[llvm] 3dc6fd5 - [llvm-objcopy][MachO] Implement --update-section
Alex Brachet via llvm-commits
llvm-commits at lists.llvm.org
Sun Jan 23 01:53:13 PST 2022
Author: Alex Brachet
Date: 2022-01-23T09:47:45Z
New Revision: 3dc6fd5151355c309f0c4595b63268138ac57910
URL: https://github.com/llvm/llvm-project/commit/3dc6fd5151355c309f0c4595b63268138ac57910
DIFF: https://github.com/llvm/llvm-project/commit/3dc6fd5151355c309f0c4595b63268138ac57910.diff
LOG: [llvm-objcopy][MachO] Implement --update-section
Implements `--update-section` which is currently supported for ELF for Mach-O as well
Reviewed By: alexander-shaposhnikov
Differential Revision: https://reviews.llvm.org/D117281
Added:
llvm/test/tools/llvm-objcopy/MachO/update-section.test
Modified:
llvm/tools/llvm-objcopy/MachO/MachOObjcopy.cpp
Removed:
################################################################################
diff --git a/llvm/test/tools/llvm-objcopy/MachO/update-section.test b/llvm/test/tools/llvm-objcopy/MachO/update-section.test
new file mode 100644
index 0000000000000..a4fa5423ee52b
--- /dev/null
+++ b/llvm/test/tools/llvm-objcopy/MachO/update-section.test
@@ -0,0 +1,115 @@
+# RUN: echo -n AAAB > %t.
diff
+# RUN: echo -n AAA > %t.smaller
+# RUN: echo -n AAAAAAAAA > %t.larger
+
+# RUN: yaml2obj --docnum=1 %s -o %t
+
+# RUN: llvm-objcopy --update-section __TEXT,__text=%t.
diff %t - | obj2yaml | FileCheck %s
+# CHECK: content: '41414142'
+
+# RUN: llvm-objcopy --update-section __TEXT,__text=%t.smaller %t - | obj2yaml | FileCheck %s --check-prefix=SMALLER
+# SMALLER: content: '414141'
+
+# RUN: not llvm-objcopy --update-section __TEXT,__text=%t.larger %t /dev/null 2>&1 | FileCheck %s --check-prefix=TOO-LARGE
+# TOO-LARGE: error: {{.*}}new section cannot be larger than previous section
+
+# RUN: not llvm-objcopy --update-section __TEXT,__text=%t.noexist %t /dev/null
+
+# RUN: not llvm-objcopy --update-section __NOEXIST,__text=%t.
diff %t /dev/null 2>&1 | FileCheck %s --check-prefix=NO-SEGMENT
+# NO-SEGMENT: error: {{.*}}could not find segment with name '__NOEXIST'
+
+# RUN: not llvm-objcopy --update-section __TEXT,__noexist=%t.
diff %t /dev/null 2>&1 | FileCheck %s --check-prefix=NO-SECTION
+# NO-SECTION: error: {{.*}}could not find section with name '__noexist'
+
+# RUN: yaml2obj --docnum=2 %s -o %t
+
+# RUN: llvm-objcopy --update-section __TEXT,__text=%t.
diff %t - | obj2yaml | FileCheck %s --check-prefix=FULL-SECNAME
+# FULL-SECNAME: content: '41414142'
+
+# RUN: not llvm-objcopy --update-section __text=%t.dff %t /dev/null 2>&1 | FileCheck %s --check-prefix=NON-CANONICAL-SECNAME
+# NON-CANONICAL-SECNAME: error: {{.*}}invalid section name '__text' (should be formatted as '<segment name>,<section name>')
+
+--- !mach-o
+FileHeader:
+ magic: 0xFEEDFACF
+ cputype: 0x01000007
+ cpusubtype: 0x00000003
+ filetype: 0x00000001
+ ncmds: 1
+ sizeofcmds: 152
+ flags: 0x00002000
+ reserved: 0x00000000
+LoadCommands:
+ - cmd: LC_SEGMENT_64
+ cmdsize: 152
+ segname: __TEXT
+ vmaddr: 0
+ vmsize: 4
+ fileoff: 184
+ filesize: 4
+ maxprot: 7
+ initprot: 7
+ nsects: 1
+ flags: 0
+ Sections:
+ - sectname: __text
+ segname: __TEXT
+ addr: 0x0000000000000000
+ content: '41414141'
+ size: 4
+ offset: 184
+ align: 0
+ reloff: 0x00000000
+ nreloc: 0
+ flags: 0x80000400
+ reserved1: 0x00000000
+ reserved2: 0x00000000
+ reserved3: 0x00000000
+
+--- !mach-o
+FileHeader:
+ magic: 0xFEEDFACF
+ cputype: 0x01000007
