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[lld][WebAssembly] Fix for --relocatable and signature mismatches 

This is a followup to https://reviews.llvm.org/D78779.

When signatures mismatch we create set of variant symbols.  Some of
the fields in these symbols were not be initialized correct.
Specifically we were seeing isUsedInRegularObj not being set correctly,
leading to the symbol not getting included in the symbol table
and a crash writing relections in --reloctable mode.

There is larger refactor due here, but this is a minimal change the
fixes the bug at hand.

Differential Revision: https://reviews.llvm.org/D79756
This commit is contained in:
Sam Clegg 2020-05-11 17:39:04 -07:00
parent 4d4ea9ac59
commit 064e9907ba
3 changed files with 75 additions and 0 deletions
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12
lld/test/wasm/Inputs/sig_mismatch.s Normal file
View File

@ -0,0 +1,12 @@
.globl foo
foo:
.functype foo (f32) -> (i32)
i32.const 0
end_function
.globl call_foo
call_foo:
.functype call_foo () -> (i32)
call foo
end_function

57
lld/test/wasm/signature-mismatch-relocatable.s Normal file
View File

@ -0,0 +1,57 @@
# RUN: llvm-mc -filetype=obj -triple=wasm32-unknown-unknown -o %t.o %s
# RUN: llvm-mc -filetype=obj -triple=wasm32-unknown-unknown -o %t2.o %S/Inputs/sig_mismatch.s
# RUN: wasm-ld --relocatable %t.o %t2.o -o %t.wasm
# RUN: obj2yaml %t.wasm | FileCheck %s
# Regression test for handling of signature mismatches (variant function
# symbols) and relocatable output. This issue only occurred when the undefined
# function was seen first and the defined function was referenced within the
# the defining file (see %S/Inputs/sig_mismatch.s).
.globl _start
_start:
.functype _start () -> ()
i32.const 1
i64.const 2
i32.const 3
call foo
end_function
.functype foo (i32, i64, i32) -> (i32)
# CHECK: - Type: CUSTOM
# CHECK-NEXT: Name: linking
# CHECK-NEXT: Version: 2
# CHECK-NEXT: SymbolTable:
# CHECK-NEXT: - Index: 0
# CHECK-NEXT: Kind: FUNCTION
# CHECK-NEXT: Name: _start
# CHECK-NEXT: Flags: [ ]
# CHECK-NEXT: Function: 1
# CHECK-NEXT: - Index: 1
# CHECK-NEXT: Kind: FUNCTION
# CHECK-NEXT: Name: foo
# CHECK-NEXT: Flags: [ ]
# CHECK-NEXT: Function: 2
# CHECK-NEXT: - Index: 2
# CHECK-NEXT: Kind: FUNCTION
# CHECK-NEXT: Name: call_foo
# CHECK-NEXT: Flags: [ ]
# CHECK-NEXT: Function: 3
# CHECK-NEXT: - Index: 3
# CHECK-NEXT: Kind: FUNCTION
# CHECK-NEXT: Name: 'signature_mismatch:foo'
# CHECK-NEXT: Flags: [ BINDING_LOCAL ]
# CHECK-NEXT: Function: 0
# CHECK-NEXT: - Type: CUSTOM
# CHECK-NEXT: Name: name
# CHECK-NEXT: FunctionNames:
# CHECK-NEXT: - Index: 0
# CHECK-NEXT: Name: 'signature_mismatch:foo'
# CHECK-NEXT: - Index: 1
# CHECK-NEXT: Name: _start
# CHECK-NEXT: - Index: 2
# CHECK-NEXT: Name: foo
# CHECK-NEXT: - Index: 3
# CHECK-NEXT: Name: call_foo
# CHECK-NEXT:...

6
lld/wasm/SymbolTable.cpp
View File

@ -113,6 +113,7 @@ std::pair<Symbol *, bool> SymbolTable::insertName(StringRef name) {
sym->isUsedInRegularObj = false;
sym->canInline = true;
sym->traced = trace;
sym->forceExport = false;
symVector.emplace_back(sym);
return {sym, true};
}
@ -598,6 +599,11 @@ bool SymbolTable::getFunctionVariant(Symbol* sym, const WasmSignature *sig,
// Create a new variant;
LLVM_DEBUG(dbgs() << "added new variant\n");
variant = reinterpret_cast<Symbol *>(make<SymbolUnion>());
variant->isUsedInRegularObj =
!file || file->kind() == InputFile::ObjectKind;
variant->canInline = true;
variant->traced = false;
variant->forceExport = false;
variants.push_back(variant);
} else {
LLVM_DEBUG(dbgs() << "variant already exists: " << toString(*variant) << "\n");