1 /* symtab.c
2 
3    Copyright 1999, 2000, 2001, 2002, 2004 Free Software Foundation, Inc.
4 
5    This file is part of GNU Binutils.
6 
7    This program is free software; you can redistribute it and/or modify
8    it under the terms of the GNU General Public License as published by
9    the Free Software Foundation; either version 2 of the License, or
10    (at your option) any later version.
11 
12    This program is distributed in the hope that it will be useful,
13    but WITHOUT ANY WARRANTY; without even the implied warranty of
14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15    GNU General Public License for more details.
16 
17    You should have received a copy of the GNU General Public License
18    along with this program; if not, write to the Free Software
19    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA
20    02110-1301, USA.  */
21 
22 #include "gprof.h"
23 #include "search_list.h"
24 #include "source.h"
25 #include "symtab.h"
26 #include "cg_arcs.h"
27 #include "corefile.h"
28 
29 static int cmp_addr (const PTR, const PTR);
30 
31 Sym_Table symtab;
32 
33 
34 /* Initialize a symbol (so it's empty).  */
35 
36 void
37 sym_init (Sym *sym)
38 {
39   memset (sym, 0, sizeof (*sym));
40 
41   /* It is not safe to assume that a binary zero corresponds
42      to a floating-point 0.0, so initialize floats explicitly.  */
43   sym->hist.time = 0.0;
44   sym->cg.child_time = 0.0;
45   sym->cg.prop.fract = 0.0;
46   sym->cg.prop.self = 0.0;
47   sym->cg.prop.child = 0.0;
48 }
49 
50 
51 /* Compare the function entry-point of two symbols and return <0, =0,
52    or >0 depending on whether the left value is smaller than, equal
53    to, or greater than the right value.  If two symbols are equal
54    but one has is_func set and the other doesn't, we make the
55    non-function symbol one "bigger" so that the function symbol will
56    survive duplicate removal.  Finally, if both symbols have the
57    same is_func value, we discriminate against is_static such that
58    the global symbol survives.  */
59 
60 static int
61 cmp_addr (const PTR lp, const PTR rp)
62 {
63   const Sym *left = (const Sym *) lp;
64   const Sym *right = (const Sym *) rp;
65 
66   if (left->addr > right->addr)
67     return 1;
68   else if (left->addr < right->addr)
69     return -1;
70 
71   if (left->is_func != right->is_func)
72     return right->is_func - left->is_func;
73 
74   return left->is_static - right->is_static;
75 }
76 
77 
78 void
79 symtab_finalize (Sym_Table *tab)
80 {
81   Sym *src, *dst;
82   bfd_vma prev_addr;
83 
84   if (!tab->len)
85     return;
86 
87   /* Sort symbol table in order of increasing function addresses.  */
88   qsort (tab->base, tab->len, sizeof (Sym), cmp_addr);
89 
90   /* Remove duplicate entries to speed-up later processing and
91      set end_addr if its not set yet.  */
92   prev_addr = tab->base[0].addr + 1;
93 
94   for (src = dst = tab->base; src < tab->limit; ++src)
95     {
96       if (src->addr == prev_addr)
97 	{
98 	  /* If same address, favor global symbol over static one,
99 	     then function over line number.  If both symbols are
100 	     either static or global and either function or line, check
101 	     whether one has name beginning with underscore while
102 	     the other doesn't.  In such cases, keep sym without
103 	     underscore.  This takes cares of compiler generated
104 	     symbols (such as __gnu_compiled, __c89_used, etc.).  */
105 	  if ((!src->is_static && dst[-1].is_static)
106 	      || ((src->is_static == dst[-1].is_static)
107 		  && ((src->is_func && !dst[-1].is_func)
108 		      || ((src->is_func == dst[-1].is_func)
109 			  && ((src->name[0] != '_' && dst[-1].name[0] == '_')
110 			      || (src->name[0]
111 				  && src->name[1] != '_'
112 				  && dst[-1].name[1] == '_'))))))
113 	    {
114 	      DBG (AOUTDEBUG | IDDEBUG,
115 		   printf ("[symtab_finalize] favor %s@%c%c over %s@%c%c",
116 			   src->name, src->is_static ? 't' : 'T',
117 			   src->is_func ? 'F' : 'f',
118 			   dst[-1].name, dst[-1].is_static ? 't' : 'T',
