS(unsigned Precedence, int64_t &Res);
@@ -61,6 +62,7 @@ private:
   bool ParseDirectiveValue(unsigned Size); // ".byte", ".long", ...
   bool ParseDirectiveFill(); // ".fill"
   bool ParseDirectiveSpace(); // ".space"
+  bool ParseDirectiveSet(); // ".set"
   
 };