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	parser->info_log = hieralloc_asprintf_append(parser->info_log,
37						  "%u:%u(%u): "
38						  "preprocessor error: ",
39						  locp->source,
40						  locp->first_line,
41						  locp->first_column);
42	va_start(ap, fmt);
43	parser->info_log = hieralloc_vasprintf_append(parser->info_log, fmt, ap);
44	va_end(ap);
45	parser->info_log = hieralloc_strdup_append(parser->info_log, "\n");
46}
47
48void
49glcpp_warning (YYLTYPE *locp, glcpp_parser_t *parser, const char *fmt, ...)
50{
51	va_list ap;
52
53	parser->info_log = hieralloc_asprintf_append(parser->info_log,
54						  "%u:%u(%u): "
55						  "preprocessor warning: ",
56						  locp->source,
57						  locp->first_line,
58						  locp->first_column);
59	va_start(ap, fmt);
60	parser->info_log = hieralloc_vasprintf_append(parser->info_log, fmt, ap);
61	va_end(ap);
62	parser->info_log = hieralloc_strdup_append(parser->info_log, "\n");
63}
64
65/* Searches backwards for '^ *#' from a given starting point. */
66static int
67in_directive(const char *shader, const char *ptr)
68{
69	assert(ptr >= shader);
70
71	/* Search backwards for '#'. If we find a \n first, it doesn't count */
72	for (; ptr >= shader && *ptr != '#'; ptr--) {
73		if (*ptr == '\n')
74			return 0;
75	}
76	if (ptr >= shader) {
77		/* Found '#'...look for spaces preceded by a newline */
78		for (ptr--; ptr >= shader && isblank(*ptr); ptr--);
79		// FIXME: I don't think the '\n' case can happen
80		if (ptr < shader || *ptr == '\n')
81			return 1;
82	}
83	return 0;
84}
85
86/* Remove any line continuation characters in preprocessing directives.
87 * However, ignore any in GLSL code, as "There is no line continuation
88 * character" (1.30 page 9) in GLSL.
89 */
90static char *
91remove_line_continuations(glcpp_parser_t *ctx, const char *shader)
92{
93	int in_continued_line = 0;
94	int extra_newlines = 0;
95	char *clean = hieralloc_strdup(ctx, "");
96	const char *search_start = shader;
97	const char *newline;
98	while ((newline = strchr(search_start, '\n')) != NULL) {
99		const char *backslash = NULL;
100
101		/* # of characters preceding the newline. */
102		int n = newline - shader;
103
104		/* Find the preceding '\', if it exists */
105		if (n >= 1 && newline[-1] == '\\')
106			backslash = newline - 1;
107		else if (n >= 2 && newline[-1] == '\r' && newline[-2] == '\\')
108			backslash = newline - 2;
109
110		/* Double backslashes don't count (the backslash is escaped) */
111		if (backslash != NULL && backslash[-1] == '\\') {
112			backslash = NULL;
113		}
114
115		if (backslash != NULL) {
116			/* We found a line continuation, but do we care? */
117			if (!in_continued_line) {
118				if (in_directive(shader, backslash)) {
119					in_continued_line = 1;
120					extra_newlines = 0;
121				}
122			}
123			if (in_continued_line) {
124				/* Copy everything before the \ */
125				clean = hieralloc_strndup_append(clean, shader, backslash - shader);
126				shader = newline + 1;
127				extra_newlines++;
128			}
129		} else if (in_continued_line) {
130			/* Copy everything up to and including the \n */
131			clean = hieralloc_strndup_append(clean, shader, newline - shader + 1);
132			shader = newline + 1;
133			/* Output extra newlines to make line numbers match */
134			for (; extra_newlines > 0; extra_newlines--)
135				clean = hieralloc_strdup_append(clean, "\n");
136			in_continued_line = 0;
137		}
138		search_start = newline + 1;
139	}
140	clean = hieralloc_strdup_append(clean, shader);
141	return clean;
142}
143
144int
145preprocess(void *hieralloc_ctx, const char **shader, char **info_log,
146	   const struct gl_extensions *extensions, int api)
147{
148	int errors;
149	glcpp_parser_t *parser = glcpp_parser_create (extensions, api);
150	*shader = remove_line_continuations(parser, *shader);
151
152	glcpp_lex_set_source_string (parser, *shader);
153
154	glcpp_parser_parse (parser);
155
156	if (parser->skip_stack)
157		glcpp_error (&parser->skip_stack->loc, parser, "Unterminated #if\n");
158
159	*info_log = hieralloc_strdup_append(*info_log, parser->info_log);
160
161	hieralloc_steal(hieralloc_ctx, parser->output);
162	*shader = parser->output;
163
164	errors = parser->error;
165	glcpp_parser_destroy (parser);
166	return errors;
167}
168