Sketch out a DWARF parser.
This introduces a new library to LLVM: libDebugInfo. It will provide debug information
parsing to LLVM. Much of the design and some of the code is taken from the LLDB project.
It also contains an llvm-dwarfdump tool that can dump the abbrevs and DIEs from an
object file. It can be used to write tests for DWARF input and output easily.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@139627 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/DebugInfo/DWARFFormValue.cpp b/lib/DebugInfo/DWARFFormValue.cpp
new file mode 100644
index 0000000..5aa7469
--- /dev/null
+++ b/lib/DebugInfo/DWARFFormValue.cpp
@@ -0,0 +1,434 @@
+//===-- DWARFFormValue.cpp ------------------------------------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "DWARFFormValue.h"
+#include "DWARFCompileUnit.h"
+#include "llvm/Support/Dwarf.h"
+#include "llvm/Support/Format.h"
+#include "llvm/Support/raw_ostream.h"
+#include <cassert>
+using namespace llvm;
+using namespace dwarf;
+
+static const uint8_t form_sizes_addr4[] = {
+ 0, // 0x00 unused
+ 4, // 0x01 DW_FORM_addr
+ 0, // 0x02 unused
+ 0, // 0x03 DW_FORM_block2
+ 0, // 0x04 DW_FORM_block4
+ 2, // 0x05 DW_FORM_data2
+ 4, // 0x06 DW_FORM_data4
+ 8, // 0x07 DW_FORM_data8
+ 0, // 0x08 DW_FORM_string
+ 0, // 0x09 DW_FORM_block
+ 0, // 0x0a DW_FORM_block1
+ 1, // 0x0b DW_FORM_data1
+ 1, // 0x0c DW_FORM_flag
+ 0, // 0x0d DW_FORM_sdata
+ 4, // 0x0e DW_FORM_strp
+ 0, // 0x0f DW_FORM_udata
+ 4, // 0x10 DW_FORM_ref_addr
+ 1, // 0x11 DW_FORM_ref1
+ 2, // 0x12 DW_FORM_ref2
+ 4, // 0x13 DW_FORM_ref4
+ 8, // 0x14 DW_FORM_ref8
+ 0, // 0x15 DW_FORM_ref_udata
+ 0, // 0x16 DW_FORM_indirect
+};
+
+static const uint8_t form_sizes_addr8[] = {
+ 0, // 0x00 unused
+ 8, // 0x01 DW_FORM_addr
+ 0, // 0x02 unused
+ 0, // 0x03 DW_FORM_block2
+ 0, // 0x04 DW_FORM_block4
+ 2, // 0x05 DW_FORM_data2
+ 4, // 0x06 DW_FORM_data4
+ 8, // 0x07 DW_FORM_data8
+ 0, // 0x08 DW_FORM_string
+ 0, // 0x09 DW_FORM_block
+ 0, // 0x0a DW_FORM_block1
+ 1, // 0x0b DW_FORM_data1
+ 1, // 0x0c DW_FORM_flag
+ 0, // 0x0d DW_FORM_sdata
+ 4, // 0x0e DW_FORM_strp
+ 0, // 0x0f DW_FORM_udata
+ 8, // 0x10 DW_FORM_ref_addr
+ 1, // 0x11 DW_FORM_ref1
+ 2, // 0x12 DW_FORM_ref2
+ 4, // 0x13 DW_FORM_ref4
+ 8, // 0x14 DW_FORM_ref8
+ 0, // 0x15 DW_FORM_ref_udata
+ 0, // 0x16 DW_FORM_indirect
+};
+
+const uint8_t *
+DWARFFormValue::getFixedFormSizesForAddressSize(uint8_t addr_size) {
+ switch (addr_size) {
+ case 4: return form_sizes_addr4;
+ case 8: return form_sizes_addr8;
+ }
+ return NULL;
+}
+
+bool
+DWARFFormValue::extractValue(DataExtractor data, uint32_t *offset_ptr,
+ const DWARFCompileUnit* cu) {
+ bool indirect = false;
+ bool is_block = false;
+ Value.data = NULL;
