1/* Some code common to C and ObjC front ends.
2   Copyright (C) 2001-2015 Free Software Foundation, Inc.
3
4This file is part of GCC.
5
6GCC is free software; you can redistribute it and/or modify it under
7the terms of the GNU General Public License as published by the Free
8Software Foundation; either version 3, or (at your option) any later
9version.
10
11GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12WARRANTY; without even the implied warranty of MERCHANTABILITY or
13FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14for more details.
15
16You should have received a copy of the GNU General Public License
17along 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 "hash-set.h"
24#include "vec.h"
25#include "symtab.h"
26#include "input.h"
27#include "alias.h"
28#include "double-int.h"
29#include "machmode.h"
30#include "flags.h"
31#include "inchash.h"
32#include "tree.h"
33#include "c-tree.h"
34#include "intl.h"
35#include "c-family/c-pretty-print.h"
36#include "diagnostic.h"
37#include "tree-pretty-print.h"
38#include "langhooks.h"
39#include "c-objc-common.h"
40
41#include <new>                          // For placement new.
42
43static bool c_tree_printer (pretty_printer *, text_info *, const char *,
44			    int, bool, bool, bool);
45
46bool
47c_missing_noreturn_ok_p (tree decl)
48{
49  /* A missing noreturn is not ok for freestanding implementations and
50     ok for the `main' function in hosted implementations.  */
51  return flag_hosted && MAIN_NAME_P (DECL_ASSEMBLER_NAME (decl));
52}
53
54/* Called from check_global_declarations.  */
55
56bool
57c_warn_unused_global_decl (const_tree decl)
58{
59  if (TREE_CODE (decl) == FUNCTION_DECL && DECL_DECLARED_INLINE_P (decl))
60    return false;
61  if (DECL_IN_SYSTEM_HEADER (decl))
62    return false;
63
64  return true;
65}
66
67/* Initialization common to C and Objective-C front ends.  */
68bool
69c_objc_common_init (void)
70{
71  c_init_decl_processing ();
72
73  return c_common_init ();
74}
75
76/* Called during diagnostic message formatting process to print a
77   source-level entity onto BUFFER.  The meaning of the format specifiers
78   is as follows:
79   %D: a general decl,
80   %E: an identifier or expression,
81   %F: a function declaration,
82   %T: a type.
83   %V: a list of type qualifiers from a tree.
84   %v: an explicit list of type qualifiers
85   %#v: an explicit list of type qualifiers of a function type.
86
87   Please notice when called, the `%' part was already skipped by the
88   diagnostic machinery.  */
89static bool
90c_tree_printer (pretty_printer *pp, text_info *text, const char *spec,
91		int precision, bool wide, bool set_locus, bool hash)
92{
93  tree t = NULL_TREE;
94  tree name;
95  // FIXME: the next cast should be a dynamic_cast, when it is permitted.
96  c_pretty_printer *cpp = (c_pretty_printer *) pp;
97  pp->padding = pp_none;
98
99  if (precision != 0 || wide)
100    return false;
101
102  if (*spec == 'K')
103    {
104      percent_K_format (text);
105      return true;
106    }
107
108  if (*spec != 'v')
109    {
110      t = va_arg (*text->args_ptr, tree);
111      if (set_locus && text->locus)
112	*text->locus = DECL_SOURCE_LOCATION (t);
113    }
114
115  switch (*spec)
116    {
117    case 'D':
118      if (TREE_CODE (t) == VAR_DECL && DECL_HAS_DEBUG_EXPR_P (t))
119	{
120	  t = DECL_DEBUG_EXPR (t);
121	  if (!DECL_P (t))
122	    {
123	      cpp->expression (t);
124	      return true;
125	    }
126	}
127      /* FALLTHRU */
128
129    case 'F':
130      if (DECL_NAME (t))
131	{
132	  pp_identifier (cpp, lang_hooks.decl_printable_name (t, 2));
133	  return true;
134	}
135      break;
136
137    case 'T':
138      {
139	gcc_assert (TYPE_P (t));
140	struct obstack *ob = pp_buffer (cpp)->obstack;
141	char *p = (char *) obstack_base (ob);
142	/* Remember the end of the initial dump.  */
143	int len = obstack_object_size (ob);
144
145	name = TYPE_NAME (t);
146	if (name && TREE_CODE (name) == TYPE_DECL && DECL_NAME (name))
147	  pp_identifier (cpp, lang_hooks.decl_printable_name (name, 2));
148	else
149	  cpp->type_id (t);
150
151	/* If we're printing a type that involves typedefs, also print the
152	   stripped version.  But sometimes the stripped version looks
153	   exactly the same, so we don't want it after all.  To avoid
154	   printing it in that case, we play ugly obstack games.  */
155	if (TYPE_CANONICAL (t) && t != TYPE_CANONICAL (t))
156	  {
157	    c_pretty_printer cpp2;
158	    /* Print the stripped version into a temporary printer.  */
159	    cpp2.type_id (TYPE_CANONICAL (t));
160	    struct obstack *ob2 = cpp2.buffer->obstack;
161	    /* Get the stripped version from the temporary printer.  */
162	    const char *aka = (char *) obstack_base (ob2);
163	    int aka_len = obstack_object_size (ob2);
164	    int type1_len = obstack_object_size (ob) - len;
165
166	    /* If they are identical, bail out.  */
167	    if (aka_len == type1_len && memcmp (p + len, aka, aka_len) == 0)
168	      return true;
169
170	    /* They're not, print the stripped version now.  */
171	    pp_c_whitespace (cpp);
172	    pp_left_brace (cpp);
173	    pp_c_ws_string (cpp, _("aka"));
174	    pp_c_whitespace (cpp);
175	    cpp->type_id (TYPE_CANONICAL (t));
176	    pp_right_brace (cpp);
177	  }
178	return true;
179      }
180
181    case 'E':
182      if (TREE_CODE (t) == IDENTIFIER_NODE)
183	pp_identifier (cpp, IDENTIFIER_POINTER (t));
184      else
185	cpp->expression (t);
186      return true;
187
188    case 'V':
189      pp_c_type_qualifier_list (cpp, t);
190      return true;
191
192    case 'v':
193      pp_c_cv_qualifiers (cpp, va_arg (*text->args_ptr, int), hash);
194      return true;
195
196    default:
197      return false;
198    }
199
200  pp_string (cpp, _("({anonymous})"));
201  return true;
202}
203
204/* In C and ObjC, all decls have "C" linkage.  */
205bool
206has_c_linkage (const_tree decl ATTRIBUTE_UNUSED)
207{
208  return true;
209}
210
211void
212c_initialize_diagnostics (diagnostic_context *context)
213{
214  pretty_printer *base = context->printer;
215  c_pretty_printer *pp = XNEW (c_pretty_printer);
216  context->printer = new (pp) c_pretty_printer ();
217
218  /* It is safe to free this object because it was previously XNEW()'d.  */
219  base->~pretty_printer ();
220  XDELETE (base);
221
222  c_common_diagnostics_set_defaults (context);
223  diagnostic_format_decoder (context) = &c_tree_printer;
224}
225
226int
227c_types_compatible_p (tree x, tree y)
228{
229  return comptypes (TYPE_MAIN_VARIANT (x), TYPE_MAIN_VARIANT (y));
230}
231
232/* Determine if the type is a vla type for the backend.  */
233
234bool
235c_vla_unspec_p (tree x, tree fn ATTRIBUTE_UNUSED)
236{
237  return c_vla_type_p (x);
238}
239