[Python-checkins] bpo-46808: remove NEXT_BLOCK() from compile.c (GH-31448)
markshannon
webhook-mailer at python.org
Fri Feb 25 07:17:54 EST 2022
https://github.com/python/cpython/commit/c579243eb62d3182c84004cd72dcf6ef59100643
commit: c579243eb62d3182c84004cd72dcf6ef59100643
branch: main
author: Irit Katriel <1055913+iritkatriel at users.noreply.github.com>
committer: markshannon <mark at hotpy.org>
date: 2022-02-25T12:17:50Z
summary:
bpo-46808: remove NEXT_BLOCK() from compile.c (GH-31448)
files:
A Misc/NEWS.d/next/Core and Builtins/2022-02-20-23-10-14.bpo-46808.vouNSF.rst
M Python/compile.c
diff --git a/Misc/NEWS.d/next/Core and Builtins/2022-02-20-23-10-14.bpo-46808.vouNSF.rst b/Misc/NEWS.d/next/Core and Builtins/2022-02-20-23-10-14.bpo-46808.vouNSF.rst
new file mode 100644
index 0000000000000..9b6009021d63a
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2022-02-20-23-10-14.bpo-46808.vouNSF.rst
@@ -0,0 +1 @@
+Remove the ``NEXT_BLOCK`` macro from compile.c, and make the compiler automatically generate implicit blocks when they are needed.
diff --git a/Python/compile.c b/Python/compile.c
index 40e6263ff7dd8..8ae4d44e9c6f3 100644
--- a/Python/compile.c
+++ b/Python/compile.c
@@ -268,6 +268,9 @@ struct compiler_unit {
int u_col_offset; /* the offset of the current stmt */
int u_end_lineno; /* the end line of the current stmt */
int u_end_col_offset; /* the end offset of the current stmt */
+
+ /* true if we need to create an implicit basicblock before the next instr */
+ int u_need_new_implicit_block;
};
/* This struct captures the global state of a compilation.
@@ -757,23 +760,13 @@ compiler_new_block(struct compiler *c)
return b;
}
-static basicblock *
-compiler_next_block(struct compiler *c)
-{
- basicblock *block = compiler_new_block(c);
- if (block == NULL)
- return NULL;
- c->u->u_curblock->b_next = block;
- c->u->u_curblock = block;
- return block;
-}
-
static basicblock *
compiler_use_next_block(struct compiler *c, basicblock *block)
{
assert(block != NULL);
c->u->u_curblock->b_next = block;
c->u->u_curblock = block;
+ c->u->u_need_new_implicit_block = 0;
return block;
}
@@ -1141,6 +1134,37 @@ PyCompile_OpcodeStackEffect(int opcode, int oparg)
return stack_effect(opcode, oparg, -1);
}
+static int is_end_of_basic_block(struct instr *instr)
+{
+ int opcode = instr->i_opcode;
+
+ return is_jump(instr) ||
+ opcode == RETURN_VALUE ||
+ opcode == RAISE_VARARGS ||
+ opcode == RERAISE;
+}
+
+static int
+compiler_use_new_implicit_block_if_needed(struct compiler *c)
+{
+ if (c->u->u_need_new_implicit_block) {
+ basicblock *b = compiler_new_block(c);
+ if (b == NULL) {
+ return -1;
+ }
+ compiler_use_next_block(c, b);
+ }
+ return 0;
+}
+
+static void
+compiler_check_if_end_of_block(struct compiler *c, struct instr *instr)
+{
+ if (is_end_of_basic_block(instr)) {
+ c->u->u_need_new_implicit_block = 1;
+ }
+}
+
/* Add an opcode with no argument.
Returns 0 on failure, 1 on success.
