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Integrated assembler incorrectly lexes ARM-style comments 

The integrated assembler fails to properly lex arm comments when
they are adjacent to an identifier in the input stream. The reason
is that the arm comment symbol '@' is also used as symbol variant in
other assembly languages so when lexing an identifier it allows the
'@' symbol as part of the identifier.

Example:
  $ cat comment.s
  foo:
    add r0, r0@got to parse this as a comment

  $ llvm-mc -triple armv7 comment.s
  comment.s:4:18: error: unexpected token in argument list
    add r0, r0@got to parse this as a comment
                   ^
This should be parsed as correctly as `add r0, r0`.

This commit modifes the assembly lexer to not include the '@' symbol
in identifiers when lexing for targets that use '@' for comments.

llvm-svn: 196607
This commit is contained in:
David Peixotto 2013-12-06 20:35:58 +00:00
parent 3e325d7490
commit 2cdc56d26b
2 changed files with 31 additions and 4 deletions
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11
llvm/lib/MC/MCParser/AsmLexer.cpp
View File

@ -139,20 +139,23 @@ AsmToken AsmLexer::LexHexFloatLiteral(bool NoIntDigits) {
} }
/// LexIdentifier: [a-zA-Z_.][a-zA-Z0-9_$.@?]* /// LexIdentifier: [a-zA-Z_.][a-zA-Z0-9_$.@?]*
static bool IsIdentifierChar(char c) { static bool IsIdentifierChar(char c, bool AllowAt) {
return isalnum(c) || c == '_' || c == '$' || c == '.' || c == '@' || c == '?'; return isalnum(c) || c == '_' || c == '$' || c == '.' ||
(c == '@' && AllowAt) || c == '?';
} }
AsmToken AsmLexer::LexIdentifier() { AsmToken AsmLexer::LexIdentifier() {
bool AllowAtInIdentifier = !StringRef(MAI.getCommentString()).startswith("@");
// Check for floating point literals. // Check for floating point literals.
if (CurPtr[-1] == '.' && isdigit(*CurPtr)) { if (CurPtr[-1] == '.' && isdigit(*CurPtr)) {
// Disambiguate a .1243foo identifier from a floating literal. // Disambiguate a .1243foo identifier from a floating literal.
while (isdigit(*CurPtr)) while (isdigit(*CurPtr))
++CurPtr; ++CurPtr;
if (*CurPtr == 'e' || *CurPtr == 'E' || !IsIdentifierChar(*CurPtr)) if (*CurPtr == 'e' || *CurPtr == 'E' ||
!IsIdentifierChar(*CurPtr, AllowAtInIdentifier))
return LexFloatLiteral(); return LexFloatLiteral();
} }
while (IsIdentifierChar(*CurPtr)) while (IsIdentifierChar(*CurPtr, AllowAtInIdentifier))
++CurPtr; ++CurPtr;
// Handle . as a special case. // Handle . as a special case.

24
llvm/test/MC/ARM/comment.s Normal file
View File

@ -0,0 +1,24 @@
@ Tests to check that '@' does not get lexed as an identifier for arm
@ RUN: llvm-mc %s -triple=armv7-linux-gnueabi | FileCheck %s
@ RUN: llvm-mc %s -triple=armv7-linux-gnueabi 2>&1 | FileCheck %s --check-prefix=ERROR
foo:
bl boo@plt should be ignored
bl goo@plt
.long bar@got to parse this as a comment
.long baz@got
add r0, r0@ignore this extra junk
@CHECK-LABEL: foo:
@CHECK: bl boo
@CHECK-NOT: @
@CHECK: bl goo
@CHECK-NOT: @
@CHECK: .long bar
@CHECK-NOT: @
@CHECK: .long baz
@CHECK-NOT: @
@CHECK: add r0, r0
@CHECK-NOT: @
@ERROR-NOT: error: