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

1 files changed, 9 insertions, 0 deletions

diff --git a/llvm/unittests/Support/StreamingMemoryObject.cpp b/llvm/unittests/Support/StreamingMemoryObject.cpp
index 20136491ab8..c043efbb5e4 100644
--- a/llvm/unittests/Support/StreamingMemoryObject.cpp
+++ b/llvm/unittests/Support/StreamingMemoryObject.cpp
@@ -27,3 +27,12 @@ TEST(StreamingMemoryObject, Test) {
   StreamingMemoryObject O(DS);
   EXPECT_TRUE(O.isValidAddress(32 * 1024));
 }
+
+TEST(StreamingMemoryObject, TestSetKnownObjectSize) {
+  auto *DS = new NullDataStreamer();
+  StreamingMemoryObject O(DS);
+  uint8_t Buf[32];
+  EXPECT_EQ((uint64_t) 16, O.readBytes(Buf, 16, 0));
+  O.setKnownObjectSize(24);
+  EXPECT_EQ((uint64_t) 8, O.readBytes(Buf, 16, 16));
+}