xref: /dragonfly/contrib/gdb-7/gdb/tui/tui-disasm.c (revision 89a89091)
1 /* Disassembly display.
2 
3    Copyright (C) 1998-2004, 2007-2012 Free Software Foundation, Inc.
4 
5    Contributed by Hewlett-Packard Company.
6 
7    This file is part of GDB.
8 
9    This program is free software; you can redistribute it and/or modify
10    it under the terms of the GNU General Public License as published by
11    the Free Software Foundation; either version 3 of the License, or
12    (at your option) any later version.
13 
14    This program is distributed in the hope that it will be useful,
15    but WITHOUT ANY WARRANTY; without even the implied warranty of
16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17    GNU General Public License for more details.
18 
19    You should have received a copy of the GNU General Public License
20    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
21 
22 #include "defs.h"
23 #include "arch-utils.h"
24 #include "symtab.h"
25 #include "breakpoint.h"
26 #include "frame.h"
27 #include "value.h"
28 #include "source.h"
29 #include "disasm.h"
30 #include "gdb_string.h"
31 #include "tui/tui.h"
32 #include "tui/tui-data.h"
33 #include "tui/tui-win.h"
34 #include "tui/tui-layout.h"
35 #include "tui/tui-winsource.h"
36 #include "tui/tui-stack.h"
37 #include "tui/tui-file.h"
38 #include "tui/tui-disasm.h"
39 #include "progspace.h"
40 
41 #include "gdb_curses.h"
42 
43 struct tui_asm_line
44 {
45   CORE_ADDR addr;
46   char *addr_string;
47   char *insn;
48 };
49 
50 /* Function to set the disassembly window's content.
51    Disassemble count lines starting at pc.
52    Return address of the count'th instruction after pc.  */
53 static CORE_ADDR
54 tui_disassemble (struct gdbarch *gdbarch, struct tui_asm_line *asm_lines,
55 		 CORE_ADDR pc, int count)
56 {
57   struct ui_file *gdb_dis_out;
58 
59   /* Now init the ui_file structure.  */
60   gdb_dis_out = tui_sfileopen (256);
61 
62   /* Now construct each line.  */
63   for (; count > 0; count--, asm_lines++)
64     {
65       if (asm_lines->addr_string)
66         xfree (asm_lines->addr_string);
67       if (asm_lines->insn)
68         xfree (asm_lines->insn);
69 
70       print_address (gdbarch, pc, gdb_dis_out);
71       asm_lines->addr = pc;
72       asm_lines->addr_string = xstrdup (tui_file_get_strbuf (gdb_dis_out));
73 
74       ui_file_rewind (gdb_dis_out);
75 
76       pc = pc + gdb_print_insn (gdbarch, pc, gdb_dis_out, NULL);
77 
78       asm_lines->insn = xstrdup (tui_file_get_strbuf (gdb_dis_out));
79 
80       /* Reset the buffer to empty.  */
81       ui_file_rewind (gdb_dis_out);
82     }
83   ui_file_delete (gdb_dis_out);
84   return pc;
85 }
86 
87 /* Find the disassembly address that corresponds to FROM lines above
88    or below the PC.  Variable sized instructions are taken into
89    account by the algorithm.  */
90 static CORE_ADDR
91 tui_find_disassembly_address (struct gdbarch *gdbarch, CORE_ADDR pc, int from)
92 {
93   CORE_ADDR new_low;
94   int max_lines;
95   int i;
96   struct tui_asm_line *asm_lines;
97 
98   max_lines = (from > 0) ? from : - from;
99   if (max_lines <= 1)
100      return pc;
101 
102   asm_lines = (struct tui_asm_line*) alloca (sizeof (struct tui_asm_line)
103                                          * max_lines);
104   memset (asm_lines, 0, sizeof (struct tui_asm_line) * max_lines);
105 
106   new_low = pc;
107   if (from > 0)
108     {
109       tui_disassemble (gdbarch, asm_lines, pc, max_lines);
110       new_low = asm_lines[max_lines - 1].addr;
111     }
112   else
113     {
114       CORE_ADDR last_addr;
115       int pos;
116       struct minimal_symbol *msymbol;
117 
118       /* Find backward an address which is a symbol and for which
119          disassembling from that address will fill completely the
120          window.  */
121       pos = max_lines - 1;
122       do {
123          new_low -= 1 * max_lines;
124          msymbol = lookup_minimal_symbol_by_pc_section (new_low, 0);
125 
126          if (msymbol)
127             new_low = SYMBOL_VALUE_ADDRESS (msymbol);
128          else
129             new_low += 1 * max_lines;
130 
131          tui_disassemble (gdbarch, asm_lines, new_low, max_lines);
132          last_addr = asm_lines[pos].addr;
133       } while (last_addr > pc && msymbol);
134 
135       /* Scan forward disassembling one instruction at a time until
136          the last visible instruction of the window matches the pc.
