xref: /netbsd-src/external/gpl3/gcc.old/dist/gcc/c/c-objc-common.c (revision 7330f729ccf0bd976a06f95fad452fe774fc7fd1)
1 /* Some code common to C and ObjC front ends.
2    Copyright (C) 2001-2017 Free Software Foundation, Inc.
3 
4 This file is part of GCC.
5 
6 GCC is free software; you can redistribute it and/or modify it under
7 the terms of the GNU General Public License as published by the Free
8 Software Foundation; either version 3, or (at your option) any later
9 version.
10 
11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14 for more details.
15 
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING3.  If not see
18 <http://www.gnu.org/licenses/>.  */
19 
20 #include "config.h"
21 #include "system.h"
22 #include "coretypes.h"
23 #include "c-tree.h"
24 #include "intl.h"
25 #include "c-family/c-pretty-print.h"
26 #include "tree-pretty-print.h"
27 #include "langhooks.h"
28 #include "c-objc-common.h"
29 
30 static bool c_tree_printer (pretty_printer *, text_info *, const char *,
31 			    int, bool, bool, bool);
32 
33 bool
34 c_missing_noreturn_ok_p (tree decl)
35 {
36   /* A missing noreturn is not ok for freestanding implementations and
37      ok for the `main' function in hosted implementations.  */
38   return flag_hosted && MAIN_NAME_P (DECL_ASSEMBLER_NAME (decl));
39 }
40 
41 /* Called from check_global_declaration.  */
42 
43 bool
44 c_warn_unused_global_decl (const_tree decl)
45 {
46   if (TREE_CODE (decl) == FUNCTION_DECL && DECL_DECLARED_INLINE_P (decl))
47     return false;
48   if (DECL_IN_SYSTEM_HEADER (decl))
49     return false;
50 
51   return true;
52 }
53 
54 /* Initialization common to C and Objective-C front ends.  */
55 bool
56 c_objc_common_init (void)
57 {
58   c_init_decl_processing ();
59 
60   return c_common_init ();
61 }
62 
63 /* Called during diagnostic message formatting process to print a
64    source-level entity onto BUFFER.  The meaning of the format specifiers
65    is as follows:
66    %D: a general decl,
67    %E: an identifier or expression,
68    %F: a function declaration,
69    %T: a type.
70    %V: a list of type qualifiers from a tree.
71    %v: an explicit list of type qualifiers
72    %#v: an explicit list of type qualifiers of a function type.
73 
74    Please notice when called, the `%' part was already skipped by the
75    diagnostic machinery.  */
76 static bool
77 c_tree_printer (pretty_printer *pp, text_info *text, const char *spec,
78 		int precision, bool wide, bool set_locus, bool hash)
79 {
80   tree t = NULL_TREE;
81   tree name;
82   // FIXME: the next cast should be a dynamic_cast, when it is permitted.
