Add ability to generate constants from dawn.json

The "constant" category has two keys:
 - `"type"`: a string, the name of the base data type
 - `"value"`: a string, the value is defined with preprocessor macro

Remove deprecated constant InputStepMode.

BUG=dawn:1201, dawn:1023

Change-Id: If4308bd5b25dddd9453514ce362bebe4fd771a57
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/70704
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Jiawei Shao <jiawei.shao@intel.com>
Commit-Queue: Junwei Fu <junwei.fu@intel.com>

dawn.json

@@ -2581,6 +2581,48 @@
             {"value": 30, "name": "sint32x4"}
         ]
     },
+    "whole size" : {
+        "category": "constant",
+        "type": "uint64_t",
+        "value":  "(0xffffffffffffffffULL)"
+    },
+    "whole map size" : {
+        "category": "constant",
+        "type": "size_t",
+        "value":  "SIZE_MAX"
+    },
+    "stride undefined" : {
+        "category": "constant",
+        "tags": ["deprecated"],
+        "_TODO": "crbug.com/dawn/520: Remove WGPU_STRIDE_UNDEFINED in favor of WGPU_COPY_STRIDE_UNDEFINED.",
+        "type": "uint32_t",
+        "value":  "(0xffffffffUL)"
+    },
+    "copy stride undefined" : {
+        "category": "constant",
+        "type": "uint32_t",
+        "value":  "(0xffffffffUL)"
+    },
+    "limit u32 undefined" : {
+        "category": "constant",
+        "type": "uint32_t",
+        "value":  "(0xffffffffUL)"
+    },
+    "limit u64 undefined" : {
+        "category": "constant",
+        "type": "uint64_t",
+        "value":  "(0xffffffffffffffffULL)"
+    },
+    "array layer count undefined" : {
+        "category": "constant",
+        "type": "uint32_t",
+        "value":  "(0xffffffffUL)"
+    },
+    "mip level count undefined" : {
+        "category": "constant",
+        "type": "uint32_t",
+        "value":  "(0xffffffffUL)"
+    },
     "ObjectType": {
       "_comment": "Only used for the wire",
       "category": "native"

docs/codegen.md

@@ -71,6 +71,10 @@ A **record** is a list of **record members**, each of which is a dictionary with
    - `"return_type"` (default to no return type) a string that's the name of the return type.
    - `"arguments"` a **record**, so an array of **record members**
 
+**`"constant"`**
+ - `"type"`: a string, the name of the base data type
+ - `"value"`: a string, the value is defined with preprocessor macro
+
 ## Dawn "wire" generators
 
 The generator for the pieces of dawn_wire need additional data which is found in [`dawn_wire_json`](../dawn_wire.json). Examples of pieces that are generated are:

generator/dawn_json_generator.py

@@ -239,6 +239,14 @@ class StructureType(Record, Type):
         return self.chained == "out" or self.extensible == "out"
 
 
+class ConstantDefinition():
+    def __init__(self, is_enabled, name, json_data):
+        self.type = None
+        self.value = json_data['value']
+        self.json_data = json_data
+        self.name = Name(name)
+
+
 class Command(Record):
     def __init__(self, name, members=None):
         Record.__init__(self, name)
@@ -310,6 +318,11 @@ def link_typedef(typedef, types):
     typedef.type = types[typedef.json_data['type']]
 
 
+def link_constant(constant, types):
+    constant.type = types[constant.json_data['type']]
+    assert constant.type.name.native
+
+
 # Sort structures so that if struct A has struct B as a member, then B is
 # listed before A.
 #
@@ -362,6 +375,7 @@ def parse_json(json, enabled_tags):
         'object': ObjectType,
         'structure': StructureType,
         'typedef': TypedefType,
+        'constant': ConstantDefinition,
     }
 
     types = {}
@@ -390,6 +404,9 @@ def parse_json(json, enabled_tags):
     for typedef in by_category['typedef']:
         link_typedef(typedef, types)
 
