xref: /dflybsd-src/contrib/binutils-2.27/gold/script-sections.h (revision e656dc90e3d65d744d534af2f5ea88cf8101ebcf)
1*a9fa9459Szrj // script-sections.h -- linker script SECTIONS for gold   -*- C++ -*-
2*a9fa9459Szrj 
3*a9fa9459Szrj // Copyright (C) 2008-2016 Free Software Foundation, Inc.
4*a9fa9459Szrj // Written by Ian Lance Taylor <iant@google.com>.
5*a9fa9459Szrj 
6*a9fa9459Szrj // This file is part of gold.
7*a9fa9459Szrj 
8*a9fa9459Szrj // This program is free software; you can redistribute it and/or modify
9*a9fa9459Szrj // it under the terms of the GNU General Public License as published by
10*a9fa9459Szrj // the Free Software Foundation; either version 3 of the License, or
11*a9fa9459Szrj // (at your option) any later version.
12*a9fa9459Szrj 
13*a9fa9459Szrj // This program is distributed in the hope that it will be useful,
14*a9fa9459Szrj // but WITHOUT ANY WARRANTY; without even the implied warranty of
15*a9fa9459Szrj // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16*a9fa9459Szrj // GNU General Public License for more details.
17*a9fa9459Szrj 
18*a9fa9459Szrj // You should have received a copy of the GNU General Public License
19*a9fa9459Szrj // along with this program; if not, write to the Free Software
20*a9fa9459Szrj // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21*a9fa9459Szrj // MA 02110-1301, USA.
22*a9fa9459Szrj 
23*a9fa9459Szrj // This is for the support of the SECTIONS clause in linker scripts.
24*a9fa9459Szrj 
25*a9fa9459Szrj #ifndef GOLD_SCRIPT_SECTIONS_H
26*a9fa9459Szrj #define GOLD_SCRIPT_SECTIONS_H
27*a9fa9459Szrj 
28*a9fa9459Szrj #include <cstdio>
29*a9fa9459Szrj #include <list>
30*a9fa9459Szrj #include <vector>
31*a9fa9459Szrj 
32*a9fa9459Szrj namespace gold
33*a9fa9459Szrj {
34*a9fa9459Szrj 
35*a9fa9459Szrj struct Parser_output_section_header;
36*a9fa9459Szrj struct Parser_output_section_trailer;
37*a9fa9459Szrj struct Input_section_spec;
38*a9fa9459Szrj class Expression;
39*a9fa9459Szrj class Sections_element;
40*a9fa9459Szrj class Memory_region;
41*a9fa9459Szrj class Phdrs_element;
42*a9fa9459Szrj class Output_data;
43*a9fa9459Szrj class Output_section_definition;
44*a9fa9459Szrj class Output_section;
45*a9fa9459Szrj class Output_segment;
46*a9fa9459Szrj class Orphan_section_placement;
47*a9fa9459Szrj 
48*a9fa9459Szrj class Script_sections
49*a9fa9459Szrj {
50*a9fa9459Szrj  public:
51*a9fa9459Szrj   // This is a list, not a vector, because we insert orphan sections
52*a9fa9459Szrj   // in the middle.
53*a9fa9459Szrj   typedef std::list<Sections_element*> Sections_elements;
54*a9fa9459Szrj 
55*a9fa9459Szrj   // Logical script section types.  We map section types returned by the
56*a9fa9459Szrj   // parser into these since some section types have the same semantics.
57*a9fa9459Szrj   enum Section_type
58*a9fa9459Szrj   {
59*a9fa9459Szrj     // No section type specified.
60*a9fa9459Szrj     ST_NONE,
61*a9fa9459Szrj     // Section is NOLOAD.  We allocate space in the output but section
62*a9fa9459Szrj     // is not loaded in runtime.
63*a9fa9459Szrj     ST_NOLOAD,
64*a9fa9459Szrj     // No space is allocated to section.
65*a9fa9459Szrj     ST_NOALLOC
66*a9fa9459Szrj   };
67*a9fa9459Szrj 
68*a9fa9459Szrj   Script_sections();
69*a9fa9459Szrj 
70*a9fa9459Szrj   // Start a SECTIONS clause.
71*a9fa9459Szrj   void
72*a9fa9459Szrj   start_sections();
73*a9fa9459Szrj 
74*a9fa9459Szrj   // Finish a SECTIONS clause.
