Create helper class for DWARF expressions.
This ensures we generate valid DWARF opcodes and
it slightly simplifies the debug info writer.
Change-Id: I2ef8a9222c9a129c58f500741acd209b67e2ecff
diff --git a/compiler/dwarf/debug_frame_opcode_writer.h b/compiler/dwarf/debug_frame_opcode_writer.h
index 5a99641..f74f37c 100644
--- a/compiler/dwarf/debug_frame_opcode_writer.h
+++ b/compiler/dwarf/debug_frame_opcode_writer.h
@@ -248,7 +248,7 @@
}
}
- void ALWAYS_INLINE DefCFAExpression(void * expr, int expr_size) {
+ void ALWAYS_INLINE DefCFAExpression(uint8_t* expr, int expr_size) {
if (UNLIKELY(enabled_)) {
ImplicitlyAdvancePC();
uses_dwarf3_features_ = true;
@@ -258,7 +258,7 @@
}
}
- void ALWAYS_INLINE Expression(Reg reg, void * expr, int expr_size) {
+ void ALWAYS_INLINE Expression(Reg reg, uint8_t* expr, int expr_size) {
if (UNLIKELY(enabled_)) {
ImplicitlyAdvancePC();
uses_dwarf3_features_ = true;
@@ -269,7 +269,7 @@
}
}
- void ALWAYS_INLINE ValExpression(Reg reg, void * expr, int expr_size) {
+ void ALWAYS_INLINE ValExpression(Reg reg, uint8_t* expr, int expr_size) {
if (UNLIKELY(enabled_)) {
ImplicitlyAdvancePC();
uses_dwarf3_features_ = true;
diff --git a/compiler/dwarf/debug_info_entry_writer.h b/compiler/dwarf/debug_info_entry_writer.h
index a551e4b..e5bbed3 100644
--- a/compiler/dwarf/debug_info_entry_writer.h
+++ b/compiler/dwarf/debug_info_entry_writer.h
@@ -22,6 +22,7 @@
#include "base/casts.h"
#include "dwarf/dwarf_constants.h"
+#include "dwarf/expression.h"
#include "dwarf/writer.h"
#include "leb128.h"
@@ -106,16 +107,16 @@
}
}
- void WriteBlock(Attribute attrib, const void* ptr, size_t num_bytes) {
+ void WriteBlock(Attribute attrib, const uint8_t* ptr, size_t num_bytes) {
AddAbbrevAttribute(attrib, DW_FORM_block);
this->PushUleb128(num_bytes);
this->PushData(ptr, num_bytes);
}
- void WriteExprLoc(Attribute attrib, const void* ptr, size_t num_bytes) {
+ void WriteExprLoc(Attribute attrib, const Expression& expr) {
AddAbbrevAttribute(attrib, DW_FORM_exprloc);
- this->PushUleb128(dchecked_integral_cast<uint32_t>(num_bytes));
- this->PushData(ptr, num_bytes);
+ this->PushUleb128(dchecked_integral_cast<uint32_t>(expr.size()));
+ this->PushData(expr.data());
}
void WriteData1(Attribute attrib, uint8_t value) {
diff --git a/compiler/dwarf/expression.h b/compiler/dwarf/expression.h
new file mode 100644
index 0000000..1503d03
--- /dev/null
+++ b/compiler/dwarf/expression.h
@@ -0,0 +1,121 @@
+/*
+ * Copyright (C) 2016 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_DWARF_EXPRESSION_H_
+#define ART_COMPILER_DWARF_EXPRESSION_H_
+
+#include <cstddef>
+#include <cstdint>
+
+#include "dwarf/dwarf_constants.h"
+#include "dwarf/writer.h"
+
+namespace art {
+namespace dwarf {
+
+// Writer for DWARF expressions which are used in .debug_info and .debug_loc sections.
+// See the DWARF specification for the precise meaning of the opcodes.
+// If multiple equivalent encodings are possible, it will choose the most compact one.
+// The writer is not exhaustive - it only implements opcodes we have needed so far.
+class Expression : private Writer<> {
+ public:
+ using Writer<>::data;
+ using Writer<>::size;
+
+ // Push signed integer on the stack.
+ void WriteOpConsts(int32_t value) {
+ if (0 <= value && value < 32) {
+ PushUint8(DW_OP_lit0 + value);
+ } else {
+ PushUint8(DW_OP_consts);
+ PushSleb128(value);
+ }
+ }
+
+ // Push unsigned integer on the stack.
+ void WriteOpConstu(uint32_t value) {
+ if (value < 32) {
+ PushUint8(DW_OP_lit0 + value);
+ } else {
+ PushUint8(DW_OP_constu);
+ PushUleb128(value);
+ }
+ }
+
+ // Variable is stored in given register.
+ void WriteOpReg(uint32_t dwarf_reg_num) {
+ if (dwarf_reg_num < 32) {
+ PushUint8(DW_OP_reg0 + dwarf_reg_num);
+ } else {
+ PushUint8(DW_OP_regx);
+ PushUleb128(dwarf_reg_num);
+ }
+ }
+
+ // Variable is stored on stack. Also see DW_AT_frame_base.
+ void WriteOpFbreg(int32_t stack_offset) {
+ PushUint8(DW_OP_fbreg);
+ PushSleb128(stack_offset);
+ }
+
+ // The variable is stored in multiple locations (pieces).
