[qfcc] Do basic error checking on layout qualifiers

I'm not sure I got all the checks right, but bsp_gbuf.geom passes the
validity (but failes due to not having implemented the application of
the qualifiers).

tools/qfcc/include/glsl-lang.h

@@ -31,6 +31,7 @@
 typedef struct specifier_s specifier_t;
 typedef struct attribute_s attribute_t;
 typedef struct expr_s expr_t;
+typedef struct ex_list_s ex_list_t;
 typedef struct type_s type_t;
 typedef struct symbol_s symbol_t;
 typedef struct symtab_s symtab_t;
@@ -91,11 +92,13 @@ void glsl_declare_block (specifier_t spec, symbol_t *block_sym,
 						 symbol_t *instance_name);
 glsl_block_t *glsl_get_block (const char *name, glsl_interface_t interface);
 symtab_t *glsl_optimize_attributes (attribute_t *attributes);
+void glsl_apply_attributes (symtab_t *attributes, specifier_t spec);
 
 void glsl_parse_declaration (specifier_t spec,
 							 symbol_t *sym, const type_t *array,
 							 const expr_t *init, symtab_t *symtab);
 void glsl_declare_field (specifier_t spec, symtab_t *symtab);
+void glsl_layout (const ex_list_t *qualifiers, specifier_t spec);
 
 bool glsl_on_include (const char *name);
 void glsl_include (int behavior, void *scanner);

tools/qfcc/source/Makemodule.am

@@ -46,6 +46,7 @@ qfcc_SOURCES = \
 	tools/qfcc/source/glsl-block.c \
 	tools/qfcc/source/glsl-builtins.c \
 	tools/qfcc/source/glsl-declaration.c \
+	tools/qfcc/source/glsl-layout.c \
 	tools/qfcc/source/glsl-parse.y \
 	tools/qfcc/source/glsl-sub_comp.c \
 	tools/qfcc/source/glsl-sub_frag.c \

tools/qfcc/source/glsl-attribute.c

@@ -42,126 +42,6 @@
 #include "tools/qfcc/include/type.h"
 #include "tools/qfcc/include/value.h"
 
-#if 0
-typedef struct layout_qual_s {
-	const char *name;
-	bool      (*valid) (symbol_t *sym, glsl_interface_t interface);
-	bool      (*apply) ();
-	bool      (*apply_expr) ();
-} layout_qual_t;
-
-// qual var block member iface
-static layout_qual_t layout_qualifiers[] = {
-	{"shared",				/* q _ b _ uniform/buffer */, ___, nullptr},
-	{"packed",				/* q _ b _ uniform/buffer */, ___, nullptr},
-	{"std140",				/* q _ b _ uniform/buffer */, ___, nullptr},
-	{"std430",				/* q _ b _ uniform/buffer */, ___, nullptr},
-	{"row_major",			/* q _ b m uniform/buffer */, ___, nullptr},
-	{"column_major",		/* q _ b m uniform/buffer */, ___, nullptr},
-
-	{"binding",				/* _ o b _ uniform/buffer */, nullptr, ___},
-	{"offset",				/* _ a _ m uniform/buffer */, nullptr, ___},
-	{"align",				/* _ o b _ uniform/buffer */, nullptr, ___},
-	{"set",					/* _ o b _ uniform/buffer */, nullptr, ___},
-	{"push_constant",		/* _ _ b _ uniform(vulkan) */, ___, nullptr},
-	{"input_attachment_index", /* _ s _ _ uniform(vulkan) */, nullptr, ___},
-	{"location",			/* _ v _ _ uniform/buffer/subroutine */, nullptr, ___},
-
-	{"location",			/* _ v b m all in/out except compute */, nullptr, ___},
-	{"component",			/* _ v _ m all in/out except compute */, nullptr, ___},
-
-	{"index",				/* _ v _ _ fragment out/subroutine */, nullptr, ___},
-
-	{"triangles",			/* q _ _ _ tese in */, ___, nullptr},
-	{"quads",				/* q _ _ _ tese in */, ___, nullptr},
-	{"isolines",			/* q _ _ _ tese in */, ___, nullptr},
-	{"equal_spacing",		/* q _ _ _ tese in */, ___, nullptr},
-	{"fractional_even_spacing", /* q _ _ _ tese in */, ___, nullptr},
-	{"fractional_odd_spacing", /* q _ _ _ tese in */, ___, nullptr},
-	{"cw",					/* q _ _ _ tese in */, ___, nullptr},
-	{"ccw",					/* q _ _ _ tese in */, ___, nullptr},
-	{"point_mode",			/* q _ _ _ tese in */, ___, nullptr},
-
-	{"points",				/* q _ _ _ geom in/out */, ___, nullptr},
-//? [ points ]				// q _ _ _ geom in
-	{"lines",				/* q _ _ _ geom in */, ___, nullptr},
-	{"lines_adjacency",		/* q _ _ _ geom in */, ___, nullptr},
-	{"triangles",			/* q _ _ _ geom in */, ___, nullptr},
-	{"triangles_adjacency",	/* q _ _ _ geom in */, ___, nullptr},
-	{"invocations",			/* q _ _ _ geom in */, nullptr, ___},
-
-	{"origin_upper_left",	/* _ f _ _ frag in */, ___, nullptr},
-	{"pixel_center_integer", /* _ f _ _ frag in */, ___, nullptr},
-	{"early_fragment_tests", /* q _ _ _ frag in */, ___, nullptr},
-
-	{"local_size_x",		/* q _ _ _ comp in */, nullptr, ___},
-	{"local_size_y",		/* q _ _ _ comp in */, nullptr, ___},
-	{"local_size_z",		/* q _ _ _ comp in */, nullptr, ___},
-	{"local_size_x_id",		/* q _ _ _ comp in */, nullptr, ___},
-	{"local_size_y_id",		/* q _ _ _ comp in */, nullptr, ___},
-	{"local_size_z_id",		/* q _ _ _ comp in */, nullptr, ___},
-
-	{"xfb_buffer",			/* q v b m vert/tess/geom out */, nullptr, ___},
-	{"xfb_stride",			/* q v b m vert/tess/geom out */, nullptr, ___},
-	{"xfb_offset",			/* _ v b m vert/tess/geom out */, nullptr, ___},
-
-	{"vertices",			/* q _ _ _ tesc out */, nullptr, ___},
-
-//? [ points ]				// q _ _ _ geom out
-	{"line_strip",			/* q _ _ _ geom out */, ___, nullptr},
-	{"triangle_strip",		/* q _ _ _ geom out */, ___, nullptr},
-	{"max_vertices",		/* q _ _ _ geom out */, nullptr, ___},
-	{"stream",				/* q v b m geom out */, nullptr, ___},
-
-	{"depth_any",			/* _ v _ _ frag out */, ___, nullptr},
-	{"depth_greater",		/* _ v _ _ frag out */, ___, nullptr},
-	{"depth_less",			/* _ v _ _ frag out */, ___, nullptr},
-	{"depth_unchanged",		/* _ v _ _ frag out */, ___, nullptr},
-
-	{"constant_id",			/* _ s _ _ const */, nullptr, ___},
-
-	{"rgba32f",				/* _ i _ _ uniform */, ___, nullptr},
-	{"rgba16f",				/* _ i _ _ uniform */, ___, nullptr},
-	{"rg32f",				/* _ i _ _ uniform */, ___, nullptr},
-	{"rg16f",				/* _ i _ _ uniform */, ___, nullptr},
-	{"r11f_g11f_b10f",		/* _ i _ _ uniform */, ___, nullptr},
-	{"r32f",				/* _ i _ _ uniform */, ___, nullptr},
-	{"r16f",				/* _ i _ _ uniform */, ___, nullptr},
-	{"rgba16",				/* _ i _ _ uniform */, ___, nullptr},
-	{"rgb10_a2",			/* _ i _ _ uniform */, ___, nullptr},
-	{"rgba8",				/* _ i _ _ uniform */, ___, nullptr},
-	{"rg16",				/* _ i _ _ uniform */, ___, nullptr},
-	{"rg8",					/* _ i _ _ uniform */, ___, nullptr},
-	{"r16",					/* _ i _ _ uniform */, ___, nullptr},
-	{"r8",					/* _ i _ _ uniform */, ___, nullptr},
-	{"rgba16_snorm",		/* _ i _ _ uniform */, ___, nullptr},
-	{"rgba8_snorm",			/* _ i _ _ uniform */, ___, nullptr},
-	{"rg16_snorm",			/* _ i _ _ uniform */, ___, nullptr},
-	{"rg8_snorm",			/* _ i _ _ uniform */, ___, nullptr},
-	{"r16_snorm",			/* _ i _ _ uniform */, ___, nullptr},
-	{"r8_snorm",			/* _ i _ _ uniform */, ___, nullptr},
-	{"rgba32i",				/* _ i _ _ uniform */, ___, nullptr},
-	{"rgba16i",				/* _ i _ _ uniform */, ___, nullptr},
-	{"rgba8i",				/* _ i _ _ uniform */, ___, nullptr},
-	{"rg32i",				/* _ i _ _ uniform */, ___, nullptr},
-	{"rg16i",				/* _ i _ _ uniform */, ___, nullptr},
-	{"rg8i",				/* _ i _ _ uniform */, ___, nullptr},
-	{"r32i",				/* _ i _ _ uniform */, ___, nullptr},
-	{"r16i",				/* _ i _ _ uniform */, ___, nullptr},
-	{"r8i",					/* _ i _ _ uniform */, ___, nullptr},
-	{"rgba32ui",			/* _ i _ _ uniform */, ___, nullptr},
-	{"rgba16ui",			/* _ i _ _ uniform */, ___, nullptr},
-	{"rgb10_a2ui",			/* _ i _ _ uniform */, ___, nullptr},
-	{"rgba8ui",				/* _ i _ _ uniform */, ___, nullptr},
-	{"rg32ui",				/* _ i _ _ uniform */, ___, nullptr},
-	{"rg16ui",				/* _ i _ _ uniform */, ___, nullptr},
-	{"rg8ui",				/* _ i _ _ uniform */, ___, nullptr},
-	{"r32ui",				/* _ i _ _ uniform */, ___, nullptr},
-	{"r16ui",				/* _ i _ _ uniform */, ___, nullptr},
-	{"r8ui",				/* _ i _ _ uniform */, ___, nullptr},
-};
-#endif
-
 const char *glsl_interface_names[glsl_num_interfaces] = {
 	"in",
 	"out",
@@ -197,6 +77,7 @@ glsl_optimize_attributes (attribute_t *attributes)
 			}
 			symtab_addsymbol (attrtab, attrsym);
 		}
+#if 0
 		notice (0, "%s", attr->name);
 		if (!attr->params) continue;
 		for (auto p = attr->params->list.head; p; p = p->next) {
@@ -208,6 +89,20 @@ glsl_optimize_attributes (attribute_t *attributes)
 				notice (0, "    %s", get_value_string (p->expr->value));
 			}
 		}
+#endif
 	}
 	return attrtab;
 }
+
+void
+glsl_apply_attributes (symtab_t *attributes, specifier_t spec)
+{
+	for (auto attr = attributes->symbols; attr; attr = attr->next) {
+		if (strcmp (attr->name, "layout") == 0) {
+			if (attr->sy_type != sy_list) {
+				internal_error (0, "bogus layout qualifier");
+			}
+			glsl_layout (&attr->list, spec);
+		}
+	}
+}