75*a9fa9459Szrj   void
76*a9fa9459Szrj   finish_sections();
77*a9fa9459Szrj 
78*a9fa9459Szrj   // Return whether we ever saw a SECTIONS clause.  If we did, then
79*a9fa9459Szrj   // all section layout needs to go through this class.
80*a9fa9459Szrj   bool
saw_sections_clause()81*a9fa9459Szrj   saw_sections_clause() const
82*a9fa9459Szrj   { return this->saw_sections_clause_; }
83*a9fa9459Szrj 
84*a9fa9459Szrj   // Return whether we are currently processing a SECTIONS clause.
85*a9fa9459Szrj   bool
in_sections_clause()86*a9fa9459Szrj   in_sections_clause() const
87*a9fa9459Szrj   { return this->in_sections_clause_; }
88*a9fa9459Szrj 
89*a9fa9459Szrj   // Return whether we ever saw a PHDRS clause.  We ignore the PHDRS
90*a9fa9459Szrj   // clause unless we also saw a SECTIONS clause.
91*a9fa9459Szrj   bool
saw_phdrs_clause()92*a9fa9459Szrj   saw_phdrs_clause() const
93*a9fa9459Szrj   { return this->saw_sections_clause_ && this->phdrs_elements_ != NULL; }
94*a9fa9459Szrj 
95*a9fa9459Szrj   // Start processing entries for an output section.
96*a9fa9459Szrj   void
97*a9fa9459Szrj   start_output_section(const char* name, size_t namelen,
98*a9fa9459Szrj 		       const Parser_output_section_header*);
99*a9fa9459Szrj 
100*a9fa9459Szrj   // Finish processing entries for an output section.
101*a9fa9459Szrj   void
102*a9fa9459Szrj   finish_output_section(const Parser_output_section_trailer*);
103*a9fa9459Szrj 
104*a9fa9459Szrj   // Add a data item to the current output section.
105*a9fa9459Szrj   void
106*a9fa9459Szrj   add_data(int size, bool is_signed, Expression* val);
107*a9fa9459Szrj 
108*a9fa9459Szrj   // Add a symbol to be defined.
109*a9fa9459Szrj   void
110*a9fa9459Szrj   add_symbol_assignment(const char* name, size_t length, Expression* value,
111*a9fa9459Szrj 			bool provide, bool hidden);
112*a9fa9459Szrj 
113*a9fa9459Szrj   // Add an assignment to the special dot symbol.
114*a9fa9459Szrj   void
115*a9fa9459Szrj   add_dot_assignment(Expression* value);
116*a9fa9459Szrj 
117*a9fa9459Szrj   // Add an assertion.
118*a9fa9459Szrj   void
119*a9fa9459Szrj   add_assertion(Expression* check, const char* message, size_t messagelen);
120*a9fa9459Szrj 
121*a9fa9459Szrj   // Add a setting for the fill value.
122*a9fa9459Szrj   void
123*a9fa9459Szrj   add_fill(Expression* val);
124*a9fa9459Szrj 
125*a9fa9459Szrj   // Add an input section specification.
126*a9fa9459Szrj   void
127*a9fa9459Szrj   add_input_section(const Input_section_spec* spec, bool keep);
128*a9fa9459Szrj 
129*a9fa9459Szrj   // Saw DATA_SEGMENT_ALIGN.
130*a9fa9459Szrj   void
131*a9fa9459Szrj   data_segment_align();
132*a9fa9459Szrj 
133*a9fa9459Szrj   // Saw DATA_SEGMENT_RELRO_END.
134*a9fa9459Szrj   void
135*a9fa9459Szrj   data_segment_relro_end();
136*a9fa9459Szrj 
137*a9fa9459Szrj   // Create any required sections.
138*a9fa9459Szrj   void
139*a9fa9459Szrj   create_sections(Layout*);
140*a9fa9459Szrj 
141*a9fa9459Szrj   // Add any symbols we are defining to the symbol table.
142*a9fa9459Szrj   void
143*a9fa9459Szrj   add_symbols_to_table(Symbol_table*);
144*a9fa9459Szrj 
145*a9fa9459Szrj   // Finalize symbol values and check assertions.
146*a9fa9459Szrj   void
147*a9fa9459Szrj   finalize_symbols(Symbol_table* symtab, const Layout* layout);
148*a9fa9459Szrj 
149*a9fa9459Szrj   // Find the name of the output section to use for an input file name
150*a9fa9459Szrj   // and section name.  This returns a name, and sets
151*a9fa9459Szrj   // *OUTPUT_SECTION_SLOT to point to the address where the actual
152*a9fa9459Szrj   // output section may be stored.
153*a9fa9459Szrj   // 1) If the input section should be discarded, this returns NULL
154*a9fa9459Szrj   //    and sets *OUTPUT_SECTION_SLOT to NULL.
155*a9fa9459Szrj   // 2) If the input section is mapped by the SECTIONS clause, this
156*a9fa9459Szrj   //    returns the name to use for the output section (in permanent
157*a9fa9459Szrj   //    storage), and sets *OUTPUT_SECTION_SLOT to point to where the
158*a9fa9459Szrj   //    output section should be stored.  **OUTPUT_SECTION_SLOT will be
159*a9fa9459Szrj   //    non-NULL if we have seen this output section already.
160*a9fa9459Szrj   // 3) If the input section is not mapped by the SECTIONS clause,
161*a9fa9459Szrj   //    this returns SECTION_NAME, and sets *OUTPUT_SECTION_SLOT to
162*a9fa9459Szrj   //    NULL.
163*a9fa9459Szrj   // PSCRIPT_SECTION_TYPE points to a location for returning the section
164*a9fa9459Szrj   // type specified in script.  This can be SCRIPT_SECTION_TYPE_NONE if
165*a9fa9459Szrj   // no type is specified.
166*a9fa9459Szrj   // *KEEP indicates whether the section should survive garbage collection.
167*a9fa9459Szrj   const char*
168*a9fa9459Szrj   output_section_name(const char* file_name, const char* section_name,
169*a9fa9459Szrj 		      Output_section*** output_section_slot,
170*a9fa9459Szrj 		      Section_type* pscript_section_type,
171*a9fa9459Szrj 		      bool* keep);
172*a9fa9459Szrj 
173*a9fa9459Szrj   // Place a marker for an orphan output section into the SECTIONS
174*a9fa9459Szrj   // clause.
175*a9fa9459Szrj   void
176*a9fa9459Szrj   place_orphan(Output_section* os);
177*a9fa9459Szrj 
178*a9fa9459Szrj   // Set the addresses of all the output sections.  Return the segment
179*a9fa9459Szrj   // which holds the file header and segment headers, if any.
180*a9fa9459Szrj   Output_segment*
181*a9fa9459Szrj   set_section_addresses(Symbol_table*, Layout*);
182*a9fa9459Szrj 
183*a9fa9459Szrj   // Add a program header definition.
184*a9fa9459Szrj   void
185*a9fa9459Szrj   add_phdr(const char* name, size_t namelen, unsigned int type,
186*a9fa9459Szrj 	   bool filehdr, bool phdrs, bool is_flags_valid, unsigned int flags,
187*a9fa9459Szrj 	   Expression* load_address);
188*a9fa9459Szrj 
189*a9fa9459Szrj   // Return the number of segments we expect to create based on the
190*a9fa9459Szrj   // SECTIONS clause.
191*a9fa9459Szrj   size_t
192*a9fa9459Szrj   expected_segment_count(const Layout*) const;
193*a9fa9459Szrj 
194*a9fa9459Szrj   // Add the file header and segment header to non-load segments as
195*a9fa9459Szrj   // specified by the PHDRS clause.
196*a9fa9459Szrj   void
197*a9fa9459Szrj   put_headers_in_phdrs(Output_data* file_header, Output_data* segment_headers);
198*a9fa9459Szrj 
199*a9fa9459Szrj   // Look for an output section by name and return the address, the
200*a9fa9459Szrj   // load address, the alignment, and the size.  This is used when an
201*a9fa9459Szrj   // expression refers to an output section which was not actually
202*a9fa9459Szrj   // created.  This returns true if the section was found, false
203*a9fa9459Szrj   // otherwise.
