1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
|
/* Output routines for graphical representation.
Copyright (C) 1998-2018 Free Software Foundation, Inc.
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998.
Rewritten for DOT output by Steven Bosscher, 2012.
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 3, or (at your option) any later
version.
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3. If not see
<http://www.gnu.org/licenses/>. */
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "backend.h"
#include "cfghooks.h"
#include "pretty-print.h"
#include "diagnostic-core.h" /* for fatal_error */
#include "cfganal.h"
#include "cfgloop.h"
#include "graph.h"
#include "dumpfile.h"
/* DOT files with the .dot extension are recognized as document templates
by a well-known piece of word processing software out of Redmond, WA.
Therefore some recommend using the .gv extension instead. Obstinately
ignore that recommendation... */
static const char *const graph_ext = ".dot";
/* Open a file with MODE for dumping our graph to.
Return the file pointer. */
static FILE *
open_graph_file (const char *base, const char *mode)
{
size_t namelen = strlen (base);
size_t extlen = strlen (graph_ext) + 1;
char *buf = XALLOCAVEC (char, namelen + extlen);
FILE *fp;
memcpy (buf, base, namelen);
memcpy (buf + namelen, graph_ext, extlen);
fp = fopen (buf, mode);
if (fp == NULL)
fatal_error (input_location, "can%'t open %s: %m", buf);
return fp;
}
/* Draw a basic block BB belonging to the function with FUNCDEF_NO
as its unique number. */
static void
draw_cfg_node (pretty_printer *pp, int funcdef_no, basic_block bb)
{
const char *shape;
const char *fillcolor;
if (bb->index == ENTRY_BLOCK || bb->index == EXIT_BLOCK)
{
shape = "Mdiamond";
fillcolor = "white";
}
else
{
shape = "record";
fillcolor =
BB_PARTITION (bb) == BB_HOT_PARTITION ? "lightpink"
: BB_PARTITION (bb) == BB_COLD_PARTITION ? "lightblue"
: "lightgrey";
}
pp_printf (pp,
"\tfn_%d_basic_block_%d "
"[shape=%s,style=filled,fillcolor=%s,label=\"",
funcdef_no, bb->index, shape, fillcolor);
if (bb->index == ENTRY_BLOCK)
pp_string (pp, "ENTRY");
else if (bb->index == EXIT_BLOCK)
pp_string (pp, "EXIT");
else
{
pp_left_brace (pp);
pp_write_text_to_stream (pp);
dump_bb_for_graph (pp, bb);
pp_right_brace (pp);
}
pp_string (pp, "\"];\n\n");
pp_flush (pp);
}
/* Draw all successor edges of a basic block BB belonging to the function
with FUNCDEF_NO as its unique number. */
static void
draw_cfg_node_succ_edges (pretty_printer *pp, int funcdef_no, basic_block bb)
{
edge e;
edge_iterator ei;
FOR_EACH_EDGE (e, ei, bb->succs)
{
const char *style = "\"solid,bold\"";
const char *color = "black";
int weight = 10;
if (e->flags & EDGE_FAKE)
{
style = "dotted";
color = "green";
weight = 0;
}
else if (e->flags & EDGE_DFS_BACK)
{
style = "\"dotted,bold\"";
color = "blue";
weight = 10;
}
else if (e->flags & EDGE_FALLTHRU)
{
color = "blue";
weight = 100;
}
if (e->flags & EDGE_ABNORMAL)
color = "red";
pp_printf (pp,
"\tfn_%d_basic_block_%d:s -> fn_%d_basic_block_%d:n "
"[style=%s,color=%s,weight=%d,constraint=%s",
funcdef_no, e->src->index,
funcdef_no, e->dest->index,
style, color, weight,
(e->flags & (EDGE_FAKE | EDGE_DFS_BACK)) ? "false" : "true");
if (e->probability.initialized_p ())
pp_printf (pp, ",label=\"[%i%%]\"",
e->probability.to_reg_br_prob_base ()
* 100 / REG_BR_PROB_BASE);
pp_printf (pp, "];\n");
}
pp_flush (pp);
}
/* Draw all the basic blocks in the CFG in case loops are not available.
