xref: /dflybsd-src/contrib/gdb-7/gdb/tui/tui-disasm.c (revision f41d807a0c7c535d8f66f0593fb6e95fa20f82d4)
1 /* Disassembly display.
2 
3    Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2007, 2008, 2009,
4    2010 Free Software Foundation, Inc.
5 
6    Contributed by Hewlett-Packard Company.
7 
8    This file is part of GDB.
9 
10    This program is free software; you can redistribute it and/or modify
11    it under the terms of the GNU General Public License as published by
12    the Free Software Foundation; either version 3 of the License, or
13    (at your option) any later version.
14 
15    This program is distributed in the hope that it will be useful,
16    but WITHOUT ANY WARRANTY; without even the implied warranty of
17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18    GNU General Public License for more details.
19 
20    You should have received a copy of the GNU General Public License
21    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
22 
23 #include "defs.h"
24 #include "arch-utils.h"
25 #include "symtab.h"
26 #include "breakpoint.h"
27 #include "frame.h"
28 #include "value.h"
29 #include "source.h"
30 #include "disasm.h"
31 #include "gdb_string.h"
32 #include "tui/tui.h"
33 #include "tui/tui-data.h"
34 #include "tui/tui-win.h"
35 #include "tui/tui-layout.h"
36 #include "tui/tui-winsource.h"
37 #include "tui/tui-stack.h"
38 #include "tui/tui-file.h"
39 #include "tui/tui-disasm.h"
40 #include "progspace.h"
41 
42 #include "gdb_curses.h"
43 
44 struct tui_asm_line
45 {
46   CORE_ADDR addr;
47   char *addr_string;
48   char *insn;
49 };
50 
51 /* Function to set the disassembly window's content.
52    Disassemble count lines starting at pc.
53    Return address of the count'th instruction after pc.  */
54 static CORE_ADDR
55 tui_disassemble (struct gdbarch *gdbarch, struct tui_asm_line *asm_lines,
56 		 CORE_ADDR pc, int count)
57 {
58   struct ui_file *gdb_dis_out;
59 
60   /* Now init the ui_file structure.  */
61   gdb_dis_out = tui_sfileopen (256);
62 
63   /* Now construct each line.  */
64   for (; count > 0; count--, asm_lines++)
65     {
66       if (asm_lines->addr_string)
67         xfree (asm_lines->addr_string);
68       if (asm_lines->insn)
69         xfree (asm_lines->insn);
70 
71       print_address (gdbarch, pc, gdb_dis_out);
72       asm_lines->addr = pc;
73       asm_lines->addr_string = xstrdup (tui_file_get_strbuf (gdb_dis_out));
74 
75       ui_file_rewind (gdb_dis_out);
76 
77       pc = pc + gdb_print_insn (gdbarch, pc, gdb_dis_out, NULL);
78 
79       asm_lines->insn = xstrdup (tui_file_get_strbuf (gdb_dis_out));
80 
81       /* Reset the buffer to empty.  */
82       ui_file_rewind (gdb_dis_out);
83     }
84   ui_file_delete (gdb_dis_out);
85   return pc;
86 }
87 
88 /* Find the disassembly address that corresponds to FROM lines above
89    or below the PC.  Variable sized instructions are taken into
90    account by the algorithm.  */
91 static CORE_ADDR
92 tui_find_disassembly_address (struct gdbarch *gdbarch, CORE_ADDR pc, int from)
93 {
94   CORE_ADDR new_low;
95   int max_lines;
96   int i;
97   struct tui_asm_line *asm_lines;
98 
99   max_lines = (from > 0) ? from : - from;
100   if (max_lines <= 1)
101      return pc;
102 
103   asm_lines = (struct tui_asm_line*) alloca (sizeof (struct tui_asm_line)
104                                          * max_lines);
105   memset (asm_lines, 0, sizeof (struct tui_asm_line) * max_lines);
106 
107   new_low = pc;
108   if (from > 0)
109     {
110       tui_disassemble (gdbarch, asm_lines, pc, max_lines);
111       new_low = asm_lines[max_lines - 1].addr;
112     }
113   else
114     {
115       CORE_ADDR last_addr;
116       int pos;
117       struct minimal_symbol *msymbol;
118 
119       /* Find backward an address which is a symbol and for which
120          disassembling from that address will fill completely the
121          window.  */
122       pos = max_lines - 1;
123       do {
124          new_low -= 1 * max_lines;
125          msymbol = lookup_minimal_symbol_by_pc_section (new_low, 0);
126 
127          if (msymbol)
128             new_low = SYMBOL_VALUE_ADDRESS (msymbol);
129          else
130             new_low += 1 * max_lines;
131 
132          tui_disassemble (gdbarch, asm_lines, new_low, max_lines);
133          last_addr = asm_lines[pos].addr;
134       } while (last_addr > pc && msymbol);
135 
136       /* Scan forward disassembling one instruction at a time until
137          the last visible instruction of the window matches the pc.
