[PATCH vkd3d 3/5] vkd3d-shader: Implement multiplication and division.

[Zebediah Figura (she/her)]

On 1/19/21 4:24 AM, Matteo Bruni wrote:
> On Mon, Jan 18, 2021 at 10:34 PM Zebediah Figura
> <zfigura at codeweavers.com> wrote:
>>
>> Signed-off-by: Zebediah Figura <zfigura at codeweavers.com>
>> ---
>>  libs/vkd3d-shader/preproc.l |  2 +-
>>  libs/vkd3d-shader/preproc.y | 24 ++++++++++++++++++++++--
>>  2 files changed, 23 insertions(+), 3 deletions(-)
>>
>> diff --git a/libs/vkd3d-shader/preproc.l b/libs/vkd3d-shader/preproc.l
>> index 011f8dbb..a522b7c8 100644
>> --- a/libs/vkd3d-shader/preproc.l
>> +++ b/libs/vkd3d-shader/preproc.l
>> @@ -157,7 +157,7 @@ IDENTIFIER      [A-Za-z_][A-Za-z0-9_]*
>>      }
>>
>>  <INITIAL>{WS}+                      {}
>> -<INITIAL>[-()\[\]{},+!]             {return yytext[0];}
>> +<INITIAL>[-()\[\]{},+!*/]           {return yytext[0];}
>>  <INITIAL>.                          {return T_TEXT;}
>>
>>  %%
>> diff --git a/libs/vkd3d-shader/preproc.y b/libs/vkd3d-shader/preproc.y
>> index 51df5d40..1060e9d7 100644
>> --- a/libs/vkd3d-shader/preproc.y
>> +++ b/libs/vkd3d-shader/preproc.y
>> @@ -335,6 +335,7 @@ static void free_parse_arg_names(struct parse_arg_names *args)
>>
>>  %type <integer> primary_expr
>>  %type <integer> unary_expr
>> +%type <integer> mul_expr
>>  %type <string> body_token
>>  %type <const_string> body_token_const
>>  %type <string_buffer> body_text
>> @@ -439,6 +440,14 @@ body_token_const
>>          {
>>              $$ = "!";
>>          }
>> +    | '*'
>> +        {
>> +            $$ = "*";
>> +        }
>> +    | '/'
>> +        {
>> +            $$ = "/";
>> +        }
>>      | T_CONCAT
>>          {
>>              $$ = "##";
>> @@ -480,7 +489,7 @@ directive
>>              }
>>              vkd3d_free($2);
>>          }
>> -    | T_IF unary_expr T_NEWLINE
>> +    | T_IF mul_expr T_NEWLINE
>>          {
>>              if (!preproc_push_if(ctx, !!$2))
>>                  YYABORT;
>> @@ -495,7 +504,7 @@ directive
>>              preproc_push_if(ctx, !preproc_find_macro(ctx, $2));
>>              vkd3d_free($2);
>>          }
>> -    | T_ELIF unary_expr T_NEWLINE
>> +    | T_ELIF mul_expr T_NEWLINE
>>          {
>>              const struct preproc_file *file = preproc_get_top_file(ctx);
>>
>> @@ -631,3 +640,14 @@ unary_expr
>>          {
>>              $$ = !$2;
>>          }
>> +
>> +mul_expr
>> +    : unary_expr
>> +    | mul_expr '*' unary_expr
>> +        {
>> +            $$ = $1 * $3;
>> +        }
>> +    | mul_expr '/' unary_expr
>> +        {
>> +            $$ = $1 / $3;
>> +        }
> 
> I don't know that we care but notice that e.g. "#if 1 / 0" causes a
> floating point exception.
> 

Yes, that probably shouldn't be allowed to crash the preprocessor,
thanks for catching that.