bpo-43244: Remove Yield macro from pycore_ast.h (GH-25243)

* pycore_ast.h no longer defines the Yield macro.
* Fix a compiler warning on Windows: "warning C4005: 'Yield': macro
  redefinition".
* Python-ast.c now defines directly functions with their real
  _Py_xxx() name, rather than xxx().
* Remove "#undef Yield" in C files including pycore_ast.h.

Include/internal/pycore_ast.h

@@ -12,8 +12,6 @@ extern "C" {
 
 #include "pycore_asdl.h"
 
-#undef Yield   /* undefine macro conflicting with <winbase.h> */
-
 typedef struct _mod *mod_ty;
 
 typedef struct _stmt *stmt_ty;
@@ -729,7 +727,6 @@ expr_ty _Py_GeneratorExp(expr_ty elt, asdl_comprehension_seq * generators, int
 #define Await(a0, a1, a2, a3, a4, a5) _Py_Await(a0, a1, a2, a3, a4, a5)
 expr_ty _Py_Await(expr_ty value, int lineno, int col_offset, int end_lineno,
                   int end_col_offset, PyArena *arena);
-#define Yield(a0, a1, a2, a3, a4, a5) _Py_Yield(a0, a1, a2, a3, a4, a5)
 expr_ty _Py_Yield(expr_ty value, int lineno, int col_offset, int end_lineno,
                   int end_col_offset, PyArena *arena);
 #define YieldFrom(a0, a1, a2, a3, a4, a5) _Py_YieldFrom(a0, a1, a2, a3, a4, a5)

Parser/asdl_c.py

@@ -325,6 +325,10 @@ class PrototypeVisitor(EmitVisitor):
         margs = "a0"
         for i in range(1, len(args)+1):
             margs += ", a%d" % i
+        # bpo-43244: <winbase.h> defines Yield macro. Don't redefine it in
+        # pycore_ast.h: it is not needed outside Python-ast.c which calls
+        # directly _Py_Yield().
+        if name != "Yield":
             self.emit("#define %s(%s) _Py_%s(%s)" % (name, margs, name, margs), 0,
                     reflow=False)
         self.emit("%s _Py_%s(%s);" % (ctype, name, argstr), False)
@@ -336,6 +340,10 @@ class PrototypeVisitor(EmitVisitor):
                            union=False)
 
 
+def pyfunc_name(name):
+    return f"_Py_{name}"
+
+
 class FunctionVisitor(PrototypeVisitor):
     """Visitor to generate constructor functions for AST."""
 
@@ -349,7 +357,7 @@ class FunctionVisitor(PrototypeVisitor):
         else:
             argstr = "PyArena *arena"
         self.emit("%s" % ctype, 0)
-        emit("%s(%s)" % (name, argstr))
+        emit("%s(%s)" % (pyfunc_name(name), argstr))
         emit("{")
         emit("%s p;" % ctype, 1)
         for argtype, argname, opt in args:
@@ -488,7 +496,7 @@ class Obj2ModVisitor(PickleVisitor):
             for f in t.fields:
                 self.visitField(f, t.name, sum=sum, depth=2)
             args = [f.name for f in t.fields] + [a.name for a in sum.attributes]
-            self.emit("*out = %s(%s);" % (t.name, self.buildArgs(args)), 2)
+            self.emit("*out = %s(%s);" % (pyfunc_name(t.name), self.buildArgs(args)), 2)
             self.emit("if (*out == NULL) goto failed;", 2)
             self.emit("return 0;", 2)
             self.emit("}", 1)
@@ -521,7 +529,7 @@ class Obj2ModVisitor(PickleVisitor):
             self.visitField(a, name, prod=prod, depth=1)
         args = [f.name for f in prod.fields]
         args.extend([a.name for a in prod.attributes])
-        self.emit("*out = %s(%s);" % (name, self.buildArgs(args)), 1)
+        self.emit("*out = %s(%s);" % (pyfunc_name(name), self.buildArgs(args)), 1)
         self.emit("return 0;", 1)
         self.emit("failed:", 0)
         self.emit("Py_XDECREF(tmp);", 1)
@@ -1423,34 +1431,29 @@ def generate_module_def(mod, f, internal_h):
 
     generate_ast_state(module_state, internal_h)
 