+    for constant in by_category['constant']:
+        link_constant(constant, types)
+
     for category in by_category.keys():
         by_category[category] = sorted(
             by_category[category], key=lambda typ: typ.name.canonical_case())

generator/templates/api.h

@@ -75,17 +75,9 @@
 #include <stddef.h>
 #include <stdbool.h>
 
-#define WGPU_WHOLE_SIZE (0xffffffffffffffffULL)
-#define WGPU_WHOLE_MAP_SIZE SIZE_MAX
-{% if 'deprecated' in enabled_tags %}
-    // TODO(crbug.com/dawn/520): Remove WGPU_STRIDE_UNDEFINED in favor of WGPU_COPY_STRIDE_UNDEFINED.
-    #define WGPU_STRIDE_UNDEFINED (0xffffffffUL)
-{% endif %}
-#define WGPU_COPY_STRIDE_UNDEFINED (0xffffffffUL)
-#define WGPU_LIMIT_U32_UNDEFINED (0xffffffffUL)
-#define WGPU_LIMIT_U64_UNDEFINED (0xffffffffffffffffULL)
-#define WGPU_ARRAY_LAYER_COUNT_UNDEFINED (0xffffffffUL)
-#define WGPU_MIP_LEVEL_COUNT_UNDEFINED (0xffffffffUL)
+{% for constant in by_category["constant"] %}
+    #define {{c_prefix}}_{{constant.name.SNAKE_CASE()}} {{constant.value}}
+{% endfor %}
 
 typedef uint32_t {{c_prefix}}Flags;
 
@@ -138,13 +130,6 @@ typedef struct {{c_prefix}}ChainedStructOut {
     typedef {{as_cType(typeDef.type.name)}} {{as_cType(typeDef.name)}};
 
 {% endfor %}
-{% if 'deprecated' in enabled_tags %}
-    // TODO(crbug.com/dawn/1023): Remove after the deprecation period.
-    #define WGPUInputStepMode_Vertex WGPUVertexStepMode_Vertex
-    #define WGPUInputStepMode_Instance WGPUVertexStepMode_Instance
-    #define WGPUInputStepMode_Force32 WGPUVertexStepMode_Force32
-
-{% endif %}
 #ifdef __cplusplus
 extern "C" {
 #endif

generator/templates/webgpu_cpp.h

@@ -19,17 +19,12 @@
 
 namespace wgpu {
 
-    static constexpr uint64_t kWholeSize = WGPU_WHOLE_SIZE;
-    static constexpr size_t kWholeMapSize = WGPU_WHOLE_MAP_SIZE;
-    {% if 'deprecated' in enabled_tags %}
-        // TODO(crbug.com/520): Remove kStrideUndefined in favor of kCopyStrideUndefined.
-        static constexpr uint32_t kStrideUndefined = WGPU_STRIDE_UNDEFINED;
-    {% endif %}
-    static constexpr uint32_t kCopyStrideUndefined = WGPU_COPY_STRIDE_UNDEFINED;
-    static constexpr uint32_t kLimitU32Undefined = WGPU_LIMIT_U32_UNDEFINED;
-    static constexpr uint64_t kLimitU64Undefined = WGPU_LIMIT_U64_UNDEFINED;
-    static constexpr uint32_t kArrayLayerCountUndefined = WGPU_ARRAY_LAYER_COUNT_UNDEFINED;
-    static constexpr uint32_t kMipLevelCountUndefined = WGPU_MIP_LEVEL_COUNT_UNDEFINED;
+    {% set c_prefix = metadata.c_prefix %}
+    {% for constant in by_category["constant"] %}
+        {% set type = as_cppType(constant.type.name) %}
+        {% set value = c_prefix + "_" +  constant.name.SNAKE_CASE() %}
+        static constexpr {{type}} k{{as_cppType(constant.name)}} = {{ value }};
+    {% endfor %}
 
     {% for type in by_category["enum"] %}
         enum class {{as_cppType(type.name)}} : uint32_t {