[llvm] r264549 - Support: Implement StreamingMemoryObject::getPointer
Duncan P. N. Exon Smith via llvm-commits
llvm-commits at lists.llvm.org
Sun Mar 27 16:01:00 PDT 2016
Author: dexonsmith
Date: Sun Mar 27 18:00:59 2016
New Revision: 264549
URL: http://llvm.org/viewvc/llvm-project?rev=264549&view=rev
Log:
Support: Implement StreamingMemoryObject::getPointer
The implementation is fairly obvious. This is preparation for using
some blobs in bitcode.
For clarity (and perhaps future-proofing?), I moved the call to
JumpToBit in BitstreamCursor::readRecord ahead of calling
MemoryObject::getPointer, since JumpToBit can theoretically (a) read
bytes, which (b) invalidates the blob pointer.
This isn't strictly necessary the two memory objects we have:
- The return of RawMemoryObject::getPointer is valid until the memory
object is destroyed.
- StreamingMemoryObject::getPointer is valid until the next chunk is
read from the stream. Since the JumpToBit call is only going ahead
to a word boundary, we'll never load another chunk.
However, reordering makes it clear by inspection that the blob returned
by BitstreamCursor::readRecord will be valid.
I added some tests for StreamingMemoryObject::getPointer and
BitstreamCursor::readRecord.
Removed:
llvm/trunk/test/Bitcode/Inputs/invalid-fixme-streaming-blob.bc
Modified:
llvm/trunk/include/llvm/Support/StreamingMemoryObject.h
llvm/trunk/lib/Bitcode/Reader/BitstreamReader.cpp
llvm/trunk/lib/Support/StreamingMemoryObject.cpp
llvm/trunk/test/Bitcode/invalid.test
llvm/trunk/unittests/Bitcode/BitstreamReaderTest.cpp
llvm/trunk/unittests/Support/StreamingMemoryObjectTest.cpp
Modified: llvm/trunk/include/llvm/Support/StreamingMemoryObject.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Support/StreamingMemoryObject.h?rev=264549&r1=264548&r2=264549&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Support/StreamingMemoryObject.h (original)
+++ llvm/trunk/include/llvm/Support/StreamingMemoryObject.h Sun Mar 27 18:00:59 2016
@@ -28,15 +28,7 @@ public:
uint64_t getExtent() const override;
uint64_t readBytes(uint8_t *Buf, uint64_t Size,
uint64_t Address) const override;
- const uint8_t *getPointer(uint64_t address, uint64_t size) const override {
- // FIXME: This could be fixed by ensuring the bytes are fetched and
- // making a copy, requiring that the bitcode size be known, or
- // otherwise ensuring that the memory doesn't go away/get reallocated,
- // but it's not currently necessary. Users that need the pointer (any
- // that need Blobs) don't stream.
- report_fatal_error("getPointer in streaming memory objects not allowed");
- return nullptr;
- }
+ const uint8_t *getPointer(uint64_t Address, uint64_t Size) const override;
bool isValidAddress(uint64_t address) const override;
/// Drop s bytes from the front of the stream, pushing the positions of the
Modified: llvm/trunk/lib/Bitcode/Reader/BitstreamReader.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Bitcode/Reader/BitstreamReader.cpp?rev=264549&r1=264548&r2=264549&view=diff
==============================================================================
--- llvm/trunk/lib/Bitcode/Reader/BitstreamReader.cpp (original)
+++ llvm/trunk/lib/Bitcode/Reader/BitstreamReader.cpp Sun Mar 27 18:00:59 2016
@@ -260,7 +260,10 @@ unsigned BitstreamCursor::readRecord(uns
break;
}
- // Otherwise, inform the streamer that we need these bytes in memory.
+ // Otherwise, inform the streamer that we need these bytes in memory. Skip
+ // over tail padding first, in case jumping to NewEnd invalidates the Blob
+ // pointer.
+ JumpToBit(NewEnd);
const char *Ptr = (const char *)getPointerToBit(CurBitPos, NumElts);
// If we can return a reference to the data, do so to avoid copying it.
@@ -271,8 +274,6 @@ unsigned BitstreamCursor::readRecord(uns
for (; NumElts; --NumElts)
Vals.push_back((unsigned char)*Ptr++);
}
- // Skip over tail padding.
