diff --git a/bolt/lib/Rewrite/RewriteInstance.cpp b/bolt/lib/Rewrite/RewriteInstance.cpp index 04ccbcf20de1..57e41d5b5724 100644 --- a/bolt/lib/Rewrite/RewriteInstance.cpp +++ b/bolt/lib/Rewrite/RewriteInstance.cpp @@ -1050,6 +1050,16 @@ void RewriteInstance::discoverFileObjects() { LLVM_DEBUG(dbgs() << "BOLT-DEBUG: considering symbol " << UniqueName << " for function\n"); + if (Address == Section->getAddress() + Section->getSize()) { + assert(SymbolSize == 0 && + "unexpect non-zero sized symbol at end of section"); + LLVM_DEBUG( + dbgs() + << "BOLT-DEBUG: rejecting as symbol points to end of its section\n"); + registerName(SymbolSize); + continue; + } + if (!Section->isText()) { assert(SymbolType != SymbolRef::ST_Function && "unexpected function inside non-code section"); diff --git a/bolt/test/X86/section-end-sym.s b/bolt/test/X86/section-end-sym.s new file mode 100644 index 000000000000..a9bca5604ec1 --- /dev/null +++ b/bolt/test/X86/section-end-sym.s @@ -0,0 +1,29 @@ +## Check that BOLT doesn't consider end-of-section symbols (e.g., _etext) as +## functions. + +# REQUIRES: system-linux + +# RUN: llvm-mc -filetype=obj -triple x86_64-unknown-linux %s -o %t.o +# RUN: ld.lld %t.o -o %t.exe -q +# RUN: llvm-bolt %t.exe -o /dev/null --print-cfg --debug-only=bolt 2>&1 \ +# RUN: | FileCheck %s + +# CHECK: considering symbol etext for function +# CHECK-NEXT: rejecting as symbol points to end of its section +# CHECK-NOT: Binary Function "etext{{.*}}" after building cfg + + + .text + .globl _start + .type _start,@function +_start: + retq + .size _start, .-_start + + .align 0x1000 + .globl etext +etext: + + .data +.Lfoo: + .word 0