[PATCH vkd3d 5/5] vkd3d-shader: Implement the "defined" keyword.

[Zebediah Figura]

Signed-off-by: Zebediah Figura 
---
 libs/vkd3d-shader/preproc.h |  1 +
 libs/vkd3d-shader/preproc.l | 16 ++++++++++++++++
 libs/vkd3d-shader/preproc.y | 15 +++++++++++++++
 3 files changed, 32 insertions(+)

diff --git a/libs/vkd3d-shader/preproc.h b/libs/vkd3d-shader/preproc.h
index 0f2d8ba9..eff70f69 100644
--- a/libs/vkd3d-shader/preproc.h
+++ b/libs/vkd3d-shader/preproc.h
@@ -125,6 +125,7 @@ struct preproc_ctx

bool last_was_newline;
     bool last_was_eof;
+    bool last_was_defined;

bool error;
 };
diff --git a/libs/vkd3d-shader/preproc.l b/libs/vkd3d-shader/preproc.l
index a2c1e26e..95b043ed 100644
--- a/libs/vkd3d-shader/preproc.l
+++ b/libs/vkd3d-shader/preproc.l
@@ -73,6 +73,8 @@ IDENTIFIER      [A-Za-z_][A-Za-z0-9_]*

<ERROR>(\{NEWLINE}|[^\n])*         {return T_STRING;}

+<INITIAL>defined/(                 {return T_DEFINED;}
+<INITIAL>defined                    {return T_DEFINED;}
 <INITIAL>{IDENTIFIER}/(            {return T_IDENTIFIER_PAREN;}
 <INITIAL>{IDENTIFIER}               {return T_IDENTIFIER;}

@@ -377,6 +379,9 @@ int yylex(YYSTYPE *lval, YYLTYPE *lloc, yyscan_t scanner)
             ctx->last_was_newline = (token == T_NEWLINE);
         }

+        if (ctx->current_directive && token == T_DEFINED)
+            ctx->last_was_defined = true;
+
         func_state = ctx->current_directive ? &ctx->directive_func : &ctx->text_func;

TRACE("Parsing token %d%s, line %d, in directive %d, state %#x, string %s.\n",
@@ -471,6 +476,17 @@ int yylex(YYSTYPE *lval, YYLTYPE *lloc, yyscan_t scanner)
                         case T_UNDEF:
                             /* Return identifiers verbatim. */
                             return return_token(token, lval, text);
+
+                        case T_IF:
+                        case T_ELIF:
+                            /* Return identifiers verbatim only if they're the
+                             * argument to "defined". */
+                            if (ctx->last_was_defined)
+                            {
+                                ctx->last_was_defined = false;
+                                return return_token(token, lval, text);
+                            }
+                            break;
                     }

/* Otherwise, expand a macro if there is one. */
diff --git a/libs/vkd3d-shader/preproc.y b/libs/vkd3d-shader/preproc.y
index 9f650549..f9047c9f 100644
--- a/libs/vkd3d-shader/preproc.y
+++ b/libs/vkd3d-shader/preproc.y
@@ -331,6 +331,7 @@ static void free_parse_arg_names(struct parse_arg_names *args)
 %token T_UNDEF "#undef"

%token T_CONCAT "##"
+%token T_DEFINED "defined"

%type <integer> expr
 %type <string> body_token
@@ -429,6 +430,10 @@ body_token_const
         {
             $$ = "##";
         }
+    | T_DEFINED
+        {
+            $$ = "defined";
+        }

directive
     : T_DEFINE T_IDENTIFIER body_text T_NEWLINE
@@ -583,3 +588,13 @@ expr
             $$ = preproc_parse_integer($1);
             vkd3d_free($1);
         }
+    | T_DEFINED T_IDENTIFIER
+        {
+            $$ = !!preproc_find_macro(ctx, $2);
+            vkd3d_free($2);
+        }
+    | T_DEFINED '(' T_IDENTIFIER ')'
+        {
+            $$ = !!preproc_find_macro(ctx, $3);
+            vkd3d_free($3);
+        }