- JumpToBit(NewEnd);
}
return Code;
Modified: llvm/trunk/lib/Support/StreamingMemoryObject.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Support/StreamingMemoryObject.cpp?rev=264549&r1=264548&r2=264549&view=diff
==============================================================================
--- llvm/trunk/lib/Support/StreamingMemoryObject.cpp (original)
+++ llvm/trunk/lib/Support/StreamingMemoryObject.cpp Sun Mar 27 18:00:59 2016
@@ -104,6 +104,12 @@ uint64_t StreamingMemoryObject::readByte
return Size;
}
+const uint8_t *StreamingMemoryObject::getPointer(uint64_t Address,
+ uint64_t Size) const {
+ fetchToPos(Address + Size - 1);
+ return &Bytes[Address + BytesSkipped];
+}
+
bool StreamingMemoryObject::dropLeadingBytes(size_t s) {
if (BytesRead < s) return true;
BytesSkipped = s;
Removed: llvm/trunk/test/Bitcode/Inputs/invalid-fixme-streaming-blob.bc
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Bitcode/Inputs/invalid-fixme-streaming-blob.bc?rev=264548&view=auto
==============================================================================
Binary files llvm/trunk/test/Bitcode/Inputs/invalid-fixme-streaming-blob.bc (original) and llvm/trunk/test/Bitcode/Inputs/invalid-fixme-streaming-blob.bc (removed) differ
Modified: llvm/trunk/test/Bitcode/invalid.test
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Bitcode/invalid.test?rev=264549&r1=264548&r2=264549&view=diff
==============================================================================
--- llvm/trunk/test/Bitcode/invalid.test (original)
+++ llvm/trunk/test/Bitcode/invalid.test Sun Mar 27 18:00:59 2016
@@ -168,11 +168,6 @@ RUN: FileCheck --check-prefix=INVALID-
INVALID-ARGUMENT-TYPE: Invalid function argument type
-RUN: not llvm-dis -disable-output %p/Inputs/invalid-fixme-streaming-blob.bc 2>&1 | \
-RUN: FileCheck --check-prefix=STREAMING-BLOB %s
-
-STREAMING-BLOB: getPointer in streaming memory objects not allowed
-
RUN: not llvm-dis -disable-output %p/Inputs/invalid-function-comdat-id.bc 2>&1 | \
RUN: FileCheck --check-prefix=INVALID-FCOMDAT-ID %s
Modified: llvm/trunk/unittests/Bitcode/BitstreamReaderTest.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/unittests/Bitcode/BitstreamReaderTest.cpp?rev=264549&r1=264548&r2=264549&view=diff
==============================================================================
--- llvm/trunk/unittests/Bitcode/BitstreamReaderTest.cpp (original)
+++ llvm/trunk/unittests/Bitcode/BitstreamReaderTest.cpp Sun Mar 27 18:00:59 2016
@@ -7,13 +7,31 @@
//
//===----------------------------------------------------------------------===//
+#include "llvm/ADT/STLExtras.h"
#include "llvm/Bitcode/BitstreamReader.h"
+#include "llvm/Bitcode/BitstreamWriter.h"
+#include "llvm/Support/StreamingMemoryObject.h"
#include "gtest/gtest.h"
using namespace llvm;
namespace {
+class BufferStreamer : public DataStreamer {
+ StringRef Buffer;
+
+public:
+ BufferStreamer(StringRef Buffer) : Buffer(Buffer) {}
+ size_t GetBytes(unsigned char *OutBuffer, size_t Length) override {
+ if (Length >= Buffer.size())
+ Length = Buffer.size();
+
+ std::copy(Buffer.begin(), Buffer.begin() + Length, OutBuffer);
+ Buffer = Buffer.drop_front(Length);
+ return Length;
+ }
+};
+
TEST(BitstreamReaderTest, AtEndOfStream) {
uint8_t Bytes[4] = {
0x00, 0x01, 0x02, 0x03
@@ -165,4 +183,65 @@ TEST(BitstreamReaderTest, setArtificialB
EXPECT_TRUE(Cursor.AtEndOfStream());
}
+TEST(BitstreamReaderTest, readRecordWithBlobWhileStreaming) {
+ SmallVector<uint8_t, 1> BlobData;
+ for (unsigned I = 0, E = 1024; I != E; ++I)
+ BlobData.push_back(I);
+
+ // Try a bunch of different sizes.
+ const unsigned Magic = 0x12345678;
+ const unsigned BlockID = bitc::FIRST_APPLICATION_BLOCKID;
+ const unsigned RecordID = 1;
+ for (unsigned I = 0, BlobSize = 0, E = BlobData.size(); BlobSize < E;
+ BlobSize += ++I) {
+ StringRef BlobIn((const char *)BlobData.begin(), BlobSize);
+
+ // Write the bitcode.
