drafting push constants

src/Module.zig

@@ -75,7 +75,6 @@ input_locations: [lib.SPIRV_MAX_INPUT_LOCATIONS]SpvWord,
 output_locations: [lib.SPIRV_MAX_OUTPUT_LOCATIONS]SpvWord,
 bindings: [lib.SPIRV_MAX_SET][lib.SPIRV_MAX_SET_BINDINGS]SpvWord,
 builtins: std.EnumMap(spv.SpvBuiltIn, SpvWord),
-push_constants: []Value,
 
 pub fn init(allocator: std.mem.Allocator, source: []const SpvWord, options: ModuleOptions) ModuleError!Self {
     var self: Self = std.mem.zeroInit(Self, .{
@@ -198,12 +197,7 @@ fn findAccessChainToMember(self: *const Self, base_id: SpvWord, member_index: Sp
     return null;
 }
 
-fn applyInterfaceDecoration(
-    self: *Self,
-    storage_class: spv.SpvStorageClass,
-    decoration: Result.Decoration,
-    id: SpvWord,
-) ModuleError!void {
+fn applyInterfaceDecoration(self: *Self, storage_class: spv.SpvStorageClass, decoration: Result.Decoration, id: SpvWord) ModuleError!void {
     switch (storage_class) {
         .Input => switch (decoration.rtype) {
             .BuiltIn => self.builtins.put(
@@ -225,12 +219,7 @@ fn applyInterfaceDecoration(
     }
 }
 
-fn applyStructMemberInterfaceDecorations(
-    self: *Self,
-    storage_class: spv.SpvStorageClass,
-    type_word: SpvWord,
-    id: SpvWord,
-) ModuleError!void {
+fn applyStructMemberInterfaceDecorations(self: *Self, storage_class: spv.SpvStorageClass, type_word: SpvWord, id: SpvWord) ModuleError!void {
     switch (storage_class) {
         .Input, .Output => {},
         else => return,
@@ -281,7 +270,10 @@ fn applyDecorations(self: *Self) ModuleError!void {
                     try self.applyInterfaceDecoration(v.storage_class, decoration, @intCast(id));
 
                     switch (v.storage_class) {
-                        .StorageBuffer, .Uniform, .UniformConstant => {
+                        .StorageBuffer,
+                        .Uniform,
+                        .UniformConstant,
+                        => {
                             switch (decoration.rtype) {
                                 .Binding => binding = decoration.literal_1,
                                 .DescriptorSet => set = decoration.literal_1,

src/Runtime.zig

@@ -240,6 +240,17 @@ fn pass(self: *Self, allocator: std.mem.Allocator, op_set: ?std.EnumSet(spv.SpvO
     }
 }
 
+pub fn populatePushConstants(self: *Self, blob: []const u8) RuntimeError!void {
+    for (self.results) |*result| {
+        if (result.variant == null or std.meta.activeTag(result.variant.?) != .Variable)
+            continue;
+        const variable = &result.variant.?.Variable;
+        if (variable.storage_class != .PushConstant)
+            continue;
+        _ = try variable.value.writeConst(blob);
+    }
+}
+
 pub fn writeDescriptorSet(self: *const Self, input: []const u8, set: SpvWord, binding: SpvWord, descriptor_index: SpvWord) RuntimeError!void {
     if (set < lib.SPIRV_MAX_SET and binding < lib.SPIRV_MAX_SET_BINDINGS) {
         const value = &self.results[self.mod.bindings[set][binding]].variant.?.Variable.value;

src/Value.zig

@@ -143,9 +143,13 @@ pub const Value = union(Type) {
 
     pub fn init(allocator: std.mem.Allocator, results: []const Result, target_type: SpvWord, is_externally_visible: bool) RuntimeError!Self {
         const resolved = results[target_type].resolveTypeWordOrNull() orelse target_type;
-        const member_count = results[resolved].getMemberCounts();
+        return initUnresolved(allocator, results, resolved, is_externally_visible);
+    }
 
-        return switch (results[resolved].variant.?) {
+    pub fn initUnresolved(allocator: std.mem.Allocator, results: []const Result, target_type: SpvWord, is_externally_visible: bool) RuntimeError!Self {
+        const member_count = results[target_type].getMemberCounts();
+
+        return switch (results[target_type].variant.?) {
             .Type => |t| switch (t) {
                 .Void => .{ .Void = .{} },
                 .Bool => .{ .Bool = false },
@@ -233,12 +237,17 @@ pub const Value = union(Type) {
                 },
                 .Image => .{
                     .Image = .{
-                        .type_word = resolved,
+                        .type_word = target_type,
                         .driver_image = undefined,
                     },
                 },
                 .Sampler => RuntimeError.ToDo,
                 .SampledImage => RuntimeError.ToDo,
+                .Pointer => .{
+                    .Pointer = .{
+                        .ptr = undefined,
+                    },
+                },
                 else => RuntimeError.InvalidSpirV,
             },
             else => RuntimeError.InvalidSpirV,

src/opcodes.zig

@@ -1197,7 +1197,7 @@ fn setupAccessChain(allocator: std.mem.Allocator, word_count: SpvWord, rt: *Runt
             .target = var_type,
             .base = base_id,
             .indexes = indexes,
-            .value = try Value.init(allocator, rt.results, var_type, false),
+            .value = try Value.initUnresolved(allocator, rt.results, var_type, false),
         },
     };
 }
@@ -3267,6 +3267,7 @@ fn opVariable(allocator: std.mem.Allocator, word_count: SpvWord, rt: *Runtime) R
     const externally_visible_data_storages = [_]spv.SpvStorageClass{
         .Uniform,
         .StorageBuffer,
+        .PushConstant,
     };
 
     const is_externally_visible = std.mem.containsAtLeastScalar(spv.SpvStorageClass, &externally_visible_data_storages, 1, storage_class);