[llvm] r223381 - Fix yet another unseen regression caused by r223113

[Asiri Rathnayake]

Author: asiri
Date: Thu Dec  4 13:34:59 2014
New Revision: 223381

URL: http://llvm.org/viewvc/llvm-project?rev=223381&view=rev
Log:
Fix yet another unseen regression caused by r223113

r223113 added support for ARM modified immediate assembly syntax. Which
assumes all immediate operands are prefixed with a '#'. This assumption
is wrong as per the ARMARM - which recommends that all '#' characters be
treated optional. The current patch fixes this regression and adds a test
case. A follow-up patch will expand the test coverage to other instructions.

Modified:
    llvm/trunk/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
    llvm/trunk/test/MC/ARM/basic-arm-instructions.s
    llvm/trunk/test/MC/ARM/ldr-pseudo-parse-errors.s

Modified: llvm/trunk/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/AsmParser/ARMAsmParser.cpp?rev=223381&r1=223380&r2=223381&view=diff
==============================================================================
--- llvm/trunk/lib/Target/ARM/AsmParser/ARMAsmParser.cpp (original)
+++ llvm/trunk/lib/Target/ARM/AsmParser/ARMAsmParser.cpp Thu Dec  4 13:34:59 2014
@@ -4418,15 +4418,31 @@ ARMAsmParser::parseModImm(OperandVector
   MCAsmLexer &Lexer = getLexer();
   int64_t Imm1, Imm2;
 
-  if ((Parser.getTok().isNot(AsmToken::Hash) &&
-       Parser.getTok().isNot(AsmToken::Dollar))
-      || Lexer.peekTok().is(AsmToken::Colon))
+  SMLoc S = Parser.getTok().getLoc();
+
+  // 1) A mod_imm operand can appear in the place of a register name:
+  //   add r0, #mod_imm
+  //   add r0, r0, #mod_imm
+  // to correctly handle the latter, we bail out as soon as we see an
+  // identifier.
+  //
+  // 2) Similarly, we do not want to parse into complex operands:
+  //   mov r0, #mod_imm
+  //   mov r0, :lower16:(_foo)
+  if (Parser.getTok().is(AsmToken::Identifier) ||
+      Parser.getTok().is(AsmToken::Colon))
     return MatchOperand_NoMatch;
 
-  SMLoc S = Parser.getTok().getLoc();
+  // Hash (dollar) is optional as per the ARMARM
+  if (Parser.getTok().is(AsmToken::Hash) ||
+      Parser.getTok().is(AsmToken::Dollar)) {
+    // Avoid parsing into complex operands (#:)
+    if (Lexer.peekTok().is(AsmToken::Colon))
+      return MatchOperand_NoMatch;
 
-  // Eat the hash (or dollar)
-  Parser.Lex();
+    // Eat the hash (dollar)
+    Parser.Lex();
+  }
 
   SMLoc Sx1, Ex1;
   Sx1 = Parser.getTok().getLoc();
@@ -4483,12 +4499,6 @@ ARMAsmParser::parseModImm(OperandVector
     return MatchOperand_ParseFail;
   }
 
-  if (Lexer.peekTok().isNot(AsmToken::Hash) &&
-       Lexer.peekTok().isNot(AsmToken::Dollar)) {
-    Error(Lexer.peekTok().getLoc(), "immediate operand expected");
-    return MatchOperand_ParseFail;
-  }
-
   // Eat the comma
   Parser.Lex();
 
@@ -4496,8 +4506,10 @@ ARMAsmParser::parseModImm(OperandVector
   SMLoc Sx2, Ex2;
   Sx2 = Parser.getTok().getLoc();
 
-  // Eat the hash (or dollar)
-  Parser.Lex();
+  // Eat the optional hash (dollar)
+  if (Parser.getTok().is(AsmToken::Hash) ||
+      Parser.getTok().is(AsmToken::Dollar))
+    Parser.Lex();
 
   const MCExpr *Imm2Exp;
   if (getParser().parseExpression(Imm2Exp, Ex2)) {

Modified: llvm/trunk/test/MC/ARM/basic-arm-instructions.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/ARM/basic-arm-instructions.s?rev=223381&r1=223380&r2=223381&view=diff
==============================================================================
--- llvm/trunk/test/MC/ARM/basic-arm-instructions.s (original)
+++ llvm/trunk/test/MC/ARM/basic-arm-instructions.s Thu Dec  4 13:34:59 2014
@@ -16,6 +16,9 @@ _func:
 @ ADC (immediate)
 @------------------------------------------------------------------------------
         adc r1, r2, #0xf
+        adc r1, r2, $0xf
+        adc r1, r2, 0xf
+        adc r1, r2, 15
         adc r7, r8, #42, #2
         adc r7, r8, #-2147483638
         adc r7, r8, #40, #2
@@ -34,6 +37,9 @@ _func:
         adceq r1, r2, #0xf00
 
 @ CHECK: adc	r1, r2, #15             @ encoding: [0x0f,0x10,0xa2,0xe2]
+@ CHECK: adc	r1, r2, #15             @ encoding: [0x0f,0x10,0xa2,0xe2]
+@ CHECK: adc	r1, r2, #15             @ encoding: [0x0f,0x10,0xa2,0xe2]
+@ CHECK: adc	r1, r2, #15             @ encoding: [0x0f,0x10,0xa2,0xe2]
 @ CHECK: adc    r7, r8, #-2147483638    @ encoding: [0x2a,0x71,0xa8,0xe2]
 @ CHECK: adc    r7, r8, #-2147483638    @ encoding: [0x2a,0x71,0xa8,0xe2]
 @ CHECK: adc    r7, r8, #40, #2         @ encoding: [0x28,0x71,0xa8,0xe2]

Modified: llvm/trunk/test/MC/ARM/ldr-pseudo-parse-errors.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/ARM/ldr-pseudo-parse-errors.s?rev=223381&r1=223380&r2=223381&view=diff
==============================================================================
--- llvm/trunk/test/MC/ARM/ldr-pseudo-parse-errors.s (original)
+++ llvm/trunk/test/MC/ARM/ldr-pseudo-parse-errors.s Thu Dec  4 13:34:59 2014
@@ -4,7 +4,7 @@
 .text
 bar:
   mov r0, =0x101
-@ CHECK: error: unexpected token in operand
+@ CHECK: error: unknown token in expression
 @ CHECK: mov r0, =0x101
 @ CHECK:         ^