-    print(textwrap.dedent(f"""
+    print(textwrap.dedent("""
+        #include "Python.h"
+        #include "pycore_ast.h"
         #include "pycore_ast_state.h"       // struct ast_state
         #include "pycore_interp.h"          // _PyInterpreterState.ast
         #include "pycore_pystate.h"         // _PyInterpreterState_GET()
-    """).rstrip(), file=f)
+        #include "structmember.h"
+        #include <stddef.h>
 
-    f.write("""
-// Forward declaration
-static int init_types(struct ast_state *state);
+        // Forward declaration
+        static int init_types(struct ast_state *state);
 
-static struct ast_state*
-get_ast_state(void)
-{
+        static struct ast_state*
+        get_ast_state(void)
+        {
             PyInterpreterState *interp = _PyInterpreterState_GET();
             struct ast_state *state = &interp->ast;
             if (!init_types(state)) {
                 return NULL;
             }
             return state;
-}
-""")
-
-    print(textwrap.dedent("""
-        // Include pycore_ast.h after pycore_interp.h to avoid conflicts
-        // with the Yield macro redefined by <winbase.h>
-        #include "pycore_ast.h"
-        #include "structmember.h"
-    """).rstrip(), file=f)
+        }
+    """).strip(), file=f)
 
     generate_ast_fini(module_state, f)
 
@@ -1477,8 +1480,6 @@ def write_header(mod, f):
 
         #include "pycore_asdl.h"
 
-        #undef Yield   /* undefine macro conflicting with <winbase.h> */
-
     """).lstrip())
     c = ChainOfVisitors(TypeDefVisitor(f),
                         SequenceDefVisitor(f),
@@ -1534,12 +1535,6 @@ def write_internal_h_footer(mod, f):
 
 
 def write_source(mod, f, internal_h_file):
-    print(textwrap.dedent(f"""
-        #include <stddef.h>
-
-        #include "Python.h"
-    """), file=f)
-
     generate_module_def(mod, f, internal_h_file)
 
     v = ChainOfVisitors(

Python/ast_opt.c

@@ -451,7 +451,7 @@ astfold_body(asdl_stmt_seq *stmts, PyArena *ctx_, _PyASTOptimizeState *state)
             return 0;
         }
         asdl_seq_SET(values, 0, st->v.Expr.value);
-        expr_ty expr = JoinedStr(values, st->lineno, st->col_offset,
+        expr_ty expr = _Py_JoinedStr(values, st->lineno, st->col_offset,
                                      st->end_lineno, st->end_col_offset, ctx_);
         if (!expr) {
             return 0;

Python/bltinmodule.c

@@ -3,7 +3,6 @@
 #include "Python.h"
 #include <ctype.h>
 #include "pycore_ast.h"           // _PyAST_Validate()
-#undef Yield   /* undefine macro conflicting with <winbase.h> */
 #include "pycore_compile.h"       // _PyAST_Compile()
 #include "pycore_object.h"        // _Py_AddToAllObjects()
 #include "pycore_pyerrors.h"      // _PyErr_NoMemory()

Python/import.c

@@ -2,7 +2,6 @@
 
 #include "Python.h"
 
-#undef Yield   /* undefine macro conflicting with <winbase.h> */
 #include "pycore_import.h"        // _PyImport_BootstrapImp()
 #include "pycore_initconfig.h"
 #include "pycore_pyerrors.h"

Python/pythonrun.c

@@ -11,8 +11,6 @@
 #include "Python.h"
 
 #include "pycore_ast.h"           // PyAST_mod2obj
-#undef Yield   /* undefine macro conflicting with <winbase.h> */
-
 #include "pycore_compile.h"       // _PyAST_Compile()
 #include "pycore_interp.h"        // PyInterpreterState.importlib
 #include "pycore_object.h"        // _PyDebug_PrintTotalRefs()

Python/symtable.c

@@ -1,6 +1,5 @@
 #include "Python.h"
 #include "pycore_ast.h"           // identifier, stmt_ty
-#undef Yield   /* undefine macro conflicting with <winbase.h> */
 #include "pycore_compile.h"       // _Py_Mangle()
 #include "pycore_parser.h"        // _PyParser_ASTFromString()
 #include "pycore_pystate.h"       // _PyThreadState_GET()