[llvm] r270115 - [obj2yaml] [yaml2obj] Support for MachO Load Command data
Chris Bieneman via llvm-commits
llvm-commits at lists.llvm.org
Thu May 19 13:40:03 PDT 2016
Author: cbieneman
Date: Thu May 19 15:40:03 2016
New Revision: 270115
URL: http://llvm.org/viewvc/llvm-project?rev=270115&view=rev
Log:
[obj2yaml] [yaml2obj] Support for MachO Load Command data
Many of the MachO load commands can have data appended after the command structure. This data is frequently strings, but can actually be anything. This patch adds support for three optional fields on load command yaml descriptions.
The new PayloadString YAML field is populated with the data after load commands known to have strings as extra data.
The new ZeroPadBytes YAML field is a count of zero'd bytes after the end of the load command structure before the next command. This can apply anywhere in the file. MachO2YAML verifies that bytes are zero before populating this field, and YAML2MachO will add zero'd bytes.
The new PayloadBytes YAML field stores all bytes after the end of the load command structure before the next command if they are non-zero. This is a catch all for all unhandled bytes. If MachO2Yaml populates PayloadBytes it will not populate ZeroPadBytes, instead zero'd bytes will be in the PayloadBytes structure.
Modified:
llvm/trunk/include/llvm/ObjectYAML/MachOYAML.h
llvm/trunk/lib/ObjectYAML/MachOYAML.cpp
llvm/trunk/tools/obj2yaml/macho2yaml.cpp
llvm/trunk/tools/yaml2obj/yaml2macho.cpp
Modified: llvm/trunk/include/llvm/ObjectYAML/MachOYAML.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/ObjectYAML/MachOYAML.h?rev=270115&r1=270114&r2=270115&view=diff
==============================================================================
--- llvm/trunk/include/llvm/ObjectYAML/MachOYAML.h (original)
+++ llvm/trunk/include/llvm/ObjectYAML/MachOYAML.h Thu May 19 15:40:03 2016
@@ -52,6 +52,9 @@ struct LoadCommand {
virtual ~LoadCommand();
llvm::MachO::macho_load_command Data;
std::vector<Section> Sections;
+ std::vector<llvm::yaml::Hex8> PayloadBytes;
+ std::string PayloadString;
+ uint64_t ZeroPadBytes;
};
struct Object {
@@ -65,6 +68,7 @@ struct Object {
LLVM_YAML_IS_SEQUENCE_VECTOR(llvm::MachOYAML::LoadCommand)
LLVM_YAML_IS_SEQUENCE_VECTOR(llvm::MachOYAML::Section)
+LLVM_YAML_IS_SEQUENCE_VECTOR(llvm::yaml::Hex8)
namespace llvm {
namespace yaml {
Modified: llvm/trunk/lib/ObjectYAML/MachOYAML.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/ObjectYAML/MachOYAML.cpp?rev=270115&r1=270114&r2=270115&view=diff
==============================================================================
--- llvm/trunk/lib/ObjectYAML/MachOYAML.cpp (original)
+++ llvm/trunk/lib/ObjectYAML/MachOYAML.cpp Thu May 19 15:40:03 2016
@@ -96,6 +96,33 @@ void MappingTraits<MachOYAML::Object>::m
IO.setContext(nullptr);
}
+template <typename StructType>
+void mapLoadCommandData(IO &IO, MachOYAML::LoadCommand &LoadCommand) {}
+
+template <>
+void mapLoadCommandData<MachO::segment_command>(
+ IO &IO, MachOYAML::LoadCommand &LoadCommand) {
+ IO.mapOptional("Sections", LoadCommand.Sections);
+}
+
+template <>
+void mapLoadCommandData<MachO::segment_command_64>(
+ IO &IO, MachOYAML::LoadCommand &LoadCommand) {
+ IO.mapOptional("Sections", LoadCommand.Sections);
+}
+
+template <>