*/
@@ -1149,23 +1173,29 @@ static int
compiler_addop_line(struct compiler *c, int opcode, int line,
int end_line, int col_offset, int end_col_offset)
{
- basicblock *b;
- struct instr *i;
- int off;
assert(!HAS_ARG(opcode) || IS_ARTIFICIAL(opcode));
- off = compiler_next_instr(c->u->u_curblock);
- if (off < 0)
+
+ if (compiler_use_new_implicit_block_if_needed(c) < 0) {
+ return -1;
+ }
+
+ basicblock *b = c->u->u_curblock;
+ int off = compiler_next_instr(b);
+ if (off < 0) {
return 0;
- b = c->u->u_curblock;
- i = &b->b_instr[off];
+ }
+ struct instr *i = &b->b_instr[off];
i->i_opcode = opcode;
i->i_oparg = 0;
- if (opcode == RETURN_VALUE)
+ if (opcode == RETURN_VALUE) {
b->b_return = 1;
+ }
i->i_lineno = line;
i->i_end_lineno = end_line;
i->i_col_offset = col_offset;
i->i_end_col_offset = end_col_offset;
+
+ compiler_check_if_end_of_block(c, i);
return 1;
}
@@ -1377,9 +1407,6 @@ compiler_addop_i_line(struct compiler *c, int opcode, Py_ssize_t oparg,
int lineno, int end_lineno,
int col_offset, int end_col_offset)
{
- struct instr *i;
- int off;
-
/* oparg value is unsigned, but a signed C int is usually used to store
it in the C code (like Python/ceval.c).
@@ -1387,19 +1414,28 @@ compiler_addop_i_line(struct compiler *c, int opcode, Py_ssize_t oparg,
The argument of a concrete bytecode instruction is limited to 8-bit.
EXTENDED_ARG is used for 16, 24, and 32-bit arguments. */
+
assert(HAS_ARG(opcode));
assert(0 <= oparg && oparg <= 2147483647);
- off = compiler_next_instr(c->u->u_curblock);
- if (off < 0)
+ if (compiler_use_new_implicit_block_if_needed(c) < 0) {
+ return -1;
+ }
+
+ basicblock *b = c->u->u_curblock;
+ int off = compiler_next_instr(b);
+ if (off < 0) {
return 0;
- i = &c->u->u_curblock->b_instr[off];
+ }
+ struct instr *i = &b->b_instr[off];
i->i_opcode = opcode;
i->i_oparg = Py_SAFE_DOWNCAST(oparg, Py_ssize_t, int);
i->i_lineno = lineno;
i->i_end_lineno = end_lineno;
i->i_col_offset = col_offset;
i->i_end_col_offset = end_col_offset;
+
+ compiler_check_if_end_of_block(c, i);
return 1;
}
@@ -1417,15 +1453,19 @@ compiler_addop_i_noline(struct compiler *c, int opcode, Py_ssize_t oparg)
return compiler_addop_i_line(c, opcode, oparg, -1, 0, 0, 0);
}
-static int add_jump_to_block(basicblock *b, int opcode,
+static int add_jump_to_block(struct compiler *c, int opcode,
int lineno, int end_lineno,
int col_offset, int end_col_offset,
basicblock *target)
{
assert(HAS_ARG(opcode));
- assert(b != NULL);
assert(target != NULL);
+ if (compiler_use_new_implicit_block_if_needed(c) < 0) {
+ return -1;
+ }
+
+ basicblock *b = c->u->u_curblock;
int off = compiler_next_instr(b);
struct instr *i = &b->b_instr[off];
if (off < 0) {
@@ -1437,13 +1477,15 @@ static int add_jump_to_block(basicblock *b, int opcode,
i->i_end_lineno = end_lineno;
i->i_col_offset = col_offset;
i->i_end_col_offset = end_col_offset;
+
+ compiler_check_if_end_of_block(c, i);
return 1;
}
static int
compiler_addop_j(struct compiler *c, int opcode, basicblock *b)
{
- return add_jump_to_block(c->u->u_curblock, opcode, c->u->u_lineno,
+ return add_jump_to_block(c, opcode, c->u->u_lineno,
c->u->u_end_lineno, c->u->u_col_offset,
c->u->u_end_col_offset, b);
}
@@ -1451,18 +1493,7 @@ compiler_addop_j(struct compiler *c, int opcode, basicblock *b)
static int
compiler_addop_j_noline(struct compiler *c, int opcode, basicblock *b)
{
- return add_jump_to_block(c->u->u_curblock, opcode, -1, 0, 0, 0, b);
-}
-
-/* NEXT_BLOCK() creates an implicit jump from the current block
- to the new block.
