1/*
2 * Copyright 2009-2010, Ingo Weinhold, ingo_weinhold@gmx.de.
3 * Distributed under the terms of the MIT License.
4 */
5#ifndef ELF_SYMBOL_LOOKUP_H
6#define ELF_SYMBOL_LOOKUP_H
7
8
9#include <stdlib.h>
10#include <string.h>
11
12#include <runtime_loader.h>
13
14
15// values for SymbolLookupInfo::flags
16#define LOOKUP_FLAG_DEFAULT_VERSION	0x01
17
18
19uint32 elf_hash(const char* name);
20
21
22struct SymbolLookupInfo {
23	const char*				name;
24	int32					type;
25	uint32					hash;
26	uint32					flags;
27	const elf_version_info*	version;
28	elf_sym*				requestingSymbol;
29
30	SymbolLookupInfo(const char* name, int32 type, uint32 hash,
31		const elf_version_info* version = NULL, uint32 flags = 0,
32		elf_sym* requestingSymbol = NULL)
33		:
34		name(name),
35		type(type),
36		hash(hash),
37		flags(flags),
38		version(version),
39		requestingSymbol(requestingSymbol)
40	{
41	}
42
43	SymbolLookupInfo(const char* name, int32 type,
44		const elf_version_info* version = NULL, uint32 flags = 0,
45		elf_sym* requestingSymbol = NULL)
46		:
47		name(name),
48		type(type),
49		hash(elf_hash(name)),
50		flags(flags),
51		version(version),
52		requestingSymbol(requestingSymbol)
53	{
54	}
55};
56
57
58struct SymbolLookupCache {
59	SymbolLookupCache(image_t* image)
60		:
61		fTableSize(image->symhash[1]),
62		fValues(NULL),
63		fValuesResolved(NULL)
64	{
65		if (fTableSize > 0) {
66			fValues = (addr_t*)malloc(sizeof(addr_t) * fTableSize);
67
68			size_t elementCount = (fTableSize + 31) / 32;
69			fValuesResolved = (uint32*)malloc(4 * elementCount);
70			memset(fValuesResolved, 0, 4 * elementCount);
71
72			if (fValues == NULL || fValuesResolved == NULL) {
73				free(fValuesResolved);
74				free(fValues);
75				fTableSize = 0;
76			}
77		}
78	}
79
80	~SymbolLookupCache()
81	{
82		free(fValuesResolved);
83		free(fValues);
84	}
85
86	bool IsSymbolValueCached(size_t index) const
87	{
88		return index < fTableSize
89			&& (fValuesResolved[index / 32] & (1 << (index % 32))) != 0;
90	}
91
92	addr_t SymbolValueAt(size_t index) const
93	{
94		return fValues[index];
95	}
96
97	void SetSymbolValueAt(size_t index, addr_t value)
98	{
99		if (index < fTableSize) {
100			fValues[index] = value;
101			fValuesResolved[index / 32] |= 1 << (index % 32);
102		}
103	}
104
105private:
106	size_t	fTableSize;
107	addr_t*	fValues;
108	uint32*	fValuesResolved;
109};
110
111
112void		patch_defined_symbol(image_t* image, const char* name,
113				void** symbol, int32* type);
114void		patch_undefined_symbol(image_t* rootImage, image_t* image,
115				const char* name, image_t** foundInImage, void** symbol,
116				int32* type);
117
118elf_sym*	find_symbol(image_t* image, const SymbolLookupInfo& lookupInfo);
119status_t	find_symbol(image_t* image, const SymbolLookupInfo& lookupInfo,
120				void** _location);
121status_t	find_symbol_breadth_first(image_t* image,
122				const SymbolLookupInfo& lookupInfo, image_t** _foundInImage,
123				void** _location);
124elf_sym*	find_undefined_symbol_beos(image_t* rootImage, image_t* image,
125				const SymbolLookupInfo& lookupInfo, image_t** foundInImage);
126elf_sym*	find_undefined_symbol_global(image_t* rootImage, image_t* image,
127				const SymbolLookupInfo& lookupInfo, image_t** foundInImage);
128elf_sym*	find_undefined_symbol_add_on(image_t* rootImage, image_t* image,
129				const SymbolLookupInfo& lookupInfo, image_t** foundInImage);
130
131
132#endif	// ELF_SYMBOL_LOOKUP_H
133