glad: add option to make glad builds reproducible.

gh: Dav1dde#162

.gitignore

@@ -1,5 +1,5 @@
 *.pyc
-*.xml
+/*.xml
 *.kdev4
 build/
 *.o
@@ -11,8 +11,9 @@ main.c
 .idea
 dist/
 *.egg-info
-khrplatform.h
-eglplatform.h
+/khrplatform.h
+/eglplatform.h
+/vk_platform.h
 /glad-rs/
 /rust/
 target/

MANIFEST.in

@@ -1 +1 @@
-recursive-include glad *.c *.h *.d *.volt *.rs *.toml
+recursive-include glad *.c *.h *.d *.volt *.rs *.toml *.xml

cmake/CMakeLists.txt

@@ -174,7 +174,7 @@ endfunction()
 
 # Create a glad library named "${TARGET}"
 function(glad_add_library TARGET)
-    cmake_parse_arguments(GG "MERGE;QUIET;KEEP_SOURCES;STATIC;SHARED;MODULE;EXCLUDE_FROM_ALL" "LOCATION;LANGUAGE" "API;EXTENSIONS" ${ARGN})
+    cmake_parse_arguments(GG "MERGE;QUIET;REPRODUCIBLE;KEEP_SOURCES;STATIC;SHARED;MODULE;EXCLUDE_FROM_ALL" "LOCATION;LANGUAGE" "API;EXTENSIONS" ${ARGN})
 
     if(NOT GG_LOCATION)
         set(GG_LOCATION "${CMAKE_CURRENT_BINARY_DIR}/gladsources/${TARGET}")
@@ -209,6 +209,10 @@ function(glad_add_library TARGET)
         list(APPEND GLAD_ARGS --merge)
     endif()
 
+    if(GG_REPRODUCIBLE)
+        list(APPEND GLAD_ARGS --reproducible)
+    endif()
+
     set(GLAD_LANGUAGE "c")
     if(GG_LANGUAGE)
         string(TOLOWER "${GG_LANGUAGE}" "${GLAD_LANGUAGE}")

example/c++/multiwin_mx/CMakeLists.txt

@@ -6,7 +6,7 @@ find_package(glfw3 REQUIRED)
 set(GLAD_SOURCES_DIR "${PROJECT_SOURCE_DIR}/../../..")
 add_subdirectory("${GLAD_SOURCES_DIR}/cmake" glad_cmake)
 
-glad_add_library(glad_gl_core_mx_33 MX API gl:core=3.3)
+glad_add_library(glad_gl_core_mx_33 REPRODUCIBLE MX API gl:core=3.3)
 
 add_executable(multiwin_mx
     multiwin_mx.cpp

example/c/egl_x11/CMakeLists.txt

@@ -6,7 +6,7 @@ find_package(X11 REQUIRED)
 set(GLAD_SOURCES_DIR "${PROJECT_SOURCE_DIR}/../../..")
 add_subdirectory("${GLAD_SOURCES_DIR}/cmake" glad_cmake)
 
-glad_add_library(glad_egl_15_gles2_20 LOADER API egl=1.5 gles2=2.0)
+glad_add_library(glad_egl_15_gles2_20 REPRODUCIBLE LOADER API egl=1.5 gles2=2.0)
 add_executable(egl_x11
     egl_x11.c
     )

example/c/vulkan_tri_glfw/CMakeLists.txt

@@ -6,7 +6,7 @@ add_subdirectory("${GLAD_SOURCES_DIR}/cmake" glad_cmake)
 
 find_package(glfw3 REQUIRED)
 
