glsl: add ast/parser support for subroutine parsing storage (v3.2)

This is the guts of the GLSL parser and AST support for
shader subroutines.

The code creates a subroutine type in the parser, and
uses that there to validate the identifiers. The parser
also distinguishes between subroutine types/function prototypes
/uniforms and subroutine defintions for functions.

Then in the AST conversion it recreates the types, and
stores the subroutine definition info or subroutine info
into the ir_function along with a side lookup table in
the parser state. It also converts subroutine calls into
the enhanced ir_call.

v2: move to handling method calls in
function handling not in field selection.
v3: merge Chris's previous parser patches in here, to
make it clearer what's changed in one place.
v3.1: add more documentation, drop unused include
v3.2: drop is_subroutine_def

Reviewed-by: Chris Forbes <[email protected]>
Signed-off-by: Dave Airlie <[email protected]>

1 files changed, 8 insertions, 0 deletions

diff --git a/src/glsl/glsl_lexer.ll b/src/glsl/glsl_lexer.ll
index 1cd1ffb98c6..efa0bb68099 100644
--- a/src/glsl/glsl_lexer.ll
+++ b/src/glsl/glsl_lexer.ll
@@ -595,6 +595,10 @@ subroutine	KEYWORD_WITH_ALT(400, 300, 400, 0, yyextra->ARB_shader_subroutine_ena
 			    return classify_identifier(state, yytext);
 			}
 
+\.			{ struct _mesa_glsl_parse_state *state = yyextra;
+			  state->is_field = true;
+			  return DOT_TOK; }
+
 .			{ return yytext[0]; }
 
 %%
@@ -602,6 +606,10 @@ subroutine	KEYWORD_WITH_ALT(400, 300, 400, 0, yyextra->ARB_shader_subroutine_ena
 int
 classify_identifier(struct _mesa_glsl_parse_state *state, const char *name)
 {
+   if (state->is_field) {
+      state->is_field = false;
+      return FIELD_SELECTION;
+   }
    if (state->symbols->get_variable(name) || state->symbols->get_function(name))
       return IDENTIFIER;
    else if (state->symbols->get_type(name))