24a669d225
This adds back r204781.
Original message:
Aliases are just another name for a position in a file. As such, the
regular symbol resolutions are not applied. For example, given
define void @my_func() {
ret void
}
@my_alias = alias weak void ()* @my_func
@my_alias2 = alias void ()* @my_alias
We produce without this patch:
.weak my_alias
my_alias = my_func
.globl my_alias2
my_alias2 = my_alias
That is, in the resulting ELF file my_alias, my_func and my_alias are
just 3 names pointing to offset 0 of .text. That is *not* the
semantics of IR linking. For example, linking in a
@my_alias = alias void ()* @other_func
would require the strong my_alias to override the weak one and
my_alias2 would end up pointing to other_func.
There is no way to represent that with aliases being just another
name, so the best solution seems to be to just disallow it, converting
a miscompile into an error.
llvm-svn: 204934
43 lines
783 B
LLVM
43 lines
783 B
LLVM
; RUN: opt < %s -globalopt -S | FileCheck %s
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@foo1 = alias void ()* @foo2
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; CHECK: @foo1 = alias void ()* @bar2
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@foo2 = alias void()* @bar1
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; CHECK: @foo2 = alias void ()* @bar2
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@bar1 = alias void ()* @bar2
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; CHECK: @bar1 = alias void ()* @bar2
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@weak1 = alias weak void ()* @bar2
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; CHECK: @weak1 = alias weak void ()* @bar2
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define void @bar2() {
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ret void
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}
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; CHECK: define void @bar2()
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define void @baz() {
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entry:
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call void @foo1()
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; CHECK: call void @bar2()
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call void @foo2()
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; CHECK: call void @bar2()
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call void @bar1()
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; CHECK: call void @bar2()
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call void @weak1()
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; CHECK: call void @weak1()
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ret void
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}
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@foo3 = alias void ()* @bar3
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; CHECK-NOT: bar3
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define internal void @bar3() {
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ret void
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}
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;CHECK: define void @foo3
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