Implement full support for parsing primary expressions. We can now parse

all of health and voronoi (ignoring directives).  We only get 409 lines into
176.gcc though because we don't have binary operators yet:

Parsing 176.gcc.llc.s:409: unexpected token in operand list
	movsbl	_arityvec+1(,%edi,8), %eax
	      	         ^

llvm-svn: 73877

1 files changed, 37 insertions, 3 deletions

diff --git a/llvm/tools/llvm-mc/AsmParser.cpp b/llvm/tools/llvm-mc/AsmParser.cpp
index c9583549bdf..397c5fe9c7c 100644
--- a/llvm/tools/llvm-mc/AsmParser.cpp
+++ b/llvm/tools/llvm-mc/AsmParser.cpp
@@ -213,10 +213,25 @@ bool AsmParser::ParseX86MemOperand(X86Operand &Op) {
   return false;
 }
 
+/// ParseParenExpr - Parse a paren expression and return it.
+/// NOTE: This assumes the leading '(' has already been consumed.
+///
+/// parenexpr ::= expr)
+///
+bool AsmParser::ParseParenExpr(int64_t &Res) {
+  if (ParseExpression(Res)) return true;
+  if (Lexer.isNot(asmtok::RParen))
+    return TokError("expected ')' in parentheses expression");
+  Lexer.Lex();
+  return false;
+}
 
-/// ParseExpression - Parse an expression and return it.
-/// FIXME: This should handle real expressions, we do something trivial for now.
-bool AsmParser::ParseExpression(int64_t &Res) {
+/// ParsePrimaryExpr - Parse a primary expression and return it.
+///  primaryexpr ::= (parenexpr
+///  primaryexpr ::= symbol
+///  primaryexpr ::= number
+///  primaryexpr ::= ~,+,- primaryexpr
+bool AsmParser::ParsePrimaryExpr(int64_t &Res) {
   switch (Lexer.getKind()) {
   default:
     return TokError("unknown token in expression");
@@ -230,8 +245,27 @@ bool AsmParser::ParseExpression(int64_t &Res) {
     Res = Lexer.getCurIntVal();
     Lexer.Lex(); // Eat identifier.
     return false;
+  case asmtok::LParen:
+    Lexer.Lex(); // Eat the '('.
+    return ParseParenExpr(Res);
+  case asmtok::Tilde:
+  case asmtok::Plus:
+  case asmtok::Minus:
+    Lexer.Lex(); // Eat the operator.
+    return ParsePrimaryExpr(Res);
   }
 }
+
+/// ParseExpression - Parse an expression and return it.
+/// 
+///  expr ::= expr +,- expr          -> lowest.
+///  expr ::= expr |,^,&,! expr      -> middle.
+///  expr ::= expr *,/,%,<<,>> expr  -> highest.
+///  expr ::= primaryexpr
+///
+bool AsmParser::ParseExpression(int64_t &Res) {
+  return ParsePrimaryExpr(Res);
+}