+void mapLoadCommandData<MachO::dylib_command>(
+ IO &IO, MachOYAML::LoadCommand &LoadCommand) {
+ IO.mapOptional("PayloadString", LoadCommand.PayloadString);
+}
+
+template <>
+void mapLoadCommandData<MachO::dylinker_command>(
+ IO &IO, MachOYAML::LoadCommand &LoadCommand) {
+ IO.mapOptional("PayloadString", LoadCommand.PayloadString);
+}
+
void MappingTraits<MachOYAML::LoadCommand>::mapping(
IO &IO, MachOYAML::LoadCommand &LoadCommand) {
IO.mapRequired(
@@ -106,15 +133,14 @@ void MappingTraits<MachOYAML::LoadComman
case MachO::LCName: \
MappingTraits<MachO::LCStruct>::mapping(IO, \
LoadCommand.Data.LCStruct##_data); \
+ mapLoadCommandData<MachO::LCStruct>(IO, LoadCommand); \
break;
switch (LoadCommand.Data.load_command_data.cmd) {
#include "llvm/Support/MachO.def"
}
- if (LoadCommand.Data.load_command_data.cmd == MachO::LC_SEGMENT ||
- LoadCommand.Data.load_command_data.cmd == MachO::LC_SEGMENT_64) {
- IO.mapOptional("Sections", LoadCommand.Sections);
- }
+ IO.mapOptional("PayloadBytes", LoadCommand.PayloadBytes);
+ IO.mapOptional("ZeroPadBytes", LoadCommand.ZeroPadBytes, 0ull);
}
void MappingTraits<MachO::dyld_info_command>::mapping(
Modified: llvm/trunk/tools/obj2yaml/macho2yaml.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/obj2yaml/macho2yaml.cpp?rev=270115&r1=270114&r2=270115&view=diff
==============================================================================
--- llvm/trunk/tools/obj2yaml/macho2yaml.cpp (original)
+++ llvm/trunk/tools/obj2yaml/macho2yaml.cpp Thu May 19 15:40:03 2016
@@ -19,6 +19,11 @@ using namespace llvm;
class MachODumper {
+ template <typename StructType>
+ const char *processLoadCommandData(
+ MachOYAML::LoadCommand &LC,
+ const llvm::object::MachOObjectFile::LoadCommandInfo &LoadCmd);
+
const object::MachOObjectFile &Obj;
public:
@@ -32,6 +37,7 @@ public:
sizeof(MachO::LCStruct)); \
if (Obj.isLittleEndian() != sys::IsLittleEndianHost) \
MachO::swapStruct(LC.Data.LCStruct##_data); \
+ EndPtr = processLoadCommandData<MachO::LCStruct>(LC, LoadCmd); \
break;
template <typename SectionType>
@@ -68,9 +74,10 @@ template <> MachOYAML::Section construct
}
template <typename SectionType, typename SegmentType>
-void extractSections(
- const llvm::object::MachOObjectFile::LoadCommandInfo &LoadCmd,
- std::vector<MachOYAML::Section> &Sections, bool IsLittleEndian) {
+const char *
+extractSections(const llvm::object::MachOObjectFile::LoadCommandInfo &LoadCmd,
+ std::vector<MachOYAML::Section> &Sections,
+ bool IsLittleEndian) {
auto End = LoadCmd.Ptr + LoadCmd.C.cmdsize;
const SectionType *Curr =
reinterpret_cast<const SectionType *>(LoadCmd.Ptr + sizeof(SegmentType));
@@ -84,6 +91,55 @@ void extractSections(
Sections.push_back(constructSection(*Curr));
}
}
+ return reinterpret_cast<const char *>(Curr);
+}
+
+template <typename StructType>
+const char *MachODumper::processLoadCommandData(
+ MachOYAML::LoadCommand &LC,
+ const llvm::object::MachOObjectFile::LoadCommandInfo &LoadCmd) {
+ return LoadCmd.Ptr + sizeof(StructType);
+}
+
+template <>
+const char *MachODumper::processLoadCommandData<MachO::segment_command>(
+ MachOYAML::LoadCommand &LC,
+ const llvm::object::MachOObjectFile::LoadCommandInfo &LoadCmd) {
+ return extractSections<MachO::section, MachO::segment_command>(
+ LoadCmd, LC.Sections, Obj.isLittleEndian());
+}
+
+template <>
+const char *MachODumper::processLoadCommandData<MachO::segment_command_64>(
+ MachOYAML::LoadCommand &LC,
+ const llvm::object::MachOObjectFile::LoadCommandInfo &LoadCmd) {
+ return extractSections<MachO::section_64, MachO::segment_command_64>(
+ LoadCmd, LC.Sections, Obj.isLittleEndian());
+}
+
+template <typename StructType>
+const char *
+readString(MachOYAML::LoadCommand &LC,
+ const llvm::object::MachOObjectFile::LoadCommandInfo &LoadCmd) {
+ auto Start = LoadCmd.Ptr + sizeof(StructType);
+ auto MaxSize = LoadCmd.C.cmdsize - sizeof(StructType);
+ auto Size = strnlen(Start, MaxSize);
+ LC.PayloadString = StringRef(Start, Size).str();
+ return Start + Size;
+}
+
+template <>
+const char *MachODumper::processLoadCommandData<MachO::dylib_command>(
+ MachOYAML::LoadCommand &LC,
+ const llvm::object::MachOObjectFile::LoadCommandInfo &LoadCmd) {
+ return readString<MachO::dylib_command>(LC, LoadCmd);
+}
+
+template <>
+const char *MachODumper::processLoadCommandData<MachO::dylinker_command>(
+ MachOYAML::LoadCommand &LC,
+ const llvm::object::MachOObjectFile::LoadCommandInfo &LoadCmd) {
+ return readString<MachO::dylinker_command>(LC, LoadCmd);
}
Expected<std::unique_ptr<MachOYAML::Object>> MachODumper::dump() {
@@ -99,25 +155,25 @@ Expected<std::unique_ptr<MachOYAML::Obje
for (auto LoadCmd : Obj.load_commands()) {
MachOYAML::LoadCommand LC;
+ const char *EndPtr = LoadCmd.Ptr;
switch (LoadCmd.C.cmd) {
default:
memcpy((void *)&(LC.Data.load_command_data), LoadCmd.Ptr,
sizeof(MachO::load_command));
if (Obj.isLittleEndian() != sys::IsLittleEndianHost)
MachO::swapStruct(LC.Data.load_command_data);
+ EndPtr = processLoadCommandData<MachO::load_command>(LC, LoadCmd);
break;
#include "llvm/Support/MachO.def"
}
- switch (LoadCmd.C.cmd) {
- case MachO::LC_SEGMENT:
- extractSections<MachO::section, MachO::segment_command>(
- LoadCmd, LC.Sections, Obj.isLittleEndian());
- break;
- case MachO::LC_SEGMENT_64:
- extractSections<MachO::section_64, MachO::segment_command_64>(
- LoadCmd, LC.Sections, Obj.isLittleEndian());
- break;
+ auto RemainingBytes = LoadCmd.C.cmdsize - (EndPtr - LoadCmd.Ptr);
+ if (!std::all_of(EndPtr, &EndPtr[RemainingBytes],
+ [](const char C) { return C == 0; })) {
+ LC.PayloadBytes.insert(LC.PayloadBytes.end(), EndPtr,
+ &EndPtr[RemainingBytes]);
+ RemainingBytes = 0;
}
+ LC.ZeroPadBytes = RemainingBytes;
Y->LoadCommands.push_back(std::move(LC));
}
Modified: llvm/trunk/tools/yaml2obj/yaml2macho.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/yaml2obj/yaml2macho.cpp?rev=270115&r1=270114&r2=270115&view=diff
==============================================================================
--- llvm/trunk/tools/yaml2obj/yaml2macho.cpp (original)
+++ llvm/trunk/tools/yaml2obj/yaml2macho.cpp Thu May 19 15:40:03 2016
@@ -94,6 +94,60 @@ SectionType constructSection(MachOYAML::
return TempSec;
}
+template <typename StructType>
+size_t writeLoadCommandData(MachOYAML::LoadCommand &LC, raw_ostream &OS) {
+ return 0;
+}
+
+template <>
+size_t writeLoadCommandData<MachO::segment_command>(MachOYAML::LoadCommand &LC,
+ raw_ostream &OS) {
+ size_t BytesWritten = 0;
+ for (auto Sec : LC.Sections) {
+ auto TempSec = constructSection<MachO::section>(Sec);
+ OS.write(reinterpret_cast<const char *>(&(TempSec)),