138          We keep the disassembled instructions in the 'lines' window
139          and shift it downward (increasing its addresses).  */
140       if (last_addr < pc)
141         do
142           {
143             CORE_ADDR next_addr;
144 
145             pos++;
146             if (pos >= max_lines)
147               pos = 0;
148 
149             next_addr = tui_disassemble (gdbarch, &asm_lines[pos],
150 					 last_addr, 1);
151 
152             /* If there are some problems while disassembling exit.  */
153             if (next_addr <= last_addr)
154               break;
155             last_addr = next_addr;
156           } while (last_addr <= pc);
157       pos++;
158       if (pos >= max_lines)
159          pos = 0;
160       new_low = asm_lines[pos].addr;
161     }
162   for (i = 0; i < max_lines; i++)
163     {
164       xfree (asm_lines[i].addr_string);
165       xfree (asm_lines[i].insn);
166     }
167   return new_low;
168 }
169 
170 /* Function to set the disassembly window's content.  */
171 enum tui_status
172 tui_set_disassem_content (struct gdbarch *gdbarch, CORE_ADDR pc)
173 {
174   enum tui_status ret = TUI_FAILURE;
175   int i;
176   int offset = TUI_DISASM_WIN->detail.source_info.horizontal_offset;
177   int line_width, max_lines;
178   CORE_ADDR cur_pc;
179   struct tui_gen_win_info *locator = tui_locator_win_info_ptr ();
180   int tab_len = tui_default_tab_len ();
181   struct tui_asm_line *asm_lines;
182   int insn_pos;
183   int addr_size, max_size;
184   char *line;
185 
186   if (pc == 0)
187     return TUI_FAILURE;
188 
189   ret = tui_alloc_source_buffer (TUI_DISASM_WIN);
190   if (ret != TUI_SUCCESS)
191     return ret;
192 
193   TUI_DISASM_WIN->detail.source_info.gdbarch = gdbarch;
194   TUI_DISASM_WIN->detail.source_info.start_line_or_addr.loa = LOA_ADDRESS;
195   TUI_DISASM_WIN->detail.source_info.start_line_or_addr.u.addr = pc;
196   cur_pc = (CORE_ADDR)
197     (((struct tui_win_element *) locator->content[0])->which_element.locator.addr);
198 
199   max_lines = TUI_DISASM_WIN->generic.height - 2;	/* Account for
200 							   hilite.  */
201 
202   /* Get temporary table that will hold all strings (addr & insn).  */
203   asm_lines = (struct tui_asm_line*) alloca (sizeof (struct tui_asm_line)
204                                          * max_lines);
205   memset (asm_lines, 0, sizeof (struct tui_asm_line) * max_lines);
206 
207   line_width = TUI_DISASM_WIN->generic.width - 1;
208 
209   tui_disassemble (gdbarch, asm_lines, pc, max_lines);
210 
211   /* See what is the maximum length of an address and of a line.  */
212   addr_size = 0;
213   max_size = 0;
214   for (i = 0; i < max_lines; i++)
215     {
216       size_t len = strlen (asm_lines[i].addr_string);
217 
218       if (len > addr_size)
219         addr_size = len;
220 
221       len = strlen (asm_lines[i].insn) + tab_len;
222       if (len > max_size)
223         max_size = len;
224     }
225   max_size += addr_size + tab_len;
226 
227   /* Allocate memory to create each line.  */
228   line = (char*) alloca (max_size);
229   insn_pos = (1 + (addr_size / tab_len)) * tab_len;
230 
231   /* Now construct each line.  */
232   for (i = 0; i < max_lines; i++)
233     {
234       struct tui_win_element *element;
235       struct tui_source_element *src;
236       int cur_len;
237 
238       element = (struct tui_win_element *) TUI_DISASM_WIN->generic.content[i];
