blob: 07cd724308063b423568ce137bad70f59a3fa35c [file] [log] [blame]
/*
* 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.
*/
#include "linker/x86/relative_patcher_x86_base.h"
#include "debug/method_debug_info.h"
namespace art {
namespace linker {
uint32_t X86BaseRelativePatcher::ReserveSpace(
uint32_t offset,
const CompiledMethod* compiled_method ATTRIBUTE_UNUSED,
MethodReference method_ref ATTRIBUTE_UNUSED) {
return offset; // No space reserved; no limit on relative call distance.
}
uint32_t X86BaseRelativePatcher::ReserveSpaceEnd(uint32_t offset) {
return offset; // No space reserved; no limit on relative call distance.
}
uint32_t X86BaseRelativePatcher::WriteThunks(OutputStream* out ATTRIBUTE_UNUSED, uint32_t offset) {
return offset; // No thunks added; no limit on relative call distance.
}
std::vector<debug::MethodDebugInfo> X86BaseRelativePatcher::GenerateThunkDebugInfo(
uint32_t executable_offset ATTRIBUTE_UNUSED) {
return std::vector<debug::MethodDebugInfo>(); // No thunks added.
}
void X86BaseRelativePatcher::PatchCall(std::vector<uint8_t>* code,
uint32_t literal_offset,
uint32_t patch_offset,
uint32_t target_offset) {
DCHECK_LE(literal_offset + 4u, code->size());
// Unsigned arithmetic with its well-defined overflow behavior is just fine here.
uint32_t displacement = target_offset - patch_offset;
displacement -= kPcDisplacement; // The base PC is at the end of the 4-byte patch.
using unaligned_int32_t __attribute__((__aligned__(1))) = int32_t;
reinterpret_cast<unaligned_int32_t*>(&(*code)[literal_offset])[0] = displacement;
}
} // namespace linker
} // namespace art