tools/elf4rom/src/dwarfframemanager.cpp
changeset 34 92d87f2e53c2
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tools/elf4rom/src/dwarfframemanager.cpp	Fri Jan 15 09:07:44 2010 +0000
@@ -0,0 +1,283 @@
+/*
+* Copyright (c) 2009 Nokia Corporation and/or its subsidiary(-ies).
+* All rights reserved.
+*
+* This program is free software: you can redistribute it and/or modify
+* it under the terms of the GNU Lesser General Public License as published by
+* the Free Software Foundation, either version 3 of the License, or
+* (at your option) any later version.
+*
+* This program is distributed in the hope that it will be useful,
+* but WITHOUT ANY WARRANTY; without even the implied warranty of
+* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+* GNU Lesser General Public License for more details.
+* 
+* You should have received a copy of the GNU Lesser General Public License
+* along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <iostream>
+#include "dwarfmanager.h"
+#include "inputfile.h"
+
+const string DwarfFrameManager::iFrameSectionName(".debug_frame");
+
+static inline size_t SizeOfEncodedValue (int encoding)
+{
+  switch (encoding & 0x7)
+    {
+    default:	/* ??? */
+    case 0:	return ENCODED_POINTER_SIZE;
+    case 2:	return 2;
+    case 3:	return 4;
+    case 4:	return 8;
+    }
+}
+
+static inline bool ValueFitsSize(Dwarf_Word val, size_t size){
+	switch (size){
+	default:
+	case 0: {
+		cerr << "Error: size of " << size << " not allowed\n";
+		exit(EXIT_FAILURE);
+		}
+	case 2:
+		return val <= 0xffff;
+	case 4:
+		return val <= 0xffffffff;
+	case 8:
+		return true;
+	}
+}
+
+
+void DwarfFrameManager::ProcessSection(FileShdrPair & aPair, Dwarf_Byte_Ptr aStart, Dwarf_Byte_Ptr aEnd){
+	CiePtrEncodingMap ptrEncodingMap;
+	CieAugmentationMap augmentationMap;
+	size_t encoded_ptr_size = ENCODED_POINTER_SIZE;
+	size_t bytes_read;
+	Dwarf_Byte_Ptr start = aStart;
+	Dwarf_Byte_Ptr section_start = start;
+	Dwarf_Byte_Ptr end = aEnd;
+	while (start < end) {
+		unsigned char *augmentation_data = NULL;
+		unsigned long augmentation_data_len = 0;
+		size_t offset_size;
+		size_t initial_length_size;
+
+		Dwarf_Byte_Ptr saved_start = start;
+		Dwarf_Word length = READ_UNALIGNED4(start); 
+		start += 4;
+
+		if (length == 0){ // ZERO terminator - shouldn't see this
+			continue;
+		}	
+
+		if (length >= 0xfffffff0u) {
+			cerr << "Error: 64 bit DWARF not supported\n";
+			exit(EXIT_FAILURE);
+		} else {	
+			offset_size = 4;
+			initial_length_size = 4;
+		}
+
+		Dwarf_Byte_Ptr block_end = saved_start + length + initial_length_size;
+		if (block_end > end) {
+			cerr << "Warning: Invalid length " << length << " in FDE at 0x" 
+				<< (unsigned long)(saved_start - section_start) << " in file " << aPair.iXIPFileDetails.iElfFile << "\n";
+			block_end = end;
+		}	
+		Dwarf_Word cie_id = READ_UNALIGNED4(start); 
+		if (cie_id != (Dwarf_Word)DW_CIE_ID)
+			WRITE_UNALIGNED4(start, cie_id + GetSectionOffset(aPair.iXIPFileDetails.iElfFile));
+		start += offset_size;
+
+		if (cie_id == (Dwarf_Word)DW_CIE_ID) {
+			Dwarf_Ubyte version = *start++;
+
+			char * augmentation = (char *) start;
+			augmentation_data = NULL;
+			start = (Dwarf_Byte_Ptr) strchr ((char *) start, '\0') + 1;
+
+			if (augmentation[0] == 'z'){
+				ULEB128(start, bytes_read);
+				ULEB128(start, bytes_read);
+
+				if (version == 1){
+					// fc->ra = GET (1);
+					start++;
+				} else {
+					// fc->ra = LEB ();
+					ULEB128(start, bytes_read);
+				}
+				augmentation_data_len = ULEB128(start, bytes_read);
+				augmentation_data = start;
+				augmentationMap[saved_start] = augmentation_data_len;
+				start += augmentation_data_len;
+			} else if (strcmp (augmentation, "eh") == 0){
+				//start += eh_addr_size;
+				start += 4;
+				// fc->code_factor = LEB ();
+				// fc->data_factor = SLEB ();
+				ULEB128(start, bytes_read);
+				ULEB128(start, bytes_read);
+				if (version == 1){
+					//c->ra = GET (1);
+					start++;
+				} else {
+					// fc->ra = LEB ();
