Running builder (content generator) functions in subprocesses on Windows

- Refactored all builder (make_*) functions into separate Python modules along to the build tree
- Introduced utility function to wrap all invocations on Windows, but does not change it elsewhere
- Introduced stub to use the builders module as a stand alone script and invoke a selected function

There is a problem with file handles related to writing generated content (*.gen.h and *.gen.cpp)
on Windows, which randomly causes a SHARING VIOLATION error to the compiler resulting in flaky
builds. Running all such content generators in a new subprocess instead of directly inside the
build script works around the issue.

Yes, I tried the multiprocessing module. It did not work due to conflict with SCons on cPickle.
Suggested workaround did not fully work either.

Using the run_in_subprocess wrapper on osx and x11 platforms as well for consistency. In case of
running a cross-compilation on Windows they would still be used, but likely it will not happen
in practice. What counts is that the build itself is running on which platform, not the target
platform.

Some generated files are written directly in an SConstruct or SCsub file, before the parallel build starts. They don't need to be written in a subprocess, apparently, so I left them as is.

1 files changed, 25 insertions, 144 deletions

diff --git a/editor/SCsub b/editor/SCsub
index a9343f7f36..4fa287c33b 100644
--- a/editor/SCsub
+++ b/editor/SCsub
@@ -5,149 +5,14 @@ env.editor_sources = []
 
 import os
 import os.path
-from compat import encode_utf8, byte_to_str, open_utf8, escape_string
-
-def make_certs_header(target, source, env):
-
-    src = source[0].srcnode().abspath
-    dst = target[0].srcnode().abspath
-    f = open(src, "rb")
-    g = open_utf8(dst, "w")
-    buf = f.read()
-    decomp_size = len(buf)
-    import zlib
-    buf = zlib.compress(buf)
-
-    g.write("/* THIS FILE IS GENERATED DO NOT EDIT */\n")
-    g.write("#ifndef _CERTS_RAW_H\n")
-    g.write("#define _CERTS_RAW_H\n")
-    g.write("static const int _certs_compressed_size = " + str(len(buf)) + ";\n")
-    g.write("static const int _certs_uncompressed_size = " + str(decomp_size) + ";\n")
-    g.write("static const unsigned char _certs_compressed[] = {\n")
-    for i in range(len(buf)):
-        g.write("\t" + byte_to_str(buf[i]) + ",\n")
-    g.write("};\n")
-    g.write("#endif")
-
-    g.close()
-    f.close()
-
-
-def make_doc_header(target, source, env):
-
-    dst = target[0].srcnode().abspath
-    g = open_utf8(dst, "w")
-    buf = ""
-    docbegin = ""
-    docend = ""
-    for s in source:
-        src = s.srcnode().abspath
-        if not src.endswith(".xml"):
-            continue
-        with open_utf8(src, "r") as f:
-            content = f.read()
-        buf += content
-
-    buf = encode_utf8(docbegin + buf + docend)
-    decomp_size = len(buf)
-    import zlib
-    buf = zlib.compress(buf)
-
-    g.write("/* THIS FILE IS GENERATED DO NOT EDIT */\n")
-    g.write("#ifndef _DOC_DATA_RAW_H\n")
-    g.write("#define _DOC_DATA_RAW_H\n")
-    g.write("static const int _doc_data_compressed_size = " + str(len(buf)) + ";\n")
-    g.write("static const int _doc_data_uncompressed_size = " + str(decomp_size) + ";\n")
-    g.write("static const unsigned char _doc_data_compressed[] = {\n")
-    for i in range(len(buf)):
-        g.write("\t" + byte_to_str(buf[i]) + ",\n")
-    g.write("};\n")
-
-    g.write("#endif")
-
-    g.close()
-
-
-def make_fonts_header(target, source, env):
-
-    dst = target[0].srcnode().abspath
-
-    g = open_utf8(dst, "w")
-
-    g.write("/* THIS FILE IS GENERATED DO NOT EDIT */\n")
-    g.write("#ifndef _EDITOR_FONTS_H\n")
-    g.write("#define _EDITOR_FONTS_H\n")
-
-    # saving uncompressed, since freetype will reference from memory pointer
-    xl_names = []
-    for i in range(len(source)):
-        with open(source[i].srcnode().abspath, "rb")as f:
-            buf = f.read()
-
-        name = os.path.splitext(os.path.basename(source[i].srcnode().abspath))[0]
-
-        g.write("static const int _font_" + name + "_size = " + str(len(buf)) + ";\n")
-        g.write("static const unsigned char _font_" + name + "[] = {\n")
-        for i in range(len(buf)):
-            g.write("\t" + byte_to_str(buf[i]) + ",\n")
-
-        g.write("};\n")
-
-    g.write("#endif")
-
-    g.close()
-
+from platform_methods import run_in_subprocess
+from compat import open_utf8
+import editor_builders
 
