glsl: move mode_string() to helper

This will be used from multiple files in the following patches.

Reviewed-by: Alejandro Piñeiro <apinheiro@igalia.com>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/28690>

src/compiler/glsl/gl_nir_link_interface_blocks.c

@@ -100,47 +100,6 @@ interstage_member_mismatch(struct gl_shader_program *prog,
    return false;
 }
 
-/**
- * Generate a string describing the mode of a variable
- */
-static const char *
-mode_string(const nir_variable *var)
-{
-   switch (var->data.mode) {
-   case nir_var_shader_temp:
-      return (var->data.read_only) ? "global constant" : "global variable";
-
-   case nir_var_uniform:
-   case nir_var_image:
-   case nir_var_mem_ubo:
-      return "uniform";
-
-   case nir_var_mem_ssbo:
-      return "buffer";
-
-   case nir_var_shader_in:
-      return "shader input";
-
-   case nir_var_shader_out:
-      return "shader output";
-
-   case nir_var_system_value:
-      return "shader input";
-
-   case nir_var_function_temp:
-      return "local variable";
-
-   case nir_var_mem_shared:
-      return "shader shared";
-
-   case nir_num_variable_modes:
-      break;
-   }
-
-   assert(!"Should not get here.");
-   return "invalid variable";
-}
-
 static bool
 is_interface_instance(nir_variable *var)
 {
@@ -173,7 +132,7 @@ validate_intrastage_arrays(struct gl_shader_program *prog,
                linker_error(prog, "%s `%s' declared as type "
                            "`%s' but outermost dimension has an index"
                            " of `%i'\n",
-                           mode_string(var),
+                           gl_nir_mode_string(var),
                            var->name, glsl_get_type_name(var->type),
                            existing->data.max_array_access);
             }
@@ -188,7 +147,7 @@ validate_intrastage_arrays(struct gl_shader_program *prog,
                linker_error(prog, "%s `%s' declared as type "
                            "`%s' but outermost dimension has an index"
                            " of `%i'\n",
-                           mode_string(var),
+                           gl_nir_mode_string(var),
                            var->name, glsl_get_type_name(existing->type),
                            var->data.max_array_access);
             }

src/compiler/glsl/gl_nir_linker.c

@@ -261,6 +261,47 @@ validate_geometry_shader_emissions(const struct gl_constants *consts,
    }
 }
 
+/**
+ * Generate a string describing the mode of a variable
+ */
+const char *
+gl_nir_mode_string(const nir_variable *var)
+{
+   switch (var->data.mode) {
+   case nir_var_shader_temp:
+      return (var->data.read_only) ? "global constant" : "global variable";
+
+   case nir_var_uniform:
+   case nir_var_image:
+   case nir_var_mem_ubo:
+      return "uniform";
+
+   case nir_var_mem_ssbo:
+      return "buffer";
+
+   case nir_var_shader_in:
+      return "shader input";
+
+   case nir_var_shader_out:
+      return "shader output";
+
+   case nir_var_system_value:
+      return "shader input";
+
+   case nir_var_function_temp:
+      return "local variable";
+
+   case nir_var_mem_shared:
+      return "shader shared";
+
+   case nir_num_variable_modes:
+      break;
+   }
+
+   assert(!"Should not get here.");
+   return "invalid variable";
+}
+
 bool
 gl_nir_can_add_pointsize_to_program(const struct gl_constants *consts,
                                     struct gl_program *prog)

src/compiler/glsl/gl_nir_linker.h

@@ -76,6 +76,8 @@ bool gl_nir_link_varyings(const struct gl_constants *consts,
                           const struct gl_extensions *exts,
                           gl_api api, struct gl_shader_program *prog);
 
+const char * gl_nir_mode_string(const nir_variable *var);
+
 struct nir_xfb_info *
 gl_to_nir_xfb_info(struct gl_transform_feedback_info *info, void *mem_ctx);