+ // Read the value for the form into value and follow and DW_FORM_indirect
+ // instances we run into
+ do {
+ indirect = false;
+ switch (Form) {
+ case DW_FORM_addr:
+ case DW_FORM_ref_addr:
+ Value.uval = data.getUnsigned(offset_ptr, cu->getAddressByteSize());
+ break;
+ case DW_FORM_block:
+ Value.uval = data.getULEB128(offset_ptr);
+ is_block = true;
+ break;
+ case DW_FORM_block1:
+ Value.uval = data.getU8(offset_ptr);
+ is_block = true;
+ break;
+ case DW_FORM_block2:
+ Value.uval = data.getU16(offset_ptr);
+ is_block = true;
+ break;
+ case DW_FORM_block4:
+ Value.uval = data.getU32(offset_ptr);
+ is_block = true;
+ break;
+ case DW_FORM_data1:
+ case DW_FORM_ref1:
+ case DW_FORM_flag:
+ Value.uval = data.getU8(offset_ptr);
+ break;
+ case DW_FORM_data2:
+ case DW_FORM_ref2:
+ Value.uval = data.getU16(offset_ptr);
+ break;
+ case DW_FORM_data4:
+ case DW_FORM_ref4:
+ Value.uval = data.getU32(offset_ptr);
+ break;
+ case DW_FORM_data8:
+ case DW_FORM_ref8:
+ Value.uval = data.getU64(offset_ptr);
+ break;
+ case DW_FORM_sdata:
+ Value.sval = data.getSLEB128(offset_ptr);
+ break;
+ case DW_FORM_strp:
+ Value.uval = data.getU32(offset_ptr);
+ break;
+ case DW_FORM_udata:
+ case DW_FORM_ref_udata:
+ Value.uval = data.getULEB128(offset_ptr);
+ break;
+ case DW_FORM_string:
+ Value.cstr = data.getCStr(offset_ptr);
+ // Set the string value to also be the data for inlined cstr form
+ // values only so we can tell the differnence between DW_FORM_string
+ // and DW_FORM_strp form values
+ Value.data = (uint8_t*)Value.cstr;
+ break;
+ case DW_FORM_indirect:
+ Form = data.getULEB128(offset_ptr);
+ indirect = true;
+ break;
+ default:
+ return false;
+ }
+ } while (indirect);
+
+ if (is_block) {
+ StringRef str = data.getData().substr(*offset_ptr, Value.uval);
+ Value.data = NULL;
+ if (!str.empty()) {
+ Value.data = reinterpret_cast<const uint8_t *>(str.data());
+ *offset_ptr += Value.uval;
+ }
+ }
+
+ return true;
+}
+
+bool
+DWARFFormValue::skipValue(DataExtractor debug_info_data, uint32_t* offset_ptr,
+ const DWARFCompileUnit* cu) const {
+ return DWARFFormValue::skipValue(Form, debug_info_data, offset_ptr, cu);
+}
+
+bool
+DWARFFormValue::skipValue(uint16_t form, DataExtractor debug_info_data,
+ uint32_t *offset_ptr, const DWARFCompileUnit *cu) {
+ bool indirect = false;
+ do {
+ indirect = false;
+ switch (form) {
+ // Blocks if inlined data that have a length field and the data bytes
+ // inlined in the .debug_info
+ case DW_FORM_block: {
+ uint64_t size = debug_info_data.getULEB128(offset_ptr);
+ *offset_ptr += size;
+ return true;
+ }
+ case DW_FORM_block1: {
+ uint8_t size = debug_info_data.getU8(offset_ptr);
+ *offset_ptr += size;
+ return true;
+ }
+ case DW_FORM_block2: {