+ cpusubtype: 0x00000003
+ filetype: 0x00000001
+ ncmds: 1
+ sizeofcmds: 312
+ flags: 0x00002000
+ reserved: 0x00000000
+LoadCommands:
+ - cmd: LC_SEGMENT_64
+ cmdsize: 312
+ segname: '__TEXT'
+ vmaddr: 0
+ vmsize: 12
+ fileoff: 344
+ filesize: 12
+ maxprot: 7
+ initprot: 7
+ nsects: 3
+ flags: 0
+ Sections:
+ - sectname: __text
+ segname: __TEXT
+ addr: 0x0000000000000000
+ content: 'AABBCCDD'
+ size: 4
+ offset: 344
+ align: 0
+ reloff: 0x00000000
+ nreloc: 0
+ flags: 0x80000400
+ reserved1: 0x00000000
+ reserved2: 0x00000000
+ - sectname: __text
+ segname: __TEXT2
+ addr: 0x0000000000000004
+ content: ''
+ size: 0
+ offset: 348
+ align: 0
+ reloff: 0x00000000
+ nreloc: 0
+ flags: 0x00000000
+ reserved1: 0x00000000
+ reserved2: 0x00000000
diff --git a/llvm/tools/llvm-objcopy/MachO/MachOObjcopy.cpp b/llvm/tools/llvm-objcopy/MachO/MachOObjcopy.cpp
index 915394b65b12d..0f92ca516bef7 100644
--- a/llvm/tools/llvm-objcopy/MachO/MachOObjcopy.cpp
+++ b/llvm/tools/llvm-objcopy/MachO/MachOObjcopy.cpp
@@ -317,6 +317,52 @@ static Error addSection(StringRef SecName, StringRef Filename, Object &Obj) {
return Error::success();
}
+static Expected<Section &> findSection(StringRef SecName, Object &O) {
+ StringRef SegName;
+ std::tie(SegName, SecName) = SecName.split(",");
+ auto FoundSeg =
+ llvm::find_if(O.LoadCommands, [SegName](const LoadCommand &LC) {
+ return LC.getSegmentName() == SegName;
+ });
+ if (FoundSeg == O.LoadCommands.end())
+ return createStringError(errc::invalid_argument,
+ "could not find segment with name '%s'",
+ SegName.str().c_str());
+ auto FoundSec = llvm::find_if(FoundSeg->Sections,
+ [SecName](const std::unique_ptr<Section> &Sec) {
+ return Sec->Sectname == SecName;
+ });
+ if (FoundSec == FoundSeg->Sections.end())
+ return createStringError(errc::invalid_argument,
+ "could not find section with name '%s'",
+ SecName.str().c_str());
+
+ assert(FoundSec->get()->CanonicalName == (SegName + "," + SecName).str());
+ return *FoundSec->get();
+}
+
+static Error updateSection(StringRef SecName, StringRef Filename, Object &O) {
+ Expected<Section &> SecToUpdateOrErr = findSection(SecName, O);
+
+ if (!SecToUpdateOrErr)
+ return SecToUpdateOrErr.takeError();
+ Section &Sec = *SecToUpdateOrErr;
+
+ ErrorOr<std::unique_ptr<MemoryBuffer>> BufOrErr =
+ MemoryBuffer::getFile(Filename);
+ if (!BufOrErr)
+ return createFileError(Filename, errorCodeToError(BufOrErr.getError()));
+ std::unique_ptr<MemoryBuffer> Buf = std::move(*BufOrErr);
+
+ if (Buf->getBufferSize() > Sec.Size)
+ return createStringError(
+ errc::invalid_argument,
+ "new section cannot be larger than previous section");
+ Sec.Content = O.NewSectionsContents.save(Buf->getBuffer());
+ Sec.Size = Sec.Content.size();
+ return Error::success();
+}
+
// isValidMachOCannonicalName returns success if Name is a MachO cannonical name
// ("<segment>,<section>") and lengths of both segment and section names are
// valid.
@@ -374,6 +420,16 @@ static Error handleArgs(const CommonConfig &Config,
return E;
}
+ for (const auto &Flag : Config.UpdateSection) {
+ StringRef SectionName;
+ StringRef FileName;
+ std::tie(SectionName, FileName) = Flag.split('=');
+ if (Error E = isValidMachOCannonicalName(SectionName))
+ return E;
+ if (Error E = updateSection(SectionName, FileName, Obj))
+ return E;
+ }
+
if (Error E = processLoadCommands(MachOConfig, Obj))
return E;
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