Author: ZezhengLi Date: 2022-02-11T11:22:50+08:00 New Revision: d7969012e40a0906512b5bb304fc8b245386bb15
URL: https://github.com/llvm/llvm-project/commit/d7969012e40a0906512b5bb304fc8b245386bb15 DIFF: https://github.com/llvm/llvm-project/commit/d7969012e40a0906512b5bb304fc8b245386bb15.diff LOG: [C++20] [Modules] Check if modulemap exists to avoid crash in implicit used C++ module An impilt used of C++ module without prebuild path may cause crash. For example: ``` // ./dir1/C.cppm export module C; // ./dir2/B.cppm export module B; import C; // ./A.cpp import B; import C; ``` When we compile A.cpp without the prebuild path of C.pcm, the compiler will crash. ``` clang++ -std=c++20 --precompile -c ./dir1/C.cppm -o ./dir1/C.pcm clang++ -std=c++20 --precompile -fprebuilt-module-path=./dir2 -c ./dir2/B.cppm -o ./dir2/B.pcm clang++ -std=c++20 -fprebuilt-module-path=./dir2 A.cpp ``` The prebuilt path of module C is cached when import module B, and in the function HeaderSearch::getCachedModuleFileName, the compiler try to get the filename by modulemap without check if modulemap exists, and there is no modulemap in C++ module. Reviewed By: ChuanqiXu Differential review: https://reviews.llvm.org/D119426 Added: clang/test/Modules/implicit-module-with-missing-path.cpp Modified: clang/lib/Lex/HeaderSearch.cpp Removed: ################################################################################ diff --git a/clang/lib/Lex/HeaderSearch.cpp b/clang/lib/Lex/HeaderSearch.cpp index 19e284f04b38..500f5693911b 100644 --- a/clang/lib/Lex/HeaderSearch.cpp +++ b/clang/lib/Lex/HeaderSearch.cpp @@ -172,6 +172,10 @@ void HeaderSearch::getHeaderMapFileNames( std::string HeaderSearch::getCachedModuleFileName(Module *Module) { const FileEntry *ModuleMap = getModuleMap().getModuleMapFileForUniquing(Module); + // The ModuleMap maybe a nullptr, when we load a cached C++ module without + // *.modulemap file. In this case, just return an empty string. + if (ModuleMap == nullptr) + return {}; return getCachedModuleFileName(Module->Name, ModuleMap->getName()); } diff --git a/clang/test/Modules/implicit-module-with-missing-path.cpp b/clang/test/Modules/implicit-module-with-missing-path.cpp new file mode 100644 index 000000000000..2ce67d58d3d6 --- /dev/null +++ b/clang/test/Modules/implicit-module-with-missing-path.cpp @@ -0,0 +1,12 @@ +// This tests that the compiler wouldn't crash if the module path misses + +// RUN: rm -rf %t +// RUN: mkdir -p %t/subdir +// RUN: echo "export module C;" >> %t/subdir/C.cppm +// RUN: echo -e "export module B;\nimport C;" >> %t/B.cppm +// RUN: %clang_cc1 -std=c++20 -emit-module-interface %t/subdir/C.cppm -o %t/subdir/C.pcm +// RUN: %clang_cc1 -std=c++20 -emit-module-interface -fprebuilt-module-path=%t/subdir %t/B.cppm -o %t/B.pcm +// RUN: %clang_cc1 -std=c++20 -fprebuilt-module-path=%t %s -fsyntax-only -verify + +import B; +import C; // expected-error {{module 'C' is needed but has not been provided, and implicit use of module files is disabled}} _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
