python · 1st1 · Oct 4, 2018 · Oct 4, 2018
diff --git a/Include/coreconfig.h b/Include/coreconfig.h
@@ -49,6 +49,7 @@ typedef struct {

    const char *allocator;  /* Memory allocator: PYTHONMALLOC */
    int dev_mode;           /* PYTHONDEVMODE, -X dev */
+    int noopt_mode;         /* -X noopt */

    /* Enable faulthandler?
       Set to 1 by -X faulthandler and PYTHONFAULTHANDLER. -1 means unset. */

diff --git a/Modules/_testcapimodule.c b/Modules/_testcapimodule.c
@@ -4687,6 +4687,8 @@ get_coreconfig(PyObject *self, PyObject *Py_UNUSED(args))
             FROM_STRING(config->allocator));
    SET_ITEM("dev_mode",
             PyLong_FromLong(config->dev_mode));
+    SET_ITEM("noopt_mode",
+             PyLong_FromLong(config->noopt_mode));
    SET_ITEM("faulthandler",
             PyLong_FromLong(config->faulthandler));
    SET_ITEM("tracemalloc",

diff --git a/Programs/_testembed.c b/Programs/_testembed.c
@@ -320,6 +320,7 @@ dump_config(void)
    printf("allocator = %s\n", config->allocator);

    printf("dev_mode = %i\n", config->dev_mode);
+    printf("noopt_mode = %i\n", config->noopt_mode);
    printf("faulthandler = %i\n", config->faulthandler);
    printf("tracemalloc = %i\n", config->tracemalloc);
    printf("import_time = %i\n", config->import_time);

diff --git a/Python/compile.c b/Python/compile.c
@@ -27,6 +27,7 @@
 #include "node.h"
 #include "ast.h"
 #include "code.h"
+#include "internal/pystate.h"
 #include "symtable.h"
 #include "opcode.h"
 #include "wordcode_helpers.h"
@@ -158,6 +159,7 @@ struct compiler {
    PyCompilerFlags *c_flags;

    int c_optimize;              /* optimization level */
+    int c_noopt;
    int c_interactive;           /* true if in interactive mode */
    int c_nestlevel;

@@ -186,7 +188,7 @@ static int compiler_visit_slice(struct compiler *, slice_ty,
                                expr_context_ty);

 static int inplace_binop(struct compiler *, operator_ty);
-static int expr_constant(expr_ty);
+static int expr_constant(struct compiler *, expr_ty);

 static int compiler_with(struct compiler *, stmt_ty, int);
 static int compiler_async_with(struct compiler *, stmt_ty, int);
@@ -300,6 +302,7 @@ PyAST_CompileObject(mod_ty mod, PyObject *filename, PyCompilerFlags *flags,
    PyCodeObject *co = NULL;
    PyCompilerFlags local_flags;
    int merged;
+    const _PyCoreConfig *conf = &_PyInterpreterState_GET_UNSAFE()->core_config;

    if (!__doc__) {
        __doc__ = PyUnicode_InternFromString("__doc__");
@@ -330,8 +333,14 @@ PyAST_CompileObject(mod_ty mod, PyObject *filename, PyCompilerFlags *flags,
    c.c_optimize = (optimize == -1) ? Py_OptimizeFlag : optimize;
    c.c_nestlevel = 0;

-    if (!_PyAST_Optimize(mod, arena, c.c_optimize)) {
-        goto finally;
+    if (conf->noopt_mode) {
+        c.c_noopt = 1;
+    }
+    else {
+        c.c_noopt = 0;
+        if (!_PyAST_Optimize(mod, arena, c.c_optimize)) {
+            goto finally;
+        }
    }

    c.c_st = PySymtable_BuildObject(mod, filename, c.c_future);
@@ -2365,7 +2374,7 @@ compiler_if(struct compiler *c, stmt_ty s)
    if (end == NULL)
        return 0;

-    constant = expr_constant(s->v.If.test);
+    constant = expr_constant(c, s->v.If.test);
    /* constant = 0: "if 0"
     * constant = 1: "if 1", "if 2", ...
     * constant = -1: rest */
@@ -2478,7 +2487,8 @@ static int
 compiler_while(struct compiler *c, stmt_ty s)
 {
    basicblock *loop, *orelse, *end, *anchor = NULL;
-    int constant = expr_constant(s->v.While.test);
+
+    int constant = expr_constant(c, s->v.While.test);

    if (constant == 0) {
        if (s->v.While.orelse)
@@ -4205,8 +4215,11 @@ compiler_visit_keyword(struct compiler *c, keyword_ty k)
 */

 static int
-expr_constant(expr_ty e)
+expr_constant(struct compiler *c, expr_ty e)
 {
+    if (c->c_noopt) {
+        return -1;
+    }
    if (e->kind == Constant_kind) {
        return PyObject_IsTrue(e->v.Constant.value);
    }
@@ -5387,9 +5400,15 @@ makecode(struct compiler *c, struct assembler *a)
    if (flags < 0)
        goto error;

-    bytecode = PyCode_Optimize(a->a_bytecode, consts, names, a->a_lnotab);
-    if (!bytecode)
-        goto error;
+    if (!c->c_noopt) {
+        bytecode = PyCode_Optimize(a->a_bytecode, consts, names, a->a_lnotab);
+        if (!bytecode)
+            goto error;
+    }
+    else {
+        bytecode = a->a_bytecode;
+        Py_INCREF(bytecode);
+    }

    tmp = PyList_AsTuple(consts); /* PyCode_New requires a tuple */
    if (!tmp)

diff --git a/Python/coreconfig.c b/Python/coreconfig.c
@@ -295,6 +295,7 @@ _PyCoreConfig_Copy(_PyCoreConfig *config, const _PyCoreConfig *config2)
    COPY_ATTR(_install_importlib);
    COPY_ATTR(allocator);
    COPY_ATTR(dev_mode);
+    COPY_ATTR(noopt_mode);
    COPY_ATTR(faulthandler);
    COPY_ATTR(tracemalloc);
    COPY_ATTR(import_time);
@@ -945,6 +946,10 @@ config_read_complex_options(_PyCoreConfig *config)
    {
        config->dev_mode = 1;
    }
+    if (config_get_xoption(config, L"noopt"))
+    {
+        config->noopt_mode = 1;
+    }

    _PyInitError err;
    if (config->tracemalloc < 0) {

diff --git a/Python/sysmodule.c b/Python/sysmodule.c
@@ -2060,6 +2060,7 @@ static PyStructSequence_Field flags_fields[] = {
    {"hash_randomization",      "-R"},
    {"isolated",                "-I"},
    {"dev_mode",                "-X dev"},
+    {"noopt_mode",              "-X noopt"},
    {"utf8_mode",               "-X utf8"},
    {0}
 };
@@ -2101,6 +2102,7 @@ make_flags(void)
    SetFlag(config->use_hash_seed == 0 || config->hash_seed != 0);
    SetFlag(config->isolated);
    PyStructSequence_SET_ITEM(seq, pos++, PyBool_FromLong(config->dev_mode));
+    PyStructSequence_SET_ITEM(seq, pos++, PyBool_FromLong(config->noopt_mode));
    SetFlag(config->utf8_mode);
 #undef SetFlag