From b093f6b61e739b905d0dcfe6f136e7917baced40 Mon Sep 17 00:00:00 2001
From: Robin Voetter <robin@voetter.nl>
Date: Fri, 24 Jan 2020 13:56:22 +0100
Subject: [PATCH] Registry: Header revision

---
 generator/main.zig     |  2 +-
 generator/registry.zig | 20 +++++++++++++++++++-
 generator/xml.zig      |  5 +++--
 3 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/generator/main.zig b/generator/main.zig
index 1094f6d..24f7342 100644
--- a/generator/main.zig
+++ b/generator/main.zig
@@ -17,7 +17,7 @@ pub fn main() !void {
 
     _ = try file.inStream().stream.read(source);
 
-    var spec = try xml.parse(std.heap.page_allocator, source);
+    const spec = try xml.parse(std.heap.page_allocator, source);
     defer spec.deinit();
 
     const registry = reg.generate(std.heap.page_allocator, spec.root);
diff --git a/generator/registry.zig b/generator/registry.zig
index c158c42..8087f98 100644
--- a/generator/registry.zig
+++ b/generator/registry.zig
@@ -38,7 +38,7 @@ pub const Registry = struct {
         return registry;
     }
 
-    fn deinit(self: *Registry) void {
+    fn deinit(self: Registry) void {
         self.declarations_by_name.deinit();
 
         // Copy to stack so that the arena doesn't destroy itself
@@ -467,6 +467,14 @@ const EnumInfo = struct {
         if (EnumInfo.isBackwardsCompatAlias(variant)) return;
         const name = variant.getAttribute("name").?;
         const value = blk: {
+            // An enum variant's value could be defined by any of the following attributes:
+            // - value: Straight up value of the enum variant, in either base 10 or 16 (prefixed with 0x).
+            // - bitpos: Used for bitmasks, and can also be set in extensions.
+            // - alias: The field is an alias of another variant within the same enum.
+            // - offset: Used with features and extensions, where a non-bitpos value is added to an enum.
+            //     The value is given by `1e9 + (extr_nr - 1) * 1e3 + offset`, where `ext_nr` is either
+            //     given by the `extnumber` field (in the case of a feature), or given in the parent <extension>
+            //     tag. In the latter case its passed via the `ext_nr` parameter.
             if (variant.getAttribute("value")) |value_str| {
                 break :blk Value{.Value = parseInt(i32, value_str) catch unreachable};
             } else if (variant.getAttribute("bitpos")) |bitpos_str| {
@@ -540,6 +548,8 @@ fn processTypes(registry: *Registry, root: *xml.Element) void {
             processFuncPointerType(registry, ty);
         } else if (mem.eql(u8, category, "basetype")) {
             processBaseType(registry, ty);
+        } else if (mem.eql(u8, category, "define")) {
+            processDefineType(registry, ty);
         }
     }
 }
@@ -605,6 +615,14 @@ fn processBaseType(registry: *Registry, ty: *xml.Element) void {
     registry.addDefinition(name, .{.BaseType = type_info});
 }
 
+fn processDefineType(registry: *Registry, ty: *xml.Element) void {
+    if (ty.getCharData("name")) |name| {
+        if (mem.eql(u8, name, "VK_HEADER_VERSION")) {
+            registry.addApiConstant("VK_HEADER_VERSION", mem.trim(u8, ty.children.at(2).CharData, " "));
+        }
+    }
+}
+
 fn processEnums(registry: *Registry, root: *xml.Element) void {
     var it = root.findChildrenByTag("enums");
     while (it.next()) |enums| {
diff --git a/generator/xml.zig b/generator/xml.zig
index 5961f4d..5cc3090 100644
--- a/generator/xml.zig
+++ b/generator/xml.zig
@@ -95,8 +95,9 @@ pub const Document = struct {
     xml_decl: ?*XmlDecl,
     root: *Element,
 
-    pub fn deinit(self: *Document) void {
-        self.arena.deinit();
+    pub fn deinit(self: Document) void {
+        var arena = self.arena; // Copy to stack so self can be taken by value.
+        arena.deinit();
     }
 };