nickdesaulniers added a subscriber: nathanchance. nickdesaulniers added a comment.
Yes; GCC does behave this way. It does not consider a non-gnu-inline redefinition an error, and it does seem to prefer the non-gnu-inline redeclaration when both are present, AFAICT. The test is verifying that behavior correctly. This patch is fixing the test case, the reported reduced cases from @manojgupta link <https://reviews.llvm.org/D111009#3068566>, @nathanchance link <https://github.com/ClangBuiltLinux/linux/issues/1477#issuecomment-943650477>, and myself link <https://github.com/ClangBuiltLinux/linux/issues/1477#issuecomment-944811052>, and fixing the kernel builds link <https://github.com/ClangBuiltLinux/continuous-integration2/runs/3854281995?check_suite_focus=true>. Further, I did a build+boot tests of: 1. mainline x86_64 + CONFIG_FORTIFY_SOURCE=y 2. mainline x86_64 + CONFIG_FORTIFY_SOURCE=y + CONFIG_LTO_CLANG_FULL=y 3. mainline x86_64 + CONFIG_FORTIFY_SOURCE=y + CONFIG_LTO_CLANG_THIN=y ================ Comment at: clang/lib/CodeGen/CodeGenFunction.cpp:1318 + // external one. That's GCC behavior too. + else { + for (auto const *Redecl : FD->redecls()) { ---------------- do we really want to be iterating every redaclaration like this, even for non-inline builtin declarations? Is there a way to avoid the below loop for most functions? Perhaps we should be doing this when we hit a redeclaration instead? Or wrap all this work in a check that there's a builtin ID associated with the FD? ================ Comment at: clang/lib/CodeGen/CodeGenFunction.cpp:1328 + } + } + } ---------------- If there are multiple redeclarations, do we want to be erasing the clone each time, or can we `break` out of this loop? ================ Comment at: clang/test/CodeGen/strlen-inline-builtin-redecl.c:10-12 +extern inline __attribute__((always_inline)) +__attribute__((gnu_inline)) unsigned long +strlen(const char *p) { ---------------- Has this example been formatted? Does rotating the attributes to the front help? ================ Comment at: clang/test/CodeGen/strlen-inline-builtin-redecl.c:42 +} +extern typeof(strlen) strlen; ---------------- I think this line can be dropped without affecting the test. Or consider using any of the further reduced test cases? Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D112059/new/ https://reviews.llvm.org/D112059 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