+ sizeof(MachO::section));
+ BytesWritten += sizeof(MachO::section);
+ }
+ return BytesWritten;
+}
+
+template <>
+size_t
+writeLoadCommandData<MachO::segment_command_64>(MachOYAML::LoadCommand &LC,
+ raw_ostream &OS) {
+ size_t BytesWritten = 0;
+ for (auto Sec : LC.Sections) {
+ auto TempSec = constructSection<MachO::section_64>(Sec);
+ TempSec.reserved3 = Sec.reserved3;
+ OS.write(reinterpret_cast<const char *>(&(TempSec)),
+ sizeof(MachO::section_64));
+ BytesWritten += sizeof(MachO::section_64);
+ }
+ return BytesWritten;
+}
+
+size_t writePayloadString(MachOYAML::LoadCommand &LC, raw_ostream &OS) {
+ size_t BytesWritten = 0;
+ if (!LC.PayloadString.empty()) {
+ OS.write(LC.PayloadString.c_str(), LC.PayloadString.length());
+ BytesWritten = LC.PayloadString.length();
+ }
+ return BytesWritten;
+}
+
+template <>
+size_t writeLoadCommandData<MachO::dylib_command>(MachOYAML::LoadCommand &LC,
+ raw_ostream &OS) {
+ return writePayloadString(LC, OS);
+}
+
+template <>
+size_t writeLoadCommandData<MachO::dylinker_command>(MachOYAML::LoadCommand &LC,
+ raw_ostream &OS) {
+ return writePayloadString(LC, OS);
+}
+
Error MachOWriter::writeLoadCommands(raw_ostream &OS) {
for (auto &LC : Obj.LoadCommands) {
size_t BytesWritten = 0;
@@ -102,6 +156,7 @@ Error MachOWriter::writeLoadCommands(raw
OS.write(reinterpret_cast<const char *>(&(LC.Data.LCStruct##_data)), \
sizeof(MachO::LCStruct)); \
BytesWritten = sizeof(MachO::LCStruct); \
+ BytesWritten += writeLoadCommandData<MachO::LCStruct>(LC, OS); \
break;
switch (LC.Data.load_command_data.cmd) {
@@ -109,27 +164,25 @@ Error MachOWriter::writeLoadCommands(raw
OS.write(reinterpret_cast<const char *>(&(LC.Data.load_command_data)),
sizeof(MachO::load_command));
BytesWritten = sizeof(MachO::load_command);
+ BytesWritten += writeLoadCommandData<MachO::load_command>(LC, OS);
break;
#include "llvm/Support/MachO.def"
}
- if(LC.Data.load_command_data.cmd == MachO::LC_SEGMENT) {
- for(auto Sec : LC.Sections) {
- auto TempSec = constructSection<MachO::section>(Sec);
- OS.write(reinterpret_cast<const char *>(&(TempSec)), sizeof(MachO::section));
- BytesWritten += sizeof(MachO::section);
- }
- } else if(LC.Data.load_command_data.cmd == MachO::LC_SEGMENT_64) {
- for(auto Sec : LC.Sections) {
- auto TempSec = constructSection<MachO::section_64>(Sec);
- TempSec.reserved3 = Sec.reserved3;
- OS.write(reinterpret_cast<const char *>(&(TempSec)), sizeof(MachO::section_64));
- BytesWritten += sizeof(MachO::section_64);
- }
+ if (LC.PayloadBytes.size() > 0) {
+ OS.write(reinterpret_cast<const char *>(LC.PayloadBytes.data()),
+ LC.PayloadBytes.size());
+ BytesWritten += LC.PayloadBytes.size();
+ }
+
+ if (LC.ZeroPadBytes > 0) {
+ std::vector<uint8_t> FillData;
+ FillData.insert(FillData.begin(), LC.ZeroPadBytes, 0);
+ OS.write(reinterpret_cast<char *>(FillData.data()), LC.ZeroPadBytes);
+ BytesWritten += LC.ZeroPadBytes;
}
- auto BytesRemaining =
- LC.Data.load_command_data.cmdsize - BytesWritten;
+ auto BytesRemaining = LC.Data.load_command_data.cmdsize - BytesWritten;
if (BytesRemaining > 0) {
// TODO: Replace all this once the load command data is present in yaml.
// For now I fill with 0xDEADBEEF because it is easy to spot on a hex
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