204*a9fa9459Szrj   bool
205*a9fa9459Szrj   get_output_section_info(const char* name, uint64_t* address,
206*a9fa9459Szrj                           uint64_t* load_address, uint64_t* addralign,
207*a9fa9459Szrj                           uint64_t* size) const;
208*a9fa9459Szrj 
209*a9fa9459Szrj   // Release all Output_segments.  This is used in relaxation.
210*a9fa9459Szrj   void
211*a9fa9459Szrj   release_segments();
212*a9fa9459Szrj 
213*a9fa9459Szrj   // Whether we ever saw a SEGMENT_START expression, the presence of which
214*a9fa9459Szrj   // changes the behaviour of -Ttext, -Tdata and -Tbss options.
215*a9fa9459Szrj   bool
saw_segment_start_expression()216*a9fa9459Szrj   saw_segment_start_expression() const
217*a9fa9459Szrj   { return this->saw_segment_start_expression_; }
218*a9fa9459Szrj 
219*a9fa9459Szrj   // Set the flag which indicates whether we saw a SEGMENT_START expression.
220*a9fa9459Szrj   void
set_saw_segment_start_expression(bool value)221*a9fa9459Szrj   set_saw_segment_start_expression(bool value)
222*a9fa9459Szrj   { this->saw_segment_start_expression_ = value; }
223*a9fa9459Szrj 
224*a9fa9459Szrj   // Add a memory region.
225*a9fa9459Szrj   void
226*a9fa9459Szrj   add_memory_region(const char*, size_t, unsigned int,
227*a9fa9459Szrj 		    Expression*, Expression*);
228*a9fa9459Szrj 
229*a9fa9459Szrj   // Find a memory region's origin.
230*a9fa9459Szrj   Expression*
231*a9fa9459Szrj   find_memory_region_origin(const char*, size_t);
232*a9fa9459Szrj 
233*a9fa9459Szrj   // Find a memory region's length.
234*a9fa9459Szrj   Expression*
235*a9fa9459Szrj   find_memory_region_length(const char*, size_t);
236*a9fa9459Szrj 
237*a9fa9459Szrj   // Find a memory region by name.
238*a9fa9459Szrj   Memory_region*
239*a9fa9459Szrj   find_memory_region(const char*, size_t);
240*a9fa9459Szrj 
241*a9fa9459Szrj   // Find a memory region that should be used by a given output section.
242*a9fa9459Szrj   Memory_region*
243*a9fa9459Szrj   find_memory_region(Output_section_definition*, bool, bool,
244*a9fa9459Szrj 		     Output_section_definition**);
245*a9fa9459Szrj 
246*a9fa9459Szrj   // Returns true if the provide block of memory is contained
247*a9fa9459Szrj   // within a memory region.
248*a9fa9459Szrj   bool
249*a9fa9459Szrj   block_in_region(Symbol_table*, Layout*, uint64_t, uint64_t) const;
250*a9fa9459Szrj 
251*a9fa9459Szrj   // Set the memory region of the section.
252*a9fa9459Szrj   void
253*a9fa9459Szrj   set_memory_region(Memory_region*, bool);
254*a9fa9459Szrj 
255*a9fa9459Szrj   // Print the contents to the FILE.  This is for debugging.
256*a9fa9459Szrj   void
257*a9fa9459Szrj   print(FILE*) const;
258*a9fa9459Szrj 
259*a9fa9459Szrj   // Used for orphan sections.
260*a9fa9459Szrj   typedef Sections_elements::iterator Elements_iterator;
261*a9fa9459Szrj 
262*a9fa9459Szrj  private:
263*a9fa9459Szrj   typedef std::vector<Memory_region*> Memory_regions;
264*a9fa9459Szrj   typedef std::vector<Phdrs_element*> Phdrs_elements;
265*a9fa9459Szrj 
266*a9fa9459Szrj   // Create segments.
267*a9fa9459Szrj   Output_segment*
268*a9fa9459Szrj   create_segments(Layout*, uint64_t);
269*a9fa9459Szrj 
270*a9fa9459Szrj   // Create PT_NOTE and PT_TLS segments.
271*a9fa9459Szrj   void
272*a9fa9459Szrj   create_note_and_tls_segments(Layout*, const std::vector<Output_section*>*);
273*a9fa9459Szrj 
274*a9fa9459Szrj   // Return whether the section is a BSS section.
