glsl: Make it possible to ignore built-ins when matching signatures.

Historically, we've implemented the rules for overriding built-in
functions by creating multiple ir_functions and relying on the symbol
table to hide the one containing built-in functions.  That works, but
has a few drawbacks, so the next patch will change it.

Instead, we'll have a single ir_function for a particular name, which
will contain both built-in and user-defined signatures.  Passing an
extra parameter to matching_signature makes it easy to ignore built-ins
when they're supposed to be hidden.

I didn't add the parameter to exact_matching_signature since it wasn't
necessary.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/src/glsl/ir_reader.cpp b/src/glsl/ir_reader.cpp
index e3566e1..ae00e79 100644
--- a/src/glsl/ir_reader.cpp
+++ b/src/glsl/ir_reader.cpp
@@ -677,7 +677,8 @@ ir_reader::read_call(s_expression *expr)
       return NULL;
    }
 
-   ir_function_signature *callee = f->matching_signature(state, &parameters);
+   ir_function_signature *callee =
+      f->matching_signature(state, &parameters, true);
    if (callee == NULL) {
       ir_read_error(expr, "couldn't find matching signature for function "
                     "%s", name->value());