bpo-39882: Py_FatalError() logs the function name (GH-18819)

The Py_FatalError() function is replaced with a macro which logs
automatically the name of the current function, unless the
Py_LIMITED_API macro is defined.

Changes:

* Add _Py_FatalErrorFunc() function.
* Remove the function name from the message of Py_FatalError() calls
  which included the function name.
* Update tests.

2 files changed, 8 insertions, 5 deletions

diff --git a/Parser/parser.c b/Parser/parser.c
index 227b918..a61b2f5 100644
--- a/Parser/parser.c
+++ b/Parser/parser.c
@@ -54,8 +54,9 @@ s_push(stack *s, const dfa *d, node *parent)
 static void
 s_pop(stack *s)
 {
-    if (s_empty(s))
-        Py_FatalError("s_pop: parser stack underflow -- FATAL");
+    if (s_empty(s)) {
+        Py_FatalError("parser stack underflow");
+    }
     s->s_top++;
 }
 
diff --git a/Parser/tokenizer.c b/Parser/tokenizer.c
index f82b102..75e8da4 100644
--- a/Parser/tokenizer.c
+++ b/Parser/tokenizer.c
@@ -1031,10 +1031,12 @@ static void
 tok_backup(struct tok_state *tok, int c)
 {
     if (c != EOF) {
-        if (--tok->cur < tok->buf)
-            Py_FatalError("tok_backup: beginning of buffer");
-        if (*tok->cur != c)
+        if (--tok->cur < tok->buf) {
+            Py_FatalError("beginning of buffer");
+        }
+        if (*tok->cur != c) {
             *tok->cur = c;
+        }
     }
 }