Author: Fangrui Song Date: 2021-01-11T09:33:22-08:00 New Revision: ac2224c02282039f41294842396cbbe47ea29a23
URL: https://github.com/llvm/llvm-project/commit/ac2224c02282039f41294842396cbbe47ea29a23 DIFF: https://github.com/llvm/llvm-project/commit/ac2224c02282039f41294842396cbbe47ea29a23.diff LOG: [ELF] --exclude-libs: localize defined libcall symbols referenced by lto.tmp Fixes PR48681: after LTO, lto.tmp may reference a libcall symbol not in an IR symbol table of any bitcode file. If such a symbol is defined in an archive matched by a --exclude-libs, we don't correctly localize the symbol. Add another `excludeLibs` after `compileBitcodeFiles` to localize such libcall symbols. Unfortunately we have keep the existing one for D43126. Using VER_NDX_LOCAL is an implementation detail of `--exclude-libs`, it does not necessarily tie to the "localize" behavior. `local:` patterns in a version script can be omitted. The `symbol ... has undefined version ...` error should not be exempted. Ideally we should error as GNU ld does. https://issuetracker.google.com/issues/73020933 Reviewed By: psmith Differential Revision: https://reviews.llvm.org/D94280 Added: lld/test/ELF/lto/exclude-libs-libcall.ll Modified: lld/ELF/Driver.cpp Removed: ################################################################################ diff --git a/lld/ELF/Driver.cpp b/lld/ELF/Driver.cpp index 5cc32f81c2ec..e1395a568ea2 100644 --- a/lld/ELF/Driver.cpp +++ b/lld/ELF/Driver.cpp @@ -2146,7 +2146,11 @@ template <class ELFT> void LinkerDriver::link(opt::InputArgList &args) { // They also might be exported if referenced by DSOs. script->declareSymbols(); - // Handle the -exclude-libs option. + // Handle --exclude-libs. This is before scanVersionScript() due to a + // workaround for Android ndk: for a defined versioned symbol in an archive + // without a version node in the version script, Android does not expect a + // 'has undefined version' error in -shared --exclude-libs=ALL mode (PR36295). + // GNU ld errors in this case. if (args.hasArg(OPT_exclude_libs)) excludeLibs(args); @@ -2179,6 +2183,11 @@ template <class ELFT> void LinkerDriver::link(opt::InputArgList &args) { // except a few linker-synthesized ones will be added to the symbol table. compileBitcodeFiles<ELFT>(); + // Handle --exclude-libs again because lto.tmp may reference additional + // libcalls symbols defined in an excluded archive. + if (args.hasArg(OPT_exclude_libs)) + excludeLibs(args); + // Symbol resolution finished. Report backward reference problems. reportBackrefs(); if (errorCount()) diff --git a/lld/test/ELF/lto/exclude-libs-libcall.ll b/lld/test/ELF/lto/exclude-libs-libcall.ll new file mode 100644 index 000000000000..ece587f1c4da --- /dev/null +++ b/lld/test/ELF/lto/exclude-libs-libcall.ll @@ -0,0 +1,28 @@ +; REQUIRES: x86 +; RUN: rm -rf %t && split-file %s %t +; RUN: llvm-as %t/a.ll -o %t/a.bc +; RUN: llvm-mc -filetype=obj -triple=x86_64 %t/b.s -o %t/b.o +; RUN: llvm-ar rc %t/b.a %t/b.o +; RUN: ld.lld -shared --exclude-libs=b.a %t/a.bc %t/b.a -o %t.so -y __divti3 2>&1 | FileCheck %s --check-prefix=TRACE +; RUN: llvm-readelf --dyn-syms %t.so | FileCheck %s + +; TRACE: {{.*}}/b.a: lazy definition of __divti3 +; TRACE-NEXT: lto.tmp: reference to __divti3 +; TRACE-NEXT: {{.*}}/b.a(b.o): definition of __divti3 + +; CHECK: Symbol table '.dynsym' contains 2 entries: +; CHECK-NOT: __divti3 + +;--- a.ll +target triple = "x86_64-unknown-linux" +target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128" + +define i128 @foo(i128 %x, i128 %y) { +entry: + %div = sdiv i128 %x, %y + ret i128 %div +} + +;--- b.s +.globl __divti3 +__divti3: _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits