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.

4 files changed, 537 insertions, 230 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"])
diff --git a/editor/editor_builders.py b/editor/editor_builders.py
new file mode 100644
index 0000000000..6c2f9e298e
--- /dev/null
+++ b/editor/editor_builders.py
@@ -0,0 +1,412 @@
+"""Functions used to generate source files during build time
+
+All such functions are invoked in a subprocess on Windows to prevent build flakiness.
+
+"""
+import os
+import os.path
+from platform_methods import subprocess_main
+from compat import encode_utf8, byte_to_str, open_utf8, escape_string
+
+
+def make_certs_header(target, source, env):
+
+    src = source[0]
+    dst = target[0]
+    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]
+    g = open_utf8(dst, "w")
+    buf = ""
+    docbegin = ""
+    docend = ""
+    for src in source:
+        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]
+
+    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], "rb")as f:
+            buf = f.read()
+
+        name = os.path.splitext(os.path.basename(source[i]))[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()
+
+
+def make_translations_header(target, source, env):
+
+    dst = target[0]
+
+    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
+
+    sorted_paths = sorted(source, 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_authors_header(target, source, env):
+
+    sections = ["Project Founders", "Lead Developer", "Project Manager", "Developers"]
+    sections_id = ["dev_founders", "dev_lead", "dev_manager", "dev_names"]
+
+    src = source[0]
+    dst = target[0]
+    f = open_utf8(src, "r")
+    g = open_utf8(dst, "w")
+
+    g.write("/* THIS FILE IS GENERATED DO NOT EDIT */\n")
+    g.write("#ifndef _EDITOR_AUTHORS_H\n")
+    g.write("#define _EDITOR_AUTHORS_H\n")
+
+    current_section = ""
+    reading = False
+
+    def close_section():
+        g.write("\t0\n")
+        g.write("};\n")
+
+    for line in f:
+        if reading:
+            if line.startswith("    "):
+                g.write("\t\"" + escape_string(line.strip()) + "\",\n")
+                continue
+        if line.startswith("## "):
+            if reading:
+                close_section()
+                reading = False
+            for i in range(len(sections)):
+                if line.strip().endswith(sections[i]):
+                    current_section = escape_string(sections_id[i])
+                    reading = True
+                    g.write("static const char *" + current_section + "[] = {\n")
+                    break
+
+    if reading:
+        close_section()
+
+    g.write("#endif\n")
+
+    g.close()
+    f.close()
+
+def make_donors_header(target, source, env):
+
+    sections = ["Platinum sponsors", "Gold sponsors", "Mini sponsors", "Gold donors", "Silver donors", "Bronze donors"]
+    sections_id = ["donor_s_plat", "donor_s_gold", "donor_s_mini", "donor_gold", "donor_silver", "donor_bronze"]
+
+    src = source[0]
+    dst = target[0]
+    f = open_utf8(src, "r")
+    g = open_utf8(dst, "w")
+
+    g.write("/* THIS FILE IS GENERATED DO NOT EDIT */\n")
+    g.write("#ifndef _EDITOR_DONORS_H\n")
+    g.write("#define _EDITOR_DONORS_H\n")
+
+    current_section = ""
+    reading = False
+
+    def close_section():
+        g.write("\t0\n")
+        g.write("};\n")
+
+    for line in f:
+        if reading >= 0:
+            if line.startswith("    "):
+                g.write("\t\"" + escape_string(line.strip()) + "\",\n")
+                continue
+        if line.startswith("## "):
+            if reading:
+                close_section()
+                reading = False
+            for i in range(len(sections)):
+                if line.strip().endswith(sections[i]):
+                    current_section = escape_string(sections_id[i])
+                    reading = True
+                    g.write("static const char *" + current_section + "[] = {\n")
+                    break
+
+    if reading:
+        close_section()
+
+    g.write("#endif\n")
+
+    g.close()
+    f.close()
+
+
+def make_license_header(target, source, env):
+
+    src_copyright = source[0]
+    src_license = source[1]
+    dst = target[0]
+    f = open_utf8(src_license, "r")
+    fc = open_utf8(src_copyright, "r")
+    g = open_utf8(dst, "w")
+
+    g.write("/* THIS FILE IS GENERATED DO NOT EDIT */\n")
+    g.write("#ifndef _EDITOR_LICENSE_H\n")
+    g.write("#define _EDITOR_LICENSE_H\n")
+    g.write("static const char *about_license =")
+
+    for line in f:
+        escaped_string = escape_string(line.strip())
+        g.write("\n\t\"" + escaped_string + "\\n\"")
+
+    g.write(";\n")
+
+    tp_current = 0
+    tp_file = ""
+    tp_comment = ""
+    tp_copyright = ""
+    tp_license = ""
+
+    tp_licensename = ""
+    tp_licensebody = ""
+
+    tp = []
+    tp_licensetext = []
+    for line in fc:
+        if line.startswith("#"):
+            continue
+
+        if line.startswith("Files:"):
+            tp_file = line[6:].strip()
+            tp_current = 1
+        elif line.startswith("Comment:"):
+            tp_comment = line[8:].strip()
+            tp_current = 2
+        elif line.startswith("Copyright:"):
+            tp_copyright = line[10:].strip()
+            tp_current = 3
+        elif line.startswith("License:"):
+            if tp_current != 0:
+                tp_license = line[8:].strip()
+                tp_current = 4
+            else:
+                tp_licensename = line[8:].strip()
+                tp_current = 5
+        elif line.startswith(" "):
+            if tp_current == 1:
+                tp_file += "\n" + line.strip()
+            elif tp_current == 3:
+                tp_copyright += "\n" + line.strip()
+            elif tp_current == 5:
+                if line.strip() == ".":
+                    tp_licensebody += "\n"
+                else:
+                    tp_licensebody += line[1:]
+        else:
+            if tp_current != 0:
+                if tp_current == 5:
+                    tp_licensetext.append([tp_licensename, tp_licensebody])
+
+                    tp_licensename = ""
+                    tp_licensebody = ""
+                else:
+                    added = False
+                    for i in tp:
+                        if i[0] == tp_comment:
+                            i[1].append([tp_file, tp_copyright, tp_license])
+                            added = True
+                            break
+                    if not added:
+                        tp.append([tp_comment,[[tp_file, tp_copyright, tp_license]]])
+
+                    tp_file = []
+                    tp_comment = ""
+                    tp_copyright = []
+                    tp_license = ""
+                tp_current = 0
+
+    tp_licensetext.append([tp_licensename, tp_licensebody])
+
+    about_thirdparty = ""
+    about_tp_copyright_count = ""
+    about_tp_license = ""
+    about_tp_copyright = ""
+    about_tp_file = ""
+
+    for i in tp:
+        about_thirdparty += "\t\"" + i[0] + "\",\n"
+        about_tp_copyright_count += str(len(i[1])) + ", "
+        for j in i[1]:
+            file_body = ""
+            copyright_body = ""
+            for k in j[0].split("\n"):
+                if file_body != "":
+                    file_body += "\\n\"\n"
+                escaped_string = escape_string(k.strip())
+                file_body += "\t\"" + escaped_string
+            for k in j[1].split("\n"):
+                if copyright_body != "":
+                    copyright_body += "\\n\"\n"
+                escaped_string = escape_string(k.strip())
+                copyright_body += "\t\"" + escaped_string
+
+            about_tp_file += "\t" + file_body + "\",\n"
+            about_tp_copyright += "\t" + copyright_body + "\",\n"
+            about_tp_license += "\t\"" + j[2] + "\",\n"
+
+    about_license_name = ""
+    about_license_body = ""
+
+    for i in tp_licensetext:
+        body = ""
+        for j in i[1].split("\n"):
+            if body != "":
+                body += "\\n\"\n"
+            escaped_string = escape_string(j.strip())
+            body += "\t\"" + escaped_string
+
+        about_license_name += "\t\"" + i[0] + "\",\n"
+        about_license_body += "\t" + body + "\",\n"
+
+    g.write("static const char *about_thirdparty[] = {\n")
+    g.write(about_thirdparty)
+    g.write("\t0\n")
+    g.write("};\n")
+    g.write("#define THIRDPARTY_COUNT " + str(len(tp)) + "\n")
+
+    g.write("static const int about_tp_copyright_count[] = {\n\t")
+    g.write(about_tp_copyright_count)
+    g.write("0\n};\n")
+
+    g.write("static const char *about_tp_file[] = {\n")
+    g.write(about_tp_file)
+    g.write("\t0\n")
+    g.write("};\n")
+
+    g.write("static const char *about_tp_copyright[] = {\n")
+    g.write(about_tp_copyright)
