llvm-project/llvm/test/ThinLTO/X86/hidden-escaped-symbols-alt.ll
serge-sans-paille 232e0a011e
[lto] Do not try to internalize symbols with escaped name
Because of LLVM mangling escape sequence (through '\01' prefix), it is possible
for a single symbols two have two different IR representations.

For instance, consider @symbol and @"\01_symbol". On OSX, because of the system
mangling rules, these two IR names point are converted in the same final symbol
upon linkage.

LTO doesn't model this behavior, which may result in symbols being incorrectly
internalized (if all reference use the escaping sequence while the definition
doesn't).

The proper approach is probably to use the mangled name to compute GUID to
avoid the dual representation, but we can also avoid discarding symbols that are
bound to two different IR names. This is an approximation, but it's less
intrusive on the codebase.

Fix #57864

Differential Revision: https://reviews.llvm.org/D135710
2022-10-14 22:34:17 +02:00

43 lines
1.4 KiB
LLVM

; Check interaction between LTO and LLVM mangling escape char, see #57864.
; RUN: split-file %s %t
; RUN: opt -module-summary %t/hide-me.ll -o %t/hide-me.bc
; RUN: opt -module-summary %t/ref.ll -o %t/ref.bc
; RUN: llvm-lto2 run \
; RUN: -r %t/hide-me.bc,_hide_me,p \
; RUN: -r %t/ref.bc,_main,plx \
; RUN: -r %t/ref.bc,_hide_me,l \
; RUN: --select-save-temps=precodegen \
; RUN: -o %t/out \
; RUN: %t/hide-me.bc %t/ref.bc
; RUN: llvm-dis %t/out.1.5.precodegen.bc -o - | FileCheck --check-prefix=CHECK-HIDE %s
; RUN: llvm-dis %t/out.2.5.precodegen.bc -o - | FileCheck --check-prefix=CHECK-REF %s
;--- hide-me.ll
target datalayout = "e-m:o-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-apple-macosx10.7.0"
@"\01_hide_me" = hidden local_unnamed_addr global i8 8, align 1
;--- ref.ll
target datalayout = "e-m:o-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-apple-macosx10.7.0"
@hide_me = external local_unnamed_addr global i8
define i8 @main() {
%1 = load i8, ptr @hide_me, align 1
ret i8 %1
}
; CHECK-HIDE: @"\01_hide_me" = hidden local_unnamed_addr global i8 8, align 1
; CHECK-REF: @hide_me = external local_unnamed_addr global i8
; CHECK-REF: define dso_local i8 @main() local_unnamed_addr #0 {
; CHECK-REF: %1 = load i8, ptr @hide_me, align 1
; CHECK-REF: ret i8 %1
; CHECK-REF: }