glsl: Eliminate ambiguity between function ins/outs and shader ins/outs

This patch replaces the three ir_variable_mode enums:

- ir_var_in
- ir_var_out
- ir_var_inout

with the following five:

- ir_var_shader_in
- ir_var_shader_out
- ir_var_function_in
- ir_var_function_out
- ir_var_function_inout

This eliminates a frustrating ambiguity: it used to be impossible to
tell whether an ir_var_{in,out} variable was a shader in/out or a
function in/out without seeing where the variable was declared in the
IR.  This complicated some optimization and lowering passes, and would
have become a problem for implementing varying structs.

In the lisp-style serialization of GLSL IR to strings performed by
ir_print_visitor.cpp and ir_reader.cpp, I've retained the names "in",
"out", and "inout" for function parameters, to avoid introducing code
churn to the src/glsl/builtins/ir/ directory.

Note: a couple of comments in the code seemed to indicate that we were
planning for a possible future in which geometry shaders could have
shader-scope inout variables.  Our GLSL grammar rejects shader-scope
inout variables, and I've been unable to find any evidence in the GLSL
standards documents (or extensions) that this will ever be allowed, so
I've eliminated these comments.

Reviewed-by: Carl Worth <[email protected]>
Reviewed-by: Jordan Justen <[email protected]>
Reviewed-by: Eric Anholt <[email protected]>

1 files changed, 6 insertions, 6 deletions

diff --git a/src/mesa/main/shader_query.cpp b/src/mesa/main/shader_query.cpp
index 27b1b8f5688..3014a97785d 100644
--- a/src/mesa/main/shader_query.cpp
+++ b/src/mesa/main/shader_query.cpp
@@ -106,7 +106,7 @@ _mesa_GetActiveAttrib(GLhandleARB program, GLuint desired_index,
       const ir_variable *const var = ((ir_instruction *) node)->as_variable();
 
       if (var == NULL
-	  || var->mode != ir_var_in
+	  || var->mode != ir_var_shader_in
 	  || var->location == -1)
 	 continue;
 
@@ -169,7 +169,7 @@ _mesa_GetAttribLocation(GLhandleARB program, const GLcharARB * name)
        *     attribute, or if an error occurs, -1 will be returned."
        */
       if (var == NULL
-	  || var->mode != ir_var_in
+	  || var->mode != ir_var_shader_in
 	  || var->location == -1
 	  || var->location < VERT_ATTRIB_GENERIC0)
 	 continue;
@@ -197,7 +197,7 @@ _mesa_count_active_attribs(struct gl_shader_program *shProg)
       const ir_variable *const var = ((ir_instruction *) node)->as_variable();
 
       if (var == NULL
-	  || var->mode != ir_var_in
+	  || var->mode != ir_var_shader_in
 	  || var->location == -1)
 	 continue;
 
@@ -223,7 +223,7 @@ _mesa_longest_attribute_name_length(struct gl_shader_program *shProg)
       const ir_variable *const var = ((ir_instruction *) node)->as_variable();
 
       if (var == NULL
-	  || var->mode != ir_var_in
+	  || var->mode != ir_var_shader_in
 	  || var->location == -1)
 	 continue;
 
@@ -333,7 +333,7 @@ _mesa_GetFragDataIndex(GLuint program, const GLchar *name)
        *     attribute, or if an error occurs, -1 will be returned."
        */
       if (var == NULL
-          || var->mode != ir_var_out
+          || var->mode != ir_var_shader_out
           || var->location == -1
           || var->location < FRAG_RESULT_DATA0)
          continue;
@@ -389,7 +389,7 @@ _mesa_GetFragDataLocation(GLuint program, const GLchar *name)
        *     attribute, or if an error occurs, -1 will be returned."
        */
       if (var == NULL
-	  || var->mode != ir_var_out
+	  || var->mode != ir_var_shader_out
 	  || var->location == -1
 	  || var->location < FRAG_RESULT_DATA0)
 	 continue;