First compute a topological order of the blocks to get a good ranking of
the nodes. Then, if any nodes are not reachable from ENTRY, add them at
the end. */
static void
draw_cfg_nodes_no_loops (pretty_printer *pp, struct function *fun)
{
int *rpo = XNEWVEC (int, n_basic_blocks_for_fn (fun));
int i, n;
auto_sbitmap visited (last_basic_block_for_fn (cfun));
bitmap_clear (visited);
n = pre_and_rev_post_order_compute_fn (fun, NULL, rpo, true);
for (i = n_basic_blocks_for_fn (fun) - n;
i < n_basic_blocks_for_fn (fun); i++)
{
basic_block bb = BASIC_BLOCK_FOR_FN (cfun, rpo[i]);
draw_cfg_node (pp, fun->funcdef_no, bb);
bitmap_set_bit (visited, bb->index);
}
free (rpo);
if (n != n_basic_blocks_for_fn (fun))
{
/* Some blocks are unreachable. We still want to dump them. */
basic_block bb;
FOR_ALL_BB_FN (bb, fun)
if (! bitmap_bit_p (visited, bb->index))
draw_cfg_node (pp, fun->funcdef_no, bb);
}
}
/* Draw all the basic blocks in LOOP. Print the blocks in breath-first
order to get a good ranking of the nodes. This function is recursive:
It first prints inner loops, then the body of LOOP itself. */
static void
draw_cfg_nodes_for_loop (pretty_printer *pp, int funcdef_no,
struct loop *loop)
{
basic_block *body;
unsigned int i;
const char *fillcolors[3] = { "grey88", "grey77", "grey66" };
if (loop->header != NULL
&& loop->latch != EXIT_BLOCK_PTR_FOR_FN (cfun))
pp_printf (pp,
"\tsubgraph cluster_%d_%d {\n"
"\tstyle=\"filled\";\n"
"\tcolor=\"darkgreen\";\n"
"\tfillcolor=\"%s\";\n"
"\tlabel=\"loop %d\";\n"
"\tlabeljust=l;\n"
"\tpenwidth=2;\n",
funcdef_no, loop->num,
fillcolors[(loop_depth (loop) - 1) % 3],
loop->num);
for (struct loop *inner = loop->inner; inner; inner = inner->next)
draw_cfg_nodes_for_loop (pp, funcdef_no, inner);
if (loop->header == NULL)
return;
if (loop->latch == EXIT_BLOCK_PTR_FOR_FN (cfun))
body = get_loop_body (loop);
else
body = get_loop_body_in_bfs_order (loop);
for (i = 0; i < loop->num_nodes; i++)
{
basic_block bb = body[i];
if (bb->loop_father == loop)
draw_cfg_node (pp, funcdef_no, bb);
}
free (body);
if (loop->latch != EXIT_BLOCK_PTR_FOR_FN (cfun))
pp_printf (pp, "\t}\n");
}
/* Draw all the basic blocks in the CFG in case the loop tree is available.
