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authorGuido van Rossum <guido@python.org>2024-02-29 18:55:29 (GMT)
committerGitHub <noreply@github.com>2024-02-29 18:55:29 (GMT)
commit0656509033948780e6703391daca773c779041f7 (patch)
treef75c2c923b52ee8367c9f033cb911ac8dc99bfca /Python
parent3b6f4cadf19e6a4edd2cbbbc96a0a4024b395648 (diff)
downloadcpython-0656509033948780e6703391daca773c779041f7.zip
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gh-116088: Insert bottom checks after all sym_set_...() calls (#116089)
This changes the `sym_set_...()` functions to return a `bool` which is `false` when the symbol is `bottom` after the operation. All calls to such functions now check this result and go to `hit_bottom`, a special error label that prints a different message and then reports that it wasn't able to optimize the trace. No executor will be produced in this case.
Diffstat (limited to 'Python')
-rw-r--r--Python/optimizer_analysis.c9
-rw-r--r--Python/optimizer_bytecodes.c36
-rw-r--r--Python/optimizer_cases.c.h36
-rw-r--r--Python/optimizer_symbols.c36
4 files changed, 85 insertions, 32 deletions
diff --git a/Python/optimizer_analysis.c b/Python/optimizer_analysis.c
index 2a7ef4e..a326e22 100644
--- a/Python/optimizer_analysis.c
+++ b/Python/optimizer_analysis.c
@@ -363,6 +363,15 @@ error:
DPRINTF(1, "Encountered error in abstract interpreter\n");
_Py_uop_abstractcontext_fini(ctx);
return 0;
+
+hit_bottom:
+ // Attempted to push a "bottom" (contradition) symbol onto the stack.
+ // This means that the abstract interpreter has hit unreachable code.
+ // We *could* generate an _EXIT_TRACE or _FATAL_ERROR here, but it's
+ // simpler to just admit failure and not create the executor.
+ DPRINTF(1, "Hit bottom in abstract interpreter\n");
+ _Py_uop_abstractcontext_fini(ctx);
+ return 0;
}
diff --git a/Python/optimizer_bytecodes.c b/Python/optimizer_bytecodes.c
index 928c22d..aa19a50 100644
--- a/Python/optimizer_bytecodes.c
+++ b/Python/optimizer_bytecodes.c
@@ -85,8 +85,12 @@ dummy_func(void) {
sym_matches_type(right, &PyLong_Type)) {
REPLACE_OP(this_instr, _NOP, 0, 0);
}
- sym_set_type(left, &PyLong_Type);
- sym_set_type(right, &PyLong_Type);
+ if (!sym_set_type(left, &PyLong_Type)) {
+ goto hit_bottom;
+ }
+ if (!sym_set_type(right, &PyLong_Type)) {
+ goto hit_bottom;
+ }
}
op(_GUARD_BOTH_FLOAT, (left, right -- left, right)) {
@@ -94,8 +98,12 @@ dummy_func(void) {
sym_matches_type(right, &PyFloat_Type)) {
REPLACE_OP(this_instr, _NOP, 0 ,0);
}
- sym_set_type(left, &PyFloat_Type);
- sym_set_type(right, &PyFloat_Type);
+ if (!sym_set_type(left, &PyFloat_Type)) {
+ goto hit_bottom;
+ }
+ if (!sym_set_type(right, &PyFloat_Type)) {
+ goto hit_bottom;
+ }
}
op(_GUARD_BOTH_UNICODE, (left, right -- left, right)) {
@@ -103,8 +111,12 @@ dummy_func(void) {
sym_matches_type(right, &PyUnicode_Type)) {
REPLACE_OP(this_instr, _NOP, 0 ,0);
}
- sym_set_type(left, &PyUnicode_Type);
- sym_set_type(right, &PyUnicode_Type);
+ if (!sym_set_type(left, &PyUnicode_Type)) {
+ goto hit_bottom;
+ }
+ if (!sym_set_type(right, &PyUnicode_Type)) {
+ goto hit_bottom;
+ }
}
op(_BINARY_OP_ADD_INT, (left, right -- res)) {
@@ -365,14 +377,20 @@ dummy_func(void) {
op(_CHECK_FUNCTION_EXACT_ARGS, (func_version/2, callable, self_or_null, unused[oparg] -- callable, self_or_null, unused[oparg])) {
- sym_set_type(callable, &PyFunction_Type);
+ if (!sym_set_type(callable, &PyFunction_Type)) {
+ goto hit_bottom;
+ }
(void)self_or_null;
(void)func_version;
}
op(_CHECK_CALL_BOUND_METHOD_EXACT_ARGS, (callable, null, unused[oparg] -- callable, null, unused[oparg])) {
- sym_set_null(null);