+    g.write("\t0\n")
+    g.write("};\n")
+
+    g.write("static const char *about_tp_license[] = {\n")
+    g.write(about_tp_license)
+    g.write("\t0\n")
+    g.write("};\n")
+
+    g.write("static const char *about_license_name[] = {\n")
+    g.write(about_license_name)
+    g.write("\t0\n")
+    g.write("};\n")
+    g.write("#define LICENSE_COUNT " + str(len(tp_licensetext)) + "\n")
+
+    g.write("static const char *about_license_body[] = {\n")
+    g.write(about_license_body)
+    g.write("\t0\n")
+    g.write("};\n")
+
+    g.write("#endif\n")
+
+    g.close()
+    fc.close()
+    f.close()
+
+
+if __name__ == '__main__':
+    subprocess_main(globals())
diff --git a/editor/icons/SCsub b/editor/icons/SCsub
index 7f94073e01..31bf8f116a 100644
--- a/editor/icons/SCsub
+++ b/editor/icons/SCsub
@@ -1,96 +1,14 @@
 #!/usr/bin/env python
 
 Import('env')
-from compat import StringIO
+from platform_methods import run_in_subprocess
+import editor_icons_builders
 
-def make_editor_icons_action(target, source, env):
 
-    import os
-
-    dst = target[0].srcnode().abspath
-    svg_icons = source
-
-    icons_string = StringIO()
-
-    for f in svg_icons:
-
-        fname = str(f)
-
-        icons_string.write('\t"')
-
-        with open(fname, 'rb') as svgf:
-            b = svgf.read(1)
-            while(len(b) == 1):
-                icons_string.write("\\" + str(hex(ord(b)))[1:])
-                b = svgf.read(1)
-
-
-        icons_string.write('"')
-        if fname != svg_icons[-1]:
-            icons_string.write(",")
-        icons_string.write('\n')
-
-    s = StringIO()
-    s.write("/* THIS FILE IS GENERATED DO NOT EDIT */\n")
-    s.write("#ifndef _EDITOR_ICONS_H\n")
-    s.write("#define _EDITOR_ICONS_H\n")
-    s.write("static const int editor_icons_count = {};\n".format(len(svg_icons)))
-    s.write("static const char *editor_icons_sources[] = {\n")
-    s.write(icons_string.getvalue())
-    s.write('};\n\n')
-    s.write("static const char *editor_icons_names[] = {\n")
-
-    # this is used to store the indices of thumbnail icons
-    thumb_medium_indices = [];
-    thumb_big_indices = [];
-    index = 0
-    for f in svg_icons:
-
-        fname = str(f)
-
-        icon_name = os.path.basename(fname)[5:-4].title().replace("_", "")
-        # some special cases
-        if icon_name in ['Int', 'Bool', 'Float']:
-            icon_name = icon_name.lower()
-        if icon_name.endswith("MediumThumb"):  # don't know a better way to handle this
-            thumb_medium_indices.append(str(index))
-        if icon_name.endswith("BigThumb"):  # don't know a better way to handle this
-            thumb_big_indices.append(str(index))
-
-        s.write('\t"{0}"'.format(icon_name))
-
-        if fname != svg_icons[-1]:
-            s.write(",")
-        s.write('\n')
-
-        index += 1
-
-    s.write('};\n')
-
-    if thumb_medium_indices:
-        s.write("\n\n")
-        s.write("static const int editor_md_thumbs_count = {};\n".format(len(thumb_medium_indices)))
-        s.write("static const int editor_md_thumbs_indices[] = {")
-        s.write(", ".join(thumb_medium_indices))
-        s.write("};\n")
-    if thumb_big_indices:
-        s.write("\n\n")
-        s.write("static const int editor_bg_thumbs_count = {};\n".format(len(thumb_big_indices)))
-        s.write("static const int editor_bg_thumbs_indices[] = {")
-        s.write(", ".join(thumb_big_indices))
-        s.write("};\n")
-
-    s.write("#endif\n")
-
-    with open(dst, "w") as f:
-        f.write(s.getvalue())
-
-    s.close()
-    icons_string.close()
-
-make_editor_icons_builder = Builder(action=make_editor_icons_action,
+make_editor_icons_builder = Builder(action=run_in_subprocess(editor_icons_builders.make_editor_icons_action),
                                     suffix='.h',
                                     src_suffix='.svg')
+
 env['BUILDERS']['MakeEditorIconsBuilder'] = make_editor_icons_builder
 env.Alias('editor_icons', [env.MakeEditorIconsBuilder('#editor/editor_icons.gen.h', Glob("*.svg"))])
 
diff --git a/editor/icons/editor_icons_builders.py b/editor/icons/editor_icons_builders.py
new file mode 100644
index 0000000000..dfd0802ce9
--- /dev/null
+++ b/editor/icons/editor_icons_builders.py
@@ -0,0 +1,96 @@
+"""Functions used to generate source files during build time
+
+All such functions are invoked in a subprocess on Windows to prevent build flakiness.