239       src = &element->which_element.source;
240       strcpy (line, asm_lines[i].addr_string);
241       cur_len = strlen (line);
242 
243       /* Add spaces to make the instructions start on the same
244 	 column.  */
245       while (cur_len < insn_pos)
246         {
247           strcat (line, " ");
248           cur_len++;
249         }
250 
251       strcat (line, asm_lines[i].insn);
252 
253       /* Now copy the line taking the offset into account.  */
254       if (strlen (line) > offset)
255         strcpy (src->line, &line[offset]);
256       else
257         src->line[0] = '\0';
258 
259       src->line_or_addr.loa = LOA_ADDRESS;
260       src->line_or_addr.u.addr = asm_lines[i].addr;
261       src->is_exec_point = asm_lines[i].addr == cur_pc;
262 
263       /* See whether there is a breakpoint installed.  */
264       src->has_break = (!src->is_exec_point
265 			&& breakpoint_here_p (current_program_space->aspace, 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 *) locator->content[0])->which_element.locator;
340 
341   if (element->addr == 0)
342     {
343       struct minimal_symbol *main_symbol;
344 
345       /* Find address of the start of program.
346          Note: this should be language specific.  */
347       main_symbol = lookup_minimal_symbol ("main", NULL, NULL);
348       if (main_symbol == 0)
349         main_symbol = lookup_minimal_symbol ("MAIN", NULL, NULL);
350       if (main_symbol == 0)
351         main_symbol = lookup_minimal_symbol ("_start", NULL, NULL);
352       if (main_symbol)
353         addr = SYMBOL_VALUE_ADDRESS (main_symbol);
354       else
355         addr = 0;
356     }
357   else				/* The target is executing.  */
358     {
359       gdbarch = element->gdbarch;
360       addr = element->addr;
361     }
362 
363   *gdbarch_p = gdbarch;
364   *addr_p = addr;
365 }
366 
367 /* Determine what the low address will be to display in the TUI's
368    disassembly window.  This may or may not be the same as the low
369    address input.  */
370 CORE_ADDR
371 tui_get_low_disassembly_address (struct gdbarch *gdbarch,
372 				 CORE_ADDR low, CORE_ADDR pc)
373 {
374   int pos;
375 
376   /* Determine where to start the disassembly so that the pc is about
377      in the middle of the viewport.  */
378   pos = tui_default_win_viewport_height (DISASSEM_WIN, DISASSEM_COMMAND) / 2;
379   pc = tui_find_disassembly_address (gdbarch, pc, -pos);
380 
381   if (pc < low)
382     pc = low;
383   return pc;
384 }
385 
386 /* Scroll the disassembly forward or backward vertically.  */
387 void
388 tui_vertical_disassem_scroll (enum tui_scroll_direction scroll_direction,
389 			      int num_to_scroll)
390 {
391   if (TUI_DISASM_WIN->generic.content != NULL)
392     {
393       struct gdbarch *gdbarch = TUI_DISASM_WIN->detail.source_info.gdbarch;
394       CORE_ADDR pc;
395       tui_win_content content;
396       struct tui_line_or_address val;
397       int dir;
398 
399       content = (tui_win_content) TUI_DISASM_WIN->generic.content;
400 
401       pc = content[0]->which_element.source.line_or_addr.u.addr;
402       num_to_scroll++;
403       dir = (scroll_direction == FORWARD_SCROLL) ? num_to_scroll : -num_to_scroll;
404 
405       val.loa = LOA_ADDRESS;
406       val.u.addr = tui_find_disassembly_address (gdbarch, pc, dir);
407       tui_update_source_window_as_is (TUI_DISASM_WIN, gdbarch, NULL, val, FALSE);
408     }
409 }
410