70 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			C++
		
	
	
	
			
		
		
	
	
			70 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			C++
		
	
	
	
| //===- DWARFDebugInfoEntry.cpp --------------------------------------------===//
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| //
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| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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| // See https://llvm.org/LICENSE.txt for license information.
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| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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| //
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| //===----------------------------------------------------------------------===//
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| 
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| #include "llvm/DebugInfo/DWARF/DWARFDebugInfoEntry.h"
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| #include "llvm/ADT/Optional.h"
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| #include "llvm/DebugInfo/DWARF/DWARFDebugAbbrev.h"
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| #include "llvm/DebugInfo/DWARF/DWARFFormValue.h"
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| #include "llvm/DebugInfo/DWARF/DWARFUnit.h"
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| #include "llvm/Support/DataExtractor.h"
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| #include <cstddef>
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| #include <cstdint>
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| 
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| using namespace llvm;
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| using namespace dwarf;
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| 
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| bool DWARFDebugInfoEntry::extractFast(const DWARFUnit &U,
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|                                              uint64_t *OffsetPtr) {
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|   DWARFDataExtractor DebugInfoData = U.getDebugInfoExtractor();
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|   const uint64_t UEndOffset = U.getNextUnitOffset();
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|   return extractFast(U, OffsetPtr, DebugInfoData, UEndOffset, 0);
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| }
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| 
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| bool DWARFDebugInfoEntry::extractFast(const DWARFUnit &U, uint64_t *OffsetPtr,
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|                                       const DWARFDataExtractor &DebugInfoData,
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|                                       uint64_t UEndOffset, uint32_t D) {
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|   Offset = *OffsetPtr;
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|   Depth = D;
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|   if (Offset >= UEndOffset || !DebugInfoData.isValidOffset(Offset))
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|     return false;
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|   uint64_t AbbrCode = DebugInfoData.getULEB128(OffsetPtr);
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|   if (0 == AbbrCode) {
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|     // NULL debug tag entry.
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|     AbbrevDecl = nullptr;
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|     return true;
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|   }
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|   AbbrevDecl = U.getAbbreviations()->getAbbreviationDeclaration(AbbrCode);
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|   if (nullptr == AbbrevDecl) {
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|     // Restore the original offset.
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|     *OffsetPtr = Offset;
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|     return false;
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|   }
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|   // See if all attributes in this DIE have fixed byte sizes. If so, we can
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|   // just add this size to the offset to skip to the next DIE.
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|   if (Optional<size_t> FixedSize = AbbrevDecl->getFixedAttributesByteSize(U)) {
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|     *OffsetPtr += *FixedSize;
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|     return true;
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|   }
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| 
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|   // Skip all data in the .debug_info for the attributes
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|   for (const auto &AttrSpec : AbbrevDecl->attributes()) {
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|     // Check if this attribute has a fixed byte size.
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|     if (auto FixedSize = AttrSpec.getByteSize(U)) {
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|       // Attribute byte size if fixed, just add the size to the offset.
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|       *OffsetPtr += *FixedSize;
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|     } else if (!DWARFFormValue::skipValue(AttrSpec.Form, DebugInfoData,
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|                                           OffsetPtr, U.getFormParams())) {
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|       // We failed to skip this attribute's value, restore the original offset
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|       // and return the failure status.
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|       *OffsetPtr = Offset;
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|       return false;
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|     }
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|   }
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|   return true;
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| }
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