+ uint16_t size = debug_info_data.getU16(offset_ptr);
+ *offset_ptr += size;
+ return true;
+ }
+ case DW_FORM_block4: {
+ uint32_t size = debug_info_data.getU32(offset_ptr);
+ *offset_ptr += size;
+ return true;
+ }
+
+ // Inlined NULL terminated C-strings
+ case DW_FORM_string:
+ debug_info_data.getCStr(offset_ptr);
+ return true;
+
+ // Compile unit address sized values
+ case DW_FORM_addr:
+ case DW_FORM_ref_addr:
+ *offset_ptr += cu->getAddressByteSize();
+ return true;
+
+ // 1 byte values
+ case DW_FORM_data1:
+ case DW_FORM_flag:
+ case DW_FORM_ref1:
+ *offset_ptr += 1;
+ return true;
+
+ // 2 byte values
+ case DW_FORM_data2:
+ case DW_FORM_ref2:
+ *offset_ptr += 2;
+ return true;
+
+ // 4 byte values
+ case DW_FORM_strp:
+ case DW_FORM_data4:
+ case DW_FORM_ref4:
+ *offset_ptr += 4;
+ return true;
+
+ // 8 byte values
+ case DW_FORM_data8:
+ case DW_FORM_ref8:
+ *offset_ptr += 8;
+ return true;
+
+ // signed or unsigned LEB 128 values
+ // case DW_FORM_APPLE_db_str:
+ case DW_FORM_sdata:
+ case DW_FORM_udata:
+ case DW_FORM_ref_udata:
+ debug_info_data.getULEB128(offset_ptr);
+ return true;
+
+ case DW_FORM_indirect:
+ indirect = true;
+ form = debug_info_data.getULEB128(offset_ptr);
+ break;
+ default:
+ return false;
+ }
+ } while (indirect);
+ return true;
+}
+
+void
+DWARFFormValue::dump(raw_ostream &OS, const DataExtractor *debug_str_data,
+ const DWARFCompileUnit *cu) const {
+ uint64_t uvalue = getUnsigned();
+ bool cu_relative_offset = false;
+
+ switch (Form)
+ {
+ case DW_FORM_addr: OS << format("0x%016x", uvalue); break;
+ case DW_FORM_flag:
+ case DW_FORM_data1: OS << format("0x%02x", uvalue); break;
+ case DW_FORM_data2: OS << format("0x%04x", uvalue); break;
+ case DW_FORM_data4: OS << format("0x%08x", uvalue); break;
+ case DW_FORM_data8: OS << format("0x%016x", uvalue); break;
+ case DW_FORM_string:
+ OS << '"';
+ OS.write_escaped(getAsCString(NULL));
+ OS << '"';
+ break;
+ case DW_FORM_block:
+ case DW_FORM_block1:
+ case DW_FORM_block2:
+ case DW_FORM_block4:
+ if (uvalue > 0) {
+ switch (Form) {
+ case DW_FORM_block: OS << format("<0x%llx> ", uvalue); break;
+ case DW_FORM_block1: OS << format("<0x%2.2x> ", (uint8_t)uvalue); break;
+ case DW_FORM_block2: OS << format("<0x%4.4x> ", (uint16_t)uvalue); break;
+ case DW_FORM_block4: OS << format("<0x%8.8x> ", (uint32_t)uvalue); break;
+ default: break;
+ }
+
+ const uint8_t* data_ptr = Value.data;
+ if (data_ptr) {
+ // uvalue contains size of block
+ const uint8_t* end_data_ptr = data_ptr + uvalue;
+ while (data_ptr < end_data_ptr) {
+ OS << format("%2.2x ", *data_ptr);
+ ++data_ptr;
+ }
+ }
+ else
+ OS << "NULL";
+ }
+ break;
+
+ case DW_FORM_sdata: OS << getSigned(); break;
+ case DW_FORM_udata: OS << getUnsigned(); break;
