1 /* Some code common to C and ObjC front ends.
2    Copyright (C) 2001-2018 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 "gimple-pretty-print.h"
28 #include "langhooks.h"
29 #include "c-objc-common.h"
30 
31 static bool c_tree_printer (pretty_printer *, text_info *, const char *,
32 			    int, bool, bool, bool, bool *, const char **);
33 
34 bool
c_missing_noreturn_ok_p(tree decl)35 c_missing_noreturn_ok_p (tree decl)
36 {
37   /* A missing noreturn is not ok for freestanding implementations and
38      ok for the `main' function in hosted implementations.  */
39   return flag_hosted && MAIN_NAME_P (DECL_ASSEMBLER_NAME (decl));
40 }
41 
42 /* Called from check_global_declaration.  */
43 
44 bool
c_warn_unused_global_decl(const_tree decl)45 c_warn_unused_global_decl (const_tree decl)
46 {
47   if (TREE_CODE (decl) == FUNCTION_DECL && DECL_DECLARED_INLINE_P (decl))
48     return false;
49   if (DECL_IN_SYSTEM_HEADER (decl))
50     return false;
51 
52   return true;
53 }
54 
55 /* Initialization common to C and Objective-C front ends.  */
56 bool
c_objc_common_init(void)57 c_objc_common_init (void)
58 {
59   c_init_decl_processing ();
60 
61   return c_common_init ();
62 }
63 
64 /* Called during diagnostic message formatting process to print a
65    source-level entity onto BUFFER.  The meaning of the format specifiers
66    is as follows:
67    %D: a general decl,
68    %E: an identifier or expression,
69    %F: a function declaration,
70    %G: a Gimple call statement,
71    %K: a CALL_EXPR,
72    %T: a type.
73    %V: a list of type qualifiers from a tree.
74    %v: an explicit list of type qualifiers
75    %#v: an explicit list of type qualifiers of a function type.
76 
77    Please notice when called, the `%' part was already skipped by the
78    diagnostic machinery.  */
79 static bool
c_tree_printer(pretty_printer * pp,text_info * text,const char * spec,int precision,bool wide,bool set_locus,bool hash,bool * quoted,const char **)80 c_tree_printer (pretty_printer *pp, text_info *text, const char *spec,
81 		int precision, bool wide, bool set_locus, bool hash,
82 		bool *quoted, const char **)
83 {
84   tree t = NULL_TREE;
85   tree name;
86   // FIXME: the next cast should be a dynamic_cast, when it is permitted.
87   c_pretty_printer *cpp = (c_pretty_printer *) pp;
88   pp->padding = pp_none;
89 
90   if (precision != 0 || wide)
91     return false;
92 
93   if (*spec == 'G')
94     {
95       percent_G_format (text);
96       return true;
97     }
98 
99   if (*spec == 'K')
100     {
101       t = va_arg (*text->args_ptr, tree);
102       percent_K_format (text, t);
103       return true;
104     }
105 
106   if (*spec != 'v')
107     {
108       t = va_arg (*text->args_ptr, tree);
109       if (set_locus)
110 	text->set_location (0, DECL_SOURCE_LOCATION (t), true);
111     }
112 
113   switch (*spec)
114     {
115     case 'D':
116       if (VAR_P (t) && DECL_HAS_DEBUG_EXPR_P (t))
117 	{
118 	  t = DECL_DEBUG_EXPR (t);
119 	  if (!DECL_P (t))
120 	    {
121 	      cpp->expression (t);
122 	      return true;
123 	    }
124 	}
125       /* FALLTHRU */
126 
127     case 'F':
128       if (DECL_NAME (t))
129 	{
130 	  pp_identifier (cpp, lang_hooks.decl_printable_name (t, 2));
131 	  return true;
132 	}
133       break;
134 
135     case 'T':
136       {
137 	gcc_assert (TYPE_P (t));
138 	struct obstack *ob = pp_buffer (cpp)->obstack;
139 	char *p = (char *) obstack_base (ob);
140 	/* Remember the end of the initial dump.  */
