forked from OSchip/llvm-project
a400ca3f3d
Fixes the main issue in PR41693
When both modes are used, two functions are created:
`sancov.module_ctor`, `sancov.module_ctor.$LastUnique`, where
$LastUnique is the current LastUnique counter that may be different in
another module.
`sancov.module_ctor.$LastUnique` belongs to the comdat group of the same
name (due to the non-null third field of the ctor in llvm.global_ctors).
COMDAT group section [ 9] `.group' [sancov.module_ctor] contains 6 sections:
[Index] Name
[ 10] .text.sancov.module_ctor
[ 11] .rela.text.sancov.module_ctor
[ 12] .text.sancov.module_ctor.6
[ 13] .rela.text.sancov.module_ctor.6
[ 23] .init_array.2
[ 24] .rela.init_array.2
# 2 problems:
# 1) If sancov.module_ctor in this module is discarded, this group
# has a relocation to a discarded section. ld.bfd and gold will
# error. (Another issue: it is silently accepted by lld)
# 2) The comdat group has an unstable name that may be different in
# another translation unit. Even if the linker allows the dangling relocation
# (with --noinhibit-exec), there will be many undesired .init_array entries
COMDAT group section [ 25] `.group' [sancov.module_ctor.6] contains 2 sections:
[Index] Name
[ 26] .init_array.2
[ 27] .rela.init_array.2
By using different module ctor names, the associated comdat group names
will also be different and thus stable across modules.
Reviewed By: morehouse, phosek
Differential Revision: https://reviews.llvm.org/D61510
llvm-svn: 360107
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| .. | ||
| abort-in-entry-block.ll | ||
| backedge-pruning.ll | ||
| chains.ll | ||
| cmp-tracing-api-x86_32.ll | ||
| cmp-tracing-api-x86_64.ll | ||
| cmp-tracing.ll | ||
| coff-comdat.ll | ||
| coff-pc-table-inline-8bit-counters.ll | ||
| coff-used-ctor.ll | ||
| const-cmp-tracing.ll | ||
| coverage-dbg.ll | ||
| coverage.ll | ||
| coverage2-dbg.ll | ||
| div-tracing.ll | ||
| gep-tracing.ll | ||
| inline-8bit-counters.ll | ||
| interposable-symbol-nocomdat.ll | ||
| no-func.ll | ||
| pc-table.ll | ||
| postdominator_check.ll | ||
| seh.ll | ||
| stack-depth-variable-declared-by-user.ll | ||
| stack-depth.ll | ||
| switch-tracing.ll | ||
| trace-pc-guard-comdat.ll | ||
| trace-pc-guard-inline-8bit-counters.ll | ||
| trace-pc-guard-nocomdat.ll | ||
| tracing-comdat.ll | ||
| tracing.ll | ||
| unreachable-critedge.ll | ||
| wineh.ll | ||