+ SmallVector<char, 1> Buffer;
+ unsigned AbbrevID;
+ {
+ BitstreamWriter Stream(Buffer);
+ Stream.Emit(Magic, 32);
+ Stream.EnterSubblock(BlockID, 3);
+
+ BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
+ Abbrev->Add(BitCodeAbbrevOp(RecordID));
+ Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
+ AbbrevID = Stream.EmitAbbrev(Abbrev);
+ unsigned Record[] = {RecordID};
+ Stream.EmitRecordWithBlob(AbbrevID, makeArrayRef(Record), BlobIn);
+
+ Stream.ExitBlock();
+ }
+
+ // Stream the buffer into the reader.
+ BitstreamReader R(make_unique<StreamingMemoryObject>(
+ make_unique<BufferStreamer>(StringRef(Buffer.begin(), Buffer.size()))));
+ BitstreamCursor Stream(R);
+
+ // Header. Included in test so that we can run llvm-bcanalyzer to debug
+ // when there are problems.
+ ASSERT_EQ(Magic, Stream.Read(32));
+
+ // Block.
+ BitstreamEntry Entry =
+ Stream.advance(BitstreamCursor::AF_DontAutoprocessAbbrevs);
+ ASSERT_EQ(BitstreamEntry::SubBlock, Entry.Kind);
+ ASSERT_EQ(BlockID, Entry.ID);
+ ASSERT_FALSE(Stream.EnterSubBlock(BlockID));
+
+ // Abbreviation.
+ Entry = Stream.advance();
+ ASSERT_EQ(BitstreamEntry::Record, Entry.Kind);
+ ASSERT_EQ(AbbrevID, Entry.ID);
+
+ // Record.
+ StringRef BlobOut;
+ SmallVector<uint64_t, 1> Record;
+ ASSERT_EQ(RecordID, Stream.readRecord(Entry.ID, Record, &BlobOut));
+ EXPECT_TRUE(Record.empty());
+ EXPECT_EQ(BlobIn, BlobOut);
+ }
+}
+
} // end anonymous namespace
Modified: llvm/trunk/unittests/Support/StreamingMemoryObjectTest.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/unittests/Support/StreamingMemoryObjectTest.cpp?rev=264549&r1=264548&r2=264549&view=diff
==============================================================================
--- llvm/trunk/unittests/Support/StreamingMemoryObjectTest.cpp (original)
+++ llvm/trunk/unittests/Support/StreamingMemoryObjectTest.cpp Sun Mar 27 18:00:59 2016
@@ -24,6 +24,21 @@ class NullDataStreamer : public DataStre
}
};
+class BufferStreamer : public DataStreamer {
+ StringRef Buffer;
+
+public:
+ BufferStreamer(StringRef Buffer) : Buffer(Buffer) {}
+ size_t GetBytes(unsigned char *OutBuffer, size_t Length) override {
+ if (Length >= Buffer.size())
+ Length = Buffer.size();
+
+ std::copy(Buffer.begin(), Buffer.begin() + Length, OutBuffer);
+ Buffer = Buffer.drop_front(Length);
+ return Length;
+ }
+};
+
TEST(StreamingMemoryObjectTest, isValidAddress) {
auto DS = make_unique<NullDataStreamer>();
StreamingMemoryObject O(std::move(DS));
@@ -39,4 +54,15 @@ TEST(StreamingMemoryObjectTest, setKnown
EXPECT_EQ(8u, O.readBytes(Buf, 16, 16));
}
+TEST(StreamingMemoryObjectTest, getPointer) {
+ uint8_t InputBuffer[] = {0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07};
+ StreamingMemoryObject O(make_unique<BufferStreamer>(StringRef(
+ reinterpret_cast<const char *>(InputBuffer), sizeof(InputBuffer))));
+
+ EXPECT_TRUE(std::equal(InputBuffer + 1, InputBuffer + 2, O.getPointer(1, 2)));
+ EXPECT_TRUE(std::equal(InputBuffer + 3, InputBuffer + 7, O.getPointer(3, 4)));
+ EXPECT_TRUE(std::equal(InputBuffer + 4, InputBuffer + 8, O.getPointer(4, 5)));
+ EXPECT_TRUE(std::equal(InputBuffer, InputBuffer + 8, O.getPointer(0, 20)));
+}
+
} // end namespace
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