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| author |   Tobias Burnus <tobias@codesourcery.com> | 2020-12-11 16:43:06 +0000 |
|---|---|---|
| committer |   Tom Stellard <tstellar@redhat.com> | 2020-12-14 17:31:14 -0500 |
| commit | 700baa009dc685a0adc5f94d258be4ae24742471 (patch) | |
| tree | cc845ce47b9344db70e3fd8646c2ed007a87c97a | |
| parent | [KernelAddressSanitizer] Fix globals exclusion for indirect aliases (diff) | |
| download | llvm-project-700baa009dc685a0adc5f94d258be4ae24742471.tar.gz llvm-project-700baa009dc685a0adc5f94d258be4ae24742471.tar.bz2 llvm-project-700baa009dc685a0adc5f94d258be4ae24742471.zip | |
[MC][ELF] Accept abbreviated form with sh_flags and sh_entsize
D73999 / commit 75af9da755721123e62b45cd0bc0c5e688a9722a
added for LLVM 11 a check that sh_flags and sh_entsize (and sh_type)
changes are an error, in line with GNU assembler.
However, GNU assembler accepts and GCC generates an abbreviated form:
while the first .section contains the flags and entsize, subsequent
sections simply contain the name without repeating entsize or flags.
Do likewise for better compatibility.
See https://bugs.llvm.org/show_bug.cgi?id=48201
Reviewed By: jhenderson, MaskRay
Differential Revision: https://reviews.llvm.org/D92052
(cherry picked from commit 1deff4009e0ae661b03682901bf6932297ce7ea1)
| -rw-r--r-- | llvm/lib/MC/MCParser/ELFAsmParser.cpp | 7 | ||||
| -rw-r--r-- | llvm/test/MC/ELF/section-flags-changed.s | 3 | ||||
| -rw-r--r-- | llvm/test/MC/ELF/section-omitted-attributes.s | 11 |
3 files changed, 19 insertions, 2 deletions
diff --git a/llvm/lib/MC/MCParser/ELFAsmParser.cpp b/llvm/lib/MC/MCParser/ELFAsmParser.cpp index e5ab13bc719d..fb8215ef2281 100644 --- a/llvm/lib/MC/MCParser/ELFAsmParser.cpp +++ b/llvm/lib/MC/MCParser/ELFAsmParser.cpp @@ -644,10 +644,13 @@ EndStmt: !(SectionName == ".eh_frame" && Type == ELF::SHT_PROGBITS)) Error(loc, "changed section type for " + SectionName + ", expected: 0x" + utohexstr(Section->getType())); - if (Section->getFlags() != Flags) + // Check that flags are used consistently. However, the GNU assembler permits + // to leave out in subsequent uses of the same sections; for compatibility, + // do likewise. + if ((Flags || Size || !TypeName.empty()) && Section->getFlags() != Flags) Error(loc, "changed section flags for " + SectionName + ", expected: 0x" + utohexstr(Section->getFlags())); - if (Section->getEntrySize() != Size) + if ((Flags || Size || !TypeName.empty()) && Section->getEntrySize() != Size) Error(loc, "changed section entsize for " + SectionName + ", expected: " + Twine(Section->getEntrySize())); diff --git a/llvm/test/MC/ELF/section-flags-changed.s b/llvm/test/MC/ELF/section-flags-changed.s index 65f52cc29a6d..d2964ef046d1 100644 --- a/llvm/test/MC/ELF/section-flags-changed.s +++ b/llvm/test/MC/ELF/section-flags-changed.s @@ -9,4 +9,7 @@ foo: # CHECK: {{.*}}.s:[[# @LINE+1]]:1: error: changed section flags for .foo, expected: 0x6 .pushsection .foo,"a",@progbits +# CHECK: {{.*}}.s:[[# @LINE+1]]:1: error: changed section flags for .foo, expected: 0x6 +.section .foo,"",@progbits + .pushsection .foo,"ax",@progbits diff --git a/llvm/test/MC/ELF/section-omitted-attributes.s b/llvm/test/MC/ELF/section-omitted-attributes.s new file mode 100644 index 000000000000..72b7c9121387 --- /dev/null +++ b/llvm/test/MC/ELF/section-omitted-attributes.s @@ -0,0 +1,11 @@ +# RUN: llvm-mc -triple=x86_64 %s -o - | FileCheck %s + +# If section flags and other attributes are omitted, don't error. + +# CHECK: .section .foo,"aM",@progbits,1 + +.section .foo,"aM",@progbits,1 + +.section .foo + +.pushsection .foo |