-
- The returns inside this macro make it impossible to decref objects
- created in the local function. Local objects should use the arena.
-*/
-#define NEXT_BLOCK(C) { \
- if (compiler_next_block((C)) == NULL) \
- return 0; \
+ return add_jump_to_block(c, opcode, -1, 0, 0, 0, b);
}
#define ADDOP(C, OP) { \
@@ -2823,12 +2854,10 @@ compiler_jump_if(struct compiler *c, expr_ty e, basicblock *next, int cond)
ADDOP_I(c, COPY, 2);
ADDOP_COMPARE(c, asdl_seq_GET(e->v.Compare.ops, i));
ADDOP_JUMP(c, POP_JUMP_IF_FALSE, cleanup);
- NEXT_BLOCK(c);
}
VISIT(c, expr, (expr_ty)asdl_seq_GET(e->v.Compare.comparators, n));
ADDOP_COMPARE(c, asdl_seq_GET(e->v.Compare.ops, n));
ADDOP_JUMP(c, cond ? POP_JUMP_IF_TRUE : POP_JUMP_IF_FALSE, next);
- NEXT_BLOCK(c);
basicblock *end = compiler_new_block(c);
if (end == NULL)
return 0;
@@ -2852,7 +2881,6 @@ compiler_jump_if(struct compiler *c, expr_ty e, basicblock *next, int cond)
/* general implementation */
VISIT(c, expr, e);
ADDOP_JUMP(c, cond ? POP_JUMP_IF_TRUE : POP_JUMP_IF_FALSE, next);
- NEXT_BLOCK(c);
return 1;
}
@@ -3128,7 +3156,6 @@ compiler_return(struct compiler *c, stmt_ty s)
ADDOP_LOAD_CONST(c, s->v.Return.value->v.Constant.value);
}
ADDOP(c, RETURN_VALUE);
- NEXT_BLOCK(c);
return 1;
}
@@ -3149,7 +3176,6 @@ compiler_break(struct compiler *c)
return 0;
}
ADDOP_JUMP(c, JUMP_ABSOLUTE, loop->fb_exit);
- NEXT_BLOCK(c);
return 1;
}
@@ -3166,7 +3192,6 @@ compiler_continue(struct compiler *c)
return compiler_error(c, "'continue' not properly in loop");
}
ADDOP_JUMP(c, JUMP_ABSOLUTE, loop->fb_block);
- NEXT_BLOCK(c)
return 1;
}
@@ -3348,7 +3373,6 @@ compiler_try_except(struct compiler *c, stmt_ty s)
compiler_pop_fblock(c, TRY_EXCEPT, body);
ADDOP_NOLINE(c, POP_BLOCK);
if (s->v.Try.orelse && asdl_seq_LEN(s->v.Try.orelse)) {
- NEXT_BLOCK(c);
VISIT_SEQ(c, stmt, s->v.Try.orelse);
}
ADDOP_JUMP_NOLINE(c, JUMP_FORWARD, end);
@@ -3374,7 +3398,6 @@ compiler_try_except(struct compiler *c, stmt_ty s)
if (handler->v.ExceptHandler.type) {
VISIT(c, expr, handler->v.ExceptHandler.type);
ADDOP_JUMP(c, JUMP_IF_NOT_EXC_MATCH, except);
- NEXT_BLOCK(c);
}
if (handler->v.ExceptHandler.name) {
basicblock *cleanup_end, *cleanup_body;
@@ -3580,7 +3603,6 @@ compiler_try_star_except(struct compiler *c, stmt_ty s)
if (handler->v.ExceptHandler.type) {
VISIT(c, expr, handler->v.ExceptHandler.type);
ADDOP_JUMP(c, JUMP_IF_NOT_EG_MATCH, except);
- NEXT_BLOCK(c);
}
basicblock *cleanup_end = compiler_new_block(c);
@@ -3665,7 +3687,6 @@ compiler_try_star_except(struct compiler *c, stmt_ty s)
ADDOP(c, PREP_RERAISE_STAR);
ADDOP_I(c, COPY, 1);
ADDOP_JUMP(c, POP_JUMP_IF_NOT_NONE, reraise);
- NEXT_BLOCK(c);