tools/qfcc/source/glsl-declaration.c

@@ -49,7 +49,7 @@ glsl_parse_declaration (specifier_t spec, symbol_t *sym, const type_t *array,
 		spec.type = append_type (array, spec.type);
 		spec.type = find_type (spec.type);
 	}
-	/*auto attributes =*/ glsl_optimize_attributes (spec.attributes);
+	auto attributes = glsl_optimize_attributes (spec.attributes);
 	if (sym && sym->sy_type == sy_expr) {
 		auto id_list = sym->expr;
 		if (id_list->type != ex_list) {
@@ -60,19 +60,22 @@ glsl_parse_declaration (specifier_t spec, symbol_t *sym, const type_t *array,
 				internal_error (id_list, "not a symbol");
 			}
 			spec.sym = id->expr->symbol;
-			declare_symbol (spec, init, symtab);
+			spec.sym = declare_symbol (spec, init, symtab);
+			glsl_apply_attributes (attributes, spec);
 		}
 	} else {
 		spec.sym = sym;
 		if (spec.sym) {
-			declare_symbol (spec, init, symtab);
+			spec.sym = declare_symbol (spec, init, symtab);
 		}
+		glsl_apply_attributes (attributes, spec);
 	}
 }
 
 void
 glsl_declare_field (specifier_t spec, symtab_t *symtab)
 {
-	/*auto attributes =*/ glsl_optimize_attributes (spec.attributes);
+	auto attributes = glsl_optimize_attributes (spec.attributes);
-	declare_field (spec, symtab);
+	spec.sym = declare_field (spec, symtab);
+	glsl_apply_attributes (attributes, spec);
 }

