From efc9a8e9800cc04ff7460c3c78f9dc2120f3aea6 Mon Sep 17 00:00:00 2001 From: Andres Freund Date: Thu, 15 Oct 2020 17:38:00 -0700 Subject: llvmjit: Work around bug in LLVM 3.9 causing crashes after 72559438f92. Unfortunately in LLVM 3.9 LLVMGetAttributeCountAtIndex(func, index) crashes when called with an index that has 0 attributes. Since there's no way to work around this in the C API, add a small C++ wrapper doing so. The only reason this didn't fail before 72559438f92 is that there always are function attributes... Author: Andres Freund Discussion: https://postgr.es/m/20201016001254.w2nfj7gd74jmb5in@alap3.anarazel.de Backpatch: 11-, like 72559438f92 --- src/backend/jit/llvm/llvmjit_wrap.cpp | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) (limited to 'src/backend/jit/llvm/llvmjit_wrap.cpp') diff --git a/src/backend/jit/llvm/llvmjit_wrap.cpp b/src/backend/jit/llvm/llvmjit_wrap.cpp index e8a7380325a..37c006a1ff5 100644 --- a/src/backend/jit/llvm/llvmjit_wrap.cpp +++ b/src/backend/jit/llvm/llvmjit_wrap.cpp @@ -16,6 +16,13 @@ extern "C" #include "postgres.h" } +#include + +/* Avoid macro clash with LLVM's C++ headers */ +#undef Min + +#include +#include #include #include @@ -44,3 +51,28 @@ char *LLVMGetHostCPUFeatures(void) { return strdup(Features.getString().c_str()); } #endif + +/* + * Like LLVM's LLVMGetAttributeCountAtIndex(), works around a bug in LLVM 3.9. + * + * In LLVM <= 3.9, LLVMGetAttributeCountAtIndex() segfaults if there are no + * attributes at an index (fixed in LLVM commit ce9bb1097dc2). + */ +unsigned +LLVMGetAttributeCountAtIndexPG(LLVMValueRef F, uint32 Idx) +{ + /* + * This is more expensive, so only do when using a problematic LLVM + * version. + */ +#if LLVM_VERSION_MAJOR < 4 + if (!llvm::unwrap(F)->getAttributes().hasAttributes(Idx)) + return 0; +#endif + + /* + * There is no nice public API to determine the count nicely, so just + * always fall back to LLVM's C API. + */ + return LLVMGetAttributeCountAtIndex(F, Idx); +} -- cgit v1.2.3