119 			   dst[-1].is_func ? 'F' : 'f');
120 		   printf (" (addr=%lx)\n", (unsigned long) src->addr));
121 
122 	      dst[-1] = *src;
123 	    }
124 	  else
125 	    {
126 	      DBG (AOUTDEBUG | IDDEBUG,
127 		   printf ("[symtab_finalize] favor %s@%c%c over %s@%c%c",
128 			   dst[-1].name, dst[-1].is_static ? 't' : 'T',
129 			   dst[-1].is_func ? 'F' : 'f',
130 			   src->name, src->is_static ? 't' : 'T',
131 			   src->is_func ? 'F' : 'f');
132 		   printf (" (addr=%lx)\n", (unsigned long) src->addr));
133 	    }
134 	}
135       else
136 	{
137 	  if (dst > tab->base && dst[-1].end_addr == 0)
138 	    dst[-1].end_addr = src->addr - 1;
139 
140 	  /* Retain sym only if it has a non-empty address range.  */
141 	  if (!src->end_addr || src->addr <= src->end_addr)
142 	    {
143 	      *dst = *src;
144 	      dst++;
145 	      prev_addr = src->addr;
146 	    }
147 	}
148     }
149 
150   if (tab->len > 0 && dst[-1].end_addr == 0)
151     dst[-1].end_addr
152       = core_text_sect->vma + bfd_get_section_size (core_text_sect) - 1;
153 
154   DBG (AOUTDEBUG | IDDEBUG,
155        printf ("[symtab_finalize]: removed %d duplicate entries\n",
156 	       tab->len - (int) (dst - tab->base)));
157 
158   tab->limit = dst;
159   tab->len = tab->limit - tab->base;
160 
161   DBG (AOUTDEBUG | IDDEBUG,
162        unsigned int j;
163 
164        for (j = 0; j < tab->len; ++j)
165 	 {
166 	   printf ("[symtab_finalize] 0x%lx-0x%lx\t%s\n",
167 		 (long) tab->base[j].addr, (long) tab->base[j].end_addr,
168 		 tab->base[j].name);
169 	 }
170   );
171 }
172 
173 
174 #ifdef DEBUG
175 
176 Sym *
177 dbg_sym_lookup (Sym_Table *sym_tab, bfd_vma address)
178 {
179   long low, mid, high;
180   Sym *sym;
181 
182   fprintf (stderr, "[dbg_sym_lookup] address 0x%lx\n",
183 	   (unsigned long) address);
184 
185   sym = sym_tab->base;
186   for (low = 0, high = sym_tab->len - 1; low != high;)
187     {
188       mid = (high + low) >> 1;
189 
190       fprintf (stderr, "[dbg_sym_lookup] low=0x%lx, mid=0x%lx, high=0x%lx\n",
191 	       low, mid, high);
192       fprintf (stderr, "[dbg_sym_lookup] sym[m]=0x%lx sym[m + 1]=0x%lx\n",
193 	       (unsigned long) sym[mid].addr,
194 	       (unsigned long) sym[mid + 1].addr);
195 
196       if (sym[mid].addr <= address && sym[mid + 1].addr > address)
197 	return &sym[mid];
198 
199       if (sym[mid].addr > address)
200 	high = mid;
201       else
202 	low = mid + 1;
203     }
204 
205   fprintf (stderr, "[dbg_sym_lookup] binary search fails???\n");
206 
207   return 0;
208 }
209 
210 #endif	/* DEBUG */
211 
212 
213 /* Look up an address in the symbol-table that is sorted by address.
214    If address does not hit any symbol, 0 is returned.  */
215 Sym *
216 sym_lookup (Sym_Table *sym_tab, bfd_vma address)
217 {
218   long low, high;
219   long mid = -1;
220   Sym *sym;
221 #ifdef DEBUG
222   int probes = 0;
223 #endif /* DEBUG */
224 
225   if (!sym_tab->len)
226     return 0;
227 
228   sym = sym_tab->base;
229   for (low = 0, high = sym_tab->len - 1; low != high;)
230     {
231       DBG (LOOKUPDEBUG, ++probes);
232       mid = (high + low) / 2;
233 
234       if (sym[mid].addr <= address && sym[mid + 1].addr > address)
235 	{
236 	  if (address > sym[mid].end_addr)
237 	    {
238 	      /* Address falls into gap between
239 		 sym[mid] and sym[mid + 1].  */
240 	      return 0;
241 	    }
242 	  else
243 	    {
244 	      DBG (LOOKUPDEBUG,
245 		   printf ("[sym_lookup] %d probes (symtab->len=%u)\n",
246 			   probes, sym_tab->len - 1));
247 	      return &sym[mid];
248 	    }
249 	}
250 
251       if (sym[mid].addr > address)
252 	high = mid;
253       else
254 	low = mid + 1;
255     }
256 
257   if (sym[mid + 1].addr <= address)
258     {
259       if (address > sym[mid + 1].end_addr)
260 	{
261 	  /* Address is beyond end of sym[mid + 1].  */
262 	  return 0;
263 	}
264       else
265 	{
266 	  DBG (LOOKUPDEBUG, printf ("[sym_lookup] %d (%u) probes, fall off\n",
267 				    probes, sym_tab->len - 1));
268 	  return &sym[mid + 1];
269 	}
270     }
271 
272   return 0;
273 }
274