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[Object, MachO] Simplify load segment parsing code. NFC.

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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239106 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Alexey Samsonov 2015-06-04 22:08:37 +00:00
parent c9f2b5d535
commit 468b904422
1 changed files with 30 additions and 52 deletions
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82
lib/Object/MachOObjectFile.cpp
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@ -65,38 +65,6 @@ static ErrorOr<T> getStructOrErr(const MachOObjectFile *O, const char *P) {
return Cmd;
}
template <typename SegmentCmd>
static ErrorOr<uint32_t> getSegmentLoadCommandNumSections(const SegmentCmd &S,
uint32_t Cmdsize) {
const unsigned SectionSize = sizeof(SegmentCmd);
if (S.nsects > std::numeric_limits<uint32_t>::max() / SectionSize ||
S.nsects * SectionSize > Cmdsize - sizeof(S))
return object_error::macho_load_segment_too_many_sections;
return S.nsects;
}
static ErrorOr<uint32_t>
getSegmentLoadCommandNumSections(const MachOObjectFile *O,
const MachOObjectFile::LoadCommandInfo &L) {
if (O->is64Bit())
return getSegmentLoadCommandNumSections(O->getSegment64LoadCommand(L),
L.C.cmdsize);
return getSegmentLoadCommandNumSections(O->getSegmentLoadCommand(L),
L.C.cmdsize);
}
static bool isPageZeroSegment(const MachOObjectFile *O,
const MachOObjectFile::LoadCommandInfo &L) {
if (O->is64Bit()) {
MachO::segment_command_64 S = O->getSegment64LoadCommand(L);
return StringRef("__PAGEZERO").equals(S.segname);
}
MachO::segment_command S = O->getSegmentLoadCommand(L);
return StringRef("__PAGEZERO").equals(S.segname);
}
static const char *
getSectionPtr(const MachOObjectFile *O, MachOObjectFile::LoadCommandInfo L,
unsigned Sec) {
@ -229,6 +197,30 @@ static void parseHeader(const MachOObjectFile *Obj, T &Header,
EC = HeaderOrErr.getError();
}
// Parses LC_SEGMENT or LC_SEGMENT_64 load command, adds addresses of all
// sections to \param Sections, and optionally sets
// \param IsPageZeroSegment to true.
template <typename SegmentCmd>
static std::error_code parseSegmentLoadCommand(
const MachOObjectFile *Obj, const MachOObjectFile::LoadCommandInfo &Load,
SmallVectorImpl<const char *> &Sections, bool &IsPageZeroSegment) {
const unsigned SegmentLoadSize = sizeof(SegmentCmd);
if (Load.C.cmdsize < SegmentLoadSize)
return object_error::macho_load_segment_too_small;
SegmentCmd S = getStruct<SegmentCmd>(Obj, Load.Ptr);
const unsigned SectionSize =
Obj->is64Bit() ? sizeof(MachO::section_64) : sizeof(MachO::section);
if (S.nsects > std::numeric_limits<uint32_t>::max() / SectionSize ||
S.nsects * SectionSize > Load.C.cmdsize - SegmentLoadSize)
return object_error::macho_load_segment_too_many_sections;
for (unsigned J = 0; J < S.nsects; ++J) {
const char *Sec = getSectionPtr(Obj, Load, J);
Sections.push_back(Sec);
}
IsPageZeroSegment |= StringRef("__PAGEZERO").equals(S.segname);
return object_error::success;
}
MachOObjectFile::MachOObjectFile(MemoryBufferRef Object, bool IsLittleEndian,
bool Is64bits, std::error_code &EC)
: ObjectFile(getMachOType(IsLittleEndian, Is64bits), Object),
@ -250,9 +242,6 @@ MachOObjectFile::MachOObjectFile(MemoryBufferRef Object, bool IsLittleEndian,
if (LoadCommandCount == 0)
return;
MachO::LoadCommandType SegmentLoadType = is64Bit() ?
MachO::LC_SEGMENT_64 : MachO::LC_SEGMENT;
auto LoadOrErr = getFirstLoadCommandInfo(this);
if (!LoadOrErr) {
EC = LoadOrErr.getError();
@ -304,25 +293,14 @@ MachOObjectFile::MachOObjectFile(MemoryBufferRef Object, bool IsLittleEndian,
return;
}
UuidLoadCmd = Load.Ptr;
} else if (Load.C.cmd == SegmentLoadType) {
const unsigned SegmentLoadSize = is64Bit()
? sizeof(MachO::segment_command_64)
: sizeof(MachO::segment_command);
if (Load.C.cmdsize < SegmentLoadSize) {
EC = object_error::macho_load_segment_too_small;
} else if (Load.C.cmd == MachO::LC_SEGMENT_64) {
if ((EC = parseSegmentLoadCommand<MachO::segment_command_64>(
this, Load, Sections, HasPageZeroSegment)))
return;
}
auto NumSectionsOrErr = getSegmentLoadCommandNumSections(this, Load);
if (!NumSectionsOrErr) {
EC = NumSectionsOrErr.getError();
} else if (Load.C.cmd == MachO::LC_SEGMENT) {
if ((EC = parseSegmentLoadCommand<MachO::segment_command>(
this, Load, Sections, HasPageZeroSegment)))
return;
}
for (unsigned J = 0; J < NumSectionsOrErr.get(); ++J) {
const char *Sec = getSectionPtr(this, Load, J);
Sections.push_back(Sec);
}
if (isPageZeroSegment(this, Load))
HasPageZeroSegment = true;
} else if (Load.C.cmd == MachO::LC_LOAD_DYLIB ||
Load.C.cmd == MachO::LC_LOAD_WEAK_DYLIB ||
Load.C.cmd == MachO::LC_LAZY_LOAD_DYLIB ||