275*a9fa9459Szrj   static bool
276*a9fa9459Szrj   is_bss_section(const Output_section*);
277*a9fa9459Szrj 
278*a9fa9459Szrj   // Return the total size of the headers.
279*a9fa9459Szrj   size_t
280*a9fa9459Szrj   total_header_size(Layout* layout) const;
281*a9fa9459Szrj 
282*a9fa9459Szrj   // Return the amount we have to subtract from the LMA to accomodate
283*a9fa9459Szrj   // headers of the given size.
284*a9fa9459Szrj   uint64_t
285*a9fa9459Szrj   header_size_adjustment(uint64_t lma, size_t sizeof_headers) const;
286*a9fa9459Szrj 
287*a9fa9459Szrj   // Create the segments from a PHDRS clause.
288*a9fa9459Szrj   Output_segment*
289*a9fa9459Szrj   create_segments_from_phdrs_clause(Layout* layout, uint64_t);
290*a9fa9459Szrj 
291*a9fa9459Szrj   // Attach sections to segments from a PHDRS clause.
292*a9fa9459Szrj   void
293*a9fa9459Szrj   attach_sections_using_phdrs_clause(Layout*);
294*a9fa9459Szrj 
295*a9fa9459Szrj   // Set addresses of segments from a PHDRS clause.
296*a9fa9459Szrj   Output_segment*
297*a9fa9459Szrj   set_phdrs_clause_addresses(Layout*, uint64_t);
298*a9fa9459Szrj 
299*a9fa9459Szrj   // True if we ever saw a SECTIONS clause.
300*a9fa9459Szrj   bool saw_sections_clause_;
301*a9fa9459Szrj   // True if we are currently processing a SECTIONS clause.
302*a9fa9459Szrj   bool in_sections_clause_;
303*a9fa9459Szrj   // The list of elements in the SECTIONS clause.
304*a9fa9459Szrj   Sections_elements* sections_elements_;
305*a9fa9459Szrj   // The current output section, if there is one.
306*a9fa9459Szrj   Output_section_definition* output_section_;
307*a9fa9459Szrj   // The list of memory regions in the MEMORY clause.
308*a9fa9459Szrj   Memory_regions* memory_regions_;
309*a9fa9459Szrj   // The list of program headers in the PHDRS clause.
310*a9fa9459Szrj   Phdrs_elements* phdrs_elements_;
311*a9fa9459Szrj   // Where to put orphan sections.
312*a9fa9459Szrj   Orphan_section_placement* orphan_section_placement_;
313*a9fa9459Szrj   // A pointer to the last Sections_element when we see
314*a9fa9459Szrj   // DATA_SEGMENT_ALIGN.
315*a9fa9459Szrj   Sections_elements::iterator data_segment_align_start_;
316*a9fa9459Szrj   // Whether we have seen DATA_SEGMENT_ALIGN.
317*a9fa9459Szrj   bool saw_data_segment_align_;
318*a9fa9459Szrj   // Whether we have seen DATA_SEGMENT_RELRO_END.
319*a9fa9459Szrj   bool saw_relro_end_;
320*a9fa9459Szrj   // Whether we have seen SEGMENT_START.
321*a9fa9459Szrj   bool saw_segment_start_expression_;
322*a9fa9459Szrj   // Whether we have created all necessary segments.
323*a9fa9459Szrj   bool segments_created_;
324*a9fa9459Szrj };
325*a9fa9459Szrj 
326*a9fa9459Szrj // Attributes for memory regions.
327*a9fa9459Szrj enum
328*a9fa9459Szrj {
329*a9fa9459Szrj   MEM_EXECUTABLE   = (1 << 0),
330*a9fa9459Szrj   MEM_WRITEABLE    = (1 << 1),
331*a9fa9459Szrj   MEM_READABLE     = (1 << 2),
332*a9fa9459Szrj   MEM_ALLOCATABLE  = (1 << 3),
333*a9fa9459Szrj   MEM_INITIALIZED  = (1 << 4),
334*a9fa9459Szrj   MEM_ATTR_MASK    = (1 << 5) - 1
335*a9fa9459Szrj };
336*a9fa9459Szrj 
337*a9fa9459Szrj } // End namespace gold.
338*a9fa9459Szrj 
339*a9fa9459Szrj #endif // !defined(GOLD_SCRIPT_SECTIONS_H
340