The difference is that now we don't error on out-of-comdat access to
internal global values. We copy them instead. This seems to match the
expectation of COFF linkers (see pr25686).
Original message:
Start deciding earlier what to link.
A traditional linker is roughly split in symbol resolution and
"copying
stuff".
The two tasks are badly mixed in lib/Linker.
This starts splitting them apart.
With this patch there are no direct call to linkGlobalValueBody or
linkGlobalValueProto. Everything is linked via WapValue.
This also includes a few fixes:
* A GV goes undefined if the comdat is dropped (comdat11.ll).
* We error if an internal GV goes undefined (comdat13.ll).
* We don't link an unused comdat.
The first two match the behavior of an ELF linker. The second one is
equivalent to running globaldce on the input.
llvm-svn: 254418
31 lines
832 B
LLVM
31 lines
832 B
LLVM
; RUN: llvm-link -S %s %p/Inputs/comdat13.ll -o - | FileCheck %s
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; In Inputs/comdat13.ll a function not in the $foo comdat (zed) references an
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; internal function in the comdat $foo.
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; The IR would be ilegal on ELF ("relocation refers to discarded section"),
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; but COFF linkers seem to just duplicate the comdat.
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$foo = comdat any
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@foo = internal global i8 0, comdat
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define i8* @bar() {
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ret i8* @foo
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}
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; CHECK: $foo = comdat any
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; CHECK: @foo = internal global i8 0, comdat
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; CHECK: @foo.1 = internal global i8 1, comdat($foo)
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; CHECK: define i8* @bar() {
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; CHECK-NEXT: ret i8* @foo
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; CHECK-NEXT: }
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; CHECK: define i8* @zed() {
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; CHECK-NEXT: call void @bax()
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; CHECK-NEXT: ret i8* @foo.1
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; CHECK-NEXT: }
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; CHECK: define internal void @bax() comdat($foo) {
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; CHECK-NEXT: ret void
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; CHECK-NEXT: }
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