Fix StreamingMemoryObject to respect known object size.
The existing code for method StreamingMemoryObject.fetchToPos does not respect
the corresonding call to setKnownObjectSize(). As a result, it allows the
StreamingMemoryObject to read bytes past the object size.
This patch provides a test case, and code to fix the problem.
Patch by Karl Schimpf
Differential Revision: http://reviews.llvm.org/D8931
llvm-svn: 237939
diff --git a/llvm/lib/Support/StreamingMemoryObject.cpp b/llvm/lib/Support/StreamingMemoryObject.cpp
index 90f3ed8..6c5652a 100644
--- a/llvm/lib/Support/StreamingMemoryObject.cpp
+++ b/llvm/lib/Support/StreamingMemoryObject.cpp
@@ -73,7 +73,7 @@
// block until we actually want to read it.
bool StreamingMemoryObject::isValidAddress(uint64_t address) const {
if (ObjectSize && address < ObjectSize) return true;
- return fetchToPos(address);
+ return fetchToPos(address);
}
uint64_t StreamingMemoryObject::getExtent() const {
@@ -87,13 +87,18 @@
uint64_t StreamingMemoryObject::readBytes(uint8_t *Buf, uint64_t Size,
uint64_t Address) const {
fetchToPos(Address + Size - 1);
- if (Address >= BytesRead)
+ // Note: For wrapped bitcode files will set ObjectSize after the
+ // first call to fetchToPos. In such cases, ObjectSize can be
+ // smaller than BytesRead.
+ size_t MaxAddress =
+ (ObjectSize && ObjectSize < BytesRead) ? ObjectSize : BytesRead;
+ if (Address >= MaxAddress)
return 0;
uint64_t End = Address + Size;
- if (End > BytesRead)
- End = BytesRead;
- assert(static_cast<int64_t>(End - Address) >= 0);
+ if (End > MaxAddress)
+ End = MaxAddress;
+ assert(End >= Address);
Size = End - Address;
memcpy(Buf, &Bytes[Address + BytesSkipped], Size);
return Size;
@@ -109,6 +114,8 @@
void StreamingMemoryObject::setKnownObjectSize(size_t size) {
ObjectSize = size;
Bytes.reserve(size);
+ if (ObjectSize <= BytesRead)
+ EOFReached = true;
}
MemoryObject *getNonStreamedMemoryObject(const unsigned char *Start,