tools/qfcc/source/glsl-layout.c

@@ -0,0 +1,814 @@
+/*
+	glsl-layout.c
+
+	GLSL layout attribute handling
+
+	Copyright (C) 2024 Bill Currie <bill@taniwha.org>
+
+	This program is free software; you can redistribute it and/or
+	modify it under the terms of the GNU General Public License
+	as published by the Free Software Foundation; either version 2
+	of the License, or (at your option) any later version.
+
+	This program is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+
+	See the GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with this program; if not, write to:
+
+		Free Software Foundation, Inc.
+		59 Temple Place - Suite 330
+		Boston, MA  02111-1307, USA
+
+*/
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include <strings.h>
+
+#include "QF/alloc.h"
+#include "QF/hash.h"
+#include "QF/heapsort.h"
+#include "QF/va.h"
+
+#include "tools/qfcc/include/attribute.h"
+#include "tools/qfcc/include/def.h"
+#include "tools/qfcc/include/diagnostic.h"
+#include "tools/qfcc/include/glsl-lang.h"
+#include "tools/qfcc/include/shared.h"
+#include "tools/qfcc/include/strpool.h"
+#include "tools/qfcc/include/symtab.h"
+#include "tools/qfcc/include/type.h"
+#include "tools/qfcc/include/value.h"
+
+typedef enum {
+	decl_var    = 1 << 0,
+	decl_qual   = 1 << 1,
+	decl_block  = 1 << 2,
+	decl_member = 1 << 3,
+} glsl_obj_t;
+
+typedef enum {
+	var_any,
+	var_opaque,
+	var_atomic,
+	var_subpass,
+	var_scalar,
+	var_image,
+	var_gl_FragCoord,
+	var_gl_FragDepth,
+} glsl_var_t;
+
+typedef struct layout_qual_s {
+	const char *name;
+	bool      (*apply) ();
+	bool      (*apply_expr) ();
+	unsigned    obj_mask;
+	glsl_var_t  var_type;
+	unsigned    if_mask;
+	const char **stage_filter;
+} layout_qual_t;
+
+#define A(a) a, nullptr
+#define E(e) nullptr, e
+#define D(d) (decl_##d)
+#define D_all D(qual)|D(var)|D(block)|D(member)
+#define V(v) (var_##v)
+#define I(i) (1 << (glsl_##i))
+#define C (const char *[])
+
+static bool sorted_layout_qualifiers;
+static layout_qual_t layout_qualifiers[] = {
+	{	.name = "shared",
+		.apply = A(nullptr),
+		.obj_mask = D(qual)|D(block),
+		.if_mask = I(uniform)|I(buffer),
+	},
+	{	.name = "packed",
+		.apply = A(nullptr),
+		.obj_mask = D(qual)|D(block),
+		.if_mask = I(uniform)|I(buffer),
+	},
+	{	.name = "std140",
+		.apply = A(nullptr),
+		.obj_mask = D(qual)|D(block),
+		.if_mask = I(uniform)|I(buffer),
+	},
+	{	.name = "std430",
+		.apply = A(nullptr),
+		.obj_mask = D(qual)|D(block),
+		.if_mask = I(uniform)|I(buffer),
+	},
+	{	.name = "row_major",
+		.apply = A(nullptr),
+		.obj_mask = D(qual)|D(block)|D(member),
+		.if_mask = I(uniform)|I(buffer),
+	},
+	{	.name = "column_major",
+		.apply = A(nullptr),
+		.obj_mask = D(qual)|D(block)|D(member),
+		.if_mask = I(uniform)|I(buffer),
+	},
+
+	{	.name = "binding",
+		.apply = E(nullptr),
+		.obj_mask = D(var)|D(block),
+		.var_type = V(opaque),
+		.if_mask = I(uniform)|I(buffer),
+	},
+	{	.name = "offset",
+		.apply = E(nullptr),
+		.obj_mask = D(var)|D(member),
+		.var_type = V(opaque),
+		.if_mask = I(uniform)|I(buffer),
+	},
+	{	.name = "align",
+		.apply = E(nullptr),
+		.obj_mask = D(var)|D(block),
+		.var_type = V(opaque),
+		.if_mask = I(uniform)|I(buffer),
+	},
+	{	.name = "set",
+		.apply = E(nullptr),
+		.obj_mask = D(var)|D(block),
+		.var_type = V(opaque),
+		.if_mask = I(uniform)|I(buffer),
+	},
+	{	.name = "push_constant",
+		.apply = A(nullptr),
+		.obj_mask = D(block),
+		.var_type = V(any),
+		.if_mask = I(uniform),
+	},
+	{	.name = "input_attachment_index",
+		.apply = E(nullptr),
+		.obj_mask = D(var),
+		.var_type = V(subpass),
+		.if_mask = I(uniform),
+	},
+	{	.name = "location",
+		.apply = E(nullptr),
+		.obj_mask = D(var),
+		.var_type = V(any),
+		.if_mask = I(uniform)|I(buffer),
