[llvm] 0794298 - [llvm-objcopy] Add --compress-sections
Fangrui Song via llvm-commits
llvm-commits at lists.llvm.org
Mon Apr 15 00:48:57 PDT 2024
Author: Fangrui Song
Date: 2024-04-15T00:48:51-07:00
New Revision: 07942987b58558a8bcb2cfb7d8bc3d46b1cb1d2b
URL: https://github.com/llvm/llvm-project/commit/07942987b58558a8bcb2cfb7d8bc3d46b1cb1d2b
DIFF: https://github.com/llvm/llvm-project/commit/07942987b58558a8bcb2cfb7d8bc3d46b1cb1d2b.diff
LOG: [llvm-objcopy] Add --compress-sections
--compress-sections is similar to --compress-debug-sections but applies
to arbitrary sections.
* `--compress-sections <section>=none`: decompress sections
* `--compress-sections <section>=[zlib|zstd]`: compress sections with zlib/zstd
Like `--remove-section`, the pattern is by default a glob, but a regex
when --regex is specified.
For `--remove-section` like options, `!` prevents matches and is not
dependent on ordering (see `ELF/wildcard-syntax.test`). Since
`--compress-sections a=zlib --compress-sections a=none` naturally allows
overriding, having an order-independent `!` would be confusing.
Therefore, `!` is disallowed.
Sections within a segment are effectively immutable. Report an error for
an attempt to (de)compress them. `SHF_ALLOC` sections in a relocatable
file can be compressed, but linkers usually reject them.
Note: Before this patch, a compressed relocation section is recognized
as a `RelocationSectionBase` as well and `removeSections` `!ToRemove(*ToRelSec)`
may incorrectly interpret a `CompressedSections` as `RelocationSectionBase`,
leading to ubsan failure for the new test. Fix this by setting
`OriginalFlags` in CompressedSection::CompressedSection.
Link: https://discourse.llvm.org/t/rfc-compress-arbitrary-sections-with-ld-lld-compress-sections/71674
Pull Request: https://github.com/llvm/llvm-project/pull/85036
Added:
llvm/test/tools/llvm-objcopy/ELF/compress-sections-within-segment.s
llvm/test/tools/llvm-objcopy/ELF/compress-sections.s
Modified:
llvm/docs/CommandGuide/llvm-objcopy.rst
llvm/docs/ReleaseNotes.rst
llvm/include/llvm/ObjCopy/CommonConfig.h
llvm/lib/ObjCopy/ELF/ELFObjcopy.cpp
llvm/lib/ObjCopy/ELF/ELFObject.cpp
llvm/test/tools/llvm-objcopy/ELF/decompress-sections.test
llvm/tools/llvm-objcopy/ObjcopyOptions.cpp
llvm/tools/llvm-objcopy/ObjcopyOpts.td
Removed:
################################################################################
diff --git a/llvm/docs/CommandGuide/llvm-objcopy.rst b/llvm/docs/CommandGuide/llvm-objcopy.rst
index 985d16eb11cfb6..57d6280d57c8bd 100644
--- a/llvm/docs/CommandGuide/llvm-objcopy.rst
+++ b/llvm/docs/CommandGuide/llvm-objcopy.rst
@@ -309,6 +309,14 @@ them.
Compress DWARF debug sections in the output, using the specified format.
Supported formats are ``zlib`` and ``zstd``. Use ``zlib`` if ``<format>`` is omitted.
+.. option:: --compress-sections <section>=<format>
+
+ Compress or decompress sections matched by ``<section>`` using the specified
+ format. Supported formats are ``zlib`` and ``zstd``. Specify ``none`` for
+ decompression. When a section is matched by multiple options, the last one
+ wins. A wildcard ``<section>`` starting with '!' is disallowed.
+ Sections within a segment cannot be (de)compressed.
+
.. option:: --decompress-debug-sections
Decompress any compressed DWARF debug sections in the output.
diff --git a/llvm/docs/ReleaseNotes.rst b/llvm/docs/ReleaseNotes.rst
index d2d542752b555e..11add9274a7a07 100644
--- a/llvm/docs/ReleaseNotes.rst
+++ b/llvm/docs/ReleaseNotes.rst
@@ -186,6 +186,10 @@ Changes to the LLVM tools
for ELF input to skip the specified symbols when executing other options
that can change a symbol's name, binding or visibility.