-glad_add_library(glad_vulkan_11 LOADER API vulkan=1.1)
+glad_add_library(glad_vulkan_11 REPRODUCIBLE LOADER API vulkan=1.1)
 add_executable(vulkan_tri_glfw
     vulkan_tri_glfw.c
     )

glad/__main__.py

@@ -9,6 +9,7 @@
 import logging
 import os
 
+import glad.files
 from glad.config import Config, ConfigOption
 from glad.sink import LoggingSink
 from glad.opener import URLOpener
@@ -48,7 +49,7 @@ class GlobalConfig(Config):
         default=None,
         description='Path to a file containing a list of extensions or '
                     'a comma separated list of extensions, if missing '
-                    'all possible extensions are included'
+                    'all possible extensions are included.'
     )
     MERGE = ConfigOption(
         converter=bool,
@@ -57,11 +58,17 @@ class GlobalConfig(Config):
     )
     QUIET = ConfigOption(
         converter=bool,
-        description='Disable logging'
+        description='Disable logging.'
+    )
+    REPRODUCIBLE = ConfigOption(
+        converter=bool,
+        default=False,
+        description='Makes the build reproducible by not fetching the latest '
+                    'specification from Khronos.'
     )
 
 
-def load_specifications(specification_names, opener, specification_classes=None):
+def load_specifications(specification_names, opener, specification_classes=None, reproducible=False):
     specifications = dict()
 
     if specification_classes is None:
@@ -71,7 +78,10 @@ def load_specifications(specification_names, opener, specification_classes=None)
         Specification = specification_classes[name]
         xml_name = name + '.xml'
 
-        if os.path.isfile(xml_name):
+        if reproducible and False:
+            logger.info('reproducible build, using packaged specification: %s', xml_name)
+            specification = Specification.from_file(glad.files.open_local(xml_name))
+        elif os.path.isfile(xml_name):
             logger.info('using local specification: %s', xml_name)
             specification = Specification.from_file(xml_name, opener=opener)
         else:
@@ -132,11 +142,15 @@ def main(args=None):
     global_config.validate()  # Done before, but doesn't hurt
     config.validate()
 
-    opener = URLOpener()
+    if global_config['REPRODUCIBLE']:
+        opener = glad.files.StaticFileOpener()
+    else:
+        opener = URLOpener()
 
     specifications = load_specifications(
         [value[0] for value in global_config['API'].values()],
-        opener=opener
+        opener=opener,
+        reproducible=global_config['REPRODUCIBLE']
     )
 
     generator = generators[ns.subparser_name](global_config['OUT_PATH'], opener=opener)

glad/files/__init__.py

@@ -0,0 +1,56 @@
+import os.path
+import logging
+import shutil
+
+try:
+    from urlparse import urlparse
+except ImportError:
+    from urllib.parse import urlparse
+
+try:
+    from pkg_resources import resource_exists, resource_stream
+except ImportError:
+    def resource_exists(*args, **kwargs):
+        return False
+
+    def resource_stream(*args, **kwargs):
+        return None
+
+
+BASE_PATH = os.path.abspath(os.path.dirname(__file__))
+
+logger = logging.getLogger('glad.files')
+
+
+class GladFileException(Exception):
+    pass
+
+
+def open_local(name, *args, **kwargs):
+    # use pkg_resources when available, makes it work in zipped modules
+    # or other environments
+    if resource_exists(__name__, name):
+        logger.info('opening packaged resource: %r', name)
+        return resource_stream(__name__, name)
+
+    # fallback to filesystem
+    logger.info('opening packaged path: %r', name)
+    local_path = os.path.normpath(os.path.join(BASE_PATH, os.path.join(name)))
+    if not local_path.startswith(BASE_PATH):
+        raise GladFileException('unsafe file path, won\'t open {!r}'.format(local_path))
+    return open(local_path, *args, **kwargs)
+
+
+class StaticFileOpener(object):
+    def urlopen(self, url, data=None, *args, **kwargs):
+        logger.debug('intercepted attempt to retrieve remote resource %r', url)
+        if data is not None:
+            raise GladFileException('can not resolve requests with payload')
+
+        filename = urlparse(url).path.rsplit('/', 1)[-1]
+        return open_local(filename, 'rb')
+
+    def urlretrieve(self, url, filename, *args, **kwargs):
+        with self.urlopen(url) as src:
+            with open(filename, 'wb') as dst:
+                shutil.copyfileobj(src, dst)