+	},
+
+	{	.name = "location",
+		.apply = E(nullptr),
+		.obj_mask = D(var)|D(block)|D(member),
+		.var_type = V(any),
+		.if_mask = I(in)|I(out),
+		.stage_filter = C { "!compute", nullptr },
+	},
+	{	.name = "component",
+		.apply = E(nullptr),
+		.obj_mask = D(var)|D(member),
+		.var_type = V(any),
+		.if_mask = I(in)|I(out),
+		.stage_filter = C { "!compute", nullptr },
+	},
+
+	{	.name = "index",
+		.apply = E(nullptr),
+		.obj_mask = D(var),
+		.var_type = V(any),
+		.if_mask = I(out),
+		.stage_filter = C { "fragment", nullptr },
+	},
+
+	{	.name = "triangles",
+		.apply = A(nullptr),
+		.obj_mask = D(qual),
+		.if_mask = I(in),
+		.stage_filter = C { "tessellation evaluation", nullptr },
+	},
+	{	.name = "quads",
+		.apply = A(nullptr),
+		.obj_mask = D(qual),
+		.if_mask = I(in),
+		.stage_filter = C { "tessellation evaluation", nullptr },
+	},
+	{	.name = "isolines",
+		.apply = A(nullptr),
+		.obj_mask = D(qual),
+		.if_mask = I(in),
+		.stage_filter = C { "tessellation evaluation", nullptr },
+	},
+	{	.name = "equal_spacing",
+		.apply = A(nullptr),
+		.obj_mask = D(qual),
+		.if_mask = I(in),
+		.stage_filter = C { "tessellation evaluation", nullptr },
+	},
+	{	.name = "fractional_even_spacing",
+		.apply = A(nullptr),
+		.obj_mask = D(qual),
+		.if_mask = I(in),
+		.stage_filter = C { "tessellation evaluation", nullptr },
+	},
+	{	.name = "fractional_odd_spacing",
+		.apply = A(nullptr),
+		.obj_mask = D(qual),
+		.if_mask = I(in),
+		.stage_filter = C { "tessellation evaluation", nullptr },
+	},
+	{	.name = "cw",
+		.apply = A(nullptr),
+		.obj_mask = D(qual),
+		.if_mask = I(in),
+		.stage_filter = C { "tessellation evaluation", nullptr },
+	},
+	{	.name = "ccw",
+		.apply = A(nullptr),
+		.obj_mask = D(qual),
+		.if_mask = I(in),
+		.stage_filter = C { "tessellation evaluation", nullptr },
+	},
+	{	.name = "point_mode",
+		.apply = A(nullptr),
+		.obj_mask = D(qual),
+		.if_mask = I(in),
+		.stage_filter = C { "tessellation evaluation", nullptr },
+	},
+
+	{	.name = "points",
+		.apply = A(nullptr),
+		.obj_mask = D(qual),
+		.if_mask = I(in)|I(out),
+		.stage_filter = C { "geometry", nullptr },
+	},
+//? [ points ]					// q _ _ _ geom in
+	{	.name = "lines",
+		.apply = A(nullptr),
+		.obj_mask = D(qual),
+		.if_mask = I(in),
+		.stage_filter = C { "geometry", nullptr },
+	},
+	{	.name = "lines_adjacency",
+		.apply = A(nullptr),
+		.obj_mask = D(qual),
+		.if_mask = I(in),
+		.stage_filter = C { "geometry", nullptr },
+	},
+	{	.name = "triangles",
+		.apply = A(nullptr),
+		.obj_mask = D(qual),
+		.if_mask = I(in),
+		.stage_filter = C { "geometry", nullptr },
+	},
+	{	.name = "triangles_adjacency",
+		.apply = A(nullptr),
+		.obj_mask = D(qual),
+		.if_mask = I(in),
+		.stage_filter = C { "geometry", nullptr },
+	},
+	{	.name = "invocations",
+		.apply = E(nullptr),
+		.obj_mask = D(qual),
+		.if_mask = I(in),
+		.stage_filter = C { "geometry", nullptr },
+	},
+
+	{	.name = "origin_upper_left",
+		.apply = A(nullptr),
+		.obj_mask = D(qual),
+		.if_mask = I(in),
+		.stage_filter = C { "fragment", nullptr },
+	},
+	{	.name = "pixel_center_integer",
+		.apply = A(nullptr),
+		.obj_mask = D(qual),
+		.if_mask = I(in),
+		.stage_filter = C { "fragment", nullptr },
+	},
+	{	.name = "early_fragment_tests",
+		.apply = A(nullptr),
+		.obj_mask = D(qual),
+		.if_mask = I(in),
+		.stage_filter = C { "fragment", nullptr },
+	},
+
+	{	.name = "local_size_x",
+		.apply = E(nullptr),
+		.obj_mask = D(qual),
+		.if_mask = I(in),
+		.stage_filter = C { "comp", nullptr },
+	},
+	{	.name = "local_size_y",
+		.apply = E(nullptr),
+		.obj_mask = D(qual),
+		.if_mask = I(in),
+		.stage_filter = C { "comp", nullptr },
+	},
+	{	.name = "local_size_z",
+		.apply = E(nullptr),