+* llvm-objcopy now supports ``--compress-sections`` to compress or decompress
+ arbitrary sections not within a segment.
+ (`#85036 <https://github.com/llvm/llvm-project/pull/85036>`_.)
+
* llvm-profgen now supports COFF+DWARF binaries. This enables Sample-based PGO
on Windows using Intel VTune's SEP. For details on usage, see the `end-user
documentation for SPGO
diff --git a/llvm/include/llvm/ObjCopy/CommonConfig.h b/llvm/include/llvm/ObjCopy/CommonConfig.h
index 9d6d5fb23b18e7..ae08d4032736e2 100644
--- a/llvm/include/llvm/ObjCopy/CommonConfig.h
+++ b/llvm/include/llvm/ObjCopy/CommonConfig.h
@@ -262,6 +262,9 @@ struct CommonConfig {
bool DecompressDebugSections = false;
DebugCompressionType CompressionType = DebugCompressionType::None;
+
+ SmallVector<std::pair<NameMatcher, llvm::DebugCompressionType>, 0>
+ compressSections;
};
} // namespace objcopy
diff --git a/llvm/lib/ObjCopy/ELF/ELFObjcopy.cpp b/llvm/lib/ObjCopy/ELF/ELFObjcopy.cpp
index 205bc1ef5b1a19..f343d1447e0554 100644
--- a/llvm/lib/ObjCopy/ELF/ELFObjcopy.cpp
+++ b/llvm/lib/ObjCopy/ELF/ELFObjcopy.cpp
@@ -215,23 +215,41 @@ static Error dumpSectionToFile(StringRef SecName, StringRef Filename,
}
Error Object::compressOrDecompressSections(const CommonConfig &Config) {
- // Build a list of the debug sections we are going to replace.
- // We can't call `AddSection` while iterating over sections,
+ // Build a list of sections we are going to replace.
+ // We can't call `addSection` while iterating over sections,
// because it would mutate the sections array.
SmallVector<std::pair<SectionBase *, std::function<SectionBase *()>>, 0>
ToReplace;
for (SectionBase &Sec : sections()) {
- if ((Sec.Flags & SHF_ALLOC) || !StringRef(Sec.Name).starts_with(".debug"))
+ std::optional<DebugCompressionType> CType;
+ for (auto &[Matcher, T] : Config.compressSections)
+ if (Matcher.matches(Sec.Name))
+ CType = T;
+ // Handle --compress-debug-sections and --decompress-debug-sections, which
+ // apply to non-ALLOC debug sections.
+ if (!(Sec.Flags & SHF_ALLOC) && StringRef(Sec.Name).starts_with(".debug")) {
+ if (Config.CompressionType != DebugCompressionType::None)
+ CType = Config.CompressionType;
+ else if (Config.DecompressDebugSections)
+ CType = DebugCompressionType::None;
+ }
+ if (!CType)
continue;
+
+ if (Sec.ParentSegment)
+ return createStringError(
+ errc::invalid_argument,
+ "section '" + Sec.Name +
+ "' within a segment cannot be (de)compressed");
+
if (auto *CS = dyn_cast<CompressedSection>(&Sec)) {
- if (Config.DecompressDebugSections) {
+ if (*CType == DebugCompressionType::None)
ToReplace.emplace_back(
&Sec, [=] { return &addSection<DecompressedSection>(*CS); });
- }
- } else if (Config.CompressionType != DebugCompressionType::None) {
- ToReplace.emplace_back(&Sec, [&, S = &Sec] {
+ } else if (*CType != DebugCompressionType::None) {
+ ToReplace.emplace_back(&Sec, [=, S = &Sec] {
return &addSection<CompressedSection>(
- CompressedSection(*S, Config.CompressionType, Is64Bits));
+ CompressedSection(*S, *CType, Is64Bits));
});
}
}
diff --git a/llvm/lib/ObjCopy/ELF/ELFObject.cpp b/llvm/lib/ObjCopy/ELF/ELFObject.cpp
index 8b6a0035dae356..02591e6f987c26 100644
--- a/llvm/lib/ObjCopy/ELF/ELFObject.cpp
+++ b/llvm/lib/ObjCopy/ELF/ELFObject.cpp
@@ -548,6 +548,7 @@ CompressedSection::CompressedSection(const SectionBase &Sec,
CompressedData);
Flags |= ELF::SHF_COMPRESSED;
+ OriginalFlags |= ELF::SHF_COMPRESSED;
size_t ChdrSize = Is64Bits ? sizeof(object::Elf_Chdr_Impl<object::ELF64LE>)
: sizeof(object::Elf_Chdr_Impl<object::ELF32LE>);
Size = ChdrSize + CompressedData.size();
@@ -2161,6 +2162,10 @@ Error Object::removeSections(
std::begin(Sections), std::end(Sections), [=](const SecPtr &Sec) {
if (ToRemove(*Sec))
return false;
+ // TODO: A compressed relocation section may be recognized as
+ // RelocationSectionBase. We don't want such a section to be removed.
