Support extern template declarations

virtuald · virtuald · commit 763456603410 · 2022-09-27T23:37:12.000-04:00
diff --git a/CppHeaderParser/CppHeaderParser.py b/CppHeaderParser/CppHeaderParser.py
@@ -1425,6 +1425,10 @@ def __str__(self):
         return self["value"]
 
 
+class CppExternTemplate(dict):
+    pass
+
+
 # Implementation is shared between CppPragma, CppDefine, CppInclude but they are
 # distinct so that they may diverge if required without interface-breaking
 # changes
@@ -2747,6 +2751,8 @@ def __init__(self, headerFileName, argType="file", encoding=None, **kwargs):
         #: List of enums in this header as :class:`.CppEnum`
         self.enums = []
 
+        self.extern_templates = []
+
         #: List of variables in this header as :class:`.CppVariable`
         self.variables = []
         self.global_enums = {}
@@ -2879,7 +2885,7 @@ def __init__(self, headerFileName, argType="file", encoding=None, **kwargs):
                     break
                 tok.value = TagStr(tok.value, location=tok.location)
 
-                # debug_print("TOK: %s", tok)
+                debug_print("TOK: %s", tok)
                 if tok.type == "NAME":
                     if tok.value in self.IGNORE_NAMES:
                         continue
@@ -3459,6 +3465,21 @@ def _evaluate_stack(self, token=None):
         self.curTemplate = None
 
     def _parse_template(self):
+        # check for 'extern template'
+        extern_template = False
+        if len(self.stmtTokens) == 1 and self.stmtTokens[0].value == "extern":
+            extern_template = True
+            tok = self._next_token_must_be("NAME")
+            if not tok.value == "class":
+                raise self._parse_error((tok,), "class")
+
+            tok = self._next_token_must_be("NAME")
+            if tok.value == "__attribute__":
+                self._parse_gcc_attribute()
+                tok = self._next_token_must_be("NAME")
+
+            extern_template_name = tok.value
+
         tok = self._next_token_must_be("<")
         consumed = self._consume_balanced_tokens(tok)
         tmpl = " ".join(tok.value for tok in consumed)
@@ -3471,7 +3492,20 @@ def _parse_template(self):
             .replace(" , ", ", ")
             .replace(" = ", "=")
         )
-        self.curTemplate = "template" + tmpl
+
+        if extern_template:
+            self.extern_templates.append(
+                CppExternTemplate(
+                    name=extern_template_name,
+                    params=tmpl,
+                    namespace=self.cur_namespace(),
+                )
+            )
+            self.stack = []
+            self.nameStack = []
+            self.stmtTokens = []
+        else:
+            self.curTemplate = "template" + tmpl
 
     def _parse_gcc_attribute(self):
         tok1 = self._next_token_must_be("(")
diff --git a/test/test_CppHeaderParser.py b/test/test_CppHeaderParser.py
@@ -4078,5 +4078,37 @@ def test_fn(self):
         self.assertEqual(c.typedefs["mmmmp"], "typedef int ( * ) ( int , int )")
 
 
+class ExternTemplateTest(unittest.TestCase):
+    def setUp(self):
+        self.cppHeader = CppHeaderParser.CppHeader(
+            """
+extern template class MyClass<1,2>;
+extern template class __attribute__(("something")) MyClass<3,4>;
+
+namespace foo {
+extern template class MyClass<5,6>;
+};
+
+""",
+            "string",
+        )
+
+    def test_fn(self):
+        c = self.cppHeader
+        et0, et1, et2 = c.extern_templates
+
+        self.assertEqual(et0["name"], "MyClass")
+        self.assertEqual(et0["namespace"], "")
+        self.assertEqual(et0["params"], "<1, 2>")
+
+        self.assertEqual(et1["name"], "MyClass")
+        self.assertEqual(et1["namespace"], "")
+        self.assertEqual(et1["params"], "<3, 4>")
+
+        self.assertEqual(et2["name"], "MyClass")
+        self.assertEqual(et2["namespace"], "foo")
+        self.assertEqual(et2["params"], "<5, 6>")
+
+
 if __name__ == "__main__":
     unittest.main()
