[llvm-objcopy] Add --dump-section
Differential Revision: https://reviews.llvm.org/D49979
llvm-svn: 339358
diff --git a/llvm/tools/llvm-objcopy/ObjcopyOpts.td b/llvm/tools/llvm-objcopy/ObjcopyOpts.td
index 8f8a24e..9b87254 100644
--- a/llvm/tools/llvm-objcopy/ObjcopyOpts.td
+++ b/llvm/tools/llvm-objcopy/ObjcopyOpts.td
@@ -102,3 +102,6 @@
HelpText<"Remove all symbols not needed by relocations">;
def keep_file_symbols : Flag<["-", "--"], "keep-file-symbols">,
HelpText<"Do not remove file symbols">;
+defm dump_section : Eq<"dump-section">,
+ MetaVarName<"section=file">,
+ HelpText<"Dump contents of section named <section> into file <file>">;
diff --git a/llvm/tools/llvm-objcopy/Object.cpp b/llvm/tools/llvm-objcopy/Object.cpp
index 0d5dbf7..c727c11 100644
--- a/llvm/tools/llvm-objcopy/Object.cpp
+++ b/llvm/tools/llvm-objcopy/Object.cpp
@@ -853,6 +853,9 @@
Sec.Align = Shdr.sh_addralign;
Sec.EntrySize = Shdr.sh_entsize;
Sec.Index = Index++;
+ Sec.OriginalData =
+ ArrayRef<uint8_t>(ElfFile.base() + Shdr.sh_offset,
+ (Shdr.sh_type == SHT_NOBITS) ? 0 : Shdr.sh_size);
}
// If a section index table exists we'll need to initialize it before we
diff --git a/llvm/tools/llvm-objcopy/Object.h b/llvm/tools/llvm-objcopy/Object.h
index 76748d5..ba6aea9 100644
--- a/llvm/tools/llvm-objcopy/Object.h
+++ b/llvm/tools/llvm-objcopy/Object.h
@@ -250,6 +250,7 @@
uint64_t Offset = 0;
uint64_t Size = 0;
uint64_t Type = ELF::SHT_NULL;
+ ArrayRef<uint8_t> OriginalData;
virtual ~SectionBase() = default;
diff --git a/llvm/tools/llvm-objcopy/llvm-objcopy.cpp b/llvm/tools/llvm-objcopy/llvm-objcopy.cpp
index edc45ee..0c153d5 100644
--- a/llvm/tools/llvm-objcopy/llvm-objcopy.cpp
+++ b/llvm/tools/llvm-objcopy/llvm-objcopy.cpp
@@ -137,6 +137,7 @@
std::vector<StringRef> Keep;
std::vector<StringRef> OnlyKeep;
std::vector<StringRef> AddSection;
+ std::vector<StringRef> DumpSection;
std::vector<StringRef> SymbolsToLocalize;
std::vector<StringRef> SymbolsToGlobalize;
std::vector<StringRef> SymbolsToWeaken;
@@ -323,6 +324,30 @@
Writer->write();
}
+static Error dumpSectionToFile(StringRef SecName, StringRef Filename,
+ Object &Obj) {
+ for (auto &Sec : Obj.sections()) {
+ if (Sec.Name == SecName) {
+ if (Sec.OriginalData.size() == 0)
+ return make_error<StringError>("Can't dump section \"" + SecName +
+ "\": it has no contents",
+ object_error::parse_failed);
+ Expected<std::unique_ptr<FileOutputBuffer>> BufferOrErr =
+ FileOutputBuffer::create(Filename, Sec.OriginalData.size());
+ if (!BufferOrErr)
+ return BufferOrErr.takeError();
+ std::unique_ptr<FileOutputBuffer> Buf = std::move(*BufferOrErr);
+ std::copy(Sec.OriginalData.begin(), Sec.OriginalData.end(),
+ Buf->getBufferStart());
+ if (Error E = Buf->commit())
+ return E;
+ return Error::success();
+ }
+ }
+ return make_error<StringError>("Section not found",
+ object_error::parse_failed);
+}
+
// This function handles the high level operations of GNU objcopy including
// handling command line options. It's important to outline certain properties
// we expect to hold of the command line operations. Any operation that "keeps"
@@ -555,6 +580,16 @@
}
}
+ if (!Config.DumpSection.empty()) {
+ for (const auto &Flag : Config.DumpSection) {
+ std::pair<StringRef, StringRef> SecPair = Flag.split("=");
+ StringRef SecName = SecPair.first;
+ StringRef File = SecPair.second;
+ if (Error E = dumpSectionToFile(SecName, File, Obj))
+ reportError(Config.InputFilename, std::move(E));
+ }
+ }
+
if (!Config.AddGnuDebugLink.empty())
Obj.addSection<GnuDebugLinkSection>(Config.AddGnuDebugLink);
}
@@ -711,6 +746,8 @@
Config.OnlyKeep.push_back(Arg->getValue());
for (auto Arg : InputArgs.filtered(OBJCOPY_add_section))
Config.AddSection.push_back(Arg->getValue());
+ for (auto Arg : InputArgs.filtered(OBJCOPY_dump_section))
+ Config.DumpSection.push_back(Arg->getValue());
Config.StripAll = InputArgs.hasArg(OBJCOPY_strip_all);
Config.StripAllGNU = InputArgs.hasArg(OBJCOPY_strip_all_gnu);
Config.StripDebug = InputArgs.hasArg(OBJCOPY_strip_debug);