+ if (isa<CompressedSection>(Sec))
+ return true;
if (auto RelSec = dyn_cast<RelocationSectionBase>(Sec.get())) {
if (auto ToRelSec = RelSec->getSection())
return !ToRemove(*ToRelSec);
diff --git a/llvm/test/tools/llvm-objcopy/ELF/compress-sections-within-segment.s b/llvm/test/tools/llvm-objcopy/ELF/compress-sections-within-segment.s
new file mode 100644
index 00000000000000..064ffcadc12e32
--- /dev/null
+++ b/llvm/test/tools/llvm-objcopy/ELF/compress-sections-within-segment.s
@@ -0,0 +1,38 @@
+## Disallow (de)compression for sections within a segment as they are
+## effectively immutable.
+# RUN: rm -rf %t && mkdir %t && cd %t
+# RUN: yaml2obj %s -o a
+# RUN: not llvm-objcopy a /dev/null --compress-sections .text=zlib 2>&1 | FileCheck %s --implicit-check-not=error:
+
+# CHECK: error: 'a': section '.text' within a segment cannot be (de)compressed
+
+# RUN: not llvm-objcopy a /dev/null --compress-sections foo=none 2>&1 | FileCheck %s --check-prefix=CHECK2 --implicit-check-not=error:
+
+# CHECK2: error: 'a': section 'foo' within a segment cannot be (de)compressed
+
+## There is an error even if 'foo' is already compressed with zlib.
+# RUN: not llvm-objcopy a /dev/null --compress-sections foo=zlib 2>&1 | FileCheck %s --check-prefix=CHECK3 --implicit-check-not=error:
+
+# CHECK3: error: 'a': section 'foo' within a segment cannot be (de)compressed
+
+--- !ELF
+FileHeader:
+ Class: ELFCLASS64
+ Data: ELFDATA2LSB
+ Type: ET_EXEC
+ Machine: EM_X86_64
+ProgramHeaders:
+ - Type: PT_LOAD
+ FirstSec: .text
+ LastSec: foo
+ Align: 0x1000
+ Offset: 0x1000
+Sections:
+ - Name: .text
+ Type: SHT_PROGBITS
+ Offset: 0x1000
+ Content: C3
+ - Name: foo
+ Type: SHT_PROGBITS
+ Flags: [ SHF_COMPRESSED ]
+ Content: 010000000000000040000000000000000100000000000000789cd36280002d3269002f800151
diff --git a/llvm/test/tools/llvm-objcopy/ELF/compress-sections.s b/llvm/test/tools/llvm-objcopy/ELF/compress-sections.s
new file mode 100644
index 00000000000000..e6fa86068a1aee
--- /dev/null
+++ b/llvm/test/tools/llvm-objcopy/ELF/compress-sections.s
@@ -0,0 +1,128 @@
+# REQUIRES: x86-registered-target, zlib, zstd
+
+# RUN: rm -rf %t && mkdir %t && cd %t
+# RUN: llvm-mc -filetype=obj -triple=x86_64 %s -o a.o
+## '*0=none' wins because it is the last. '*0' sections are decompressed (if originally compressed) or kept unchanged (if uncompressed).
+## No section is named 'nomatch'. The third option is a no-op.