+					ULEB128(start, bytes_read);
+				}
+			} else {
+				ULEB128(start, bytes_read);
+				ULEB128(start, bytes_read);
+
+				if (version == 1){
+					// fc->ra = GET (1);
+					start++;
+				} else {
+					// fc->ra = LEB ();
+					ULEB128(start, bytes_read);
+				}
+			}
+
+			if (augmentation_data_len){
+				unsigned char *p, *q;
+				p = (unsigned char *) augmentation + 1;
+				q = augmentation_data;
+				Dwarf_Ubyte encoding = 0;
+				while (1){
+					if (*p == 'L')
+						q++;
+					else if (*p == 'P')
+						q += 1 + SizeOfEncodedValue(*q);
+					else if (*p == 'R')
+						encoding = *q++;
+					else
+						break;
+					p++;
+				}
+				if (encoding)
+					ptrEncodingMap[saved_start] = encoding;
+			}
+	  
+		} else {
+			Dwarf_Byte_Ptr look_for = section_start + cie_id;
+			Dwarf_Ubyte encoding = 0;
+			CiePtrEncodingMap::iterator iE = ptrEncodingMap.find(look_for);
+			if (iE != ptrEncodingMap.end()){
+				encoding = iE->second;
+				encoded_ptr_size = SizeOfEncodedValue(encoding);
+			}
+			if ((encoding & 0x70) != DW_EH_PE_pcrel){
+				// do the nasty
+				LinearAddr addr = GetValue(start, encoded_ptr_size);
+				LinearAddr relocatedAddr = aPair.iXIPFileDetails.Relocate(addr);
+				if (ValueFitsSize(relocatedAddr, encoded_ptr_size)){
+					WriteValue(start, relocatedAddr, encoded_ptr_size);
+				} else {
+					cerr << "Warning: relocated addresses in " << GetSectionName().c_str() 
+					<< " section of " << aPair.iXIPFileDetails.iElfFile.c_str() 
+					<< " too large for encoding. Backtraces may be misleading.\n";
+					}
+			}
+			start += encoded_ptr_size;
+			// skip the range size
+			start += encoded_ptr_size;
+
+			CieAugmentationMap::iterator iP =  augmentationMap.find(look_for);
+			if (iP != augmentationMap.end()){
+				ULEB128(start, bytes_read);
+				start += bytes_read;
+			}
+		}
+		
+		Dwarf_Word tmp = 0;
+		while (start < block_end){
+			unsigned op, opa;
+			op = *start++;
+			opa = op & 0x3f;
+			if (op & 0xc0)
+				op &= 0xc0;
+			switch (op){
+			case DW_CFA_advance_loc:
+				break;
+			case DW_CFA_offset:
+				ULEB128(start, bytes_read);
+				break;
+			case DW_CFA_restore:
+				break;
+			case DW_CFA_set_loc:
+				start += encoded_ptr_size;
+				break;
+			case DW_CFA_advance_loc1:
+				start += 1;
+				break;
+			case DW_CFA_advance_loc2:
+				start += 2;
+				break;
+			case DW_CFA_advance_loc4:
+				start += 4;
+				break;
+			case DW_CFA_offset_extended:
+			case DW_CFA_val_offset:
+				ULEB128(start, bytes_read);
+				ULEB128(start, bytes_read);
+				break;
+			case DW_CFA_restore_extended:
+			case DW_CFA_undefined:
+			case DW_CFA_same_value:
+				ULEB128(start, bytes_read);
+				break;
+			case DW_CFA_register:
+			case DW_CFA_def_cfa:
+				ULEB128(start, bytes_read);
+				ULEB128(start, bytes_read);
+				break;
+			case DW_CFA_def_cfa_register:
+			case DW_CFA_def_cfa_offset:
+				ULEB128(start, bytes_read);
+				break;
+			case DW_CFA_def_cfa_expression:
+				tmp = ULEB128(start, bytes_read);
+				EditLocationExpression (start, encoded_ptr_size, tmp, aPair);
+				start += tmp;
+				break;
+			case DW_CFA_expression: 
+			case DW_CFA_val_expression: 
+				ULEB128(start, bytes_read);
+				tmp = ULEB128(start, bytes_read);
+				EditLocationExpression (start, encoded_ptr_size, tmp, aPair);
+				start += tmp;
+				break;
+#ifndef DW_CFA_offset_extended_sf
+// seems to be type in dwarf.h
+#define DW_CFA_offset_extended_sf 0x11
+				//DW_CFA_cfa_offset_extended_sf
+#endif
+			case DW_CFA_offset_extended_sf:
+			case DW_CFA_val_offset_sf:
+			case DW_CFA_def_cfa_sf:
+				ULEB128(start, bytes_read);
+				ULEB128(start, bytes_read);
+				break;
+			case DW_CFA_def_cfa_offset_sf:
+				ULEB128(start, bytes_read);
+				break;
+			case DW_CFA_MIPS_advance_loc8:
+				start += 8;
+				break;
+			case DW_CFA_GNU_args_size:
+				ULEB128(start, bytes_read);
+				break;
+			case DW_CFA_GNU_negative_offset_extended:
+				ULEB128(start, bytes_read);
+				ULEB128(start, bytes_read);
+				break;
+			default:
+				break;
+			}
+		}
+	}
+
+}