bpo-39882: Add _Py_FatalErrorFormat() function

Include/cpython/pyerrors.h

@@ -182,6 +182,11 @@ PyAPI_FUNC(void) _Py_NO_RETURN _Py_FatalErrorFunc(
     const char *func,
     const char *message);
 
+PyAPI_FUNC(void) _Py_NO_RETURN _Py_FatalErrorFormat(
+    const char *func,
+    const char *format,
+    ...);
+
 #define Py_FatalError(message) _Py_FatalErrorFunc(__func__, message)
 
 #ifdef __cplusplus

Modules/_io/bufferedio.c

@@ -292,12 +292,11 @@ _enter_buffered_busy(buffered *self)
     }
     Py_END_ALLOW_THREADS
     if (relax_locking && st != PY_LOCK_ACQUIRED) {
-        PyObject *msgobj = PyUnicode_FromFormat(
-            "could not acquire lock for %A at interpreter "
+        PyObject *ascii = PyObject_ASCII((PyObject*)self);
+        _Py_FatalErrorFormat(__func__,
+            "could not acquire lock for %s at interpreter "
             "shutdown, possibly due to daemon threads",
-            (PyObject *) self);
-        const char *msg = PyUnicode_AsUTF8(msgobj);
-        Py_FatalError(msg);
+            ascii ? PyUnicode_AsUTF8(ascii) : "<ascii(self) failed>");
     }
     return 1;
 }

Objects/call.c

@@ -46,7 +46,8 @@ _Py_CheckFunctionResult(PyThreadState *tstate, PyObject *callable,
                               "%s returned NULL without setting an error",
                               where);
 #ifdef Py_DEBUG
-            /* Ensure that the bug is caught in debug mode */
+            /* Ensure that the bug is caught in debug mode.
+               Py_FatalError() logs the SystemError exception raised above. */
             Py_FatalError("a function returned NULL without setting an error");
 #endif
             return NULL;
@@ -67,7 +68,8 @@ _Py_CheckFunctionResult(PyThreadState *tstate, PyObject *callable,
                     "%s returned a result with an error set", where);
             }
 #ifdef Py_DEBUG
-            /* Ensure that the bug is caught in debug mode */
+            /* Ensure that the bug is caught in debug mode.
+               Py_FatalError() logs the SystemError exception raised above. */
             Py_FatalError("a function returned a result with an error set");
 #endif
             return NULL;

Objects/frameobject.c

@@ -957,8 +957,9 @@ void
 PyFrame_BlockSetup(PyFrameObject *f, int type, int handler, int level)
 {
     PyTryBlock *b;
-    if (f->f_iblock >= CO_MAXBLOCKS)
-        Py_FatalError("XXX block stack overflow");
+    if (f->f_iblock >= CO_MAXBLOCKS) {
+        Py_FatalError("block stack overflow");
+    }
     b = &f->f_blockstack[f->f_iblock++];
     b->b_type = type;
     b->b_level = level;
@@ -969,8 +970,9 @@ PyTryBlock *
 PyFrame_BlockPop(PyFrameObject *f)
 {
     PyTryBlock *b;
-    if (f->f_iblock <= 0)
-        Py_FatalError("XXX block stack underflow");
+    if (f->f_iblock <= 0) {
+        Py_FatalError("block stack underflow");
+    }
     b = &f->f_blockstack[--f->f_iblock];
     return b;
 }

Objects/obmalloc.c

@@ -2361,26 +2361,22 @@ _PyMem_DebugRealloc(void *ctx, void *ptr, size_t nbytes)
 static void
 _PyMem_DebugCheckAddress(const char *func, char api, const void *p)
 {
+    assert(p != NULL);
+
     const uint8_t *q = (const uint8_t *)p;
-    char msgbuf[64];
-    const char *msg;
     size_t nbytes;
     const uint8_t *tail;
     int i;
     char id;
 
-    if (p == NULL) {
-        msg = "didn't expect a NULL pointer";
-        goto error;
-    }
-
     /* Check the API id */
     id = (char)q[-SST];
     if (id != api) {
-        msg = msgbuf;
-        snprintf(msgbuf, sizeof(msgbuf), "bad ID: Allocated using API '%c', verified using API '%c'", id, api);
-        msgbuf[sizeof(msgbuf)-1] = 0;
-        goto error;
+        _PyObject_DebugDumpAddress(p);
+        _Py_FatalErrorFormat(func,
+                             "bad ID: Allocated using API '%c', "
+                             "verified using API '%c'",
+                             id, api);
     }
 
