Add ElfWriter::GetStream().
This will be used for writing the OatHeader which is
currently oddly written through the .text stream.
Also move the error delaying output stream out of the
ElfBuilder<> to its own file and move all output stream
files to compiler/linker/.
Change-Id: I00db4e33ed80ac4757ec459946c7b5ae014a3a2e
diff --git a/compiler/linker/error_delaying_output_stream.h b/compiler/linker/error_delaying_output_stream.h
new file mode 100644
index 0000000..99410e4
--- /dev/null
+++ b/compiler/linker/error_delaying_output_stream.h
@@ -0,0 +1,101 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ART_COMPILER_LINKER_ERROR_DELAYING_OUTPUT_STREAM_H_
+#define ART_COMPILER_LINKER_ERROR_DELAYING_OUTPUT_STREAM_H_
+
+#include "output_stream.h"
+
+#include "base/logging.h"
+
+namespace art {
+
+// OutputStream wrapper that delays reporting an error until Flush().
+class ErrorDelayingOutputStream FINAL : public OutputStream {
+ public:
+ explicit ErrorDelayingOutputStream(OutputStream* output)
+ : OutputStream(output->GetLocation()),
+ output_(output),
+ output_good_(true),
+ output_offset_(0) { }
+
+ // This function always succeeds to simplify code.
+ // Use Good() to check the actual status of the output stream.
+ bool WriteFully(const void* buffer, size_t byte_count) OVERRIDE {
+ if (output_good_) {
+ if (!output_->WriteFully(buffer, byte_count)) {
+ PLOG(ERROR) << "Failed to write " << byte_count
+ << " bytes to " << GetLocation() << " at offset " << output_offset_;
+ output_good_ = false;
+ }
+ }
+ output_offset_ += byte_count;
+ return true;
+ }
+
+ // This function always succeeds to simplify code.
+ // Use Good() to check the actual status of the output stream.
+ off_t Seek(off_t offset, Whence whence) OVERRIDE {
+ // We keep shadow copy of the offset so that we return
+ // the expected value even if the output stream failed.
+ off_t new_offset;
+ switch (whence) {
+ case kSeekSet:
+ new_offset = offset;
+ break;
+ case kSeekCurrent:
+ new_offset = output_offset_ + offset;
+ break;
+ default:
+ LOG(FATAL) << "Unsupported seek type: " << whence;
+ UNREACHABLE();
+ }
+ if (output_good_) {
+ off_t actual_offset = output_->Seek(offset, whence);
+ if (actual_offset == static_cast<off_t>(-1)) {
+ PLOG(ERROR) << "Failed to seek in " << GetLocation() << ". Offset=" << offset
+ << " whence=" << whence << " new_offset=" << new_offset;
+ output_good_ = false;
+ }
+ DCHECK_EQ(actual_offset, new_offset);
+ }
+ output_offset_ = new_offset;
+ return new_offset;
+ }
+
+ // Flush the output and return whether all operations have succeeded.
+ // Do nothing if we already have a pending error.
+ bool Flush() OVERRIDE {
+ if (output_good_) {
+ output_good_ = output_->Flush();
+ }
+ return output_good_;
+ }
+
+ // Check (without flushing) whether all operations have succeeded so far.
+ bool Good() const {
+ return output_good_;
+ }
+
+ private:
+ OutputStream* output_;
+ bool output_good_; // True if all writes to output succeeded.
+ off_t output_offset_; // Keep track of the current position in the stream.
+};
+
+} // namespace art
+
+#endif // ART_COMPILER_LINKER_ERROR_DELAYING_OUTPUT_STREAM_H_