[Mesa-dev] [PATCH 3/5] glcpp: Allow arithmetic integer expressions in #line
Ian Romanick
idr at freedesktop.org
Tue Jun 9 10:15:00 PDT 2015
On 03/11/2015 02:01 AM, Eduardo Lima Mitev wrote:
> From: Antia Puentes <apuentes at igalia.com>
>
> From section 3.4 ("Preprocessor") of the GLSL ES 3.00 specification:
> "#line must have, after macro substitution, one of the following forms:
> #line line
> #line line source-string-number
> where line and source-string-number are constant integral expressions."
>
> From section 4.3.3 ("Constant Expressions") of the same specification:
> "A constant integral expression is a constant expression that evaluates
> to a scalar signed or unsigned integer."
FFS. I can't believe they have a test for this. For what it's worth,
this makes the grammar non-LALR. Not too long ago it came up for a vote
to remove this since it does not work on *ANY* desktop OpenGL
implementation. While there was a majority vote to remove it, it was
not a large enough majority (by a single vote). It is also a deviation
from C / C++ preprocessors.
Carl spent some time on this, and he couldn't find a way to make it work
without adding significant bison warnings or have it fail for some cases.
Does this patch work for:
#line 3 +3
#line 3 (+3)
#line 3 +3 3
#line 3 +3 (+3)
#line 3 +3 3 +3
It seems like there were a couple other cases, but I can't remember what
they were. Perhaps Carl remembers.
> Fixes 4 dEQP tests:
> * dEQP-GLES3.functional.shaders.preprocessor.builtin.line_expression_vertex
> * dEQP-GLES3.functional.shaders.preprocessor.builtin.line_expression_fragment
> * dEQP-GLES3.functional.shaders.preprocessor.builtin.line_and_file_expression_vertex
> * dEQP-GLES3.functional.shaders.preprocessor.builtin.line_and_file_expression_fragment
> ---
> src/glsl/glcpp/glcpp-parse.y | 91 ++++++++++++++++++++++++++++++++++++++------
> 1 file changed, 80 insertions(+), 11 deletions(-)
>
> diff --git a/src/glsl/glcpp/glcpp-parse.y b/src/glsl/glcpp/glcpp-parse.y
> index c2f5223..0e96f53 100644
> --- a/src/glsl/glcpp/glcpp-parse.y
> +++ b/src/glsl/glcpp/glcpp-parse.y
> @@ -180,7 +180,7 @@ add_builtin_define(glcpp_parser_t *parser, const char *name, int value);
> * (such as the <HASH> and <DEFINE> start conditions in the lexer). */
> %token DEFINED ELIF_EXPANDED HASH_TOKEN DEFINE_TOKEN FUNC_IDENTIFIER OBJ_IDENTIFIER ELIF ELSE ENDIF ERROR_TOKEN IF IFDEF IFNDEF LINE PRAGMA UNDEF VERSION_TOKEN GARBAGE IDENTIFIER IF_EXPANDED INTEGER INTEGER_STRING LINE_EXPANDED NEWLINE OTHER PLACEHOLDER SPACE PLUS_PLUS MINUS_MINUS
> %token PASTE
> -%type <ival> INTEGER operator SPACE integer_constant
> +%type <ival> INTEGER operator SPACE integer_constant constant_integral_expression
> %type <expression_value> expression
> %type <str> IDENTIFIER FUNC_IDENTIFIER OBJ_IDENTIFIER INTEGER_STRING OTHER ERROR_TOKEN PRAGMA
> %type <string_list> identifier_list
> @@ -229,7 +229,7 @@ expanded_line:
> glcpp_error(& @1, parser, "undefined macro %s in expression (illegal in GLES)", $2.undefined_macro);
> _glcpp_parser_skip_stack_change_if (parser, & @1, "elif", $2.value);
> }
> -| LINE_EXPANDED integer_constant NEWLINE {
> +| LINE_EXPANDED constant_integral_expression NEWLINE {
> parser->has_new_line_number = 1;
