From 15a5e86fb387359f736e919eeb5cc2b9f4477d48 Mon Sep 17 00:00:00 2001 From: Thomas Lively Date: Thu, 24 Sep 2020 20:35:29 -0700 Subject: [lld][WebAssembly] Allow `atomics` feature with unshared memory https://github.com/WebAssembly/threads/issues/144 updated the WebAssembly threads proposal to make atomic operations on unshared memories valid. This change updates the feature checking in the linker accordingly. Production WebAssembly engines have recently been updated to allow this behvaior, but after this change users who accidentally use atomics with unshared memories on older versions of the engines will get validation errors at runtime rather than link errors. Differential Revision: https://reviews.llvm.org/D79530 --- lld/test/wasm/shared-memory.yaml | 4 ---- lld/wasm/Writer.cpp | 9 --------- 2 files changed, 13 deletions(-) (limited to 'lld') diff --git a/lld/test/wasm/shared-memory.yaml b/lld/test/wasm/shared-memory.yaml index 8a03e0e..1c238a5 100644 --- a/lld/test/wasm/shared-memory.yaml +++ b/lld/test/wasm/shared-memory.yaml @@ -8,8 +8,6 @@ # RUN: not wasm-ld --no-entry --shared-memory --max-memory=131072 --features=atomics %t1.o -o - 2>&1 | FileCheck %s --check-prefix SHARED-NO-BULK-MEM -# RUN: not wasm-ld --no-entry --features=atomics %t1.o -o - 2>&1 | FileCheck %s --check-prefix ATOMICS-NO-SHARED - # RUN: wasm-ld --relocatable --features=atomics %t1.o -o - | obj2yaml | FileCheck %s --check-prefix ATOMICS-RELOCATABLE # RUN: wasm-ld --no-entry --shared-memory --max-memory=131072 --features=atomics,bulk-memory %t1.o -o - | obj2yaml | FileCheck %s --check-prefix SHARED @@ -65,8 +63,6 @@ Sections: # SHARED-NO-BULK-MEM: 'bulk-memory' feature must be used in order to use shared memory -# ATOMICS-NO-SHARED: 'atomics' feature is used, so --shared-memory must be used{{$}} - # ATOMICS-RELOCATABLE: - Type: MEMORY # ATOMICS-RELOCATABLE-NEXT: Memories: # ATOMICS-RELOCATABLE-NEXT: Initial: 0x00000001 diff --git a/lld/wasm/Writer.cpp b/lld/wasm/Writer.cpp index b7adec7..3d49417 100644 --- a/lld/wasm/Writer.cpp +++ b/lld/wasm/Writer.cpp @@ -450,15 +450,6 @@ void Writer::populateTargetFeatures() { for (const auto &key : used.keys()) allowed.insert(std::string(key)); - if (!config->relocatable && allowed.count("atomics") && - !config->sharedMemory) { - if (inferFeatures) - error(Twine("'atomics' feature is used by ") + used["atomics"] + - ", so --shared-memory must be used"); - else - error("'atomics' feature is used, so --shared-memory must be used"); - } - if (!config->checkFeatures) return; -- cgit v1.1