+		.obj_mask = D(qual),
+		.if_mask = I(in),
+		.stage_filter = C { "comp", nullptr },
+	},
+	{	.name = "local_size_x_id",
+		.apply = E(nullptr),
+		.obj_mask = D(qual),
+		.if_mask = I(in),
+		.stage_filter = C { "comp", nullptr },
+	},
+	{	.name = "local_size_y_id",
+		.apply = E(nullptr),
+		.obj_mask = D(qual),
+		.if_mask = I(in),
+		.stage_filter = C { "comp", nullptr },
+	},
+	{	.name = "local_size_z_id",
+		.apply = E(nullptr),
+		.obj_mask = D(qual),
+		.if_mask = I(in),
+		.stage_filter = C { "comp", nullptr },
+	},
+
+	{	.name = "xfb_buffer",
+		.apply = E(nullptr),
+		.obj_mask = D_all,
+		.var_type = V(any),
+		.if_mask = I(out),
+		.stage_filter = C {
+			"vertex",
+			"tessellation control",
+			"tessellation evaluation",
+			"geometry",
+			nullptr
+		},
+	},
+	{	.name = "xfb_stride",
+		.apply = E(nullptr),
+		.obj_mask = D_all,
+		.var_type = V(any),
+		.if_mask = I(out),
+		.stage_filter = C {
+			"vertex",
+			"tessellation control",
+			"tessellation evaluation",
+			"geometry",
+			nullptr
+		},
+	},
+	{	.name = "xfb_offset",
+		.apply = E(nullptr),
+		.obj_mask = D_all,
+		.var_type = V(any),
+		.if_mask = I(out),
+		.stage_filter = C {
+			"vertex",
+			"tessellation control",
+			"tessellation evaluation",
+			"geometry",
+			nullptr
+		},
+	},
+
+	{	.name = "vertices",
+		.apply = E(nullptr),
+		.obj_mask = D(qual),
+		.if_mask = I(out),
+		.stage_filter = C { "tessellation control", nullptr },
+	},
+
+//? [ points ]					// q _ _ _ geom out
+	{	.name = "line_strip",
+		.apply = A(nullptr),
+		.obj_mask = D(qual),
+		.if_mask = I(out),
+		.stage_filter = C { "geometry", nullptr },
+	},
+	{	.name = "triangle_strip",
+		.apply = A(nullptr),
+		.obj_mask = D(qual),
+		.if_mask = I(out),
+		.stage_filter = C { "geometry", nullptr },
+	},
+	{	.name = "max_vertices",
+		.apply = E(nullptr),
+		.obj_mask = D(qual),
+		.if_mask = I(out),
+		.stage_filter = C { "geometry", nullptr },
+	},
+	{	.name = "stream",
+		.apply = E(nullptr),
+		.obj_mask = D_all,
+		.var_type = V(any),
+		.if_mask = I(out),
+		.stage_filter = C { "geometry", nullptr },
+	},
+
+	{	.name = "depth_any",
+		.apply = A(nullptr),
+		.obj_mask = D(var),
+		.var_type = V(any),
+		.if_mask = I(out),
+		.stage_filter = C { "fragment", nullptr },
+	},
+	{	.name = "depth_greater",
+		.apply = A(nullptr),
+		.obj_mask = D(var),
+		.var_type = V(any),
+		.if_mask = I(out),
+		.stage_filter = C { "fragment", nullptr },
+	},
+	{	.name = "depth_less",
+		.apply = A(nullptr),
+		.obj_mask = D(var),
+		.var_type = V(any),
+		.if_mask = I(out),
+		.stage_filter = C { "fragment", nullptr },
+	},
+	{	.name = "depth_unchanged",
+		.apply = A(nullptr),
+		.obj_mask = D(var),
+		.var_type = V(any),
+		.if_mask = I(out),
+		.stage_filter = C { "fragment", nullptr },
+	},
+
+	{	.name = "constant_id",
+		.apply = E(nullptr),
+		.obj_mask = D(var),
+		.var_type = V(scalar),
+	},
+
+	{	.name = "rgba32f",
+		.apply = A(nullptr),
+		.obj_mask = D(var),
+		.var_type = V(image),
+		.if_mask = I(uniform),
+	},
+	{	.name = "rgba16f",
+		.apply = A(nullptr),
+		.obj_mask = D(var),
+		.var_type = V(image),
+		.if_mask = I(uniform),
+	},
+	{	.name = "rg32f",
+		.apply = A(nullptr),
+		.obj_mask = D(var),
+		.var_type = V(image),
+		.if_mask = I(uniform),
+	},
+	{	.name = "rg16f",
+		.apply = A(nullptr),
+		.obj_mask = D(var),
+		.var_type = V(image),
+		.if_mask = I(uniform),
+	},
+	{	.name = "r11f_g11f_b10f",
+		.apply = A(nullptr),
+		.obj_mask = D(var),
+		.var_type = V(image),
+		.if_mask = I(uniform),
+	},
+	{	.name = "r32f",
+		.apply = A(nullptr),
+		.obj_mask = D(var),
+		.var_type = V(image),
+		.if_mask = I(uniform),
+	},
+	{	.name = "r16f",
+		.apply = A(nullptr),
+		.obj_mask = D(var),
+		.var_type = V(image),
