1 files changed, 196 insertions, 0 deletions
diff --git a/js/src/vm/make_opcode_doc.py b/js/src/vm/make_opcode_doc.py
new file mode 100755
index 0000000000..43a3c72593
--- /dev/null
+++ b/js/src/vm/make_opcode_doc.py
@@ -0,0 +1,196 @@
+#!/usr/bin/env python3 -B
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this file,
+# You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+""" Usage: python make_opcode_doc.py
+
+    This script generates SpiderMonkey bytecode documentation
+    from js/src/vm/Opcodes.h.
+
+    Output is written to stdout and should be pasted into the following
+    MDN page:
+    https://developer.mozilla.org/en-US/docs/SpiderMonkey/Internals/Bytecode
+"""
+
+import sys
+import os
+
+
+# Allow this script to be run from anywhere.
+this_dir = os.path.dirname(os.path.realpath(__file__))
+sys.path.insert(0, this_dir)
+
+
+import jsopcode
+from xml.sax.saxutils import escape
+
+
+try:
+    import markdown
+except ModuleNotFoundError as exc:
+    if exc.name == "markdown":
+        # Right, most people won't have python-markdown installed. Suggest the
+        # most likely path to getting this running.
+        print("Failed to import markdown: " + exc.msg, file=sys.stderr)
+        if os.path.exists(os.path.join(this_dir, "venv")):
+            print(
+                "It looks like you previously created a virtualenv here. Try this:\n"
+                "    . venv/bin/activate",
+                file=sys.stderr,
+            )
+            sys.exit(1)
+        print(
+            "Try this:\n"
+            "    pip3 install markdown\n"
+            "Or, if you want to avoid installing things globally:\n"
+            "    python3 -m venv venv && . venv/bin/activate && pip3 install markdown",
+            file=sys.stderr,
+        )
+        sys.exit(1)
+    raise exc
+except ImportError as exc:
+    # Oh no! Markdown failed to load. Check for a specific known issue.
+    if exc.msg.startswith("bad magic number in 'opcode'") and os.path.isfile(
+        os.path.join(this_dir, "opcode.pyc")
+    ):
+        print(
+            "Failed to import markdown due to bug 1506380.\n"
+            "This is dumb--it's an old Python cache file in your directory. Try this:\n"
+            "    rm " + this_dir + "/opcode.pyc\n"
+            "The file is obsolete since November 2018.",
+            file=sys.stderr,
+        )
+        sys.exit(1)
+    raise exc
+
+
+SOURCE_BASE = "https://searchfox.org/mozilla-central/source"
+
+FORMAT_TO_IGNORE = {
+    "JOF_BYTE",
+    "JOF_UINT8",
+    "JOF_UINT16",
+    "JOF_UINT24",
+    "JOF_UINT32",
+    "JOF_INT8",
+    "JOF_INT32",
+    "JOF_TABLESWITCH",
+    "JOF_REGEXP",
+    "JOF_DOUBLE",
+    "JOF_LOOPHEAD",
+    "JOF_BIGINT",
+}
+
+
+def format_format(format):
+    format = [flag for flag in format if flag not in FORMAT_TO_IGNORE]
+    if len(format) == 0:
+        return ""
+    return "<div>Format: {format}</div>\n".format(format=", ".join(format))
+
+
+def maybe_escape(value, format_str, fallback=""):
+    if value:
+        return format_str.format(escape(value))
+    return fallback
+
+
+OPCODE_FORMAT = """\
+<dt id="{id}">{names}</dt>
+<dd>
+{operands}{stack}{desc}
+{format}</dd>
+"""
+
+
+def print_opcode(opcode):
+    opcodes = [opcode] + opcode.group
+    names = ", ".join(maybe_escape(code.op, "<code>{}</code>") for code in opcodes)
+    operands = maybe_escape(opcode.operands, "<div>Operands: <code>({})</code></div>\n")
+    stack_uses = maybe_escape(opcode.stack_uses, "<code>{}</code> ")
+    stack_defs = maybe_escape(opcode.stack_defs, " <code>{}</code>")
+    if stack_uses or stack_defs:
+        stack = "<div>Stack: {}&rArr;{}</div>\n".format(stack_uses, stack_defs)
+    else:
+        stack = ""
+
+    print(
+        OPCODE_FORMAT.format(
+            id=opcodes[0].op,
+            names=names,
+            operands=operands,
+            stack=stack,
+            desc=markdown.markdown(opcode.desc),
+            format=format_format(opcode.format_),
+        )
+    )
+
+
+id_cache = dict()
+id_count = dict()
+
+
+def make_element_id(category, type=""):
+    key = "{}:{}".format(category, type)
+    if key in id_cache:
+        return id_cache[key]
+
+    if type == "":
+        id = category.replace(" ", "_")
+    else:
+        id = type.replace(" ", "_")
+
+    if id in id_count:
+        id_count[id] += 1
+        id = "{}_{}".format(id, id_count[id])
+    else:
+        id_count[id] = 1
+
+    id_cache[key] = id
+    return id
+
+
+def print_doc(index):
+    print(
+        """<div>{{{{SpiderMonkeySidebar("Internals")}}}}</div>
+
+<h2 id="Bytecode_Listing">Bytecode Listing</h2>
+
+<p>This document is automatically generated from
+<a href="{source_base}/js/src/vm/Opcodes.h">Opcodes.h</a> by
+<a href="{source_base}/js/src/vm/make_opcode_doc.py">make_opcode_doc.py</a>.</p>
+""".format(
+            source_base=SOURCE_BASE
+        )
+    )
+
+    for (category_name, types) in index:
+        print(
+            '<h3 id="{id}">{name}</h3>'.format(
+                name=category_name, id=make_element_id(category_name)
+            )
+        )
+        for (type_name, opcodes) in types:
+            if type_name:
+                print(
+                    '<h4 id="{id}">{name}</h4>'.format(
+                        name=type_name, id=make_element_id(category_name, type_name)
+                    )
+                )
+            print("<dl>")
+            for opcode in opcodes:
+                print_opcode(opcode)
+            print("</dl>")
+
+
+if __name__ == "__main__":
+    if len(sys.argv) != 1:
+        print("Usage: mach python make_opcode_doc.py", file=sys.stderr)
+        sys.exit(1)
+    js_src_vm_dir = os.path.dirname(os.path.realpath(__file__))
+    root_dir = os.path.abspath(os.path.join(js_src_vm_dir, "..", "..", ".."))
+
+    index, _ = jsopcode.get_opcodes(root_dir)
+    print_doc(index)