137          We keep the disassembled instructions in the 'lines' window
138          and shift it downward (increasing its addresses).  */
139       if (last_addr < pc)
140         do
141           {
142             CORE_ADDR next_addr;
143 
144             pos++;
145             if (pos >= max_lines)
146               pos = 0;
147 
148             next_addr = tui_disassemble (gdbarch, &asm_lines[pos],
149 					 last_addr, 1);
150 
151             /* If there are some problems while disassembling exit.  */
152             if (next_addr <= last_addr)
153               break;
154             last_addr = next_addr;
155           } while (last_addr <= pc);
156       pos++;
157       if (pos >= max_lines)
158          pos = 0;
159       new_low = asm_lines[pos].addr;
160     }
161   for (i = 0; i < max_lines; i++)
162     {
163       xfree (asm_lines[i].addr_string);
164       xfree (asm_lines[i].insn);
165     }
166   return new_low;
167 }
168 
169 /* Function to set the disassembly window's content.  */
170 enum tui_status
171 tui_set_disassem_content (struct gdbarch *gdbarch, CORE_ADDR pc)
172 {
173   enum tui_status ret = TUI_FAILURE;
174   int i;
175   int offset = TUI_DISASM_WIN->detail.source_info.horizontal_offset;
176   int line_width, max_lines;
177   CORE_ADDR cur_pc;
178   struct tui_gen_win_info *locator = tui_locator_win_info_ptr ();
179   int tab_len = tui_default_tab_len ();
180   struct tui_asm_line *asm_lines;
181   int insn_pos;
182   int addr_size, max_size;
183   char *line;
184 
185   if (pc == 0)
186     return TUI_FAILURE;
187 
188   ret = tui_alloc_source_buffer (TUI_DISASM_WIN);
189   if (ret != TUI_SUCCESS)
190     return ret;
191 
192   TUI_DISASM_WIN->detail.source_info.gdbarch = gdbarch;
193   TUI_DISASM_WIN->detail.source_info.start_line_or_addr.loa = LOA_ADDRESS;
194   TUI_DISASM_WIN->detail.source_info.start_line_or_addr.u.addr = pc;
195   cur_pc = (CORE_ADDR) (((struct tui_win_element *)
196 			 locator->content[0])->which_element.locator.addr);
197 
198   max_lines = TUI_DISASM_WIN->generic.height - 2;	/* Account for
199 							   hilite.  */
200 
201   /* Get temporary table that will hold all strings (addr & insn).  */
202   asm_lines = (struct tui_asm_line*) alloca (sizeof (struct tui_asm_line)
203                                          * max_lines);
204   memset (asm_lines, 0, sizeof (struct tui_asm_line) * max_lines);
205 
206   line_width = TUI_DISASM_WIN->generic.width - 1;
207 
208   tui_disassemble (gdbarch, asm_lines, pc, max_lines);
209 
210   /* See what is the maximum length of an address and of a line.  */
211   addr_size = 0;
212   max_size = 0;
213   for (i = 0; i < max_lines; i++)
214     {
215       size_t len = strlen (asm_lines[i].addr_string);
216 
217       if (len > addr_size)
218         addr_size = len;
219 
220       len = strlen (asm_lines[i].insn) + tab_len;
221       if (len > max_size)
222         max_size = len;
223     }
224   max_size += addr_size + tab_len;
225 
226   /* Allocate memory to create each line.  */
227   line = (char*) alloca (max_size);
228   insn_pos = (1 + (addr_size / tab_len)) * tab_len;
229 
230   /* Now construct each line.  */
231   for (i = 0; i < max_lines; i++)
232     {
233       struct tui_win_element *element;
234       struct tui_source_element *src;
235       int cur_len;
236 
237       element = (struct tui_win_element *) TUI_DISASM_WIN->generic.content[i];
238       src = &element->which_element.source;
239       strcpy (line, asm_lines[i].addr_string);
240       cur_len = strlen (line);
241 
242       /* Add spaces to make the instructions start on the same
243 	 column.  */
244       while (cur_len < insn_pos)
245         {
246           strcat (line, " ");
247           cur_len++;
248         }
249 
250       strcat (line, asm_lines[i].insn);
251 
252       /* Now copy the line taking the offset into account.  */
253       if (strlen (line) > offset)
254         strcpy (src->line, &line[offset]);
255       else
256         src->line[0] = '\0';
257 
258       src->line_or_addr.loa = LOA_ADDRESS;
259       src->line_or_addr.u.addr = asm_lines[i].addr;
260       src->is_exec_point = asm_lines[i].addr == cur_pc;
261 
262       /* See whether there is a breakpoint installed.  */
263       src->has_break = (!src->is_exec_point
264 			&& breakpoint_here_p (current_program_space->aspace,
265 					      pc)
266 			!= no_breakpoint_here);
267 
268       xfree (asm_lines[i].addr_string);
269       xfree (asm_lines[i].insn);
270     }
271   TUI_DISASM_WIN->generic.content_size = i;
272   return TUI_SUCCESS;
273 }
274 
