Author: sstwcw Date: 2022-10-30T02:18:58Z New Revision: d5be1550f1406844501ab87a3e92622927a203e0
URL: https://github.com/llvm/llvm-project/commit/d5be1550f1406844501ab87a3e92622927a203e0 DIFF: https://github.com/llvm/llvm-project/commit/d5be1550f1406844501ab87a3e92622927a203e0.diff LOG: [clang-format] Don't crash on malformed preprocessor conditions Previously the program would crash on this input: ``` #else #if X ``` The problem was that in `parsePPElse`, `PPBranchLevel` would be incremented when the first `#else` gets parsed, but `PPLevelBranchCount` and `PPLevelBranchIndex` would not be updated together. I found the problem when working on D135740. Differential Revision: https://reviews.llvm.org/D135972 Added: Modified: clang/lib/Format/UnwrappedLineParser.cpp clang/unittests/Format/FormatTest.cpp Removed: ################################################################################ diff --git a/clang/lib/Format/UnwrappedLineParser.cpp b/clang/lib/Format/UnwrappedLineParser.cpp index 25d9018fa1093..0372b89397db9 100644 --- a/clang/lib/Format/UnwrappedLineParser.cpp +++ b/clang/lib/Format/UnwrappedLineParser.cpp @@ -1215,9 +1215,12 @@ void UnwrappedLineParser::parsePPElse() { // If a potential include guard has an #else, it's not an include guard. if (IncludeGuard == IG_Defined && PPBranchLevel == 0) IncludeGuard = IG_Rejected; + // Don't crash when there is an #else without an #if. + assert(PPBranchLevel >= -1); + if (PPBranchLevel == -1) + conditionalCompilationStart(/*Unreachable=*/true); conditionalCompilationAlternative(); - if (PPBranchLevel > -1) - --PPBranchLevel; + --PPBranchLevel; parsePPUnknown(); ++PPBranchLevel; } diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp index 69bd39590589f..e2eced46c3b4b 100644 --- a/clang/unittests/Format/FormatTest.cpp +++ b/clang/unittests/Format/FormatTest.cpp @@ -5193,6 +5193,34 @@ TEST_F(FormatTest, MacroDefinitionsWithIncompleteCode) { verifyNoCrash("a={0,1\n#if a\n#else\n;\n#endif\n}"); verifyNoCrash("#if a\na(\n#else\n#endif\n) a {a,b,c,d,f,g};"); verifyNoCrash("#ifdef A\n a(\n #else\n #endif\n) = []() { \n)}"); + verifyNoCrash("#else\n" + "#else\n" + "#endif\n" + "#endif"); + verifyNoCrash("#else\n" + "#if X\n" + "#endif\n" + "#endif"); + verifyNoCrash("#else\n" + "#endif\n" + "#if X\n" + "#endif"); + verifyNoCrash("#if X\n" + "#else\n" + "#else\n" + "#endif\n" + "#endif"); + verifyNoCrash("#if X\n" + "#elif Y\n" + "#elif Y\n" + "#endif\n" + "#endif"); + verifyNoCrash("#endif\n" + "#endif"); + verifyNoCrash("#endif\n" + "#else"); + verifyNoCrash("#endif\n" + "#elif Y"); } TEST_F(FormatTest, MacrosWithoutTrailingSemicolon) { _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