+
+"""
+import os
+from platform_methods import subprocess_main
+from compat import StringIO
+
+
+def make_editor_icons_action(target, source, env):
+
+    dst = target[0]
+    svg_icons = source
+
+    icons_string = StringIO()
+
+    for f in svg_icons:
+
+        fname = str(f)
+
+        icons_string.write('\t"')
+
+        with open(fname, 'rb') as svgf:
+            b = svgf.read(1)
+            while(len(b) == 1):
+                icons_string.write("\\" + str(hex(ord(b)))[1:])
+                b = svgf.read(1)
+
+
+        icons_string.write('"')
+        if fname != svg_icons[-1]:
+            icons_string.write(",")
+        icons_string.write('\n')
+
+    s = StringIO()
+    s.write("/* THIS FILE IS GENERATED DO NOT EDIT */\n")
+    s.write("#ifndef _EDITOR_ICONS_H\n")
+    s.write("#define _EDITOR_ICONS_H\n")
+    s.write("static const int editor_icons_count = {};\n".format(len(svg_icons)))
+    s.write("static const char *editor_icons_sources[] = {\n")
+    s.write(icons_string.getvalue())
+    s.write('};\n\n')
+    s.write("static const char *editor_icons_names[] = {\n")
+
+    # this is used to store the indices of thumbnail icons
+    thumb_medium_indices = [];
+    thumb_big_indices = [];
+    index = 0
+    for f in svg_icons:
+
+        fname = str(f)
+
+        icon_name = os.path.basename(fname)[5:-4].title().replace("_", "")
+        # some special cases
+        if icon_name in ['Int', 'Bool', 'Float']:
+            icon_name = icon_name.lower()
+        if icon_name.endswith("MediumThumb"):  # don't know a better way to handle this
+            thumb_medium_indices.append(str(index))
+        if icon_name.endswith("BigThumb"):  # don't know a better way to handle this
+            thumb_big_indices.append(str(index))
+
+        s.write('\t"{0}"'.format(icon_name))
+
+        if fname != svg_icons[-1]:
+            s.write(",")
+        s.write('\n')
+
+        index += 1
+
+    s.write('};\n')
+
+    if thumb_medium_indices:
+        s.write("\n\n")
+        s.write("static const int editor_md_thumbs_count = {};\n".format(len(thumb_medium_indices)))
+        s.write("static const int editor_md_thumbs_indices[] = {")
+        s.write(", ".join(thumb_medium_indices))
+        s.write("};\n")
+    if thumb_big_indices:
+        s.write("\n\n")
+        s.write("static const int editor_bg_thumbs_count = {};\n".format(len(thumb_big_indices)))
+        s.write("static const int editor_bg_thumbs_indices[] = {")
+        s.write(", ".join(thumb_big_indices))
+        s.write("};\n")
+
+    s.write("#endif\n")
+
+    with open(dst, "w") as f:
+        f.write(s.getvalue())
+
+    s.close()
+    icons_string.close()
+
+
+if __name__ == '__main__':
+    subprocess_main(globals())