Add GDExtension support to Script

* Ability to create script languages from GDExtension
* Some additions to gdnative_extension.h to make this happen
* Moved the GDExtension binder to core

This now allows creating scripting languages from GDExtension, with the same ease as if it was a module. It replaces the old PluginScript from Godot 3.x.
Warning: GodotCPP will need to be updated to support this (it may be a bit of work as ScriptInstance needs to be created over there again).

1 files changed, 93 insertions, 0 deletions

diff --git a/core/extension/make_wrappers.py b/core/extension/make_wrappers.py
new file mode 100644
index 0000000000..862d313fba
--- /dev/null
+++ b/core/extension/make_wrappers.py
@@ -0,0 +1,93 @@
+proto = """
+#define EXBIND$VER($RETTYPE m_name$ARG) \\
+GDVIRTUAL$VER($RETTYPE_##m_name$ARG)\\
+virtual $RETVAL m_name($FUNCARGS) $CONST override { \\
+    $RETPRE\\
+    GDVIRTUAL_REQUIRED_CALL(_##m_name$CALLARGS$RETREF);\\
+    $RETPOST\\
+}
+"""
+
+
+def generate_version(argcount, const=False, returns=False):
+    s = proto
+    sproto = str(argcount)
+    method_info = ""
+    if returns:
+        sproto += "R"
+        s = s.replace("$RETTYPE", "m_ret, ")
+        s = s.replace("$RETVAL", "m_ret")
+        s = s.replace("$RETPRE", "m_ret ret; ZeroInitializer<m_ret>::initialize(ret);\\\n")
+        s = s.replace("$RETPOST", "return ret;\\\n")
+
+    else:
+        s = s.replace("$RETTYPE", "")
+        s = s.replace("$RETVAL", "void")
+        s = s.replace("$RETPRE", "")
+        s = s.replace("$RETPOST", "return;")
+
+    if const:
+        sproto += "C"
+        s = s.replace("$CONST", "const")
+    else:
+        s = s.replace("$CONST", "")
+
+    s = s.replace("$VER", sproto)
+    argtext = ""
+    funcargs = ""
+    callargs = ""
+
+    for i in range(argcount):
+        if i > 0:
+            funcargs += ", "
+
+        argtext += ", m_type" + str(i + 1)
+        funcargs += "m_type" + str(i + 1) + " arg" + str(i + 1)
+        callargs += ", arg" + str(i + 1)
+
+    if argcount:
+        s = s.replace("$ARG", argtext)
+        s = s.replace("$FUNCARGS", funcargs)
+        s = s.replace("$CALLARGS", callargs)
+    else:
+        s = s.replace("$ARG", "")
+        s = s.replace("$FUNCARGS", funcargs)
+        s = s.replace("$CALLARGS", callargs)
+
+    if returns:
+        s = s.replace("$RETREF", ", ret")
+    else:
+        s = s.replace("$RETREF", "")
+
+    return s
+
+
+def run(target, source, env):
+
+    max_versions = 12
+
+    txt = """
+#ifndef GDEXTENSION_WRAPPERS_GEN_H
+#define GDEXTENSION_WRAPPERS_GEN_H
+
+
+"""
+
+    for i in range(max_versions + 1):
+
+        txt += "/* " + str(i) + " Arguments */\n\n"
+        txt += generate_version(i, False, False)
+        txt += generate_version(i, False, True)
+        txt += generate_version(i, True, False)
+        txt += generate_version(i, True, True)
+
+    txt += "#endif"
+
+    with open(target[0], "w") as f:
+        f.write(txt)
+
+
+if __name__ == "__main__":
+    from platform_methods import subprocess_main
+
+    subprocess_main(globals())