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| author | Sam Clegg <sbc@chromium.org> | 2021-04-27 13:45:10 -0700 |
|---|---|---|
| committer | Sam Clegg <sbc@chromium.org> | 2021-04-28 10:29:41 -0700 |
| commit | 3e7bc0da57f17673ac61e5af3b005ffabfb449f3 (patch) | |
| tree | 59513c1d2b417d75f2d909b13e6d7c2ec338bf5b | |
| parent | bf72f6baccfe7d39a12f9319d108d6d55aefeeef (diff) | |
| download | llvm-3e7bc0da57f17673ac61e5af3b005ffabfb449f3.tar.gz | |
[lld][WebAssembly] Allow relocations against non-live global symbols
Just like the in case for function and data symbols this is needed to
support relocations in debug info sections which are allowed contains
relocations against non-live symbols.
The motivating use case is an object file that contains debug info that
references `__stack_pointer` (a local symbol) but does not actually
contain any uses of `__stack_pointer`.
Fixes: https://github.com/emscripten-core/emscripten/issues/14025
Differential Revision: https://reviews.llvm.org/D101399
| -rw-r--r-- | lld/test/wasm/debuginfo-undefined-global.s | 23 | ||||
| -rw-r--r-- | lld/test/wasm/globals.s | 2 | ||||
| -rw-r--r-- | lld/wasm/InputFiles.cpp | 2 |
3 files changed, 25 insertions, 2 deletions
diff --git a/lld/test/wasm/debuginfo-undefined-global.s b/lld/test/wasm/debuginfo-undefined-global.s new file mode 100644 index 000000000000..76794779e3c4 --- /dev/null +++ b/lld/test/wasm/debuginfo-undefined-global.s @@ -0,0 +1,23 @@ +# RUN: llvm-mc -filetype=obj -triple=wasm32-unknown-unknown -o %t.o %s +# RUN: wasm-ld -o %t.wasm %t.o +# RUN: obj2yaml %t.wasm | FileCheck %s + +# Debug sections are allowed to contains references to non-live symbols that +# then get GC'd. In this test the .debug_info seciton contains a reference to +# foo which is not otherwise used and will not be marked a live in the output. +# Verify the tombstone value is written to debug_info section. + +.globl _start +_start: + .functype _start () -> () + end_function + +.section .debug_info,"",@ + .int32 foo + +.globaltype foo, i32 +foo: + +# CHECK: - Type: CUSTOM +# CHECK-NEXT: Name: .debug_info +# CHECK-NEXT: Payload: FFFFFFFF diff --git a/lld/test/wasm/globals.s b/lld/test/wasm/globals.s index 6e049e1e73f9..bc3f7824cb20 100644 --- a/lld/test/wasm/globals.s +++ b/lld/test/wasm/globals.s @@ -1,4 +1,4 @@ -# RUN: llvm-mc -filetype=obj -triple=wasm32-unknown-unknown -o %t.o %s +mm# RUN: llvm-mc -filetype=obj -triple=wasm32-unknown-unknown -o %t.o %s # RUN: wasm-ld %t.o -o %t.wasm # RUN: obj2yaml %t.wasm | FileCheck %s diff --git a/lld/wasm/InputFiles.cpp b/lld/wasm/InputFiles.cpp index 6b3b0d2c2e52..889280a71c1a 100644 --- a/lld/wasm/InputFiles.cpp +++ b/lld/wasm/InputFiles.cpp @@ -212,7 +212,7 @@ uint64_t ObjFile::calcNewValue(const WasmRelocation &reloc, uint64_t tombstone, // so this will not produce a valid range conflicting with ranges of actual // code. In other sections we return reloc.Addend. - if ((isa<FunctionSymbol>(sym) || isa<DataSymbol>(sym)) && !sym->isLive()) + if (!isa<SectionSymbol>(sym) && !sym->isLive()) return tombstone ? tombstone : reloc.Addend; } |