From 3b8d2be527259b303d6c3428df16fb3fd02af2bc Mon Sep 17 00:00:00 2001 From: Sam Clegg Date: Fri, 26 Feb 2021 16:09:32 -0800 Subject: Reland: "[lld][WebAssembly] Initial support merging string data" This change was originally landed in: 5000a1b4b9edeb9e994f2a5b36da8d48599bea49 It was reverted in: 061e071d8c9b98526f35cad55a918a4f1615afd4 This change adds support for a new WASM_SEG_FLAG_STRINGS flag in the object format which works in a similar fashion to SHF_STRINGS in the ELF world. Unlike the ELF linker this support is currently limited: - No support for SHF_MERGE (non-string merging) - Always do full tail merging ("lo" can be merged with "hello") - Only support single byte strings (p2align 0) Like the ELF linker merging is only performed at `-O1` and above. This fixes part of https://bugs.llvm.org/show_bug.cgi?id=48828, although crucially it doesn't not currently support debug sections because they are not represented by data segments (they are custom sections) Differential Revision: https://reviews.llvm.org/D97657 --- llvm/lib/Object/WasmObjectFile.cpp | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'llvm/lib/Object/WasmObjectFile.cpp') diff --git a/llvm/lib/Object/WasmObjectFile.cpp b/llvm/lib/Object/WasmObjectFile.cpp index 946721a..df64a46 100644 --- a/llvm/lib/Object/WasmObjectFile.cpp +++ b/llvm/lib/Object/WasmObjectFile.cpp @@ -462,7 +462,7 @@ Error WasmObjectFile::parseLinkingSection(ReadContext &Ctx) { for (uint32_t I = 0; I < Count; I++) { DataSegments[I].Data.Name = readString(Ctx); DataSegments[I].Data.Alignment = readVaruint32(Ctx); - DataSegments[I].Data.LinkerFlags = readVaruint32(Ctx); + DataSegments[I].Data.LinkingFlags = readVaruint32(Ctx); } break; } @@ -1431,7 +1431,7 @@ Error WasmObjectFile::parseDataSection(ReadContext &Ctx) { // The rest of these Data fields are set later, when reading in the linking // metadata section. Segment.Data.Alignment = 0; - Segment.Data.LinkerFlags = 0; + Segment.Data.LinkingFlags = 0; Segment.Data.Comdat = UINT32_MAX; Segment.SectionOffset = Ctx.Ptr - Ctx.Start; Ctx.Ptr += Size; -- cgit v1.1