Refactor RelativePatcher out of OatWriter.
Move the relative patcher classes to compiler/linker/ and
compiler/linker/<arch>/ . Refactor them to avoid OatWriter
dependency so that they can be unit tested. Add tests for
x86 and x86-64.
Change-Id: I1b42baa9fc431378e4cce1399bec590c5b5a409f
diff --git a/compiler/linker/arm/relative_patcher_thumb2.cc b/compiler/linker/arm/relative_patcher_thumb2.cc
new file mode 100644
index 0000000..4267743
--- /dev/null
+++ b/compiler/linker/arm/relative_patcher_thumb2.cc
@@ -0,0 +1,84 @@
+/*
+ * 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/arm/relative_patcher_thumb2.h"
+
+#include "compiled_method.h"
+#include "mirror/art_method.h"
+#include "utils/arm/assembler_thumb2.h"
+
+namespace art {
+namespace linker {
+
+Thumb2RelativePatcher::Thumb2RelativePatcher(RelativePatcherTargetProvider* provider)
+ : ArmBaseRelativePatcher(provider, kThumb2, CompileThunkCode(),
+ kMaxPositiveDisplacement, kMaxNegativeDisplacement) {
+}
+
+void Thumb2RelativePatcher::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());
+ DCHECK_EQ(literal_offset & 1u, 0u);
+ DCHECK_EQ(patch_offset & 1u, 0u);
+ DCHECK_EQ(target_offset & 1u, 1u); // Thumb2 mode bit.
+ uint32_t displacement = CalculateDisplacement(patch_offset, target_offset & ~1u);
+ displacement -= kPcDisplacement; // The base PC is at the end of the 4-byte patch.
+ DCHECK_EQ(displacement & 1u, 0u);
+ DCHECK((displacement >> 24) == 0u || (displacement >> 24) == 255u); // 25-bit signed.
+ uint32_t signbit = (displacement >> 31) & 0x1;
+ uint32_t i1 = (displacement >> 23) & 0x1;
+ uint32_t i2 = (displacement >> 22) & 0x1;
+ uint32_t imm10 = (displacement >> 12) & 0x03ff;
+ uint32_t imm11 = (displacement >> 1) & 0x07ff;
+ uint32_t j1 = i1 ^ (signbit ^ 1);
+ uint32_t j2 = i2 ^ (signbit ^ 1);
+ uint32_t value = (signbit << 26) | (j1 << 13) | (j2 << 11) | (imm10 << 16) | imm11;
+ value |= 0xf000d000; // BL
+
+ uint8_t* addr = &(*code)[literal_offset];
+ // Check that we're just overwriting an existing BL.
+ DCHECK_EQ(addr[1] & 0xf8, 0xf0);
+ DCHECK_EQ(addr[3] & 0xd0, 0xd0);
+ // Write the new BL.
+ addr[0] = (value >> 16) & 0xff;
+ addr[1] = (value >> 24) & 0xff;
+ addr[2] = (value >> 0) & 0xff;
+ addr[3] = (value >> 8) & 0xff;
+}
+
+void Thumb2RelativePatcher::PatchDexCacheReference(std::vector<uint8_t>* code ATTRIBUTE_UNUSED,
+ const LinkerPatch& patch ATTRIBUTE_UNUSED,
+ uint32_t patch_offset ATTRIBUTE_UNUSED,
+ uint32_t target_offset ATTRIBUTE_UNUSED) {
+ LOG(FATAL) << "Unexpected relative dex cache array patch.";
+}
+
+std::vector<uint8_t> Thumb2RelativePatcher::CompileThunkCode() {
+ // The thunk just uses the entry point in the ArtMethod. This works even for calls
+ // to the generic JNI and interpreter trampolines.
+ arm::Thumb2Assembler assembler;
+ assembler.LoadFromOffset(
+ arm::kLoadWord, arm::PC, arm::R0,
+ mirror::ArtMethod::EntryPointFromQuickCompiledCodeOffset(kArmPointerSize).Int32Value());
+ assembler.bkpt(0);
+ std::vector<uint8_t> thunk_code(assembler.CodeSize());
+ MemoryRegion code(thunk_code.data(), thunk_code.size());
+ assembler.FinalizeInstructions(code);
+ return thunk_code;
+}
+
+} // namespace linker
+} // namespace art