Merge pull request RustPython#762 from palaviv/doc

windelbouwman · web-flow · commit aede03c1b284 · 2019-03-31T20:01:05.000+02:00
Support class and function __doc__
diff --git a/tests/snippets/class.py b/tests/snippets/class.py
@@ -37,8 +37,7 @@ def kungfu(x):
         assert x == 3
 
 
-# TODO:
-# assert Bar.__doc__ == " W00t "
+assert Bar.__doc__ == " W00t "
 
 bar = Bar(42)
 
@@ -117,3 +116,31 @@ def f(self):
 assert type(a) is super
 assert a.conjugate() == 1
 
+
+class T1:
+    "test1"
+
+assert T1.__doc__ == "test1"
+
+class T2:
+    '''test2'''
+
+assert T2.__doc__ == "test2"
+
+class T3:
+    """
+    test3
+    """
+
+assert T3.__doc__ == "\n    test3\n    "
+
+class T4:
+
+    """test4"""
+
+    def t1(self):
+        """t1"""
+        pass
+
+assert T4.__doc__ == "test4"
+assert T4.t1.__doc__ == "t1"
diff --git a/tests/snippets/function.py b/tests/snippets/function.py
@@ -1,9 +1,39 @@
 def foo():
+    """test"""
     return 42
 
 assert foo() == 42
+assert foo.__doc__ == "test"
 
 def my_func(a,):
     return a+2
 
 assert my_func(2) == 4
+
+
+def f1():
+
+    """test1"""
+    pass
+
+assert f1.__doc__ == "test1"
+
+def f2():
+    '''test2'''
+    pass
+
+assert f2.__doc__ == "test2"
+
+def f3():
+    """
+    test3
+    """
+    pass
+
+assert f3.__doc__ == "\n    test3\n    "
+
+def f4():
+    "test4"
+    pass
+
+assert f4.__doc__ == "test4"
diff --git a/vm/src/compile.rs b/vm/src/compile.rs
@@ -597,7 +597,10 @@ impl Compiler {
         self.in_loop = false;
         self.in_function_def = true;
         let mut flags = self.enter_function(name, args)?;
-        self.compile_statements(body)?;
+
+        let (new_body, doc_str) = get_doc(body);
+
+        self.compile_statements(new_body)?;
 
         // Emit None at end:
         self.emit(Instruction::LoadConst {
@@ -662,6 +665,20 @@ impl Compiler {
         self.emit(Instruction::StoreName {
             name: name.to_string(),
         });
+
+        if let Some(doc_string) = doc_str {
+            self.emit(Instruction::LoadConst {
+                value: bytecode::Constant::String {
+                    value: doc_string.to_string(),
+                },
+            });
+            self.emit(Instruction::LoadName {
+                name: name.to_string(),
+            });
+            self.emit(Instruction::StoreAttr {
+                name: "__doc__".to_string(),
+            });
+        }
         self.in_loop = was_in_loop;
         self.in_function_def = was_in_function_def;
         Ok(())
@@ -689,13 +706,17 @@ impl Compiler {
             line_number,
             name.to_string(),
         ));
-        self.compile_statements(body)?;
+
+        let (new_body, doc_str) = get_doc(body);
+
+        self.compile_statements(new_body)?;
         self.emit(Instruction::LoadConst {
             value: bytecode::Constant::None,
         });
         self.emit(Instruction::ReturnValue);
 
         let code = self.pop_code_object();
+
         self.emit(Instruction::LoadConst {
             value: bytecode::Constant::Code {
                 code: Box::new(code),
@@ -755,6 +776,19 @@ impl Compiler {
         self.emit(Instruction::StoreName {
             name: name.to_string(),
         });
+        if let Some(doc_string) = doc_str {
+            self.emit(Instruction::LoadConst {
+                value: bytecode::Constant::String {
+                    value: doc_string.to_string(),
+                },
+            });
+            self.emit(Instruction::LoadName {
+                name: name.to_string(),
+            });
+            self.emit(Instruction::StoreAttr {
+                name: "__doc__".to_string(),
+            });
+        }
         self.in_loop = was_in_loop;
         Ok(())
     }
@@ -1511,6 +1545,21 @@ impl Compiler {
     }
 }
 
+fn get_doc(body: &[ast::LocatedStatement]) -> (&[ast::LocatedStatement], Option<String>) {
+    if let Some(val) = body.get(0) {
+        if let ast::Statement::Expression { ref expression } = val.node {
+            if let ast::Expression::String { ref value } = expression {
+                if let ast::StringGroup::Constant { ref value } = value {
+                    if let Some((_, body_rest)) = body.split_first() {
+                        return (body_rest, Some(value.to_string()));
+                    }
+                }
+            }
+        }
+    }
+    (body, None)
+}
+
 #[cfg(test)]
 mod tests {
     use super::Compiler;