+ case DW_FORM_strp:
+ if (debug_str_data) {
+ OS << format(" .debug_str[0x%8.8x] = ", (uint32_t)uvalue);
+ const char* dbg_str = getAsCString(debug_str_data);
+ if (dbg_str) {
+ OS << '"';
+ OS.write_escaped(dbg_str);
+ OS << '"';
+ }
+ } else {
+ OS << format("0x%08x", uvalue);
+ }
+ break;
+ case DW_FORM_ref_addr:
+ OS << format("0x%016x", uvalue);
+ break;
+ case DW_FORM_ref1:
+ cu_relative_offset = true;
+ OS << format("cu + 0x%2.2x", (uint8_t)uvalue);
+ break;
+ case DW_FORM_ref2:
+ cu_relative_offset = true;
+ OS << format("cu + 0x%4.4x", (uint16_t)uvalue);
+ break;
+ case DW_FORM_ref4:
+ cu_relative_offset = true;
+ OS << format("cu + 0x%4.4x", (uint32_t)uvalue);
+ break;
+ case DW_FORM_ref8:
+ cu_relative_offset = true;
+ OS << format("cu + 0x%8.8llx", uvalue);
+ break;
+ case DW_FORM_ref_udata:
+ cu_relative_offset = true;
+ OS << format("cu + 0x%llx", uvalue);
+ break;
+
+ // All DW_FORM_indirect attributes should be resolved prior to calling
+ // this function
+ case DW_FORM_indirect:
+ OS << "DW_FORM_indirect";
+ break;
+ default:
+ OS << format("DW_FORM(0x%4.4x)", Form);
+ break;
+ }
+
+ if (cu_relative_offset)
+ OS << format(" => {0x%8.8x}", (uvalue + (cu ? cu->getOffset() : 0)));
+}
+
+const char*
+DWARFFormValue::getAsCString(const DataExtractor *debug_str_data_ptr) const {
+ if (isInlinedCStr()) {
+ return Value.cstr;
+ } else if (debug_str_data_ptr) {
+ uint32_t offset = Value.uval;
+ return debug_str_data_ptr->getCStr(&offset);
+ }
+ return NULL;
+}
+
+uint64_t
+DWARFFormValue::getReference(const DWARFCompileUnit *cu) const {
+ uint64_t die_offset = Value.uval;
+ switch (Form) {
+ case DW_FORM_ref1:
+ case DW_FORM_ref2:
+ case DW_FORM_ref4:
+ case DW_FORM_ref8:
+ case DW_FORM_ref_udata:
+ die_offset += (cu ? cu->getOffset() : 0);
+ break;
+ default:
+ break;
+ }
+
+ return die_offset;
+}
+
+bool
+DWARFFormValue::resolveCompileUnitReferences(const DWARFCompileUnit* cu) {
+ switch (Form) {
+ case DW_FORM_ref1:
+ case DW_FORM_ref2:
+ case DW_FORM_ref4:
+ case DW_FORM_ref8:
+ case DW_FORM_ref_udata:
+ Value.uval += cu->getOffset();
+ Form = DW_FORM_ref_addr;
+ return true;
+ default:
+ break;
+ }
+
+ return false;
+}
+
+const uint8_t *DWARFFormValue::BlockData() const {
+ if (!isInlinedCStr())
+ return Value.data;
+ return NULL;
+}
+
+bool DWARFFormValue::isBlockForm(uint16_t form) {
+ switch (form)
+ {
+ case DW_FORM_block:
+ case DW_FORM_block1:
+ case DW_FORM_block2:
+ case DW_FORM_block4:
+ return true;
+ }
+ return false;
+}
+
+bool DWARFFormValue::isDataForm(uint16_t form) {
+ switch (form)
+ {
+ case DW_FORM_sdata:
+ case DW_FORM_udata:
+ case DW_FORM_data1:
+ case DW_FORM_data2:
+ case DW_FORM_data4:
+ case DW_FORM_data8:
+ return true;
+ }
+ return false;
+}