83   c_pretty_printer *cpp = (c_pretty_printer *) pp;
84   pp->padding = pp_none;
85 
86   if (precision != 0 || wide)
87     return false;
88 
89   if (*spec == 'K')
90     {
91       percent_K_format (text);
92       return true;
93     }
94 
95   if (*spec != 'v')
96     {
97       t = va_arg (*text->args_ptr, tree);
98       if (set_locus)
99 	text->set_location (0, DECL_SOURCE_LOCATION (t), true);
100     }
101 
102   switch (*spec)
103     {
104     case 'D':
105       if (VAR_P (t) && DECL_HAS_DEBUG_EXPR_P (t))
106 	{
107 	  t = DECL_DEBUG_EXPR (t);
108 	  if (!DECL_P (t))
109 	    {
110 	      cpp->expression (t);
111 	      return true;
112 	    }
113 	}
114       /* FALLTHRU */
115 
116     case 'F':
117       if (DECL_NAME (t))
118 	{
119 	  pp_identifier (cpp, lang_hooks.decl_printable_name (t, 2));
120 	  return true;
121 	}
122       break;
123 
124     case 'T':
125       {
126 	gcc_assert (TYPE_P (t));
127 	struct obstack *ob = pp_buffer (cpp)->obstack;
128 	char *p = (char *) obstack_base (ob);
129 	/* Remember the end of the initial dump.  */
130 	int len = obstack_object_size (ob);
131 
132 	name = TYPE_NAME (t);
133 	if (name && TREE_CODE (name) == TYPE_DECL && DECL_NAME (name))
134 	  pp_identifier (cpp, lang_hooks.decl_printable_name (name, 2));
135 	else
136 	  cpp->type_id (t);
137 
138 	/* If we're printing a type that involves typedefs, also print the
139 	   stripped version.  But sometimes the stripped version looks
140 	   exactly the same, so we don't want it after all.  To avoid
141 	   printing it in that case, we play ugly obstack games.  */
142 	if (TYPE_CANONICAL (t) && t != TYPE_CANONICAL (t))
143 	  {
144 	    c_pretty_printer cpp2;
145 	    /* Print the stripped version into a temporary printer.  */
146 	    cpp2.type_id (TYPE_CANONICAL (t));
147 	    struct obstack *ob2 = cpp2.buffer->obstack;
148 	    /* Get the stripped version from the temporary printer.  */
149 	    const char *aka = (char *) obstack_base (ob2);
150 	    int aka_len = obstack_object_size (ob2);
151 	    int type1_len = obstack_object_size (ob) - len;
152 
153 	    /* If they are identical, bail out.  */
154 	    if (aka_len == type1_len && memcmp (p + len, aka, aka_len) == 0)
155 	      return true;
156 
157 	    /* They're not, print the stripped version now.  */
158 	    pp_c_whitespace (cpp);
159 	    pp_left_brace (cpp);
160 	    pp_c_ws_string (cpp, _("aka"));
161 	    pp_c_whitespace (cpp);
162 	    cpp->type_id (TYPE_CANONICAL (t));
163 	    pp_right_brace (cpp);
164 	  }
165 	return true;
166       }
167 
168     case 'E':
169       if (TREE_CODE (t) == IDENTIFIER_NODE)
170 	pp_identifier (cpp, IDENTIFIER_POINTER (t));
171       else
172 	cpp->expression (t);
173       return true;
174 
175     case 'V':
176       pp_c_type_qualifier_list (cpp, t);
177       return true;
178 
179     case 'v':
180       pp_c_cv_qualifiers (cpp, va_arg (*text->args_ptr, int), hash);
181       return true;
182 
183     default:
184       return false;
185     }
186 
187   pp_string (cpp, _("({anonymous})"));
188   return true;
189 }
190 
191 /* In C and ObjC, all decls have "C" linkage.  */
192 bool
193 has_c_linkage (const_tree decl ATTRIBUTE_UNUSED)
194 {
195   return true;
196 }
197 
198 void
199 c_initialize_diagnostics (diagnostic_context *context)
200 {
201   pretty_printer *base = context->printer;
202   c_pretty_printer *pp = XNEW (c_pretty_printer);
203   context->printer = new (pp) c_pretty_printer ();
204 
205   /* It is safe to free this object because it was previously XNEW()'d.  */
206   base->~pretty_printer ();
207   XDELETE (base);
208 
209   c_common_diagnostics_set_defaults (context);
210   diagnostic_format_decoder (context) = &c_tree_printer;
211 }
212 
213 int
214 c_types_compatible_p (tree x, tree y)
215 {
216   return comptypes (TYPE_MAIN_VARIANT (x), TYPE_MAIN_VARIANT (y));
217 }
218 
219 /* Determine if the type is a vla type for the backend.  */
220 
221 bool
222 c_vla_unspec_p (tree x, tree fn ATTRIBUTE_UNUSED)
223 {
224   return c_vla_type_p (x);
225 }
226