+		.if_mask = I(uniform),
+	},
+	{	.name = "rgba16",
+		.apply = A(nullptr),
+		.obj_mask = D(var),
+		.var_type = V(image),
+		.if_mask = I(uniform),
+	},
+	{	.name = "rgb10_a2",
+		.apply = A(nullptr),
+		.obj_mask = D(var),
+		.var_type = V(image),
+		.if_mask = I(uniform),
+	},
+	{	.name = "rgba8",
+		.apply = A(nullptr),
+		.obj_mask = D(var),
+		.var_type = V(image),
+		.if_mask = I(uniform),
+	},
+	{	.name = "rg16",
+		.apply = A(nullptr),
+		.obj_mask = D(var),
+		.var_type = V(image),
+		.if_mask = I(uniform),
+	},
+	{	.name = "rg8",
+		.apply = A(nullptr),
+		.obj_mask = D(var),
+		.var_type = V(image),
+		.if_mask = I(uniform),
+	},
+	{	.name = "r16",
+		.apply = A(nullptr),
+		.obj_mask = D(var),
+		.var_type = V(image),
+		.if_mask = I(uniform),
+	},
+	{	.name = "r8",
+		.apply = A(nullptr),
+		.obj_mask = D(var),
+		.var_type = V(image),
+		.if_mask = I(uniform),
+	},
+	{	.name = "rgba16_snorm",
+		.apply = A(nullptr),
+		.obj_mask = D(var),
+		.var_type = V(image),
+		.if_mask = I(uniform),
+	},
+	{	.name = "rgba8_snorm",
+		.apply = A(nullptr),
+		.obj_mask = D(var),
+		.var_type = V(image),
+		.if_mask = I(uniform),
+	},
+	{	.name = "rg16_snorm",
+		.apply = A(nullptr),
+		.obj_mask = D(var),
+		.var_type = V(image),
+		.if_mask = I(uniform),
+	},
+	{	.name = "rg8_snorm",
+		.apply = A(nullptr),
+		.obj_mask = D(var),
+		.var_type = V(image),
+		.if_mask = I(uniform),
+	},
+	{	.name = "r16_snorm",
+		.apply = A(nullptr),
+		.obj_mask = D(var),
+		.var_type = V(image),
+		.if_mask = I(uniform),
+	},
+	{	.name = "r8_snorm",
+		.apply = A(nullptr),
+		.obj_mask = D(var),
+		.var_type = V(image),
+		.if_mask = I(uniform),
+	},
+	{	.name = "rgba32i",
+		.apply = A(nullptr),
+		.obj_mask = D(var),
+		.var_type = V(image),
+		.if_mask = I(uniform),
+	},
+	{	.name = "rgba16i",
+		.apply = A(nullptr),
+		.obj_mask = D(var),
+		.var_type = V(image),
+		.if_mask = I(uniform),
+	},
+	{	.name = "rgba8i",
+		.apply = A(nullptr),
+		.obj_mask = D(var),
+		.var_type = V(image),
+		.if_mask = I(uniform),
+	},
+	{	.name = "rg32i",
+		.apply = A(nullptr),
+		.obj_mask = D(var),
+		.var_type = V(image),
+		.if_mask = I(uniform),
+	},
+	{	.name = "rg16i",
+		.apply = A(nullptr),
+		.obj_mask = D(var),
+		.var_type = V(image),
+		.if_mask = I(uniform),
+	},
+	{	.name = "rg8i",
+		.apply = A(nullptr),
+		.obj_mask = D(var),
+		.var_type = V(image),
+		.if_mask = I(uniform),
+	},
+	{	.name = "r32i",
+		.apply = A(nullptr),
+		.obj_mask = D(var),
+		.var_type = V(image),
+		.if_mask = I(uniform),
+	},
+	{	.name = "r16i",
+		.apply = A(nullptr),
+		.obj_mask = D(var),
+		.var_type = V(image),
+		.if_mask = I(uniform),
+	},
+	{	.name = "r8i",
+		.apply = A(nullptr),
+		.obj_mask = D(var),
+		.var_type = V(image),
+		.if_mask = I(uniform),
+	},
+	{	.name = "rgba32ui",
+		.apply = A(nullptr),
+		.obj_mask = D(var),
+		.var_type = V(image),
+		.if_mask = I(uniform),
+	},
+	{	.name = "rgba16ui",
+		.apply = A(nullptr),
+		.obj_mask = D(var),
+		.var_type = V(image),
+		.if_mask = I(uniform),
+	},
+	{	.name = "rgb10_a2ui",
+		.apply = A(nullptr),
+		.obj_mask = D(var),
+		.var_type = V(image),
+		.if_mask = I(uniform),
+	},
+	{	.name = "rgba8ui",
+		.apply = A(nullptr),
+		.obj_mask = D(var),
+		.var_type = V(image),
+		.if_mask = I(uniform),
+	},
+	{	.name = "rg32ui",
+		.apply = A(nullptr),
+		.obj_mask = D(var),
+		.var_type = V(image),
+		.if_mask = I(uniform),
+	},
+	{	.name = "rg16ui",
+		.apply = A(nullptr),
+		.obj_mask = D(var),
+		.var_type = V(image),
+		.if_mask = I(uniform),
+	},
+	{	.name = "rg8ui",
+		.apply = A(nullptr),
+		.obj_mask = D(var),
+		.var_type = V(image),
+		.if_mask = I(uniform),
+	},
+	{	.name = "r32ui",
+		.apply = A(nullptr),
+		.obj_mask = D(var),
+		.var_type = V(image),
