diff options
| author | Nirav Dave <niravd@google.com> | 2017-06-09 14:04:03 +0000 |
|---|---|---|
| committer | Nirav Dave <niravd@google.com> | 2017-06-09 14:04:03 +0000 |
| commit | 670109d89a24ca84250b02e83ac7ec86c5d50f56 (patch) | |
| tree | f5182253d7579650be49014a606d0bce5f3e5601 /llvm/lib/MC/MCParser/AsmParser.cpp | |
| parent | 24f7101876203bb7906c161bb808ec39dcf95d76 (diff) | |
| download | bcm5719-llvm-670109d89a24ca84250b02e83ac7ec86c5d50f56.tar.gz bcm5719-llvm-670109d89a24ca84250b02e83ac7ec86c5d50f56.zip | |
[MC] Fix compiler crash in AsmParser::Lex
When an empty comment is present in an assembly file, the compiler will crash because it checks the first character for '\n' or '\r'.
The fix consists of also checking if the string is empty before accessing the *front* method of the StringRef.
A test is included for the x86 target, but this issue is reproducible with other targets as well.
Patch by Alexandru Guduleasa!
Reviewers: niravd, grosbach, llvm-commits
Reviewed By: niravd
Differential Revision: https://reviews.llvm.org/D33993
llvm-svn: 305077
Diffstat (limited to 'llvm/lib/MC/MCParser/AsmParser.cpp')
| -rw-r--r-- | llvm/lib/MC/MCParser/AsmParser.cpp | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/llvm/lib/MC/MCParser/AsmParser.cpp b/llvm/lib/MC/MCParser/AsmParser.cpp index 2e6ca7be15f..dad47e49e2c 100644 --- a/llvm/lib/MC/MCParser/AsmParser.cpp +++ b/llvm/lib/MC/MCParser/AsmParser.cpp @@ -703,7 +703,7 @@ const AsmToken &AsmParser::Lex() { // if it's a end of statement with a comment in it if (getTok().is(AsmToken::EndOfStatement)) { // if this is a line comment output it. - if (getTok().getString().front() != '\n' && + if (!getTok().getString().empty() && getTok().getString().front() != '\n' && getTok().getString().front() != '\r' && MAI.preserveAsmComments()) Out.addExplicitComment(Twine(getTok().getString())); } @@ -1523,7 +1523,7 @@ bool AsmParser::parseStatement(ParseStatementInfo &Info, Lex(); if (Lexer.is(AsmToken::EndOfStatement)) { // if this is a line comment we can drop it safely - if (getTok().getString().front() == '\r' || + if (getTok().getString().empty() || getTok().getString().front() == '\r' || getTok().getString().front() == '\n') Out.AddBlankLine(); Lex(); |