> parser->new_line_number = $2;
> ralloc_asprintf_rewrite_tail (&parser->output,
> @@ -237,15 +237,53 @@ expanded_line:
> "#line %" PRIiMAX "\n",
> $2);
> }
> -| LINE_EXPANDED integer_constant integer_constant NEWLINE {
> +| LINE_EXPANDED constant_integral_expression SPACE constant_integral_expression NEWLINE {
> parser->has_new_line_number = 1;
> parser->new_line_number = $2;
> parser->has_new_source_number = 1;
> - parser->new_source_number = $3;
> + parser->new_source_number = $4;
> ralloc_asprintf_rewrite_tail (&parser->output,
> &parser->output_length,
> "#line %" PRIiMAX " %" PRIiMAX "\n",
> - $2, $3);
> + $2, $4);
> + }
> +;
> +
> +constant_integral_expression:
> + integer_constant {
> + $$ = $1;
> + }
> +| constant_integral_expression '+' constant_integral_expression {
> + $$ = $1 + $3;
> + }
> +| constant_integral_expression '-' constant_integral_expression {
> + $$ = $1 - $3;
> + }
> +| constant_integral_expression '*' constant_integral_expression {
> + $$ = $1 * $3;
> + }
> +| constant_integral_expression '/' constant_integral_expression {
> + if ($3 == 0)
> + yyerror (&@1, parser,
> + "division by 0 in preprocessor directive");
> + else
> + $$ = $1 / $3;
> + }
> +| constant_integral_expression '%' constant_integral_expression {
> + if ($3 == 0)
> + yyerror (&@1, parser,
> + "zero modulus in preprocessor directive");
> + else
> + $$ = $1 % $3;
> + }
> +| '+' constant_integral_expression %prec UNARY {
> + $$ = $2;
> + }
> +| '-' constant_integral_expression %prec UNARY {
> + $$ = -$2;
> + }
> +| '(' constant_integral_expression ')' {
> + $$ = $2;
> }
> ;
>
> @@ -2275,14 +2313,45 @@ glcpp_parser_lex_from (glcpp_parser_t *parser, token_list_t *list)
> assert (parser->lex_from_list == NULL);
>
> /* Copy list, eliminating any space tokens. */
> - parser->lex_from_list = _token_list_create (parser);
>
> - for (node = list->head; node; node = node->next) {
> - if (node->token->type == SPACE)
> - continue;
> - _token_list_append (parser->lex_from_list, node->token);
> - }
> + parser->lex_from_list = _token_list_create (parser);
>
> + /* If the list comes from a LINE_EXPANDED, do not remove the
> + * SPACE tokens that act as parameter separator, i.e., SPACE tokens
> + * inside parentheses will be removed, consecutive SPACE tokens
> + * outside parentheses will be reduced to one.
> + */
> + if (list->head->token->type == LINE_EXPANDED) {
> + int bracket_num = 0;
> + bool separator = false;
> +
> + _token_list_append (parser->lex_from_list, list->head->token);
> +
> + for (node = list->head->next; node; node = node->next) {
> + token_t *token = node->token;
> +
> + if (token->type == '(')
> + bracket_num++;
> + if (token->type == ')')
> + bracket_num--;
> +
> + if (token->type == SPACE) {
> + if (bracket_num > 0 || separator)
> + continue;
> + separator = true;
> + } else {
> + separator = false;
> + }
> +
> + _token_list_append (parser->lex_from_list, token);
> + }
> + } else {
> + for (node = list->head; node; node = node->next) {
> + if (node->token->type == SPACE)
> + continue;
> + _token_list_append (parser->lex_from_list, node->token);
> + }
> + }
> ralloc_free (list);
>
> parser->lex_from_node = parser->lex_from_list->head;
>
More information about the mesa-dev
mailing list