+# RUN: llvm-objcopy a.o out --compress-sections='*0=zlib' --compress-sections '*0=none' --compress-sections 'nomatch=none' 2>&1 | count 0
+# RUN: llvm-readelf -S out | FileCheck %s --check-prefix=CHECK1
+
+# CHECK1: Name Type Address Off Size ES Flg Lk Inf Al
+# CHECK1: .text PROGBITS [[#%x,TEXT:]] [[#%x,]] [[#%x,]] 00 AX 0 0 4
+# CHECK1: foo0 PROGBITS [[#%x,FOO0:]] [[#%x,]] [[#%x,]] 00 A 0 0 8
+# CHECK1-NEXT: .relafoo0 RELA [[#%x,]] [[#%x,]] [[#%x,]] 18 I 11 3 8
+# CHECK1-NEXT: foo1 PROGBITS [[#%x,FOO1:]] [[#%x,]] [[#%x,]] 00 A 0 0 8
+# CHECK1-NEXT: .relafoo1 RELA [[#%x,]] [[#%x,]] [[#%x,]] 18 I 11 5 8
+# CHECK1: nonalloc0 PROGBITS 0000000000000000 [[#%x,]] [[#%x,]] 00 0 0 8
+# CHECK1-NEXT: .relanonalloc0 RELA [[#%x,]] [[#%x,]] [[#%x,]] 18 I 11 7 8
+# CHECK1-NEXT: nonalloc1 PROGBITS 0000000000000000 [[#%x,]] [[#%x,]] 00 0 0 8
+# CHECK1-NEXT: .debug_str PROGBITS 0000000000000000 [[#%x,]] [[#%x,]] 01 MS 0 0 1
+
+## Mixing zlib and zstd.
+# RUN: llvm-objcopy a.o out2 --compress-sections '*c0=zlib' --compress-sections .debug_str=zstd
+# RUN: llvm-readelf -Sr -x nonalloc0 -x .debug_str out2 2>&1 | FileCheck %s --check-prefix=CHECK2
+# RUN: llvm-readelf -z -x nonalloc0 -x .debug_str out2 | FileCheck %s --check-prefix=CHECK2DE
+
+# CHECK2: Name Type Address Off Size ES Flg Lk Inf Al
+# CHECK2: .text PROGBITS [[#%x,TEXT:]] [[#%x,]] [[#%x,]] 00 AX 0 0 4
+# CHECK2: foo0 PROGBITS [[#%x,FOO0:]] [[#%x,]] [[#%x,]] 00 A 0 0 8
+# CHECK2-NEXT: .relafoo0 RELA [[#%x,]] [[#%x,]] [[#%x,]] 18 I 11 3 8
+# CHECK2-NEXT: foo1 PROGBITS [[#%x,FOO1:]] [[#%x,]] [[#%x,]] 00 A 0 0 8
+# CHECK2-NEXT: .relafoo1 RELA [[#%x,]] [[#%x,]] [[#%x,]] 18 I 11 5 8
+# CHECK2: nonalloc0 PROGBITS 0000000000000000 [[#%x,]] [[#%x,]] 00 C 0 0 8
+# CHECK2-NEXT: .relanonalloc0 RELA [[#%x,]] [[#%x,]] [[#%x,]] 18 IC 11 7 8
+# CHECK2-NEXT: nonalloc1 PROGBITS 0000000000000000 [[#%x,]] [[#%x,]] 00 0 0 8
+# CHECK2-NEXT: .debug_str PROGBITS 0000000000000000 [[#%x,]] [[#%x,]] 01 MSC 0 0 8
+
+## llvm-readelf -r doesn't support SHF_COMPRESSED SHT_RELA.
+# CHECK2: warning: {{.*}}: unable to read relocations from SHT_RELA section with index 8: section [index 8] has an invalid sh_size ([[#]]) which is not a multiple of its sh_entsize (24)
+
+# CHECK2: Hex dump of section 'nonalloc0':
+## zlib with ch_size=0x10
+# CHECK2-NEXT: 01000000 00000000 10000000 00000000
+# CHECK2-NEXT: 08000000 00000000 {{.*}}
+# CHECK2: Hex dump of section '.debug_str':
+## zstd with ch_size=0x38
+# CHECK2-NEXT: 02000000 00000000 38000000 00000000
+# CHECK2-NEXT: 01000000 00000000 {{.*}}
+
+# CHECK2DE: Hex dump of section 'nonalloc0':
+# CHECK2DE-NEXT: 0x00000000 00000000 00000000 00000000 00000000 ................
