[Qemu-devel] [PATCH 19/22] qidl: add C parser (based on QC parser)

[Michael Roth <mdroth@linux.vnet.ibm.com>]

This introduces the QIDL parser to process QIDL annotations in C files.
This code is mostly a straight import from qc.git, with some reworking
to handle the declaration/annotation format and lexer we're using for
QEMU.

Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
---
 scripts/qidl_parser.py |  262 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 262 insertions(+)
 create mode 100644 scripts/qidl_parser.py

diff --git a/scripts/qidl_parser.py b/scripts/qidl_parser.py
new file mode 100644
index 0000000..fe155f7
--- /dev/null
+++ b/scripts/qidl_parser.py
@@ -0,0 +1,262 @@
+#
+# QEMU IDL Parser
+#
+# Copyright IBM, Corp. 2012
+#
+# Authors:
+#  Anthony Liguori <aliguori@us.ibm.com>
+#  Michael Roth    <mdroth@linux.vnet.ibm.com>
+#
+# This work is licensed under the terms of the GNU GPLv2.
+# See the COPYING file in the top-level directory.
+
+import sys, json
+from lexer import Input, CLexer
+
+def process_annotation(node, params):
+    annotation_type = params[0]
+    if annotation_type == "derived":
+        node['is_derived'] = True
+    elif annotation_type == 'immutable':
+        node['is_immutable'] = True
+    elif annotation_type == 'elsewhere':
+        node['is_elsewhere'] = True
+    elif annotation_type == 'broken':
+        node['is_broken'] = True
+    elif annotation_type == 'size_is':
+        node['is_array'] = True
+        node['array_size'] = params[1]
+    elif annotation_type == 'optional':
+        node['is_optional'] = True
+    elif annotation_type == 'property':
+        node['is_property'] = True
+        if node.has_key('property_fields'):
+            node['property_fields'].append(params[1:])
+        else:
+            node['property_fields'] = [params[1:]]
+
+    return node
+
+def parse_annotations(l, node):
+    while l.check_token('symbol', 'QIDL'):
+        params = []
+        l.pop()
+
+        l.pop_expected('operator', '(')
+        open_parens = 1
+        param = ""
+        while open_parens:
+            if l.check_token('operator', ','):
+                params.append(param)
+                param = ""
+                l.pop()
+                continue
+
+            if l.check_token('operator', '('):
+                open_parens += 1
+            elif l.check_token('operator', ')'):
+                open_parens -= 1
+
+            if open_parens > 0:
+                param += l.peek()
+
+            l.pop()
+
+        if param != "":
+            params.append(param)
+
+        node = process_annotation(node, params)
+
+    return node
+
+def parse_type(l):
+    node = {}
+
+    typename = ''
+    if l.check_token('const', 'const'):
+        typename += l.pop() + ' '
+
+    if l.check_token('struct', 'struct'):
+        typename += l.pop() + ' '
+
+    if l.check_token('unsigned', 'unsigned'):
+        typename += l.pop() + ' '
+
+    if l.check_token('union', 'union'):
+        typename += l.pop() + ' '
+
+    if l.check_token('enum', 'enum'):
+        typename += l.pop() + ' '
+
+    # we don't currently handle embedded struct declarations, skip them for now
+    if l.check_token('operator', '{'):
+        open_braces = 1
+        while open_braces:
+            l.pop()
+            if l.check_token('operator', '{'):
+                open_braces += 1
+            elif l.check_token('operator', '}'):
+                open_braces -= 1
+        l.pop()
+        typename += "<anon>"
+        node['is_nested_decl'] = True
+    else:
+        if l.check_token('operator', '*'):
+            l.pop()
+            node['is_pointer'] = True
+        else:
+            typename += l.pop_expected('symbol')
+
+    node['type'] = typename
+
+    node = parse_annotations(l, node)
+
+    if l.check_token('operator', '*'):
+        l.pop()
+        node['is_pointer'] = True
+
+    return node
+
+def parse_var_decl(l, repeating_type=None):
