Fix bug 34051 by handling empty .res files gracefully.

Summary:
Previously, llvm-cvtres crashes on .res files which are empty except for
the null header.  This allows the library to simply pass over them.

Subscribers: llvm-commits, hiraditya

Differential Revision: https://reviews.llvm.org/D37044

llvm-svn: 311625
This commit is contained in:
Eric Beckmann 2017-08-24 02:36:50 +00:00
parent 23bb21cb92
commit b85172f6ff
2 changed files with 37 additions and 15 deletions

View File

@ -85,6 +85,12 @@ struct WinResHeaderSuffix {
support::ulittle32_t Characteristics;
};
class EmptyResError : public GenericBinaryError {
public:
EmptyResError(Twine Msg, object_error ECOverride)
: GenericBinaryError(Msg, ECOverride) {}
};
class ResourceEntryRef {
public:
Error moveNext(bool &End);
@ -103,11 +109,12 @@ public:
private:
friend class WindowsResource;
ResourceEntryRef(BinaryStreamRef Ref, const WindowsResource *Owner,
Error &Err);
ResourceEntryRef(BinaryStreamRef Ref, const WindowsResource *Owner);
Error loadNext();
static Expected<ResourceEntryRef> create(BinaryStreamRef Ref,
const WindowsResource *Owner);
BinaryStreamReader Reader;
bool IsStringType;
ArrayRef<UTF16> Type;

View File

@ -57,19 +57,22 @@ WindowsResource::createWindowsResource(MemoryBufferRef Source) {
}
Expected<ResourceEntryRef> WindowsResource::getHeadEntry() {
Error Err = Error::success();
auto Ref = ResourceEntryRef(BinaryStreamRef(BBS), this, Err);
if (Err)
return std::move(Err);
return Ref;
if (BBS.getLength() < sizeof(WinResHeaderPrefix) + sizeof(WinResHeaderSuffix))
return make_error<EmptyResError>(".res contains no entries",
object_error::unexpected_eof);
return ResourceEntryRef::create(BinaryStreamRef(BBS), this);
}
ResourceEntryRef::ResourceEntryRef(BinaryStreamRef Ref,
const WindowsResource *Owner, Error &Err)
: Reader(Ref), OwningRes(Owner) {
if (loadNext())
Err = make_error<GenericBinaryError>("Could not read first entry.\n",
object_error::unexpected_eof);
const WindowsResource *Owner)
: Reader(Ref), OwningRes(Owner) {}
Expected<ResourceEntryRef>
ResourceEntryRef::create(BinaryStreamRef BSR, const WindowsResource *Owner) {
auto Ref = ResourceEntryRef(BSR, Owner);
if (auto E = Ref.loadNext())
return std::move(E);
return Ref;
}
Error ResourceEntryRef::moveNext(bool &End) {
@ -127,8 +130,20 @@ WindowsResourceParser::WindowsResourceParser() : Root(false) {}
Error WindowsResourceParser::parse(WindowsResource *WR) {
auto EntryOrErr = WR->getHeadEntry();
if (!EntryOrErr)
return EntryOrErr.takeError();
if (!EntryOrErr) {
auto E = EntryOrErr.takeError();
if (E.isA<EmptyResError>()) {
// Check if the .res file contains no entries. In this case we don't have
// to throw an error but can rather just return without parsing anything.
// This applies for files which have a valid PE header magic and the
// mandatory empty null resource entry. Files which do not fit this
// criteria would have already been filtered out by
// WindowsResource::createWindowsResource().
consumeError(std::move(E));
return Error::success();
}
return E;
}
ResourceEntryRef Entry = EntryOrErr.get();
bool End = false;