87c43f3aa9
The linkage/visibility of `__profn_*` variables are derived
from the profiled functions.
extern_weak => linkonce
available_externally => linkonce_odr
internal => private
extern => private
_ => unchanged
The linkage/visibility of `__profc_*`/`__profd_*` variables are derived from
`__profn_*` with linkage/visibility wrestling for Windows.
The changes can be folded to the following without changing semantics.
```
if (TT.isOSBinFormatCOFF() && !NeedComdat) {
Linkage = GlobalValue::InternalLinkage;
Visibility = GlobalValue::DefaultVisibility;
}
```
That said, I think we can just delete the code block.
An extern/internal function will now use private `__profc_*`/`__profd_*`
variables, instead of internal ones. This saves some symbol table entries.
A non-comdat {linkonce,weak}_odr function will now use hidden external
`__profc_*`/`__profd_*` variables instead of internal ones. There is potential
object file size increase because such symbols need `/INCLUDE:` directives.
However such non-comdat functions are rare (note that non-comdat weak
definitions don't prevent duplicate definition error).
The behavior changes match ELF.
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D103355
88 lines
3.4 KiB
C++
88 lines
3.4 KiB
C++
// REQUIRES: lld-available
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// RUN: %clang_profgen -fcoverage-mapping -c %s -o %t0.o
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// RUN: %clang_profgen -fcoverage-mapping -c %s -DOBJ_1 -o %t1.o
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// RUN: %clang_profgen -fcoverage-mapping -c %s -DOBJ_2 -o %t2.o
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/// An external symbol can override a weak external symbol.
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// RUN: %clang_profgen -fcoverage-mapping -fuse-ld=lld -Wl,-opt:noref %t0.o %t1.o -o %t1
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// RUN: env LLVM_PROFILE_FILE=%t.profraw %run %t1 | FileCheck %s --check-prefix=CHECK1
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// RUN: llvm-profdata show %t.profraw --all-functions | FileCheck %s --check-prefix=PROFILE1
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// RUN: %clang_profgen -fcoverage-mapping -fuse-ld=lld -Wl,-opt:ref %t0.o %t1.o -o %t1
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// RUN: env LLVM_PROFILE_FILE=%t.profraw %run %t1 | FileCheck %s --check-prefix=CHECK1
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// RUN: llvm-profdata show %t.profraw --all-functions | FileCheck %s --check-prefix=PROFILE1
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/// link.exe does not support weak overridding weak.
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// RUN: %clang_profgen -fcoverage-mapping -fuse-ld=lld -Wl,-lldmingw,-opt:ref %t0.o %t2.o -o %t2
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// RUN: env LLVM_PROFILE_FILE=%t.profraw %run %t2 | FileCheck %s --check-prefix=CHECK2
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// RUN: llvm-profdata show %t.profraw --all-functions | FileCheck %s --check-prefix=PROFILE2
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/// Repeat the above tests with -ffunction-sections (associative comdat).
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// RUN: %clang_profgen -fcoverage-mapping -ffunction-sections -c %s -o %t0.o
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// RUN: %clang_profgen -fcoverage-mapping -ffunction-sections -c %s -DOBJ_1 -o %t1.o
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// RUN: %clang_profgen -fcoverage-mapping -ffunction-sections -c %s -DOBJ_2 -o %t2.o
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// RUN: %clang_profgen -fcoverage-mapping -fuse-ld=lld -Wl,-opt:noref %t0.o %t1.o -o %t1
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// RUN: env LLVM_PROFILE_FILE=%t.profraw %run %t1 | FileCheck %s --check-prefix=CHECK1
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// RUN: llvm-profdata show %t.profraw --all-functions | FileCheck %s --check-prefix=PROFILE1
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// RUN: %clang_profgen -fcoverage-mapping -fuse-ld=lld -Wl,-opt:ref %t0.o %t1.o -o %t1
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// RUN: env LLVM_PROFILE_FILE=%t.profraw %run %t1 | FileCheck %s --check-prefix=CHECK1
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// RUN: llvm-profdata show %t.profraw --all-functions | FileCheck %s --check-prefix=PROFILE1
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// RUN: %clang_profgen -fcoverage-mapping -fuse-ld=lld -Wl,-lldmingw,-opt:ref %t0.o %t2.o -o %t2
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// RUN: env LLVM_PROFILE_FILE=%t.profraw %run %t2 | FileCheck %s --check-prefix=CHECK2
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// RUN: llvm-profdata show %t.profraw --all-functions | FileCheck %s --check-prefix=PROFILE2
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// CHECK1: strong
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// CHECK1: strong
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/// Document the current behavior:
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/// __profc_?weak@@YAXXZ in %t1.o is local and has a zero value.
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/// Without GC it takes a duplicate entry.
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// PROFILE1: ?weak@@YAXXZ:
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// PROFILE1-NEXT: Hash:
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// PROFILE1-NEXT: Counters: 1
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// PROFILE1-NEXT: Function count: 0
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// PROFILE1: ?weak@@YAXXZ:
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// PROFILE1-NEXT: Hash:
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// PROFILE1-NEXT: Counters: 1
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// PROFILE1-NEXT: Function count: 2
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// CHECK2: weak
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// CHECK2: weak
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/// __profc__Z4weakv in %t2.o is weak and resolves to the value of %t0.o's copy.
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/// Without GC it takes a duplicate entry.
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// PROFILE2: ?weak@@YAXXZ:
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// PROFILE2-NEXT: Hash:
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// PROFILE2-NEXT: Counters: 1
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// PROFILE2-NEXT: Function count: 2
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// PROFILE2: ?weak@@YAXXZ:
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// PROFILE2-NEXT: Hash:
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// PROFILE2-NEXT: Counters: 1
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// PROFILE2-NEXT: Function count: 2
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#ifdef OBJ_1
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#include <stdio.h>
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void weak() { puts("strong"); }
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void foo() { weak(); }
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#elif defined(OBJ_2)
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#include <stdio.h>
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__attribute__((weak)) void weak() { puts("unreachable"); }
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void foo() { weak(); }
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#else
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#include <stdio.h>
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__attribute__((weak)) void weak() { puts("weak"); }
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void foo();
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int main() {
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foo();
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weak();
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}
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#endif
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