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1 /* Define new symbol for current position in given section.
2    Copyright (C) 2002, 2005, 2016, 2017 Red Hat, Inc.
3    This file is part of elfutils.
4    Written by Ulrich Drepper <drepper@redhat.com>, 2002.
5 
6    This file is free software; you can redistribute it and/or modify
7    it under the terms of either
8 
9      * the GNU Lesser General Public License as published by the Free
10        Software Foundation; either version 3 of the License, or (at
11        your option) any later version
12 
13    or
14 
15      * the GNU General Public License as published by the Free
16        Software Foundation; either version 2 of the License, or (at
17        your option) any later version
18 
19    or both in parallel, as here.
20 
21    elfutils is distributed in the hope that it will be useful, but
22    WITHOUT ANY WARRANTY; without even the implied warranty of
23    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
24    General Public License for more details.
25 
26    You should have received copies of the GNU General Public License and
27    the GNU Lesser General Public License along with this program.  If
28    not, see <http://www.gnu.org/licenses/>.  */
29 
30 #ifdef HAVE_CONFIG_H
31 # include <config.h>
32 #endif
33 
34 #include <inttypes.h>
35 #include <stdio.h>
36 #include <stdlib.h>
37 #include <string.h>
38 
39 #include <libasmP.h>
40 #include <system.h>
41 
42 
43 AsmSym_t *
asm_newsym(AsmScn_t * asmscn,const char * name,GElf_Xword size,int type,int binding)44 asm_newsym (AsmScn_t *asmscn, const char *name, GElf_Xword size,
45 	    int type, int binding)
46 {
47 /* We don't really expect labels with many digits, but in theory it could
48    be 10 digits (plus ".L" and a zero terminator).  */
49 #define TEMPSYMLEN 13
50   char tempsym[TEMPSYMLEN];
51   AsmSym_t *result;
52 
53   if (asmscn == NULL)
54     /* Something went wrong before.  */
55     return NULL;
56 
57   /* Generate a temporary symbol if necessary.  */
58   if (name == NULL)
59     {
60       /* If a local symbol name is created the symbol better have
61 	 local binding.  */
62       if (binding != STB_LOCAL)
63 	{
64 	  __libasm_seterrno (ASM_E_INVALID);
65 	  return NULL;
66 	}
67 
68       // XXX This requires getting the format from the machine backend.  */
69       snprintf (tempsym, TEMPSYMLEN, ".L%07u", asmscn->ctx->tempsym_count++);
70 
71       name = tempsym;
72     }
73 
74   size_t name_len = strlen (name) + 1;
75 
76   result = (AsmSym_t *) malloc (sizeof (AsmSym_t) + name_len);
77   if (result == NULL)
78     return NULL;
79 
80   rwlock_wrlock (asmscn->ctx->lock);
81 
82   result->scn = asmscn;
83   result->offset = asmscn->offset;
84   result->size = size;
85   result->type = type;
86   result->binding = binding;
87   result->symidx = 0;
88   result->strent = dwelf_strtab_add (asmscn->ctx->symbol_strtab,
89 				     memcpy (result + 1, name, name_len));
90 
91   if (unlikely (asmscn->ctx->textp))
92     {
93       /* We are only interested in the name and don't need to know whether
94 	 it is a local name or not.  */
95       /* First print the binding pseudo-op.  */
96       if (binding == STB_GLOBAL)
97 	fprintf (asmscn->ctx->out.file, "\t.globl\t%s\n", name);
98       else if (binding == STB_WEAK)
99 	fprintf (asmscn->ctx->out.file, "\t.weak\t%s\n", name);
100 
101       /* Next the symbol type.  */
102       if (type == STT_OBJECT)
103 	fprintf (asmscn->ctx->out.file, "\t.type\t%s,@object\n", name);
104       else if (type == STT_FUNC)
105 	fprintf (asmscn->ctx->out.file, "\t.type\t%s,@function\n", name);
106 
107       /* Finally the size and the label.  */
108       fprintf (asmscn->ctx->out.file, "\t.size\t%s,%" PRIuMAX "\n%s:\n",
109 	       name, (uintmax_t) size, name);
110     }
111   else
112     {
113       /* Put the symbol in the hash table so that we can later find it.  */
114       if (asm_symbol_tab_insert (&asmscn->ctx->symbol_tab, elf_hash (name),
115 				 result) != 0)
116 	{
117 	  /* The symbol already exists.  */
118 	  __libasm_seterrno (ASM_E_DUPLSYM);
119 	  /* Note that we can free the entry since there must be no
120 	     reference in the string table to the string.  We can only
121 	     fail to insert the symbol into the symbol table if there
122 	     is already a symbol with this name.  In this case the
123 	     dwelf_strtab_add function would use the previously provided
124 	     name.  */
125 	  free (result);
126 	  result = NULL;
127 	}
128       else if (name != tempsym && asm_emit_symbol_p (name))
129 	/* Only count non-private symbols.  */
130 	++asmscn->ctx->nsymbol_tab;
131     }
132 
133   rwlock_unlock (asmscn->ctx->lock);
134 
135   return result;
136 }
137