+		.if_mask = I(uniform),
+	},
+	{	.name = "r16ui",
+		.apply = A(nullptr),
+		.obj_mask = D(var),
+		.var_type = V(image),
+		.if_mask = I(uniform),
+	},
+	{	.name = "r8ui",
+		.apply = A(nullptr),
+		.obj_mask = D(var),
+		.var_type = V(image),
+		.if_mask = I(uniform),
+	},
+};
+#undef A
+#undef E
+#undef D
+#undef D_all
+#undef V
+#undef I
+#undef C
+#define num_quals (sizeof (layout_qualifiers) / sizeof (layout_qualifiers[0]))
+#define layout_qual_sz num_quals, sizeof (layout_qual_t)
+
+static int
+layout_qual_cmp (const void *_a, const void *_b)
+{
+	auto a = (const layout_qual_t *) _a;
+	auto b = (const layout_qual_t *) _b;
+	return strcasecmp (a->name, b->name);
+}
+
+static bool
+layout_check_qualifier (const layout_qual_t *qual, specifier_t spec)
+{
+	unsigned obj_mask = 0;
+	glsl_var_t var_type = var_any;
+	unsigned if_mask = 0;
+
+	auto interface = glsl_iftype_from_sc (spec.storage);
+	if (interface < glsl_num_interfaces) {
+		if_mask = 1 << interface;
+	}
+	if (spec.sym) {
+		auto sym = spec.sym;
+		if (is_handle (sym->type)) {
+			var_type = var_opaque;
+		} else if (is_scalar (sym->type)) {
+			var_type = var_scalar;
+		} else if (strcmp (sym->name, "gl_FragCoord") == 0) {
+			var_type = var_gl_FragCoord;
+		} else if (strcmp (sym->name, "gl_FragDepth") == 0) {
+			var_type = var_gl_FragDepth;
+		}
+		obj_mask = decl_var;
+		if (sym->table->parent && sym->table->parent->type == stab_struct) {
+			obj_mask = decl_member;
+		}
+	} else {
+		obj_mask = decl_qual;
+	}
+	if (!(qual->obj_mask & obj_mask)) {
+		return false;
+	}
+	if (qual->var_type != var_type) {
+		return false;
+	}
+	if (!(qual->if_mask & if_mask)) {
+		return false;
+	}
+	if (qual->stage_filter) {
+		bool ok = false;
+		for (auto sf = qual->stage_filter; *sf; sf++) {
+			if (**sf == '!') {
+				if (strcmp (*sf + 1, glsl_sublang.name) == 0) {
+					return false;
+				}
+				ok = true;
+			} else {
+				if (strcmp (*sf, glsl_sublang.name) == 0) {
+					return true;
+				}
+			}
+		}
+		return ok;
+	}
+	return true;
+}
+
+static void
+layout_apply_qualifier (const expr_t *qualifier, specifier_t spec)
+{
+	layout_qual_t key = {
+		.name = qualifier->type == ex_expr
+				? expr_string (qualifier->expr.e1)
+				: expr_string (qualifier)
+	};
+	auto val = qualifier->type == ex_expr
+				? qualifier->expr.e2
+				: nullptr;
+
+	notice (qualifier, "%s %p", key.name, spec.sym);
+	const layout_qual_t *qual;
+	qual = bsearch (&key, layout_qualifiers, layout_qual_sz, layout_qual_cmp);
+	if (!qual) {
+		error (0, "invalid layout qualifier: %s", key.name);
+		return;
+	}
+	// there may be multiple entries with the same qualifier name, so find
+	// the first one
+	while (qual > layout_qualifiers && layout_qual_cmp (&key, qual - 1) == 0) {
+		qual--;
+	}
+	// check all matching entries
+	while (qual - layout_qualifiers < (ptrdiff_t) num_quals
+		   && layout_qual_cmp (&key, qual) == 0) {
+		if (layout_check_qualifier (qual, spec)) {
+			if (qual->apply_expr) {
+				if (!val) {
+					error (qualifier, "%s requires a value", key.name);
+				} else {
+					qual->apply_expr ();
+				}
+				return;
+			} else if (qual->apply) {
+				if (!val) {
+					error (qualifier, "%s does not take a value", key.name);
+				} else {
+					qual->apply ();
+				}
+				return;
+			} else {
+				error (0, "unsupported layout qualifier: %s", key.name);
+				return;
+			}
+		}
+
+		qual++;
+	}
+	error (0, "invalid layout qualifier: %s", key.name);
+	return;
+}
+
+void
+glsl_layout (const ex_list_t *qualifiers, specifier_t spec)
+{
+	if (!sorted_layout_qualifiers) {
+		heapsort (layout_qualifiers, layout_qual_sz, layout_qual_cmp);
+	}
+	for (auto q = qualifiers->head; q; q = q->next) {
+		layout_apply_qualifier (q->expr, spec);
+	}
+}