Files
clang-p2996/lld/test/ELF/common-shared.s
Fangrui Song 69d10d282e [ELF] Update st_size when merging a common symbol with a shared symbol
When a common symbol is merged with a shared symbol, increase st_size if
the shared symbol has a larger st_size. At runtime, the executable's
symbol overrides the shared symbol.  The shared symbol may be created
from common symbols in a previous link.  This rule makes sure we pick
the largest size among all common symbols.

This behavior matches GNU ld. See
https://sourceware.org/bugzilla/show_bug.cgi?id=25236 for discussions.

A shared symbol does not hold alignment constraints. Ignore the
alignment update.

Reviewed By: peter.smith

Differential Revision: https://reviews.llvm.org/D71161
2019-12-13 09:23:36 -08:00

17 lines
493 B
ArmAsm

# REQUIRES: x86
## When a common symbol is merged with a shared symbol, pick the larger st_size.
# RUN: llvm-mc -filetype=obj -triple=x86_64 %s -o %t.o
# RUN: echo '.globl com; .comm com, 16' | llvm-mc -filetype=obj -triple=x86_64 - -o %t1.o
# RUN: ld.lld -shared %t1.o -o %t1.so
# RUN: ld.lld %t.o %t1.so -o %t
# RUN: llvm-readelf -s %t | FileCheck %s
# RUN: ld.lld %t1.so %t.o -o %t
# RUN: llvm-readelf -s %t | FileCheck %s
# CHECK: 16 OBJECT GLOBAL DEFAULT 7 com
.globl com
.comm com,1