1/*
2 * Copyright © 2010 Intel Corporation
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
21 * DEALINGS IN THE SOFTWARE.
22 */
23
24#include <assert.h>
25#include <string.h>
26#include <ctype.h>
27#include "glcpp.h"
28#include "main/core.h" /* for isblank() on MSVC */
29
30void
31glcpp_error (YYLTYPE *locp, glcpp_parser_t *parser, const char *fmt, ...)
32{
33	va_list ap;
34
35	parser->error = 1;
36	ralloc_asprintf_rewrite_tail(&parser->info_log,
37				     &parser->info_log_length,
38				     "%u:%u(%u): "
39				     "preprocessor error: ",
40				     locp->source,
41				     locp->first_line,
42				     locp->first_column);
43	va_start(ap, fmt);
44	ralloc_vasprintf_rewrite_tail(&parser->info_log,
45				      &parser->info_log_length,
46				      fmt, ap);
47	va_end(ap);
48	ralloc_asprintf_rewrite_tail(&parser->info_log,
49				     &parser->info_log_length, "\n");
50}
51
52void
53glcpp_warning (YYLTYPE *locp, glcpp_parser_t *parser, const char *fmt, ...)
54{
55	va_list ap;
56
57	ralloc_asprintf_rewrite_tail(&parser->info_log,
58				     &parser->info_log_length,
59				     "%u:%u(%u): "
60				     "preprocessor warning: ",
61				     locp->source,
62				     locp->first_line,
63				     locp->first_column);
64	va_start(ap, fmt);
65	ralloc_vasprintf_rewrite_tail(&parser->info_log,
66				      &parser->info_log_length,
67				      fmt, ap);
68	va_end(ap);
69	ralloc_asprintf_rewrite_tail(&parser->info_log,
70				     &parser->info_log_length, "\n");
71}
72
73/* Searches backwards for '^ *#' from a given starting point. */
74static int
75in_directive(const char *shader, const char *ptr)
76{
77	assert(ptr >= shader);
78
79	/* Search backwards for '#'. If we find a \n first, it doesn't count */
80	for (; ptr >= shader && *ptr != '#'; ptr--) {
81		if (*ptr == '\n')
82			return 0;
83	}
84	if (ptr >= shader) {
85		/* Found '#'...look for spaces preceded by a newline */
86		for (ptr--; ptr >= shader && isblank(*ptr); ptr--);
87		// FIXME: I don't think the '\n' case can happen
88		if (ptr < shader || *ptr == '\n')
89			return 1;
90	}
91	return 0;
92}
93
94/* Remove any line continuation characters in preprocessing directives.
95 * However, ignore any in GLSL code, as "There is no line continuation
96 * character" (1.30 page 9) in GLSL.
97 */
98static char *
99remove_line_continuations(glcpp_parser_t *ctx, const char *shader)
100{
101	int in_continued_line = 0;
102	int extra_newlines = 0;
103	char *clean = ralloc_strdup(ctx, "");
104	const char *search_start = shader;
105	const char *newline;
106	while ((newline = strchr(search_start, '\n')) != NULL) {
107		const char *backslash = NULL;
108
109		/* # of characters preceding the newline. */
110		int n = newline - shader;
111
112		/* Find the preceding '\', if it exists */
113		if (n >= 1 && newline[-1] == '\\')
114			backslash = newline - 1;
115		else if (n >= 2 && newline[-1] == '\r' && newline[-2] == '\\')
116			backslash = newline - 2;
117
118		/* Double backslashes don't count (the backslash is escaped) */
119		if (backslash != NULL && backslash[-1] == '\\') {
120			backslash = NULL;
121		}
122
123		if (backslash != NULL) {
124			/* We found a line continuation, but do we care? */
125			if (!in_continued_line) {
126				if (in_directive(shader, backslash)) {
127					in_continued_line = 1;
128					extra_newlines = 0;
129				}
130			}
131			if (in_continued_line) {
132				/* Copy everything before the \ */
133				ralloc_strncat(&clean, shader, backslash - shader);
134				shader = newline + 1;
135				extra_newlines++;
136			}
137		} else if (in_continued_line) {
138			/* Copy everything up to and including the \n */
139			ralloc_strncat(&clean, shader, newline - shader + 1);
140			shader = newline + 1;
141			/* Output extra newlines to make line numbers match */
142			for (; extra_newlines > 0; extra_newlines--)
143				ralloc_strcat(&clean, "\n");
144			in_continued_line = 0;
145		}
146		search_start = newline + 1;
147	}
148	ralloc_strcat(&clean, shader);
149	return clean;
150}
151
152int
153glcpp_preprocess(void *ralloc_ctx, const char **shader, char **info_log,
154	   const struct gl_extensions *extensions, int api)
155{
156	int errors;
157	glcpp_parser_t *parser = glcpp_parser_create (extensions, api);
158	*shader = remove_line_continuations(parser, *shader);
159
160	glcpp_lex_set_source_string (parser, *shader);
161
162	glcpp_parser_parse (parser);
163
164	if (parser->skip_stack)
165		glcpp_error (&parser->skip_stack->loc, parser, "Unterminated #if\n");
166
167	ralloc_strcat(info_log, parser->info_log);
168
169	ralloc_steal(ralloc_ctx, parser->output);
170	*shader = parser->output;
171
172	errors = parser->error;
173	glcpp_parser_destroy (parser);
174	return errors;
175}
176