+# CHECK2DE-EMPTY:
+# CHECK2DE-NEXT: Hex dump of section '.debug_str':
+# CHECK2DE-NEXT: 0x00000000 41414141 41414141 41414141 41414141 AAAAAAAAAAAAAAAA
+
+## --decompress-debug-sections takes precedence, even if it is before --compress-sections.
+# RUN: llvm-objcopy a.o out3 --decompress-debug-sections --compress-sections .debug_str=zstd
+# RUN: llvm-readelf -S out3 | FileCheck %s --check-prefix=CHECK3
+
+# CHECK3: .debug_str PROGBITS 0000000000000000 [[#%x,]] [[#%x,]] 01 MS 0 0 1
+
+# RUN: llvm-objcopy a.o out4 --compress-sections '*0=zlib'
+# RUN: llvm-readelf -S out4 | FileCheck %s --check-prefix=CHECK4
+
+# CHECK4: Name Type Address Off Size ES Flg Lk Inf Al
+# CHECK4: .text PROGBITS [[#%x,TEXT:]] [[#%x,]] [[#%x,]] 00 AX 0 0 4
+# CHECK4: foo0 PROGBITS [[#%x,FOO0:]] [[#%x,]] [[#%x,]] 00 AC 0 0 8
+# CHECK4-NEXT: .relafoo0 RELA [[#%x,]] [[#%x,]] [[#%x,]] 18 IC 11 3 8
+# CHECK4-NEXT: foo1 PROGBITS [[#%x,FOO1:]] [[#%x,]] [[#%x,]] 00 A 0 0 8
+# CHECK4-NEXT: .relafoo1 RELA [[#%x,]] [[#%x,]] [[#%x,]] 18 I 11 5 8
+# CHECK4: nonalloc0 PROGBITS 0000000000000000 [[#%x,]] [[#%x,]] 00 C 0 0 8
+# CHECK4-NEXT: .relanonalloc0 RELA [[#%x,]] [[#%x,]] [[#%x,]] 18 IC 11 7 8
+# CHECK4-NEXT: nonalloc1 PROGBITS 0000000000000000 [[#%x,]] [[#%x,]] 00 0 0 8
+# CHECK4-NEXT: .debug_str PROGBITS 0000000000000000 [[#%x,]] [[#%x,]] 01 MS 0 0 1
+
+## If a section is already compressed, compression request for another format is ignored.
+# RUN: llvm-objcopy a.o out5 --compress-sections 'nonalloc0=zlib'
+# RUN: llvm-readelf -x nonalloc0 out5 | FileCheck %s --check-prefix=CHECK5
+# RUN: llvm-objcopy out5 out5a --compress-sections 'nonalloc0=zstd'
+# RUN: cmp out5 out5a
+
+# CHECK5: Hex dump of section 'nonalloc0':
+## zlib with ch_size=0x10
+# CHECK5-NEXT: 01000000 00000000 10000000 00000000
+# CHECK5-NEXT: 08000000 00000000 {{.*}}
+
+# RUN: not llvm-objcopy --compress-sections=foo a.o out 2>&1 | \
+# RUN: FileCheck %s --check-prefix=ERR1 --implicit-check-not=error:
+# ERR1: error: --compress-sections: parse error, not 'section-glob=[none|zlib|zstd]'
+
+# RUN: llvm-objcopy --compress-sections 'a[=zlib' a.o out 2>&1 | \
+# RUN: FileCheck %s --check-prefix=ERR2 --implicit-check-not=error:
+# ERR2: warning: invalid glob pattern, unmatched '['
+
+# RUN: not llvm-objcopy a.o out --compress-sections='.debug*=zlib-gabi' --compress-sections='.debug*=' 2>&1 | \
+# RUN: FileCheck -check-prefix=ERR3 %s
+# ERR3: error: invalid or unsupported --compress-sections format: .debug*=zlib-gabi
+
+# RUN: not llvm-objcopy a.o out --compress-sections='!.debug*=zlib' 2>&1 | \
+# RUN: FileCheck -check-prefix=ERR4 %s
+# ERR4: error: --compress-sections: negative pattern is unsupported
+
+.globl _start
+_start:
+ ret
+
+.section foo0,"a"
+.balign 8
+.quad .text-.