/* Nothing to reraise */
ADDOP(c, POP_TOP);
@@ -3957,7 +3978,6 @@ compiler_visit_stmt(struct compiler *c, stmt_ty s)
}
}
ADDOP_I(c, RAISE_VARARGS, (int)n);
- NEXT_BLOCK(c);
break;
case Try_kind:
return compiler_try(c, s);
@@ -4503,7 +4523,6 @@ compiler_compare(struct compiler *c, expr_ty e)
ADDOP_I(c, COPY, 2);
ADDOP_COMPARE(c, asdl_seq_GET(e->v.Compare.ops, i));
ADDOP_JUMP(c, JUMP_IF_FALSE_OR_POP, cleanup);
- NEXT_BLOCK(c);
}
VISIT(c, expr, (expr_ty)asdl_seq_GET(e->v.Compare.comparators, n));
ADDOP_COMPARE(c, asdl_seq_GET(e->v.Compare.ops, n));
@@ -5093,7 +5112,6 @@ compiler_sync_comprehension_generator(struct compiler *c,
depth++;
compiler_use_next_block(c, start);
ADDOP_JUMP(c, FOR_ITER, anchor);
- NEXT_BLOCK(c);
}
VISIT(c, expr, gen->target);
@@ -5103,7 +5121,6 @@ compiler_sync_comprehension_generator(struct compiler *c,
expr_ty e = (expr_ty)asdl_seq_GET(gen->ifs, i);
if (!compiler_jump_if(c, e, if_cleanup, 0))
return 0;
- NEXT_BLOCK(c);
}
if (++gen_index < asdl_seq_LEN(generators))
@@ -5198,7 +5215,6 @@ compiler_async_comprehension_generator(struct compiler *c,
expr_ty e = (expr_ty)asdl_seq_GET(gen->ifs, i);
if (!compiler_jump_if(c, e, if_cleanup, 0))
return 0;
- NEXT_BLOCK(c);
}
depth++;
@@ -5410,7 +5426,6 @@ compiler_with_except_finish(struct compiler *c, basicblock * cleanup) {
if (exit == NULL)
return 0;
ADDOP_JUMP(c, POP_JUMP_IF_TRUE, exit);
- NEXT_BLOCK(c);
ADDOP_I(c, RERAISE, 2);
compiler_use_next_block(c, cleanup);
POP_EXCEPT_AND_RERAISE(c);
@@ -6149,7 +6164,6 @@ jump_to_fail_pop(struct compiler *c, pattern_context *pc, int op)
Py_ssize_t pops = pc->on_top + PyList_GET_SIZE(pc->stores);
RETURN_IF_FALSE(ensure_fail_pop(c, pc, pops));
ADDOP_JUMP(c, op, pc->fail_pop[pops]);
- NEXT_BLOCK(c);
return 1;
}
@@ -6159,7 +6173,6 @@ emit_and_reset_fail_pop(struct compiler *c, pattern_context *pc)
{
if (!pc->fail_pop_size) {
assert(pc->fail_pop == NULL);
- NEXT_BLOCK(c);
return 1;
}
while (--pc->fail_pop_size) {
@@ -6662,7 +6675,6 @@ compiler_pattern_or(struct compiler *c, pattern_ty p, pattern_context *pc)
}
assert(control);
if (!compiler_addop_j(c, JUMP_FORWARD, end) ||
- !compiler_next_block(c) ||
!emit_and_reset_fail_pop(c, pc))
{
goto error;
@@ -8136,10 +8148,7 @@ assemble(struct compiler *c, int addNone)
PyCodeObject *co = NULL;
PyObject *consts = NULL;
- /* Make sure every block that falls off the end returns None.
- XXX NEXT_BLOCK() isn't quite right, because if the last
- block ends with a jump or return b_next shouldn't set.
- */
+ /* Make sure every block that falls off the end returns None. */
if (!c->u->u_curblock->b_return) {
UNSET_LOC(c);
if (addNone)
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