From 7f8141818358375cc626fc7e4779d61e39ee9276 Mon Sep 17 00:00:00 2001 From: Sam Clegg Date: Thu, 8 Mar 2018 01:16:05 +0000 Subject: [PATCH] [WebAssembly] Honor --allow-undefined even for explicit exports When a symbol is exported via --export=foo but --allow-undefined is also specified, the symbol is now allowed to be undefined. Previously we were special casing such symbols. This combinations of behavior is exactly what emescripten requires. Although we are trying hard not to allow emscripten specific features in lld, this one makes sense. Enforce this behavior by added this case to test/wasm/undefined.ll. Differential Revision: https://reviews.llvm.org/D44237 llvm-svn: 326976 --- lld/test/wasm/undefined.ll | 5 ++++- lld/wasm/Driver.cpp | 2 +- 2 files changed, 5 insertions(+), 2 deletions(-) diff --git a/lld/test/wasm/undefined.ll b/lld/test/wasm/undefined.ll index 69b7a82..a74dd6d 100644 --- a/lld/test/wasm/undefined.ll +++ b/lld/test/wasm/undefined.ll @@ -6,10 +6,13 @@ ; CHECK: error: {{.*}}.o: undefined symbol: foo ; CHECK: error: undefined symbol: baz -; But succeeds if we pass a file containing 'foo' as --allow-undefined-file. +; Succeeds if we pass a file containing 'foo' as --allow-undefined-file. ; RUN: echo 'foo' > %t.txt ; RUN: wasm-ld --check-signatures --allow-undefined-file=%t.txt -o %t.wasm %t.o +; Succeeds even if a missing symbol is added via --export +; RUN: wasm-ld --check-signatures --allow-undefined --export=xxx -o %t.wasm %t.o + target triple = "wasm32-unknown-unknown-wasm" ; Takes the address of the external foo() resulting in undefined external diff --git a/lld/wasm/Driver.cpp b/lld/wasm/Driver.cpp index ef0794c..a97026d 100644 --- a/lld/wasm/Driver.cpp +++ b/lld/wasm/Driver.cpp @@ -346,7 +346,7 @@ void LinkerDriver::link(ArrayRef ArgsArr) { Symbol *Sym = Symtab->find(Name); if (Sym && Sym->isDefined()) Sym->setHidden(false); - else + else if (!Config->AllowUndefined) error("symbol exported via --export not found: " + Name); } -- 2.7.4