+.quad .text-.
+.section foo1,"a"
+.balign 8
+.quad .text-.
+.quad .text-.
+.section nonalloc0,""
+.balign 8
+.quad .text+1
+.quad .text+2
+sym0:
+.section nonalloc1,""
+.balign 8
+.quad 42
+sym1:
+
+.section .debug_str,"MS", at progbits,1
+.Linfo_string0:
+ .asciz "AAAAAAAAAAAAAAAAAAAAAAAAAAA"
+.Linfo_string1:
+ .asciz "BBBBBBBBBBBBBBBBBBBBBBBBBBB"
diff --git a/llvm/test/tools/llvm-objcopy/ELF/decompress-sections.test b/llvm/test/tools/llvm-objcopy/ELF/decompress-sections.test
index 4258ddbe66a3e5..d9f4f3809c4dd9 100644
--- a/llvm/test/tools/llvm-objcopy/ELF/decompress-sections.test
+++ b/llvm/test/tools/llvm-objcopy/ELF/decompress-sections.test
@@ -4,6 +4,8 @@
# RUN: yaml2obj %s -o %t
# RUN: llvm-objcopy --decompress-debug-sections %t %t.de
# RUN: llvm-readelf -S %t.de | FileCheck %s
+# RUN: llvm-objcopy --compress-sections '*nonalloc=none' --compress-sections .debugx=none %t %t.1.de
+# RUN: cmp %t.de %t.1.de
# CHECK: Name Type Address Off Size ES Flg Lk Inf Al
# CHECK: .debug_alloc PROGBITS 0000000000000000 [[#%x,]] [[#%x,]] 00 AC 0 0 0
@@ -11,6 +13,33 @@
# CHECK-NEXT: .debugx PROGBITS 0000000000000000 [[#%x,]] [[#%x,]] 00 0 0 1
# CHECK-NEXT: nodebug PROGBITS 0000000000000000 [[#%x,]] [[#%x,]] 00 C 0 0 0
+# RUN: llvm-objcopy --compress-sections '.debug*=none' %t %t2.de
+# RUN: llvm-readelf -S -x .debug_alloc -x .debug_nonalloc -x .debugx %t2.de | FileCheck %s --check-prefix=CHECK2
+
+# CHECK2: Name Type Address Off Size ES Flg Lk Inf Al
+# CHECK2: .debug_alloc PROGBITS 0000000000000000 [[#%x,]] [[#%x,]] 00 A 0 0 1
+# CHECK2-NEXT: .debug_nonalloc PROGBITS 0000000000000000 [[#%x,]] [[#%x,]] 00 0 0 1
+# CHECK2-NEXT: .debugx PROGBITS 0000000000000000 [[#%x,]] [[#%x,]] 00 0 0 1
+# CHECK2-NEXT: nodebug PROGBITS 0000000000000000 [[#%x,]] [[#%x,]] 00 C 0 0 0
+
+# CHECK2: Hex dump of section '.debug_alloc':
+# CHECK2-NEXT: 0x00000000 2a000000 00000000 2a000000 00000000 *.......*.......
+# CHECK2-NEXT: 0x00000010 2a000000 00000000 2a000000 00000000 *.......*.......
+# CHECK2-NEXT: 0x00000020 2a000000 00000000 2a000000 00000000 *.......*.......
+# CHECK2-NEXT: 0x00000030 2a000000 00000000 2a000000 00000000 *.......*.......
+# CHECK2-EMPTY:
+# CHECK2: Hex dump of section '.debug_nonalloc':
+# CHECK2-NEXT: 0x00000000 2a000000 00000000 2a000000 00000000 *.......*.......
+# CHECK2-NEXT: 0x00000010 2a000000 00000000 2a000000 00000000 *.......*.......
+# CHECK2-NEXT: 0x00000020 2a000000 00000000 2a000000 00000000 *.......*.......