+ void WriteOpPiece(uint32_t num_bytes) {
+ PushUint8(DW_OP_piece);
+ PushUleb128(num_bytes);
+ }
+
+ // Loads 32-bit or 64-bit value depending on architecture.
+ void WriteOpDeref() { PushUint8(DW_OP_deref); }
+
+ // Loads value of given byte size.
+ void WriteOpDerefSize(uint8_t num_bytes) {
+ PushUint8(DW_OP_deref_size);
+ PushUint8(num_bytes);
+ }
+
+ // Pop two values and push their sum.
+ void WriteOpPlus() { PushUint8(DW_OP_plus); }
+
+ // Add constant value to value on top of stack.
+ void WriteOpPlusUconst(uint32_t offset) {
+ PushUint8(DW_OP_plus_uconst);
+ PushUleb128(offset);
+ }
+
+ // Negate top of stack.
+ void WriteOpNeg() { PushUint8(DW_OP_neg); }
+
+ // Pop two values and push their bitwise-AND.
+ void WriteOpAnd() { PushUint8(DW_OP_and); }
+
+ // Push stack base pointer as determined from .debug_frame.
+ void WriteOpCallFrameCfa() { PushUint8(DW_OP_call_frame_cfa); }
+
+ // Push address of the variable we are working with.
+ void WriteOpPushObjectAddress() { PushUint8(DW_OP_push_object_address); }
+
+ // Return the top stack as the value of the variable.
+ // Otherwise, the top of stack is the variable's location.
+ void WriteOpStackValue() { PushUint8(DW_OP_stack_value); }
+
+ explicit Expression(std::vector<uint8_t>* buffer) : Writer<>(buffer) {
+ buffer->clear();
+ }
+};
+} // namespace dwarf
+} // namespace art
+
+#endif // ART_COMPILER_DWARF_EXPRESSION_H_
diff --git a/compiler/dwarf/headers.h b/compiler/dwarf/headers.h
index f76f76f..137c566 100644
--- a/compiler/dwarf/headers.h
+++ b/compiler/dwarf/headers.h
@@ -70,7 +70,7 @@
writer.PushUint8(DW_EH_PE_absptr | DW_EH_PE_udata4); // R: Pointer encoding.
}
}
- writer.PushData(*opcodes.data());
+ writer.PushData(opcodes.data());
writer.Pad(is64bit ? 8 : 4);
writer.UpdateUint32(cie_header_start_, writer.data()->size() - cie_header_start_ - 4);
}
@@ -117,7 +117,7 @@
writer.PushUint32(code_size);
}
writer.PushUleb128(0); // Augmentation data size.
- writer.PushData(opcodes);
+ writer.PushData(opcodes.data(), opcodes.size());
writer.Pad(is64bit ? 8 : 4);
writer.UpdateUint32(fde_header_start, writer.data()->size() - fde_header_start - 4);
}
@@ -139,7 +139,7 @@
writer.PushUint8(entries.Is64bit() ? 8 : 4);
size_t entries_offset = writer.data()->size();
DCHECK_EQ(entries_offset, DebugInfoEntryWriter<Vector>::kCompilationUnitHeaderSize);
- writer.PushData(*entries.data());
+ writer.PushData(entries.data());
writer.UpdateUint32(start, writer.data()->size() - start - 4);
// Copy patch locations and make them relative to .debug_info section.
for (uintptr_t patch_location : entries.GetPatchLocations()) {
@@ -193,7 +193,7 @@
writer.PushUint8(0); // Terminate file list.
writer.UpdateUint32(header_length_pos, writer.data()->size() - header_length_pos - 4);
size_t opcodes_offset = writer.data()->size();
- writer.PushData(*opcodes.data());
+ writer.PushData(opcodes.data());
writer.UpdateUint32(header_start, writer.data()->size() - header_start - 4);
// Copy patch locations and make them relative to .debug_line section.
for (uintptr_t patch_location : opcodes.GetPatchLocations()) {
diff --git a/compiler/dwarf/writer.h b/compiler/dwarf/writer.h
index d2add7f..74acf07 100644
--- a/compiler/dwarf/writer.h
+++ b/compiler/dwarf/writer.h
@@ -114,16 +114,16 @@
data_->insert(data_->end(), value, value + strlen(value) + 1);
}
- void PushData(const void* ptr, size_t num_bytes) {
- const char* p = reinterpret_cast<const char*>(ptr);
- data_->insert(data_->end(), p, p + num_bytes);
+ void PushData(const uint8_t* ptr, size_t num_bytes) {
+ data_->insert(data_->end(), ptr, ptr + num_bytes);
}
- template<typename Vector2>
- void PushData(const Vector2& buffer) {
- static_assert(std::is_same<typename std::add_const<typename Vector::value_type>::type,
- const uint8_t>::value, "Invalid value type");
- data_->insert(data_->end(), buffer.begin(), buffer.end());
+ void PushData(const char* ptr, size_t num_bytes) {
+ data_->insert(data_->end(), ptr, ptr + num_bytes);
+ }
+
+ void PushData(const Vector* buffer) {
+ data_->insert(data_->end(), buffer->begin(), buffer->end());
}
void UpdateUint32(size_t offset, uint32_t value) {