     /* Check the stuff at the start of p first:  if there's underwrite
@@ -2389,25 +2385,19 @@ _PyMem_DebugCheckAddress(const char *func, char api, const void *p)
      */
     for (i = SST-1; i >= 1; --i) {
         if (*(q-i) != PYMEM_FORBIDDENBYTE) {
-            msg = "bad leading pad byte";
-            goto error;
+            _PyObject_DebugDumpAddress(p);
+            _Py_FatalErrorFunc(func, "bad leading pad byte");
         }
     }
 
     nbytes = read_size_t(q - 2*SST);
     tail = q + nbytes;
     for (i = 0; i < SST; ++i) {
         if (tail[i] != PYMEM_FORBIDDENBYTE) {
-            msg = "bad trailing pad byte";
-            goto error;
+            _PyObject_DebugDumpAddress(p);
+            _Py_FatalErrorFunc(func, "bad trailing pad byte");
         }
     }
-
-    return;
-
-error:
-    _PyObject_DebugDumpAddress(p);
-    _Py_FatalErrorFunc(func, msg);
 }
 
 /* Display info to stderr about the memory block at p. */

Parser/grammar1.c

@@ -41,7 +41,7 @@ PyGrammar_LabelRepr(label *lb)
         }
     }
     else {
-        Py_FatalError("invalid label");
+        Py_FatalError("invalid grammar label");
         return NULL;
     }
 }

Parser/tokenizer.c

@@ -1032,7 +1032,7 @@ tok_backup(struct tok_state *tok, int c)
 {
     if (c != EOF) {
         if (--tok->cur < tok->buf) {
-            Py_FatalError("beginning of buffer");
+            Py_FatalError("tokenizer beginning of buffer");
         }
         if (*tok->cur != c) {
             *tok->cur = c;

Python/ast.c

@@ -727,11 +727,8 @@ num_stmts(const node *n)
                 return l;
             }
         default: {
-            char buf[128];
-
-            sprintf(buf, "Non-statement found: %d %d",
-                    TYPE(n), NCH(n));
-            Py_FatalError(buf);
+            _Py_FatalErrorFormat(__func__, "Non-statement found: %d %d",
+                                 TYPE(n), NCH(n));
         }
     }
     Py_UNREACHABLE();
@@ -1664,7 +1661,7 @@ ast_for_decorator(struct compiling *c, const node *n)
     REQ(n, decorator);
     REQ(CHILD(n, 0), AT);
     REQ(CHILD(n, 2), NEWLINE);
-    
+
     return ast_for_expr(c, CHILD(n, 1));
 }
 

Python/compile.c

@@ -1876,18 +1876,15 @@ get_ref_type(struct compiler *c, PyObject *name)
         return CELL;
     scope = PyST_GetScope(c->u->u_ste, name);
     if (scope == 0) {
-        char buf[350];
-        PyOS_snprintf(buf, sizeof(buf),
-                      "unknown scope for %.100s in %.100s(%s)\n"
-                      "symbols: %s\nlocals: %s\nglobals: %s",
-                      PyUnicode_AsUTF8(name),
-                      PyUnicode_AsUTF8(c->u->u_name),
-                      PyUnicode_AsUTF8(PyObject_Repr(c->u->u_ste->ste_id)),
-                      PyUnicode_AsUTF8(PyObject_Repr(c->u->u_ste->ste_symbols)),
-                      PyUnicode_AsUTF8(PyObject_Repr(c->u->u_varnames)),
-                      PyUnicode_AsUTF8(PyObject_Repr(c->u->u_names))
-        );
-        Py_FatalError(buf);
+        _Py_FatalErrorFormat(__func__,
+           "unknown scope for %.100s in %.100s(%s)\n"
+           "symbols: %s\nlocals: %s\nglobals: %s",
+           PyUnicode_AsUTF8(name),
+           PyUnicode_AsUTF8(c->u->u_name),
+           PyUnicode_AsUTF8(PyObject_Repr(c->u->u_ste->ste_id)),
+           PyUnicode_AsUTF8(PyObject_Repr(c->u->u_ste->ste_symbols)),
+           PyUnicode_AsUTF8(PyObject_Repr(c->u->u_varnames)),
+           PyUnicode_AsUTF8(PyObject_Repr(c->u->u_names)));
     }
 
     return scope;
@@ -1930,15 +1927,14 @@ compiler_make_closure(struct compiler *c, PyCodeObject *co, Py_ssize_t flags, Py
             else /* (reftype == FREE) */
                 arg = compiler_lookup_arg(c->u->u_freevars, name);
             if (arg == -1) {
-                fprintf(stderr,
+                _Py_FatalErrorFormat(__func__,
                     "lookup %s in %s %d %d\n"
                     "freevars of %s: %s\n",
                     PyUnicode_AsUTF8(PyObject_Repr(name)),
                     PyUnicode_AsUTF8(c->u->u_name),
                     reftype, arg,
                     PyUnicode_AsUTF8(co->co_name),
                     PyUnicode_AsUTF8(PyObject_Repr(co->co_freevars)));
-                Py_FatalError("compiler_make_closure()");
             }
             ADDOP_I(c, LOAD_CLOSURE, arg);
         }
@@ -5411,8 +5407,8 @@ stackdepth(struct compiler *c)
             struct instr *instr = &b->b_instr[i];
             int effect = stack_effect(instr->i_opcode, instr->i_oparg, 0);
             if (effect == PY_INVALID_STACK_EFFECT) {
-                fprintf(stderr, "opcode = %d\n", instr->i_opcode);
-                Py_FatalError("PyCompile_OpcodeStackEffect()");
+                _Py_FatalErrorFormat(__func__,
+                    "opcode = %d", instr->i_opcode);
             }
             int new_depth = depth + effect;
             if (new_depth > maxdepth) {

