Mesa (10.1): glsl: Compile error if fs defines conflicting qualifiers for gl_FragCoord
Carl Worth
cworth at kemper.freedesktop.org
Fri May 2 00:06:08 UTC 2014
Module: Mesa
Branch: 10.1
Commit: 619fff1342168538a021048a48cf6f62b13b9fb0
URL: http://cgit.freedesktop.org/mesa/mesa/commit/?id=619fff1342168538a021048a48cf6f62b13b9fb0
Author: Anuj Phogat <anuj.phogat at gmail.com>
Date: Tue Feb 4 10:38:18 2014 -0800
glsl: Compile error if fs defines conflicting qualifiers for gl_FragCoord
GLSL 1.50 spec says:
"If gl_FragCoord is redeclared in any fragment shader in a program,
it must be redeclared in all the fragment shaders in that
program that have a static use gl_FragCoord. All redeclarations of
gl_FragCoord in all fragment shaders in a single program must
have the same set of qualifiers."
This patch makes the glsl compiler to generate an error if we have a
fragment shader defined with conflicting layout qualifier declarations
for gl_FragCoord. For example:
layout(origin_upper_left, pixel_center_integer) in vec4 gl_FragCoord;
layout(pixel_center_integer) in vec4 gl_FragCoord;
void main()
{
}
V2: Some code refactoring for better readability.
Add compiler error conditions for redeclarations like:
layout(origin_upper_left) in vec4 gl_FragCoord;
layout(origin_upper_left, pixel_center_integer) in vec4 gl_FragCoord;
and
in vec4 gl_FragCoord;
layout(origin_upper_left, pixel_center_integer) in vec4 gl_FragCoord;
V3: Simplify function is_conflicting_fragcoord_redeclaration()
V4: Check for null pointer before doing strcmp(var->name, "gl_FragCoord").
Signed-off-by: Anuj Phogat <anuj.phogat at gmail.com>
Cc: <mesa-stable at lists.freedesktop.org>
Reviewed-by: Ian Romanick <ian.d.romanick at intel.com>
(cherry picked from commit 581e4acb0d68eb1063df3919e19e0ef9d86eebff)
---
src/glsl/ast_to_hir.cpp | 58 +++++++++++++++++++++++++++++++++++++++++
src/glsl/glsl_parser_extras.h | 12 +++++++++
2 files changed, 70 insertions(+)
diff --git a/src/glsl/ast_to_hir.cpp b/src/glsl/ast_to_hir.cpp
index 3a9c124..c04b6ae 100644
--- a/src/glsl/ast_to_hir.cpp
+++ b/src/glsl/ast_to_hir.cpp
@@ -2203,6 +2203,34 @@ validate_explicit_location(const struct ast_type_qualifier *qual,
return;
}
+static inline const char*
+get_layout_qualifier_string(bool origin_upper_left, bool pixel_center_integer)
+{
+ if (origin_upper_left && pixel_center_integer)
+ return "origin_upper_left, pixel_center_integer";
+ else if (origin_upper_left)
+ return "origin_upper_left";
+ else if (pixel_center_integer)
+ return "pixel_center_integer";
+ else
+ return " ";
+}
+
+static inline bool
+is_conflicting_fragcoord_redeclaration(struct _mesa_glsl_parse_state *state,
+ const struct ast_type_qualifier *qual)
+{
+ /* If gl_FragCoord was previously declared, and the qualifiers were
+ * different in any way, return true.
+ */
+ if (state->fs_redeclares_gl_fragcoord) {
+ return (state->fs_pixel_center_integer != qual->flags.q.pixel_center_integer
+ || state->fs_origin_upper_left != qual->flags.q.origin_upper_left);
+ }
+
+ return false;
+}
+
static void
apply_type_qualifier_to_variable(const struct ast_type_qualifier *qual,
ir_variable *var,
@@ -2357,6 +2385,36 @@ apply_type_qualifier_to_variable(const struct ast_type_qualifier *qual,
qual_string);
}
+ if (var->name != NULL && strcmp(var->name, "gl_FragCoord") == 0) {
+
+ /* Make sure all gl_FragCoord redeclarations specify the same layout
+ * qualifiers.
+ */
+ if (is_conflicting_fragcoord_redeclaration(state, qual)) {
+ const char *const qual_string =
+ get_layout_qualifier_string(qual->flags.q.origin_upper_left,
+ qual->flags.q.pixel_center_integer);
+
+ const char *const state_string =
+ get_layout_qualifier_string(state->fs_origin_upper_left,
+ state->fs_pixel_center_integer);
+
+ _mesa_glsl_error(loc, state,
+ "gl_FragCoord redeclared with different layout "
+ "qualifiers (%s) and (%s) ",
+ state_string,
+ qual_string);
+ }
+ state->fs_origin_upper_left = qual->flags.q.origin_upper_left;
+ state->fs_pixel_center_integer = qual->flags.q.pixel_center_integer;
+ state->fs_redeclares_gl_fragcoord_with_no_layout_qualifiers =
+ !qual->flags.q.origin_upper_left && !qual->flags.q.pixel_center_integer;
+ state->fs_redeclares_gl_fragcoord =
+ state->fs_origin_upper_left ||
+ state->fs_pixel_center_integer ||
+ state->fs_redeclares_gl_fragcoord_with_no_layout_qualifiers;
+ }
+
if (qual->flags.q.explicit_location) {
validate_explicit_location(qual, var, state, loc);
} else if (qual->flags.q.explicit_index) {
diff --git a/src/glsl/glsl_parser_extras.h b/src/glsl/glsl_parser_extras.h
index 8a4cbf1..82a83a5 100644
--- a/src/glsl/glsl_parser_extras.h
+++ b/src/glsl/glsl_parser_extras.h
@@ -182,6 +182,18 @@ struct _mesa_glsl_parse_state {
struct ast_type_qualifier *default_uniform_qualifier;
/**
+ * Variables to track different cases if a fragment shader redeclares
+ * built-in variable gl_FragCoord.
+ *
+ * Note: These values are computed at ast_to_hir time rather than at parse
+ * time.
+ */
+ bool fs_redeclares_gl_fragcoord;
+ bool fs_origin_upper_left;
+ bool fs_pixel_center_integer;
+ bool fs_redeclares_gl_fragcoord_with_no_layout_qualifiers;
+
+ /**
* True if a geometry shader input primitive type was specified using a
* layout directive.
*
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