All loop bodys are printed in clusters. */
static void
draw_cfg_nodes (pretty_printer *pp, struct function *fun)
{
if (loops_for_fn (fun))
draw_cfg_nodes_for_loop (pp, fun->funcdef_no, get_loop (fun, 0));
else
draw_cfg_nodes_no_loops (pp, fun);
}
/* Draw all edges in the CFG. Retreating edges are drawin as not
constraining, this makes the layout of the graph better. */
static void
draw_cfg_edges (pretty_printer *pp, struct function *fun)
{
basic_block bb;
/* Save EDGE_DFS_BACK flag to dfs_back. */
auto_bitmap dfs_back;
edge e;
edge_iterator ei;
unsigned int idx = 0;
FOR_EACH_BB_FN (bb, cfun)
FOR_EACH_EDGE (e, ei, bb->succs)
{
if (e->flags & EDGE_DFS_BACK)
bitmap_set_bit (dfs_back, idx);
idx++;
}
mark_dfs_back_edges ();
FOR_ALL_BB_FN (bb, cfun)
draw_cfg_node_succ_edges (pp, fun->funcdef_no, bb);
/* Restore EDGE_DFS_BACK flag from dfs_back. */
idx = 0;
FOR_EACH_BB_FN (bb, cfun)
FOR_EACH_EDGE (e, ei, bb->succs)
{
if (bitmap_bit_p (dfs_back, idx))
e->flags |= EDGE_DFS_BACK;
else
e->flags &= ~EDGE_DFS_BACK;
idx++;
}
/* Add an invisible edge from ENTRY to EXIT, to improve the graph layout. */
pp_printf (pp,
"\tfn_%d_basic_block_%d:s -> fn_%d_basic_block_%d:n "
"[style=\"invis\",constraint=true];\n",
fun->funcdef_no, ENTRY_BLOCK,
fun->funcdef_no, EXIT_BLOCK);
pp_flush (pp);
}
/* Print a graphical representation of the CFG of function FUN.
First print all basic blocks. Draw all edges at the end to get
subgraphs right for GraphViz, which requires nodes to be defined
before edges to cluster nodes properly. */
void DEBUG_FUNCTION
print_graph_cfg (FILE *fp, struct function *fun)
{
pretty_printer graph_slim_pp;
graph_slim_pp.buffer->stream = fp;
pretty_printer *const pp = &graph_slim_pp;
const char *funcname = function_name (fun);
pp_printf (pp, "subgraph \"cluster_%s\" {\n"
"\tstyle=\"dashed\";\n"
"\tcolor=\"black\";\n"
"\tlabel=\"%s ()\";\n",
funcname, funcname);
draw_cfg_nodes (pp, fun);
draw_cfg_edges (pp, fun);
pp_printf (pp, "}\n");
pp_flush (pp);
}
/* Overload with additional flag argument. */
void DEBUG_FUNCTION
print_graph_cfg (FILE *fp, struct function *fun, dump_flags_t flags)
{
dump_flags_t saved_dump_flags = dump_flags;
dump_flags = flags;
print_graph_cfg (fp, fun);
dump_flags = saved_dump_flags;
}
/* Print a graphical representation of the CFG of function FUN.
First print all basic blocks. Draw all edges at the end to get
subgraphs right for GraphViz, which requires nodes to be defined
before edges to cluster nodes properly. */
void
print_graph_cfg (const char *base, struct function *fun)
{
FILE *fp = open_graph_file (base, "a");
print_graph_cfg (fp, fun);
fclose (fp);
}
/* Start the dump of a graph. */
static void
start_graph_dump (FILE *fp, const char *base)
{
pretty_printer graph_slim_pp;
graph_slim_pp.buffer->stream = fp;
pretty_printer *const pp = &graph_slim_pp;
pp_string (pp, "digraph \"");
pp_write_text_to_stream (pp);
pp_string (pp, base);
pp_write_text_as_dot_label_to_stream (pp, /*for_record=*/false);
pp_string (pp, "\" {\n");
pp_string (pp, "overlap=false;\n");
pp_flush (pp);
}
/* End the dump of a graph. */
static void
end_graph_dump (FILE *fp)
{
fputs ("}\n", fp);
}
/* Similar as clean_dump_file, but this time for graph output files. */
void
clean_graph_dump_file (const char *base)
{
FILE *fp = open_graph_file (base, "w");
start_graph_dump (fp, base);
fclose (fp);
}
/* Do final work on the graph output file. */
void
finish_graph_dump_file (const char *base)
{
FILE *fp = open_graph_file (base, "a");
end_graph_dump (fp);
fclose (fp);
}
|