275 
276 /* Function to display the disassembly window with disassembled code.  */
277 void
278 tui_show_disassem (struct gdbarch *gdbarch, CORE_ADDR start_addr)
279 {
280   struct symtab *s = find_pc_symtab (start_addr);
281   struct tui_win_info *win_with_focus = tui_win_with_focus ();
282   struct tui_line_or_address val;
283 
284   val.loa = LOA_ADDRESS;
285   val.u.addr = start_addr;
286   tui_add_win_to_layout (DISASSEM_WIN);
287   tui_update_source_window (TUI_DISASM_WIN, gdbarch, s, val, FALSE);
288 
289   /* If the focus was in the src win, put it in the asm win, if the
290      source view isn't split.  */
291   if (tui_current_layout () != SRC_DISASSEM_COMMAND
292       && win_with_focus == TUI_SRC_WIN)
293     tui_set_win_focus_to (TUI_DISASM_WIN);
294 
295   return;
296 }
297 
298 
299 /* Function to display the disassembly window.  */
300 void
301 tui_show_disassem_and_update_source (struct gdbarch *gdbarch,
302 				     CORE_ADDR start_addr)
303 {
304   struct symtab_and_line sal;
305 
306   tui_show_disassem (gdbarch, start_addr);
307   if (tui_current_layout () == SRC_DISASSEM_COMMAND)
308     {
309       struct tui_line_or_address val;
310 
311       /* Update what is in the source window if it is displayed too,
312          note that it follows what is in the disassembly window and
313          visa-versa.  */
314       sal = find_pc_line (start_addr, 0);
315       val.loa = LOA_LINE;
316       val.u.line_no = sal.line;
317       tui_update_source_window (TUI_SRC_WIN, gdbarch, sal.symtab, val, TRUE);
318       if (sal.symtab)
319 	{
320 	  set_current_source_symtab_and_line (&sal);
321 	  tui_update_locator_filename (sal.symtab->filename);
322 	}
323       else
324 	tui_update_locator_filename ("?");
325     }
326 
327   return;
328 }
329 
330 void
331 tui_get_begin_asm_address (struct gdbarch **gdbarch_p, CORE_ADDR *addr_p)
332 {
333   struct tui_gen_win_info *locator;
334   struct tui_locator_element *element;
335   struct gdbarch *gdbarch = get_current_arch ();
336   CORE_ADDR addr;
337 
338   locator = tui_locator_win_info_ptr ();
339   element = &((struct tui_win_element *)
340 	      locator->content[0])->which_element.locator;
341 
342   if (element->addr == 0)
343     {
344       struct minimal_symbol *main_symbol;
345 
346       /* Find address of the start of program.
347          Note: this should be language specific.  */
348       main_symbol = lookup_minimal_symbol ("main", NULL, NULL);
349       if (main_symbol == 0)
350         main_symbol = lookup_minimal_symbol ("MAIN", NULL, NULL);
351       if (main_symbol == 0)
352         main_symbol = lookup_minimal_symbol ("_start", NULL, NULL);
353       if (main_symbol)
354         addr = SYMBOL_VALUE_ADDRESS (main_symbol);
355       else
356         addr = 0;
357     }
358   else				/* The target is executing.  */
359     {
360       gdbarch = element->gdbarch;
361       addr = element->addr;
362     }
363 
364   *gdbarch_p = gdbarch;
365   *addr_p = addr;
366 }
367 
368 /* Determine what the low address will be to display in the TUI's
369    disassembly window.  This may or may not be the same as the low
370    address input.  */
371 CORE_ADDR
372 tui_get_low_disassembly_address (struct gdbarch *gdbarch,
373 				 CORE_ADDR low, CORE_ADDR pc)
374 {
375   int pos;
376 
377   /* Determine where to start the disassembly so that the pc is about
378      in the middle of the viewport.  */
379   pos = tui_default_win_viewport_height (DISASSEM_WIN, DISASSEM_COMMAND) / 2;
380   pc = tui_find_disassembly_address (gdbarch, pc, -pos);
381 
382   if (pc < low)
383     pc = low;
384   return pc;
385 }
386 
387 /* Scroll the disassembly forward or backward vertically.  */
388 void
389 tui_vertical_disassem_scroll (enum tui_scroll_direction scroll_direction,
390 			      int num_to_scroll)
391 {
392   if (TUI_DISASM_WIN->generic.content != NULL)
393     {
394       struct gdbarch *gdbarch = TUI_DISASM_WIN->detail.source_info.gdbarch;
395       CORE_ADDR pc;
396       tui_win_content content;
397       struct tui_line_or_address val;
398       int dir;
399 
400       content = (tui_win_content) TUI_DISASM_WIN->generic.content;
401 
402       pc = content[0]->which_element.source.line_or_addr.u.addr;
403       num_to_scroll++;
404       dir = (scroll_direction == FORWARD_SCROLL)
405 	? num_to_scroll : -num_to_scroll;
406 
407       val.loa = LOA_ADDRESS;
408       val.u.addr = tui_find_disassembly_address (gdbarch, pc, dir);
409       tui_update_source_window_as_is (TUI_DISASM_WIN, gdbarch,
410 				      NULL, val, FALSE);
411     }
412 }
413