+    if repeating_type == None:
+        node = parse_type(l)
+    else:
+        node = { 'type': repeating_type }
+
+    if l.check_token('operator', '('):
+        node['is_function'] = True
+        l.pop()
+        l.pop_expected('operator', '*')
+        variable = l.pop_expected('symbol')
+        l.pop_expected('operator', ')')
+
+        # skip the param list since we don't use it currently
+        l.pop_expected('operator', '(')
+        open_parens = 1
+        while open_parens:
+            if l.check_token('operator', '('):
+                open_parens += 1
+            elif l.check_token('operator', ')'):
+                open_parens -= 1
+            l.pop()
+    else:
+        variable = l.pop_expected('symbol')
+    node['variable'] = variable
+
+    if l.check_token('operator', '['):
+        l.pop()
+        expression = ""
+        while not l.check_token('operator', ']'):
+            expression += l.pop()
+        l.pop_expected('operator', ']')
+
+        if not node.has_key('is_array'):
+            node['is_array'] = True
+            node['array_size'] = expression
+        else:
+            node['array_capacity'] = expression
+
+    node = parse_annotations(l, node)
+
+    return node
+
+def parse_struct(l):
+    l.pop_expected('struct', 'struct')
+
+    name = None
+    if l.check_token('symbol'):
+        name = l.pop()
+
+    l.pop_expected('operator', '{')
+
+    nodes = []
+
+    while not l.check_token('operator', '}'):
+        node = parse_var_decl(l)
+        nodes.append(node)
+        while l.check_token('operator', ','):
+            l.pop()
+            node = parse_var_decl(l, node['type'])
+            nodes.append(node)
+
+        l.pop_expected('operator', ';')
+
+    l.pop()
+
+    return { 'struct': name, 'fields': nodes }
+
+def parse_typedef(l):
+    l.pop_expected('typedef', 'typedef')
+
+    node = parse_struct(l)
+    typename = l.pop_expected('symbol')
+
+    return { 'typedef': typename, 'type': node }
+
+def parse_declaration_params(l):
+    declaration_info = {}
+    params = []
+    arg_string = ""
+    parens = 0
+    l.pop_expected('symbol', 'QIDL_START')
+    while not l.eof():
+        if l.check_token('operator', '('):
+            parens += 1
+        elif l.check_token('operator', ')'):
+            parens -= 1
+            if parens == 0:
+                break
+        elif parens > 0:
+            if not l.check_token('operator', ','):
+                params.append(l.peek())
+        l.pop()
+    l.pop_expected('operator', ')')
+    if parens != 0:
+        raise Exception("unmatched parenthesis in QIDL macro")
+
+    declaration_info['id'] = params[0]
+    declaration_info['do_state'] = True
+    declaration_info['do_properties'] = True
+    if "skip_state" in params:
+        declaration_info['do_state'] = False
+    if "skip_properties" in params:
+        declaration_info['do_properties'] = False
+
+    return declaration_info
+
+def parse_declaration(l):
+    declaration_info = parse_declaration_params(l)
+
+    if l.check_token('typedef'):
+        node = parse_typedef(l)
+    elif l.check_token('struct'):
+        node = parse_struct(l)
+    else:
+        raise Exception("unsupported QIDL declaration")
+
+    l.pop_expected('operator', ';')
+    node['id'] = declaration_info['id']
+    node['do_state'] = declaration_info['do_state']
+    node['do_properties'] = declaration_info['do_properties']
+
+    return node
+
+def parse_file(f):
+    nodes = []
+    filtered_tokens = ['whitespace', 'comment', 'directive']
+    l = CLexer(Input(f), filtered_tokens)
+    while not l.eof():
+        line = l.peek_line()
+        if line.startswith("QIDL_START("):
+            node = parse_declaration(l)
+            nodes.append(node)
+        else:
+            l.pop_line()
+    return nodes
+
+def main():
+    nodes = parse_file(sys.stdin)
+    print json.dumps(nodes, sort_keys=True, indent=2)
+
+if __name__ == '__main__':
+    main()
-- 
1.7.9.5