ZezhengLi created this revision.
ZezhengLi added reviewers: ChuanqiXu, rsmith, urnathan.
ZezhengLi added a project: clang.
ZezhengLi requested review of this revision.
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An impilt used of 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 B.cppm -o
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.
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D119426
Files:
clang/lib/Lex/HeaderSearch.cpp
clang/test/Modules/implicit-module-with-missing-path.cpp
Index: clang/test/Modules/implicit-module-with-missing-path.cpp
===
--- /dev/null
+++ 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}}
\ No newline at end of file
Index: clang/lib/Lex/HeaderSearch.cpp
===
--- clang/lib/Lex/HeaderSearch.cpp
+++ clang/lib/Lex/HeaderSearch.cpp
@@ -172,6 +172,10 @@
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());
}
Index: clang/test/Modules/implicit-module-with-missing-path.cpp
===
--- /dev/null
+++ 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}}
\ No newline at end of file
Index: clang/lib/Lex/HeaderSearch.cpp
===
--- clang/lib/Lex/HeaderSearch.cpp
+++ clang/lib/Lex/HeaderSearch.cpp
@@ -172,6 +172,10 @@
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());
}
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