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glcpp: Support line continuations within preprocessor directives.

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Fixes CorrectPreprocess5.frag.
This commit is contained in:
Kenneth Graunke 2010-06-23 12:31:09 -07:00 • committed by Ian Romanick
parent 186e2634bf
commit bc1097d151
1 changed files with 79 additions and 0 deletions
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79
glcpp/pp.c
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@ -21,6 +21,8 @@
* DEALINGS IN THE SOFTWARE.
*/
#include <assert.h>
#include <ctype.h>
#include "glcpp.h"
void
@ -56,11 +58,88 @@ glcpp_warning (YYLTYPE *locp, glcpp_parser_t *parser, const char *fmt, ...)
parser->info_log = talloc_strdup_append(parser->info_log, "\n");
}
/* Searches backwards for '^ *#' from a given starting point. */
static int
in_directive(const char *shader, const char *ptr)
{
assert(ptr >= shader);
/* Search backwards for '#'. If we find a \n first, it doesn't count */
for (; ptr >= shader && *ptr != '#'; ptr--) {
if (*ptr == '\n')
return 0;
}
if (ptr >= shader) {
/* Found '#'...look for spaces preceded by a newline */
for (ptr--; ptr >= shader && isblank(*ptr); ptr--);
// FIXME: I don't think the '\n' case can happen
if (ptr < shader || *ptr == '\n')
return 1;
}
return 0;
}
/* Remove any line continuation characters in preprocessing directives.
* However, ignore any in GLSL code, as "There is no line continuation
* character" (1.30 page 9) in GLSL.
*/
static char *
remove_line_continuations(glcpp_parser_t *ctx, const char *shader)
{
int in_continued_line = 0;
int extra_newlines = 0;
char *clean = talloc_strdup(ctx, "");
const char *search_start = shader;
const char *newline;
while ((newline = strchr(search_start, '\n')) != NULL) {
const char *backslash = NULL;
/* Find the preceding '\', if it exists */
if (newline[-1] == '\\') {
backslash = newline - 1;
} else if (newline[-1] == '\r' && newline[-2] == '\\') {
backslash = newline - 2;
}
/* Double backslashes don't count (the backslash is escaped) */
if (backslash != NULL && backslash[-1] == '\\') {
backslash = NULL;
}
if (backslash != NULL) {
/* We found a line continuation, but do we care? */
if (!in_continued_line) {
if (in_directive(shader, backslash)) {
in_continued_line = 1;
extra_newlines = 0;
}
}
if (in_continued_line) {
/* Copy everything before the \ */
clean = talloc_strndup_append(clean, shader, backslash - shader);
shader = newline + 1;
extra_newlines++;
}
} else if (in_continued_line) {
/* Copy everything up to and including the \n */
clean = talloc_strndup_append(clean, shader, newline - shader + 1);
shader = newline + 1;
/* Output extra newlines to make line numbers match */
for (; extra_newlines > 0; extra_newlines--)
clean = talloc_strdup_append(clean, "\n");
in_continued_line = 0;
}
search_start = newline + 1;
}
clean = talloc_strdup_append(clean, shader);
return clean;
}
extern int
preprocess(void *talloc_ctx, const char **shader, char **info_log)
{
int errors;
glcpp_parser_t *parser = glcpp_parser_create ();
*shader = remove_line_continuations(parser, *shader);
glcpp_lex_set_source_string (parser, *shader);
glcpp_parser_parse (parser);