gh-139109: Dynamic opcode targets (GH-139111)

Make opcode targets table dynamic

Author: Fidget-Spinner

Python/ceval.c

@@ -1022,6 +1022,7 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, _PyInterpreterFrame *frame, int
 #if USE_COMPUTED_GOTOS && !_Py_TAIL_CALL_INTERP
 /* Import the static jump table */
 #include "opcode_targets.h"
+    void **opcode_targets = opcode_targets_table;
 #endif
 
 #ifdef Py_STATS
@@ -1101,9 +1102,9 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, _PyInterpreterFrame *frame, int
         stack_pointer = _PyFrame_GetStackPointer(frame);
 #if _Py_TAIL_CALL_INTERP
 #   if Py_STATS
-        return _TAIL_CALL_error(frame, stack_pointer, tstate, next_instr, 0, lastopcode);
+        return _TAIL_CALL_error(frame, stack_pointer, tstate, next_instr, instruction_funcptr_table, 0, lastopcode);
 #   else
-        return _TAIL_CALL_error(frame, stack_pointer, tstate, next_instr, 0);
+        return _TAIL_CALL_error(frame, stack_pointer, tstate, next_instr, instruction_funcptr_table, 0);
 #   endif
 #else
         goto error;
@@ -1112,9 +1113,9 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, _PyInterpreterFrame *frame, int
 
 #if _Py_TAIL_CALL_INTERP
 #   if Py_STATS
-        return _TAIL_CALL_start_frame(frame, NULL, tstate, NULL, 0, lastopcode);
+        return _TAIL_CALL_start_frame(frame, NULL, tstate, NULL, instruction_funcptr_table, 0, lastopcode);
 #   else
-        return _TAIL_CALL_start_frame(frame, NULL, tstate, NULL, 0);
+        return _TAIL_CALL_start_frame(frame, NULL, tstate, NULL, instruction_funcptr_table, 0);
 #   endif
 #else
     goto start_frame;

Python/ceval_macros.h

@@ -71,11 +71,11 @@
 #endif
 
 #ifdef Py_STATS
-#   define TAIL_CALL_PARAMS _PyInterpreterFrame *frame, _PyStackRef *stack_pointer, PyThreadState *tstate, _Py_CODEUNIT *next_instr, int oparg, int lastopcode
-#   define TAIL_CALL_ARGS frame, stack_pointer, tstate, next_instr, oparg, lastopcode
+#   define TAIL_CALL_PARAMS _PyInterpreterFrame *frame, _PyStackRef *stack_pointer, PyThreadState *tstate, _Py_CODEUNIT *next_instr, const void *instruction_funcptr_table, int oparg, int lastopcode
+#   define TAIL_CALL_ARGS frame, stack_pointer, tstate, next_instr, instruction_funcptr_table, oparg, lastopcode
 #else
-#   define TAIL_CALL_PARAMS _PyInterpreterFrame *frame, _PyStackRef *stack_pointer, PyThreadState *tstate, _Py_CODEUNIT *next_instr, int oparg
-#   define TAIL_CALL_ARGS frame, stack_pointer, tstate, next_instr, oparg
+#   define TAIL_CALL_PARAMS _PyInterpreterFrame *frame, _PyStackRef *stack_pointer, PyThreadState *tstate, _Py_CODEUNIT *next_instr, const void *instruction_funcptr_table, int oparg
+#   define TAIL_CALL_ARGS frame, stack_pointer, tstate, next_instr, instruction_funcptr_table, oparg
 #endif
 
 #if _Py_TAIL_CALL_INTERP
@@ -87,7 +87,7 @@
 #   define TARGET(op) Py_PRESERVE_NONE_CC PyObject *_TAIL_CALL_##op(TAIL_CALL_PARAMS)
 #   define DISPATCH_GOTO() \
         do { \
-            Py_MUSTTAIL return (INSTRUCTION_TABLE[opcode])(TAIL_CALL_ARGS); \
+            Py_MUSTTAIL return (((py_tail_call_funcptr *)instruction_funcptr_table)[opcode])(TAIL_CALL_ARGS); \
         } while (0)
 #   define JUMP_TO_LABEL(name) \
         do { \
@@ -96,12 +96,12 @@
 #   ifdef Py_STATS
 #       define JUMP_TO_PREDICTED(name) \
             do { \
-                Py_MUSTTAIL return (_TAIL_CALL_##name)(frame, stack_pointer, tstate, this_instr, oparg, lastopcode); \
+                Py_MUSTTAIL return (_TAIL_CALL_##name)(frame, stack_pointer, tstate, this_instr, instruction_funcptr_table, oparg, lastopcode); \
             } while (0)
 #   else
 #       define JUMP_TO_PREDICTED(name) \
             do { \
-                Py_MUSTTAIL return (_TAIL_CALL_##name)(frame, stack_pointer, tstate, this_instr, oparg); \
+                Py_MUSTTAIL return (_TAIL_CALL_##name)(frame, stack_pointer, tstate, this_instr, instruction_funcptr_table, oparg); \
             } while (0)
 #   endif
 #    define LABEL(name) TARGET(name)

Python/opcode_targets.h

@@ -80,6 +80,7 @@ def format_tsv_lines(lines):
     'Python/generated_cases.c.h',
     'Python/executor_cases.c.h',
     'Python/optimizer_cases.c.h',
+    'Python/opcode_targets.h',
     # XXX: Throws errors if PY_VERSION_HEX is not mocked out
     'Modules/clinic/_testclinic_depr.c.h',
 

Tools/c-analyzer/cpython/_parser.py

@@ -27,7 +27,7 @@ def write_opcode_targets(analysis: Analysis, out: CWriter) -> None:
         if op < 256:
             targets[op] = f"&&TARGET_{name},\n"
     out.emit("#if !_Py_TAIL_CALL_INTERP\n")
-    out.emit("static void *opcode_targets[256] = {\n")
+    out.emit("static void *opcode_targets_table[256] = {\n")
     for target in targets:
         out.emit(target)
     out.emit("};\n")
@@ -38,7 +38,7 @@ def function_proto(name: str) -> str:
 
 
 def write_tailcall_dispatch_table(analysis: Analysis, out: CWriter) -> None:
-    out.emit("static py_tail_call_funcptr INSTRUCTION_TABLE[256];\n")
+    out.emit("static py_tail_call_funcptr instruction_funcptr_table[256];\n")
     out.emit("\n")
 
     # Emit function prototypes for labels.
@@ -60,7 +60,7 @@ def write_tailcall_dispatch_table(analysis: Analysis, out: CWriter) -> None:
     out.emit("\n")
 
     # Emit the dispatch table.
-    out.emit("static py_tail_call_funcptr INSTRUCTION_TABLE[256] = {\n")
+    out.emit("static py_tail_call_funcptr instruction_funcptr_table[256] = {\n")
     for name in sorted(analysis.instructions.keys()):
         out.emit(f"[{name}] = _TAIL_CALL_{name},\n")
     named_values = analysis.opmap.values()