Python/frozenmain.c

@@ -99,7 +99,7 @@ Py_FrozenMain(int argc, char **argv)
 
     n = PyImport_ImportFrozenModule("__main__");
     if (n == 0)
-        Py_FatalError("__main__ not frozen");
+        Py_FatalError("the __main__ module is not frozen");
     if (n < 0) {
         PyErr_Print();
         sts = 1;

Python/import.c

@@ -209,7 +209,7 @@ _PyImport_ReInitLock(void)
     if (import_lock != NULL) {
         import_lock = PyThread_allocate_lock();
         if (import_lock == NULL) {
-            Py_FatalError("PyImport_ReInitLock failed to create a new lock");
+            _Py_FatalErrorFunc(__func__, "failed to create a new lock");
         }
     }
     if (import_lock_level > 1) {
@@ -310,7 +310,7 @@ PyImport_GetModuleDict(void)
 {
     PyInterpreterState *interp = _PyInterpreterState_GET_UNSAFE();
     if (interp->modules == NULL) {
-        Py_FatalError("no module dictionary");
+        Py_FatalError("interpreter has no modules dictionary");
     }
     return interp->modules;
 }
@@ -982,7 +982,7 @@ PyImport_ExecCodeModuleWithPathnames(const char *name, PyObject *co,
         _Py_IDENTIFIER(_get_sourcefile);
 
         if (interp == NULL) {
-            Py_FatalError("no interpreter!");
+            Py_FatalError("no current interpreter");
         }
 
         external= PyObject_GetAttrString(interp->importlib,

Python/mysnprintf.c

@@ -81,12 +81,12 @@ PyOS_vsnprintf(char *str, size_t size, const char  *format, va_list va)
     }
 
     len = vsprintf(buffer, format, va);
-    if (len < 0)
+    if (len < 0) {
         /* ignore the error */;
-
-    else if ((size_t)len >= size + _PyOS_vsnprintf_EXTRA_SPACE)
-        Py_FatalError("Buffer overflow in PyOS_snprintf/PyOS_vsnprintf");
-
+    }
+    else if ((size_t)len >= size + _PyOS_vsnprintf_EXTRA_SPACE) {
+        _Py_FatalErrorFunc(__func__, "Buffer overflow");
+    }
     else {
         const size_t to_copy = (size_t)len < size ?
                                 (size_t)len : size - 1;

Python/pathconfig.c

@@ -484,6 +484,12 @@ pathconfig_global_init(void)
 
 /* External interface */
 
+static void _Py_NO_RETURN
+path_out_of_memory(const char *func)
+{
+    _Py_FatalErrorFunc(func, "out of memory");
+}
+
 void
 Py_SetPath(const wchar_t *path)
 {
@@ -515,7 +521,7 @@ Py_SetPath(const wchar_t *path)
         || _Py_path_config.exec_prefix == NULL
         || _Py_path_config.module_search_path == NULL)
     {
-        Py_FatalError("out of memory");
+        path_out_of_memory(__func__);
     }
 }
 
@@ -536,7 +542,7 @@ Py_SetPythonHome(const wchar_t *home)
     PyMem_SetAllocator(PYMEM_DOMAIN_RAW, &old_alloc);
 
     if (_Py_path_config.home == NULL) {
-        Py_FatalError("out of memory");
+        path_out_of_memory(__func__);
     }
 }
 
@@ -557,7 +563,7 @@ Py_SetProgramName(const wchar_t *program_name)
     PyMem_SetAllocator(PYMEM_DOMAIN_RAW, &old_alloc);
 
     if (_Py_path_config.program_name == NULL) {
-        Py_FatalError("out of memory");
+        path_out_of_memory(__func__);
     }
 }
 
@@ -577,7 +583,7 @@ _Py_SetProgramFullPath(const wchar_t *program_full_path)
     PyMem_SetAllocator(PYMEM_DOMAIN_RAW, &old_alloc);
 
     if (_Py_path_config.program_full_path == NULL) {
-        Py_FatalError("out of memory");
+        path_out_of_memory(__func__);
     }
 }