Enum Utils: Add method to return enum value from string.

We'll use this in the trace interpreter to parse enum values.

Bug: angleproject:7752
Change-Id: I232a00baac2f74c9618029929bbb3e5822654046
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3963366
Reviewed-by: Cody Northrop <cnorthrop@google.com>
Reviewed-by: Yuxin Hu <yuxinhu@google.com>
Commit-Queue: Jamie Madill <jmadill@chromium.org>

scripts/code_generation_hashes/GLenum_value_to_string_map.json

@@ -1,12 +1,12 @@
 {
   "scripts/gen_gl_enum_utils.py":
-    "5adc7d4cfc7d17d89d6917015664a060",
+    "bc90f067f124c1cae63a348e9ae057ce",
   "scripts/gl_angle_ext.xml":
     "8dd9662655c39ce22fecdc2449594e54",
   "scripts/registry_xml.py":
     "a532782ba7caa6af314e535b7e467a5b",
   "src/common/gl_enum_utils_autogen.cpp":
-    "109c491a507e139473176a99530308d4",
+    "05b48bda3e66bbc6b413cf2374899b26",
   "src/common/gl_enum_utils_autogen.h":
     "4d2876469ba95955182c21c09c466333",
   "third_party/OpenGL-Registry/src/xml/gl.xml":

scripts/gen_gl_enum_utils.py

@@ -54,6 +54,7 @@ template_gl_enums_source = """// GENERATED FILE - DO NOT EDIT.
 
 #include "common/gl_enum_utils_autogen.h"
 
+#include "common/debug.h"
 #include "common/gl_enum_utils.h"
 
 namespace gl
@@ -88,6 +89,13 @@ const char *GLenumToString(BigGLEnum enumGroup, unsigned int value)
             return UnknownEnumToString(value);
     }}
 }}
+
+unsigned int StringToGLenum(const char *str)
+{{
+{string_to_enum_table}
+    UNREACHABLE();
+    return 0;
+}}
 }}  // namespace gl
 
 """
@@ -150,6 +158,28 @@ def dump_value_to_string_mapping(enum_groups, api_enum):
     ])
 
 
+def dump_string_to_value_mapping(enums_and_values):
+    templ = """\
+    if (strcmp(str, "{enum}") == 0)
+    {{
+        return {value};
+    }}
+"""
+
+    def f(value):
+        if value < 0:
+            return str(value)
+        if value < 0xFFFF:
+            return "0x%04X" % value
+        if value <= 0xFFFFFFFF:
+            return "0x%X" % value
+        else:
+            return "0xFFFFFFFF"
+
+    items = [templ.format(enum=k, value=f(v)) for (k, v) in sorted(enums_and_values)]
+    return ''.join(items)
+
+
 def main(header_output_path, source_output_path):
     xml = registry_xml.RegistryXML('gl.xml', 'gl_angle_ext.xml')
 
@@ -189,11 +219,13 @@ def main(header_output_path, source_output_path):
     gles_default_enums = dict()
     gl_enum_groups[registry_xml.default_enum_group_name] = gl_default_enums
     gles_enum_groups[registry_xml.default_enum_group_name] = gles_default_enums
+    enums_and_values = []
 
     for enums_node in xml.root.findall('enums'):
         for enum in enums_node.findall('enum'):
             enum_name = enum.attrib['name']
             enum_value = int(enum.attrib['value'], base=16)
+            enums_and_values.append((enum_name, enum_value))
 
             if enum_name in gles_enums:
                 gles_default_enums[enum_name] = enum_value
@@ -234,11 +266,13 @@ def main(header_output_path, source_output_path):
     # Write mapping to source file
     gles_enums_value_to_string_table = dump_value_to_string_mapping(gles_enum_groups, 'GLESEnum')
     gl_enums_value_to_string_table = dump_value_to_string_mapping(gl_enum_groups, 'BigGLEnum')
+    string_to_enum_table = dump_string_to_value_mapping(enums_and_values)
     source_content = template_gl_enums_source.format(
         script_name=os.path.basename(sys.argv[0]),
         data_source_name="gl.xml and gl_angle_ext.xml",
         gles_enums_value_to_string_table=gles_enums_value_to_string_table,
         gl_enums_value_to_string_table=gl_enums_value_to_string_table,
+        string_to_enum_table=string_to_enum_table,
     )
 
     source_output_path = registry_xml.script_relative(source_output_path)

src/common/gl_enum_utils.cpp

@@ -9,6 +9,7 @@
 #include "common/gl_enum_utils.h"
 
 #include "common/bitset_utils.h"
+#include "common/string_utils.h"
 
 #include <iomanip>
 #include <sstream>
@@ -121,4 +122,17 @@ const char *GLinternalFormatToString(unsigned int format)
 {
     return GLenumToString(gl::GLESEnum::InternalFormat, format);
 }
+
+unsigned int StringToGLbitfield(const char *str)
+{
+    unsigned int value = 0;
+    std::vector<std::string> strings =
+        angle::SplitString(str, " |", angle::WhitespaceHandling::TRIM_WHITESPACE,
+                           angle::SplitResult::SPLIT_WANT_NONEMPTY);
+    for (const std::string &enumString : strings)
+    {
+        value |= StringToGLenum(enumString.c_str());
+    }
+    return value;
+}
 }  // namespace gl

src/common/gl_enum_utils.h

@@ -25,6 +25,8 @@ void OutputGLenumString(std::ostream &out, GLESEnum enumGroup, unsigned int valu
 void OutputGLenumString(std::ostream &out, BigGLEnum enumGroup, unsigned int value);
 void OutputGLbitfieldString(std::ostream &out, GLESEnum enumGroup, unsigned int value);
 const char *GLinternalFormatToString(unsigned int format);
+unsigned int StringToGLenum(const char *str);
+unsigned int StringToGLbitfield(const char *str);
 
 extern const char kUnknownGLenumString[];
 }  // namespace gl