[cfe-commits] [patch] Fix uninitialized variables causing assert in TokenConcatenation::AvoidConcat

[Michael Spencer]

On Tue, Jun 15, 2010 at 2:56 PM, Chris Lattner <clattner at apple.com> wrote:
>
> On Jun 14, 2010, at 11:50 PM, Michael Spencer wrote:
>
>> The test case in the attached patch caused an assert to fail in
>> TokenConcatenation::AvoidConcat due to uninitialized variables in
>> PrintPreprocessedOutput.cpp/PrintPreprocessedTokens. The rest of the
>> patch fixes it.
>
> I applied the uninit variable fix in r106025 and testcase in r106026.  The testcase works for me without the other hunk so I left it out.  Thanks!
>
> -Chris

I still get:

C:\Users\Michael\Projects\llvm\tools\clang\test\Frontend>clang
-fms-extensions -E preprocessed-output-macro-first-token.c
Assertion failed: ((getOffset()+Offset) & MacroIDBit) == 0 && "invalid
location", file
C:\Users\Michael\Projects\llvm\tools\clang\include\clang/Basic/SourceLocation.h,
line 112
Stack dump:
0.      Program arguments:
C:/Users/Michael/Projects/llvm-build/VS9/bin/Debug/clang.exe -cc1
-triple i686-pc-win32 -E -d
isable-free -main-file-name preprocessed-output-macro-first-token.c
-mrelocation-model static -mdisable-fp-elim -masm-ve
rbose -mconstructor-aliases -resource-dir
C:/Users/Michael/Projects/llvm-build/VS9/bin/lib/clang/2.0
-ferror-limit 19 -f
message-length 120 -fms-extensions -fgnu-runtime
-fdiagnostics-show-option -fcolor-diagnostics -o - -x c
preprocessed-ou
tput-macro-first-token.c
74F8C355 (0x0000000A 0x0000006C 0x00000000 0x00000000),
_get_pgmptr()+0453 bytes(s)
7502E9AD (0x02EEE5F4 0x02EEE578 0x00000000 0x001C0150), abort()+0045 bytes(s)
7501E8D6 (0x01CA2D58 0x01C98030 0x00000070 0x02EEE874), _wassert()+0214 bytes(s)
0035222A (0x02EEE5D0 0xCCCCCCCC 0x02EEE5D8 0x02EEE7AC),
clang::SourceLocation::getFileLocWithOffset()+0074 bytes(s),
c:\users\michael\projects\llvm\tools\clang\include\clang\basic\sourcelocation.h,
line 112+0047 byte(s)
00B5BD0D (0x02EEE68C 0x02EEE674 0x02EEE81C 0x024A0E10),
clang::TokenConcatenation::AvoidConcat()+0125 bytes(s),
c:\users\michael\projects\llvm\tools\clang\lib\lex\tokenconcatenation.cpp,
line 135+0097 byte(s)
003E1525 (0x02EEE68C 0x02EEE674 0x02EEE81C 0xB1F768D7), `anonymous
namespace'::PrintPPOutputPPCallbacks::AvoidConcat()+0037 bytes(s),
c:\users\michael\projects\llvm\tools\clang\lib\frontend\printpreprocessedoutput.cpp,
line 131
003E0628 (0x02480A20 0x02EEE81C 0x024A0E10 0x02491E10),
PrintPreprocessedTokens()+0216 bytes(s),
c:\users\michael\projects\llvm\tools\clang\lib\frontend\printpreprocessedoutput.cpp,
line 432+0056 byte(s)
003E04F2 (0x02480A20 0x02491E10 0x024764AC 0xCCCCCCCC),
clang::DoPrintPreprocessedInput()+0610 bytes(s),
c:\users\michael\projects\llvm\tools\clang\lib\frontend\printpreprocessedoutput.cpp,
line 540+0021 byte(s)
0032BB1A (0xB1F767DB 0x02EEE91C 0x02EEE8BC 0x02EEE86C),
clang::PrintPreprocessedAction::ExecuteAction()+0122 bytes(s),
c:\users\michael\projects\llvm\tools\clang\lib\frontend\frontendactions.cpp,
line 192+0027 byte(s)
0032CEDA (0xB1F76647 0x02EEF10C 0x02EEE934 0xCCCCCCCC),
clang::FrontendAction::Execute()+0282 bytes(s),
c:\users\michael\projects\llvm\tools\clang\lib\frontend\frontendaction.cpp,
line 177+0015 byte(s)
0030A66D (0x0247CF68 0xB1F77E77 0x02EEF910 0x00000000),
clang::CompilerInstance::ExecuteAction()+0717 bytes(s),
c:\users\michael\projects\llvm\tools\clang\lib\frontend\compilerinstance.cpp,
line 498
002EE904 (0x03059130 0x03059198 0x0305919C 0x002E1794),
cc1_main()+2004 bytes(s),
c:\users\michael\projects\llvm\tools\clang\tools\driver\cc1_main.cpp,
line 288+0027 byte(s)
002E328D (0x0000001C 0x03059128 0x030526F0 0xB1F77603), main()+0253
bytes(s), c:\users\michael\projects\llvm\tools\clang\tools\driver\driver.cpp,
line 186+0033 byte(s)
01646C38 (0x02EEF980 0x75983677 0x7EFDE000 0x02EEF9C0),
__tmainCRTStartup()+0424 bytes(s),
f:\dd\vctools\crt_bld\self_x86\crt\src\crtexe.c, line 582+0025 byte(s)
01646A7F (0x7EFDE000 0x02EEF9C0 0x77D39D72 0x7EFDE000),
mainCRTStartup()+0015 bytes(s),
f:\dd\vctools\crt_bld\self_x86\crt\src\crtexe.c, line 399
75983677 (0x7EFDE000 0x7D1AC7C1 0x00000000 0x00000000),
BaseThreadInitThunk()+0018 bytes(s)
77D39D72 (0x01646A70 0x7EFDE000 0x00000000 0x00000000),
RtlInitializeExceptionChain()+0099 bytes(s)
77D39D45 (0x01646A70 0x7EFDE000 0x00000000 0x00000000),
RtlInitializeExceptionChain()+0054 bytes(s)
clang: error: clang frontend command failed due to signal 2147483645
(use -v to see invocation)

Which makes sense considering that in PrintPreprocessedTokens()
PrevPrevTok and PrevTok are invalid until the while(1) loop is on its
3rd iteration. This doesn't happen on every platform because the
values of PrevPrevTok and PrevTok are undefined. I recommend that
either PrintPreprocessedTokens() make sure that they are valid before
they are used, or that a value be given to an invalid token so the
callee (TokenConcatenation::AvoidConcat() in this case) can decide
what to do.

- Michael Spencer