- sym_set_type(callable, &PyMethod_Type);
+ if (!sym_set_null(null)) {
+ goto hit_bottom;
+ }
+ if (!sym_set_type(callable, &PyMethod_Type)) {
+ goto hit_bottom;
+ }
}
op(_INIT_CALL_PY_EXACT_ARGS, (callable, self_or_null, args[oparg] -- new_frame: _Py_UOpsAbstractFrame *)) {
diff --git a/Python/optimizer_cases.c.h b/Python/optimizer_cases.c.h
index b38c03b..b34c573 100644
--- a/Python/optimizer_cases.c.h
+++ b/Python/optimizer_cases.c.h
@@ -172,8 +172,12 @@
sym_matches_type(right, &PyLong_Type)) {
REPLACE_OP(this_instr, _NOP, 0, 0);
}
- sym_set_type(left, &PyLong_Type);
- sym_set_type(right, &PyLong_Type);
+ if (!sym_set_type(left, &PyLong_Type)) {
+ goto hit_bottom;
+ }
+ if (!sym_set_type(right, &PyLong_Type)) {
+ goto hit_bottom;
+ }
break;
}
@@ -276,8 +280,12 @@
sym_matches_type(right, &PyFloat_Type)) {
REPLACE_OP(this_instr, _NOP, 0 ,0);
}
- sym_set_type(left, &PyFloat_Type);
- sym_set_type(right, &PyFloat_Type);
+ if (!sym_set_type(left, &PyFloat_Type)) {
+ goto hit_bottom;
+ }
+ if (!sym_set_type(right, &PyFloat_Type)) {
+ goto hit_bottom;
+ }
break;
}
@@ -383,8 +391,12 @@
sym_matches_type(right, &PyUnicode_Type)) {
REPLACE_OP(this_instr, _NOP, 0 ,0);
}
- sym_set_type(left, &PyUnicode_Type);
- sym_set_type(right, &PyUnicode_Type);
+ if (!sym_set_type(left, &PyUnicode_Type)) {
+ goto hit_bottom;
+ }
+ if (!sym_set_type(right, &PyUnicode_Type)) {
+ goto hit_bottom;
+ }
break;
}
@@ -1397,8 +1409,12 @@
_Py_UopsSymbol *callable;
null = stack_pointer[-1 - oparg];
callable = stack_pointer[-2 - oparg];
- sym_set_null(null);
- sym_set_type(callable, &PyMethod_Type);
+ if (!sym_set_null(null)) {
+ goto hit_bottom;
+ }
+ if (!sym_set_type(callable, &PyMethod_Type)) {
+ goto hit_bottom;
+ }
break;
}
@@ -1425,7 +1441,9 @@
self_or_null = stack_pointer[-1 - oparg];
callable = stack_pointer[-2 - oparg];
uint32_t func_version = (uint32_t)this_instr->operand;
- sym_set_type(callable, &PyFunction_Type);
+ if (!sym_set_type(callable, &PyFunction_Type)) {
+ goto hit_bottom;
+ }
(void)self_or_null;
(void)func_version;
break;
diff --git a/Python/optimizer_symbols.c b/Python/optimizer_symbols.c
index a529cc2..5c3ec2b 100644
--- a/Python/optimizer_symbols.c
+++ b/Python/optimizer_symbols.c
@@ -113,60 +113,68 @@ _Py_uop_sym_get_const(_Py_UopsSymbol *sym)
return sym->const_val;
}
-void
+bool
_Py_uop_sym_set_type(_Py_UopsSymbol *sym, PyTypeObject *typ)
{
assert(typ != NULL && PyType_Check(typ));
if (sym->flags & IS_NULL) {
sym_set_bottom(sym);
- return;
+ return false;
}
if (sym->typ != NULL) {
if (sym->typ != typ) {
sym_set_bottom(sym);
+ return false;
}
- return;
}
- sym_set_flag(sym, NOT_NULL);
- sym->typ = typ;
+ else {
+ sym_set_flag(sym, NOT_NULL);
+ sym->typ = typ;
+ }
+ return true;
}
-void
+bool
_Py_uop_sym_set_const(_Py_UopsSymbol *sym, PyObject *const_val)
{
assert(const_val != NULL);
if (sym->flags & IS_NULL) {
sym_set_bottom(sym);
- return;
+ return false;
}
PyTypeObject *typ = Py_TYPE(const_val);
if (sym->typ != NULL && sym->typ != typ) {
sym_set_bottom(sym);
- return;
+ return false;
}
if (sym->const_val != NULL) {
if (sym->const_val != const_val) {
// TODO: What if they're equal?
sym_set_bottom(sym);
+ return false;
}
- return;
}
- sym_set_flag(sym, NOT_NULL);
- sym->typ = typ;
- sym->const_val = Py_NewRef(const_val);
+ else {
+ sym_set_flag(sym, NOT_NULL);
+ sym->typ = typ;
+ sym->const_val = Py_NewRef(const_val);
+ }
+ return true;
}
-void
+bool
_Py_uop_sym_set_null(_Py_UopsSymbol *sym)
{
sym_set_flag(sym, IS_NULL);
+ return !_Py_uop_sym_is_bottom(sym);
}
-void
+bool
_Py_uop_sym_set_non_null(_Py_UopsSymbol *sym)
{
sym_set_flag(sym, NOT_NULL);
+ return !_Py_uop_sym_is_bottom(sym);
}