fix comparison of function signatures that use C++ exception mappings

CHANGES.rst

@@ -16,6 +16,9 @@ Bugs fixed
 
 * Comparisons of (inferred) ctuples failed to compile.
 
+* C++ exception declarations with mapping functions could fail to compile when
+  pre-declared in .pxd files.
+
 * C compilation could fail in pypy3.
 
 

Cython/Compiler/PyrexTypes.py

@@ -2572,10 +2572,26 @@ class CFuncType(CType):
             return 0
         if not self.same_calling_convention_as(other_type):
             return 0
-        if self.exception_value != other_type.exception_value:
-            return 0
         if self.exception_check != other_type.exception_check:
             return 0
+        if not self._same_exception_value(other_type.exception_value):
+            return 0
+        return 1
+
+    def _same_exception_value(self, other_exc_value):
+        if self.exception_value == other_exc_value:
+            return 1
+        if self.exception_check != '+':
+            return 0
+        if not self.exception_value or not other_exc_value:
+            return 0
+        if self.exception_value.type != other_exc_value.type:
+            return 0
+        if self.exception_value.entry and other_exc_value.entry:
+            if self.exception_value.entry.cname != other_exc_value.entry.cname:
+                return 0
+        if self.exception_value.name != other_exc_value.name:
+            return 0
         return 1
 
     def compatible_signature_with(self, other_type, as_cmethod = 0):
@@ -2610,11 +2626,11 @@ class CFuncType(CType):
             return 0
         if self.nogil != other_type.nogil:
             return 0
-        if self.exception_value != other_type.exception_value:
-            return 0
         if not self.exception_check and other_type.exception_check:
             # a redundant exception check doesn't make functions incompatible, but a missing one does
             return 0
+        if not self._same_exception_value(other_type.exception_value):
+            return 0
         self.original_sig = other_type.original_sig or other_type
         return 1
 
@@ -2641,11 +2657,11 @@ class CFuncType(CType):
             return 0
         if not self.return_type.subtype_of_resolved_type(other_type.return_type):
             return 0
-        if self.exception_value != other_type.exception_value:
-            return 0
         if not self.exception_check and other_type.exception_check:
             # a redundant exception check doesn't make functions incompatible, but a missing one does
             return 0
+        if not self._same_exception_value(other_type.exception_value):
+            return 0
         return 1
 
     def same_calling_convention_as(self, other):

tests/run/cpp_exception_declaration_compatibility.srctree

+# tag: cpp
+
+"""
+PYTHON setup.py build_ext -i
+PYTHON test.py
+"""
+
+############### setup.py ###################
+from distutils.core import setup
+from Cython.Build import cythonize
+
+setup(
+    name="cython_test",
+    ext_modules=cythonize('*.pyx', language="c++")
+)
+
+
+############### test.py ###################
+
+from cpp_exc import TestClass
+
+TestClass().test_func()
+
+
+############### cpp_exc.pxd ###################
+
+cdef inline void handle_exception():
+    pass
+
+cdef class TestClass:
+    cpdef test_func(self) except +handle_exception
+
+
+############### cpp_exc.pyx ###################
+
+cdef class TestClass:
+    cpdef test_func(self) except +handle_exception:
+        print('test')