141 	int len = obstack_object_size (ob);
142 
143 	name = TYPE_NAME (t);
144 	if (name && TREE_CODE (name) == TYPE_DECL && DECL_NAME (name))
145 	  pp_identifier (cpp, lang_hooks.decl_printable_name (name, 2));
146 	else
147 	  cpp->type_id (t);
148 
149 	/* If we're printing a type that involves typedefs, also print the
150 	   stripped version.  But sometimes the stripped version looks
151 	   exactly the same, so we don't want it after all.  To avoid
152 	   printing it in that case, we play ugly obstack games.  */
153 	if (TYPE_CANONICAL (t) && t != TYPE_CANONICAL (t))
154 	  {
155 	    c_pretty_printer cpp2;
156 	    /* Print the stripped version into a temporary printer.  */
157 	    cpp2.type_id (TYPE_CANONICAL (t));
158 	    struct obstack *ob2 = cpp2.buffer->obstack;
159 	    /* Get the stripped version from the temporary printer.  */
160 	    const char *aka = (char *) obstack_base (ob2);
161 	    int aka_len = obstack_object_size (ob2);
162 	    int type1_len = obstack_object_size (ob) - len;
163 
164 	    /* If they are identical, bail out.  */
165 	    if (aka_len == type1_len && memcmp (p + len, aka, aka_len) == 0)
166 	      return true;
167 
168 	    /* They're not, print the stripped version now.  */
169 	    if (*quoted)
170 	      pp_end_quote (pp, pp_show_color (pp));
171 	    pp_c_whitespace (cpp);
172 	    pp_left_brace (cpp);
173 	    pp_c_ws_string (cpp, _("aka"));
174 	    pp_c_whitespace (cpp);
175 	    if (*quoted)
176 	      pp_begin_quote (pp, pp_show_color (pp));
177 	    cpp->type_id (TYPE_CANONICAL (t));
178 	    if (*quoted)
179 	      pp_end_quote (pp, pp_show_color (pp));
180 	    pp_right_brace (cpp);
181 	    /* No further closing quotes are needed.  */
182 	    *quoted = false;
183 	  }
184 	return true;
185       }
186 
187     case 'E':
188       if (TREE_CODE (t) == IDENTIFIER_NODE)
189 	pp_identifier (cpp, IDENTIFIER_POINTER (t));
190       else
191 	cpp->expression (t);
192       return true;
193 
194     case 'V':
195       pp_c_type_qualifier_list (cpp, t);
196       return true;
197 
198     case 'v':
199       pp_c_cv_qualifiers (cpp, va_arg (*text->args_ptr, int), hash);
200       return true;
201 
202     default:
203       return false;
204     }
205 
206   pp_string (cpp, _("({anonymous})"));
207   return true;
208 }
209 
210 /* In C and ObjC, all decls have "C" linkage.  */
211 bool
has_c_linkage(const_tree decl ATTRIBUTE_UNUSED)212 has_c_linkage (const_tree decl ATTRIBUTE_UNUSED)
213 {
214   return true;
215 }
216 
217 void
c_initialize_diagnostics(diagnostic_context * context)218 c_initialize_diagnostics (diagnostic_context *context)
219 {
220   pretty_printer *base = context->printer;
221   c_pretty_printer *pp = XNEW (c_pretty_printer);
222   context->printer = new (pp) c_pretty_printer ();
223 
224   /* It is safe to free this object because it was previously XNEW()'d.  */
225   base->~pretty_printer ();
226   XDELETE (base);
227 
228   c_common_diagnostics_set_defaults (context);
229   diagnostic_format_decoder (context) = &c_tree_printer;
230 }
231 
232 int
c_types_compatible_p(tree x,tree y)233 c_types_compatible_p (tree x, tree y)
234 {
235   return comptypes (TYPE_MAIN_VARIANT (x), TYPE_MAIN_VARIANT (y));
236 }
237 
238 /* Determine if the type is a vla type for the backend.  */
239 
240 bool
c_vla_unspec_p(tree x,tree fn ATTRIBUTE_UNUSED)241 c_vla_unspec_p (tree x, tree fn ATTRIBUTE_UNUSED)
242 {
243   return c_vla_type_p (x);
244 }
245