Jun 17, 2024 · Jun 12, 2024 · Jun 17, 2024 · Jun 12, 2024 · Jun 16, 2024
diff --git a/Lib/test/test_compile.py b/Lib/test/test_compile.py
        with self.assertRaisesRegex(TypeError, "NamedExpr target must be a Name"):
            compile(ast.fix_missing_locations(m), "<file>", "exec")

    def test_compile_redundant_jumps_and_nops_after_moving_cold_blocks(self):
        # See gh-120367
        code=textwrap.dedent("""
            try:
                pass
            except:
                pass
            else:
                match name_2:
                    case b'':
                        pass
            finally:
                something
            """)

        tree = ast.parse(code)
        for node in ast.walk(tree):
            if hasattr(node,"lineno"):
                 del node.lineno
                 del node.end_lineno
                 del node.col_offset
                 del node.end_col_offset

        compile(ast.fix_missing_locations(tree), "<file>", "exec")

    def test_compile_ast(self):
        fname = __file__
        if fname.lower().endswith('pyc'):
diff --git a/Misc/NEWS.d/next/Core and Builtins/2024-06-12-18-50-29.gh-issue-120367.LmXx2y.rst b/Misc/NEWS.d/next/Core and Builtins/2024-06-12-18-50-29.gh-issue-120367.LmXx2y.rst
 Fix crash in compiler on code with redundant NOPs and JUMPs which show up
 after exception handlers are moved to the end of the code.
diff --git a/Python/flowgraph.c b/Python/flowgraph.c

 static int resolve_line_numbers(cfg_builder *g, int firstlineno);

 static int
 remove_redundant_nops_and_jumps(cfg_builder *g)
 {
    int removed_nops, removed_jumps;
    do {
        /* Convergence is guaranteed because the number of
         * redundant jumps and nops only decreases.
         */
        removed_nops = remove_redundant_nops(g);
        RETURN_IF_ERROR(removed_nops);
        removed_jumps = remove_redundant_jumps(g);
        RETURN_IF_ERROR(removed_jumps);
    } while(removed_nops + removed_jumps > 0);
    return SUCCESS;
 }

 /* Perform optimizations on a control flow graph.
   The consts object should still be in list form to allow new constants
   to be appended.
    }
    RETURN_IF_ERROR(remove_redundant_nops_and_pairs(g->g_entryblock));
    RETURN_IF_ERROR(remove_unreachable(g->g_entryblock));

    int removed_nops, removed_jumps;
    do {
        /* Convergence is guaranteed because the number of
         * redundant jumps and nops only decreases.
         */
        removed_nops = remove_redundant_nops(g);
        RETURN_IF_ERROR(removed_nops);
        removed_jumps = remove_redundant_jumps(g);
        RETURN_IF_ERROR(removed_jumps);
    } while(removed_nops + removed_jumps > 0);
    RETURN_IF_ERROR(remove_redundant_nops_and_jumps(g));
    assert(no_redundant_jumps(g));
    return SUCCESS;
 }
    b->b_next = cold_blocks;

    if (cold_blocks != NULL) {
        RETURN_IF_ERROR(remove_redundant_jumps(g));
        RETURN_IF_ERROR(remove_redundant_nops_and_jumps(g));
    }
    return SUCCESS;
 }
Original file line number	Diff line number	Diff line change
Expand Up		@@ -502,6 +502,31 @@ def test_compile_invalid_namedexpr(self):
		with self.assertRaisesRegex(TypeError, "NamedExpr target must be a Name"):
		compile(ast.fix_missing_locations(m), "<file>", "exec")

		def test_compile_redundant_jumps_and_nops_after_moving_cold_blocks(self):
		# See gh-120367
		code=textwrap.dedent("""
		try:
		pass
		except:
		pass
		else:
		match name_2:
		case b'':
		pass
		finally:
		something
		""")

		tree = ast.parse(code)
iritkatriel marked this conversation as resolved. Show resolvedHide resolved
		for node in ast.walk(tree):
		if hasattr(node,"lineno"):
		del node.lineno
		del node.end_lineno
		del node.col_offset
		del node.end_col_offset
Comment on lines +524 to +528 Copy link Member carljmJun 16, 2024 Choose a reason for hiding this comment The reason will be displayed to describe this comment to others.Learn more. why is it important for this test to remove node locations and then use`ast.fix_missing_locations`? maybe worth a comment?

		compile(ast.fix_missing_locations(tree), "<file>", "exec")

		def test_compile_ast(self):
		fname = __file__
		if fname.lower().endswith('pyc'):
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Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,2 @@
		Fix crash in compiler on code with redundant NOPs and JUMPs which show up
		after exception handlers are moved to the end of the code.
Original file line number	Diff line number	Diff line change
Expand Up		@@ -1857,6 +1857,22 @@ optimize_basic_block(PyObject const_cache, basicblock bb, PyObject *consts)

		static int resolve_line_numbers(cfg_builder *g, int firstlineno);

		static int
		remove_redundant_nops_and_jumps(cfg_builder *g)
		{
		int removed_nops, removed_jumps;
		do {
		/* Convergence is guaranteed because the number of
		* redundant jumps and nops only decreases.
		*/
		removed_nops = remove_redundant_nops(g);
		RETURN_IF_ERROR(removed_nops);
		removed_jumps = remove_redundant_jumps(g);
		RETURN_IF_ERROR(removed_jumps);
		} while(removed_nops + removed_jumps > 0);
		return SUCCESS;
		}

		/* Perform optimizations on a control flow graph.
		The consts object should still be in list form to allow new constants
		to be appended.
Expand All		@@ -1878,17 +1894,7 @@ optimize_cfg(cfg_builder g, PyObject consts, PyObject *const_cache, int firstl
		}
		RETURN_IF_ERROR(remove_redundant_nops_and_pairs(g->g_entryblock));
		RETURN_IF_ERROR(remove_unreachable(g->g_entryblock));

		int removed_nops, removed_jumps;
		do {
		/* Convergence is guaranteed because the number of
		* redundant jumps and nops only decreases.
		*/
		removed_nops = remove_redundant_nops(g);
		RETURN_IF_ERROR(removed_nops);
		removed_jumps = remove_redundant_jumps(g);
		RETURN_IF_ERROR(removed_jumps);
		} while(removed_nops + removed_jumps > 0);
		RETURN_IF_ERROR(remove_redundant_nops_and_jumps(g));
		assert(no_redundant_jumps(g));
		return SUCCESS;
		}
Expand DownExpand Up		@@ -2358,7 +2364,7 @@ push_cold_blocks_to_end(cfg_builder *g) {
		b->b_next = cold_blocks;

		if (cold_blocks != NULL) {
		RETURN_IF_ERROR(remove_redundant_jumps(g));
		RETURN_IF_ERROR(remove_redundant_nops_and_jumps(g));
		}
		return SUCCESS;
		}
Expand Down