+# CHECK2-NEXT: 0x00000030 2a000000 00000000 2a000000 00000000 *.......*.......
+# CHECK2-EMPTY:
+# CHECK2-NEXT: Hex dump of section '.debugx':
+# CHECK2-NEXT: 0x00000000 2a000000 00000000 2a000000 00000000 *.......*.......
+# CHECK2-NEXT: 0x00000010 2a000000 00000000 2a000000 00000000 *.......*.......
+# CHECK2-NEXT: 0x00000020 2a000000 00000000 2a000000 00000000 *.......*.......
+# CHECK2-NEXT: 0x00000030 2a000000 00000000 2a000000 00000000 *.......*.......
+
--- !ELF
FileHeader:
Class: ELFCLASS64
diff --git a/llvm/tools/llvm-objcopy/ObjcopyOptions.cpp b/llvm/tools/llvm-objcopy/ObjcopyOptions.cpp
index 7269c51a08d6b5..70e85460d3df0d 100644
--- a/llvm/tools/llvm-objcopy/ObjcopyOptions.cpp
+++ b/llvm/tools/llvm-objcopy/ObjcopyOptions.cpp
@@ -736,6 +736,42 @@ objcopy::parseObjcopyOptions(ArrayRef<const char *> RawArgsArr,
return createStringError(errc::invalid_argument, Reason);
}
+ for (const auto *A : InputArgs.filtered(OBJCOPY_compress_sections)) {
+ SmallVector<StringRef, 0> Fields;
+ StringRef(A->getValue()).split(Fields, '=');
+ if (Fields.size() != 2 || Fields[1].empty()) {
+ return createStringError(
+ errc::invalid_argument,
+ A->getSpelling() +
+ ": parse error, not 'section-glob=[none|zlib|zstd]'");
+ }
+
+ auto Type = StringSwitch<DebugCompressionType>(Fields[1])
+ .Case("zlib", DebugCompressionType::Zlib)
+ .Case("zstd", DebugCompressionType::Zstd)
+ .Default(DebugCompressionType::None);
+ if (Type == DebugCompressionType::None && Fields[1] != "none") {
+ return createStringError(
+ errc::invalid_argument,
+ "invalid or unsupported --compress-sections format: %s",
+ A->getValue());
+ }
+
+ auto &P = Config.compressSections.emplace_back();
+ P.second = Type;
+ auto Matcher =
+ NameOrPattern::create(Fields[0], SectionMatchStyle, ErrorCallback);
+ // =none allows overriding a previous =zlib or =zstd. Reject negative
+ // patterns, which would be confusing.
+ if (Matcher && !Matcher->isPositiveMatch()) {
+ return createStringError(
+ errc::invalid_argument,
+ "--compress-sections: negative pattern is unsupported");
+ }
+ if (Error E = P.first.addMatcher(std::move(Matcher)))
+ return std::move(E);
+ }
+
Config.AddGnuDebugLink = InputArgs.getLastArgValue(OBJCOPY_add_gnu_debuglink);
// The gnu_debuglink's target is expected to not change or else its CRC would
// become invalidated and get rejected. We can avoid recalculating the
diff --git a/llvm/tools/llvm-objcopy/ObjcopyOpts.td b/llvm/tools/llvm-objcopy/ObjcopyOpts.td
index be02616e8c68e3..4bc80eba05f8e6 100644
--- a/llvm/tools/llvm-objcopy/ObjcopyOpts.td
+++ b/llvm/tools/llvm-objcopy/ObjcopyOpts.td
@@ -35,6 +35,12 @@ def : Flag<["--"], "compress-debug-sections">, Alias<compress_debug_sections>,
AliasArgs<["zlib"]>;
def decompress_debug_sections : Flag<["--"], "decompress-debug-sections">,
HelpText<"Decompress DWARF debug sections">;
+defm compress_sections
+ : Eq<"compress-sections",
+ "Compress or decompress sections using specified format. Supported "
+ "formats: zlib, zstd. Specify 'none' for decompression">,
+ MetaVarName<"<section-glob>=<format>">;
+
defm split_dwo
: Eq<"split-dwo", "Equivalent to --extract-dwo and <dwo-file> as the output file and no other options, "
"and then --strip-dwo on the input file">,
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