1/* scan-decls.c - Extracts declarations from cpp output.
2   Copyright (C) 1993, 1995, 1997, 1998,
3   1999, 2000, 2003, 2004 Free Software Foundation, Inc.
4
5This program is free software; you can redistribute it and/or modify it
6under the terms of the GNU General Public License as published by the
7Free Software Foundation; either version 2, or (at your option) any
8later version.
9
10This program is distributed in the hope that it will be useful,
11but WITHOUT ANY WARRANTY; without even the implied warranty of
12MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13GNU General Public License for more details.
14
15You should have received a copy of the GNU General Public License
16along with this program; if not, write to the Free Software
17Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
18
19   Written by Per Bothner <bothner@cygnus.com>, July 1993.  */
20
21#include "bconfig.h"
22#include "system.h"
23#include "coretypes.h"
24#include "tm.h"
25#include "cpplib.h"
26#include "scan.h"
27
28static void skip_to_closing_brace (cpp_reader *);
29static const cpp_token *get_a_token (cpp_reader *);
30
31int brace_nesting = 0;
32
33/* The first extern_C_braces_length elements of extern_C_braces
34   indicate the (brace nesting levels of) left braces that were
35   prefixed by extern "C".  */
36int extern_C_braces_length = 0;
37/* 20 is not enough anymore on Solaris 9.  */
38#define MAX_EXTERN_C_BRACES  200
39char extern_C_braces[MAX_EXTERN_C_BRACES];
40#define in_extern_C_brace (extern_C_braces_length>0)
41
42/* True if the function declaration currently being scanned is
43   prefixed by extern "C".  */
44int current_extern_C = 0;
45
46/* Get a token but skip padding.  */
47static const cpp_token *
48get_a_token (cpp_reader *pfile)
49{
50  for (;;)
51    {
52      const cpp_token *result = cpp_get_token (pfile);
53      if (result->type != CPP_PADDING)
54	return result;
55    }
56}
57
58static void
59skip_to_closing_brace (cpp_reader *pfile)
60{
61  int nesting = 1;
62  for (;;)
63    {
64      enum cpp_ttype token = get_a_token (pfile)->type;
65
66      if (token == CPP_EOF)
67	break;
68      if (token == CPP_OPEN_BRACE)
69	nesting++;
70      if (token == CPP_CLOSE_BRACE && --nesting == 0)
71	break;
72    }
73}
74
75/* This function scans a C source file (actually, the output of cpp),
76   reading from FP.  It looks for function declarations, and
77   external variable declarations.
78
79   The following grammar (as well as some extra stuff) is recognized:
80
81   declaration:
82     (decl-specifier)* declarator ("," declarator)* ";"
83   decl-specifier:
84     identifier
85     keyword
86     extern "C"
87   declarator:
88     (ptr-operator)* dname [ "(" argument-declaration-list ")" ]
89   ptr-operator:
90     ("*" | "&") ("const" | "volatile")*
91   dname:
92     identifier
93
94Here dname is the actual name being declared.
