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[LLD] [COFF] Fix handling of comdat .drectve sections #68116

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Merged
merged 1 commit into from
Oct 4, 2023
Merged

[LLD] [COFF] Fix handling of comdat .drectve sections #68116

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2 changes: 2 additions & 0 deletions lld/COFF/InputFiles.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -661,6 +661,8 @@ std::optional<Symbol *> ObjFile::createDefined(
if (prevailing) {
SectionChunk *c = readSection(sectionNumber, def, getName());
sparseChunks[sectionNumber] = c;
if (!c)
return nullptr;
c->sym = cast<DefinedRegular>(leader);
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nit: you could also insert at L664:

      if (!c)
        return nullptr;

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Thanks, I guess that'd work too.

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Updated it that way; thanks, that looks even neater!

c->selection = selection;
cast<DefinedRegular>(leader)->data = &c->repl;
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31 changes: 31 additions & 0 deletions lld/test/COFF/comdat-drectve.s
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@@ -0,0 +1,31 @@
# REQUIRES: x86

# RUN: llvm-mc -triple=x86_64-windows-gnu %s -filetype=obj -o %t.obj

# RUN: lld-link %t.obj -out:%t.exe -debug:symtab -subsystem:console
# RUN: llvm-readobj --coff-exports %t.exe | FileCheck %s

# CHECK: Name: exportedFunc

## This assembly snippet has been reduced from what Clang generates from
## this C snippet, with -fsanitize=address. Normally, the .drectve
## section would be a regular section - but when compiled with
## -fsanitize=address, it becomes a comdat section.
##
# void exportedFunc(void) {}
# void mainCRTStartup(void) {}
# static __attribute__((section(".drectve"), used)) const char export_chkstk[] =
# "-export:exportedFunc";

.text
.globl exportedFunc
exportedFunc:
retq

.globl mainCRTStartup
mainCRTStartup:
retq

.section .drectve,"dr",one_only,export_chkstk
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Should we leave that many spaces between .sectionand .drectve, or is this a tab character I don't see?

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It's tabs; the whitespace in the test file is exactly as the compiler output it - I've just stripped out parts of the compiler output but not rewritten the whitespace and all that.

export_chkstk:
.asciz "-export:exportedFunc"