-def make_translations_header(target, source, env):
-
-    dst = target[0].srcnode().abspath
-
-    g = open_utf8(dst, "w")
-
-    g.write("/* THIS FILE IS GENERATED DO NOT EDIT */\n")
-    g.write("#ifndef _EDITOR_TRANSLATIONS_H\n")
-    g.write("#define _EDITOR_TRANSLATIONS_H\n")
-
-    import zlib
-    import os.path
-
-    paths = [node.srcnode().abspath for node in source]
-    sorted_paths = sorted(paths, key=lambda path: os.path.splitext(os.path.basename(path))[0])
-
-    xl_names = []
-    for i in range(len(sorted_paths)):
-        with open(sorted_paths[i], "rb") as f:
-            buf = f.read()
-        decomp_size = len(buf)
-        buf = zlib.compress(buf)
-        name = os.path.splitext(os.path.basename(sorted_paths[i]))[0]
-
-        g.write("static const unsigned char _translation_" + name + "_compressed[] = {\n")
-        for i in range(len(buf)):
-            g.write("\t" + byte_to_str(buf[i]) + ",\n")
-
-        g.write("};\n")
-
-        xl_names.append([name, len(buf), str(decomp_size)])
-
-    g.write("struct EditorTranslationList {\n")
-    g.write("\tconst char* lang;\n")
-    g.write("\tint comp_size;\n")
-    g.write("\tint uncomp_size;\n")
-    g.write("\tconst unsigned char* data;\n")
-    g.write("};\n\n")
-    g.write("static EditorTranslationList _editor_translations[] = {\n")
-    for x in xl_names:
-        g.write("\t{ \"" + x[0] + "\", " + str(x[1]) + ", " + str(x[2]) + ", _translation_" + x[0] + "_compressed},\n")
-    g.write("\t{NULL, 0, 0, NULL}\n")
-    g.write("};\n")
-
-    g.write("#endif")
-
-    g.close()
 
 def _make_doc_data_class_path(to_path):
-    g = open_utf8(os.path.join(to_path,"doc_data_class_path.gen.h"), "w")
+    # NOTE: It is safe to generate this file here, since this is still executed serially
+    g = open_utf8(os.path.join(to_path, "doc_data_class_path.gen.h"), "w")
     g.write("static const int _doc_data_class_path_count = " + str(len(env.doc_class_path)) + ";\n")
     g.write("struct _DocDataClassPath { const char* name; const char* path; };\n")
 
@@ -169,6 +34,8 @@ if env['tools']:
         reg_exporters += '\tregister_' + e + '_exporter();\n'
         reg_exporters_inc += '#include "platform/' + e + '/export/export.h"\n'
     reg_exporters += '}\n'
+
+    # NOTE: It is safe to generate this file here, since this is still executed serially
     with open_utf8("register_exporters.gen.cpp", "w") as f:
         f.write(reg_exporters_inc)
         f.write(reg_exporters)
@@ -192,24 +59,38 @@ if env['tools']:
 
     docs = sorted(docs)
     env.Depends("#editor/doc_data_compressed.gen.h", docs)
-    env.CommandNoCache("#editor/doc_data_compressed.gen.h", docs, make_doc_header)
+    env.CommandNoCache("#editor/doc_data_compressed.gen.h", docs, run_in_subprocess(editor_builders.make_doc_header))
+
     # Certificates
     env.Depends("#editor/certs_compressed.gen.h", "#thirdparty/certs/ca-certificates.crt")
-    env.CommandNoCache("#editor/certs_compressed.gen.h", "#thirdparty/certs/ca-certificates.crt", make_certs_header)
+    env.CommandNoCache("#editor/certs_compressed.gen.h", "#thirdparty/certs/ca-certificates.crt", run_in_subprocess(editor_builders.make_certs_header))
 
     import glob
+
     path = env.Dir('.').abspath
 
     # Translations
     tlist = glob.glob(path + "/translations/*.po")
     env.Depends('#editor/translations.gen.h', tlist)
-    env.CommandNoCache('#editor/translations.gen.h', tlist, make_translations_header)
+    env.CommandNoCache('#editor/translations.gen.h', tlist, run_in_subprocess(editor_builders.make_translations_header))
 
     # Fonts
     flist = glob.glob(path + "/../thirdparty/fonts/*.ttf")
     flist.append(glob.glob(path + "/../thirdparty/fonts/*.otf"))
     env.Depends('#editor/builtin_fonts.gen.h', flist)
-    env.CommandNoCache('#editor/builtin_fonts.gen.h', flist, make_fonts_header)
+    env.CommandNoCache('#editor/builtin_fonts.gen.h', flist, run_in_subprocess(editor_builders.make_fonts_header))
+
+    # Authors
+    env.Depends('#editor/authors.gen.h', "../AUTHORS.md")
+    env.CommandNoCache('#editor/authors.gen.h', "../AUTHORS.md", run_in_subprocess(editor_builders.make_authors_header))
+
+    # Donors
+    env.Depends('#editor/donors.gen.h', "../DONORS.md")
+    env.CommandNoCache('#editor/donors.gen.h', "../DONORS.md", run_in_subprocess(editor_builders.make_donors_header))
+
+    # License
+    env.Depends('#editor/license.gen.h', ["../COPYRIGHT.txt", "../LICENSE.txt"])
+    env.CommandNoCache('#editor/license.gen.h', ["../COPYRIGHT.txt", "../LICENSE.txt"], run_in_subprocess(editor_builders.make_license_header))
 
     env.add_source_files(env.editor_sources, "*.cpp")
     env.add_source_files(env.editor_sources, ["#thirdparty/misc/clipper.cpp"])