95*/
96
97int
98scan_decls (cpp_reader *pfile, int argc ATTRIBUTE_UNUSED,
99	    char **argv ATTRIBUTE_UNUSED)
100{
101  int saw_extern, saw_inline;
102  cpp_token prev_id;
103  const cpp_token *token;
104
105 new_statement:
106  token = get_a_token (pfile);
107
108 handle_statement:
109  current_extern_C = 0;
110  saw_extern = 0;
111  saw_inline = 0;
112  if (token->type == CPP_OPEN_BRACE)
113    {
114      /* Pop an 'extern "C"' nesting level, if appropriate.  */
115      if (extern_C_braces_length
116	  && extern_C_braces[extern_C_braces_length - 1] == brace_nesting)
117	extern_C_braces_length--;
118      brace_nesting--;
119      goto new_statement;
120    }
121  if (token->type == CPP_OPEN_BRACE)
122    {
123      brace_nesting++;
124      goto new_statement;
125    }
126
127  if (token->type == CPP_EOF)
128    return 0;
129
130  if (token->type == CPP_SEMICOLON)
131    goto new_statement;
132  if (token->type != CPP_NAME)
133    goto new_statement;
134
135  prev_id.type = CPP_EOF;
136  for (;;)
137    {
138      switch (token->type)
139	{
140	default:
141	  goto handle_statement;
142	case CPP_MULT:
143	case CPP_AND:
144	  /* skip */
145	  break;
146
147	case CPP_COMMA:
148	case CPP_SEMICOLON:
149	  if (prev_id.type != CPP_EOF && saw_extern)
150	    {
151	      recognized_extern (&prev_id);
152	    }
153	  if (token->type == CPP_COMMA)
154	    break;
155	  /* ... fall through ...  */
156	case CPP_OPEN_BRACE:  case CPP_CLOSE_BRACE:
157	  goto new_statement;
158
159	case CPP_EOF:
160	  return 0;
161
162	case CPP_OPEN_PAREN:
163	  /* Looks like this is the start of a formal parameter list.  */
164	  if (prev_id.type != CPP_EOF)
165	    {
166	      int nesting = 1;
167	      int have_arg_list = 0;
168	      const struct line_map *map;
169	      unsigned int line;
170	      for (;;)
171		{
172		  token = get_a_token (pfile);
173		  if (token->type == CPP_OPEN_PAREN)
174		    nesting++;
175		  else if (token->type == CPP_CLOSE_PAREN)
176		    {
177		      nesting--;
178		      if (nesting == 0)
179			break;
180		    }
181		  else if (token->type == CPP_EOF)
182		    break;
183		  else if (token->type == CPP_NAME
184			   || token->type == CPP_ELLIPSIS)
185		    have_arg_list = 1;
186		}
187	      map = linemap_lookup (&line_table, token->src_loc);
188	      line = SOURCE_LINE (map, token->src_loc);
189	      recognized_function (&prev_id, line,
190				   (saw_inline ? 'I'
191				    : in_extern_C_brace || current_extern_C
192				    ? 'F' : 'f'), have_arg_list);
193	      token = get_a_token (pfile);
194	      if (token->type == CPP_OPEN_BRACE)
195		{
196		  /* skip body of (normally) inline function */
197		  skip_to_closing_brace (pfile);
198		  goto new_statement;
199		}
200
201	      /* skip a possible __attribute__ or throw expression after the
202		 parameter list */
203	      while (token->type != CPP_SEMICOLON && token->type != CPP_EOF)
204		token = get_a_token (pfile);
205	      if (token->type == CPP_EOF)
206		return 0;
207	      goto new_statement;
208	    }
209	  break;
210	case CPP_NAME:
211	  /* "inline" and "extern" are recognized but skipped */
212	  if (cpp_ideq (token, "inline"))
213	    {
214	      saw_inline = 1;
215	    }
216	  else if (cpp_ideq (token, "extern"))
217	    {
218	      saw_extern = 1;
219	      token = get_a_token (pfile);
220	      if (token->type == CPP_STRING
221		  && token->val.str.len == 1
222		  && token->val.str.text[0] == 'C')
223		{
224		  current_extern_C = 1;
225		  token = get_a_token (pfile);
226		  if (token->type == CPP_OPEN_BRACE)
227		    {
228		      brace_nesting++;
229		      extern_C_braces[extern_C_braces_length++]
230			= brace_nesting;
231		      if (extern_C_braces_length >= MAX_EXTERN_C_BRACES)
232			{
233			  fprintf (stderr,
234			  	   "Internal error: out-of-bounds index\n");
235			  exit (FATAL_EXIT_CODE);
236			}
237		      goto new_statement;
238		    }
239		}
240	      else
241		continue;
242	      break;
243	    }
244	  /* This may be the name of a variable or function.  */
245	  prev_id = *token;
246	  break;
247	}
248      token = get_a_token (pfile);
249    }
250}
251