From 82271f13e7eab69b909d538556e4781e971f7584 Mon Sep 17 00:00:00 2001 From: Jeremy Hylton Date: Wed, 4 Oct 2006 02:24:52 +0000 Subject: Fix for SF bug 1569998: break permitted inside try. The compiler was checking that there was something on the fblock stack, but not that there was a loop on the stack. Fixed that and added a test for the specific syntax error. Bug fix candidate. --- Lib/test/test_syntax.py | 14 ++++++++++++++ Python/compile.c | 14 +++++++++++++- 2 files changed, 27 insertions(+), 1 deletion(-) diff --git a/Lib/test/test_syntax.py b/Lib/test/test_syntax.py index 692ba57..8143032 100644 --- a/Lib/test/test_syntax.py +++ b/Lib/test/test_syntax.py @@ -322,6 +322,20 @@ This is essentially a continue in a finally which should not be allowed. ... SyntaxError: 'continue' not supported inside 'finally' clause (, line 8) +There is one test for a break that is not in a loop. The compiler +uses a single data structure to keep track of try-finally and loops, +so we need to be sure that a break is actually inside a loop. If it +isn't, there should be a syntax error. + + >>> try: + ... print 1 + ... break + ... print 2 + ... finally: + ... print 3 + Traceback (most recent call last): + ... + SyntaxError: 'break' outside loop (, line 3) """ import re diff --git a/Python/compile.c b/Python/compile.c index a03de0d..374cf1c 100644 --- a/Python/compile.c +++ b/Python/compile.c @@ -187,6 +187,8 @@ static int compiler_push_fblock(struct compiler *, enum fblocktype, basicblock *); static void compiler_pop_fblock(struct compiler *, enum fblocktype, basicblock *); +/* Returns true if there is a loop on the fblock stack. */ +static int compiler_in_loop(struct compiler *); static int inplace_binop(struct compiler *, operator_ty); static int expr_constant(expr_ty e); @@ -2157,7 +2159,7 @@ compiler_visit_stmt(struct compiler *c, stmt_ty s) case Pass_kind: break; case Break_kind: - if (!c->u->u_nfblocks) + if (!compiler_in_loop(c)) return compiler_error(c, "'break' outside loop"); ADDOP(c, BREAK_LOOP); break; @@ -3147,6 +3149,16 @@ compiler_pop_fblock(struct compiler *c, enum fblocktype t, basicblock *b) assert(u->u_fblock[u->u_nfblocks].fb_block == b); } +static int +compiler_in_loop(struct compiler *c) { + int i; + struct compiler_unit *u = c->u; + for (i = 0; i < u->u_nfblocks; ++i) { + if (u->u_fblock[i].fb_type == LOOP) + return 1; + } + return 0; +} /* Raises a SyntaxError and returns 0. If something goes wrong, a different exception may be raised. */ -- cgit v0.12