b72998da359eab1eb0c2878969e744c325142f2b
1 // target.h -- target support for gold -*- C++ -*-
3 // The abstract class Target is the interface for target specific
4 // support. It defines abstract methods which each target must
5 // implement. Typically there will be one target per processor, but
6 // in some cases it may be necessary to have subclasses.
8 // For speed and consistency we want to use inline functions to handle
9 // relocation processing. So besides implementations of the abstract
10 // methods, each target is expected to define a template
11 // specialization of the relocation functions.
24 class General_options
;
26 template<int size
, bool big_endian
>
28 template<int size
, bool big_endian
>
31 // The abstract class for target specific handling.
39 // Return the bit size that this target implements. This should
43 { return this->pti_
->size
; }
45 // Return whether this target is big-endian.
48 { return this->pti_
->is_big_endian
; }
50 // Machine code to store in e_machine field of ELF header.
53 { return this->pti_
->machine_code
; }
55 // Whether this target has a specific make_symbol function.
57 has_make_symbol() const
58 { return this->pti_
->has_make_symbol
; }
60 // Whether this target has a specific resolve function.
63 { return this->pti_
->has_resolve
; }
65 // Return the default address to use for the text segment.
67 text_segment_address() const
68 { return this->pti_
->text_segment_address
; }
70 // Return the ABI specified page size.
73 { return this->pti_
->abi_pagesize
; }
75 // Return the common page size used on actual systems.
77 common_pagesize() const
78 { return this->pti_
->common_pagesize
; }
81 // This struct holds the constant information for a child class. We
82 // use a struct to avoid the overhead of virtual function calls for
83 // simple information.
86 // Address size (32 or 64).
88 // Whether the target is big endian.
90 // The code to store in the e_machine field of the ELF header.
91 elfcpp::EM machine_code
;
92 // Whether this target has a specific make_symbol function.
94 // Whether this target has a specific resolve function.
96 // The default text segment address.
97 uint64_t text_segment_address
;
98 // The ABI specified page size.
99 uint64_t abi_pagesize
;
100 // The common page size used by actual implementations.
101 uint64_t common_pagesize
;
104 Target(const Target_info
* pti
)
109 Target(const Target
&);
110 Target
& operator=(const Target
&);
112 // The target information.
113 const Target_info
* pti_
;
116 // The abstract class for a specific size and endianness of target.
117 // Each actual target implementation class should derive from an
118 // instantiation of Sized_target.
120 template<int size
, bool big_endian
>
121 class Sized_target
: public Target
124 // Make a new symbol table entry for the target. This should be
125 // overridden by a target which needs additional information in the
126 // symbol table. This will only be called if has_make_symbol()
128 virtual Sized_symbol
<size
>*
132 // Resolve a symbol for the target. This should be overridden by a
133 // target which needs to take special action. TO is the
134 // pre-existing symbol. SYM is the new symbol, seen in OBJECT.
135 // This will only be called if has_resolve() returns true.
137 resolve(Symbol
*, const elfcpp::Sym
<size
, big_endian
>&, Object
*)
140 // Scan the relocs for a section, and record any information
141 // required for the symbol. OPTIONS is the command line options.
142 // SYMTAB is the symbol table. OBJECT is the object in which the
143 // section appears. SH_TYPE is the type of the relocation section,
144 // SHT_REL or SHT_RELA. PRELOCS points to the relocation data.
145 // RELOC_COUNT is the number of relocs. LOCAL_SYMBOL_COUNT is the
146 // number of local symbols. PLOCAL_SYMBOLS points to the local
147 // symbol data from OBJECT. GLOBAL_SYMBOLS is the array of pointers
148 // to the global symbol table from OBJECT.
150 scan_relocs(const General_options
& options
,
151 Symbol_table
* symtab
,
153 Sized_object
<size
, big_endian
>* object
,
154 unsigned int sh_type
,
155 const unsigned char* prelocs
,
157 size_t local_symbol_count
,
158 const unsigned char* plocal_symbols
,
159 Symbol
** global_symbols
) = 0;
161 // Relocate section data. SH_TYPE is the type of the relocation
162 // section, SHT_REL or SHT_RELA. PRELOCS points to the relocation
163 // information. RELOC_COUNT is the number of relocs. VIEW is a
164 // view into the output file holding the section contents,
165 // VIEW_ADDRESS is the virtual address of the view, and VIEW_SIZE is
166 // the size of the view.
168 relocate_section(const Relocate_info
<size
, big_endian
>*,
169 unsigned int sh_type
,
170 const unsigned char* prelocs
,
173 typename
elfcpp::Elf_types
<size
>::Elf_Addr view_address
,
174 off_t view_size
) = 0;
177 Sized_target(const Target::Target_info
* pti
)
180 assert(pti
->size
== size
);
181 assert(pti
->is_big_endian
? big_endian
: !big_endian
);
185 } // End namespace gold.
187 #endif // !defined(GOLD_TARGET_H)
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