From 0223e4f514d36b505bf23ae213b99886bebe0dad Mon Sep 17 00:00:00 2001 From: Joseph Myers Date: Fri, 1 Apr 2005 00:34:44 +0100 Subject: [PATCH] re PR c/17855 (modification of function struct return not diagnosed) PR c/17855 * gimplify.c (gimplify_expr): Create a temporary for lvalue COND_EXPR and CALL_EXPR. testsuite: * gcc.c-torture/compile/struct-non-lval-1.c, gcc.c-torture/compile/struct-non-lval-2.c, gcc.c-torture/compile/struct-non-lval-3.c: New tests. From-SVN: r97352 --- gcc/ChangeLog | 6 ++++++ gcc/gimplify.c | 18 ++++++++++++++++++ gcc/testsuite/ChangeLog | 7 +++++++ .../gcc.c-torture/compile/struct-non-lval-1.c | 7 +++++++ .../gcc.c-torture/compile/struct-non-lval-2.c | 7 +++++++ .../gcc.c-torture/compile/struct-non-lval-3.c | 7 +++++++ 6 files changed, 52 insertions(+) create mode 100644 gcc/testsuite/gcc.c-torture/compile/struct-non-lval-1.c create mode 100644 gcc/testsuite/gcc.c-torture/compile/struct-non-lval-2.c create mode 100644 gcc/testsuite/gcc.c-torture/compile/struct-non-lval-3.c diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 9b9ff0d25ce..fac7f920737 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2005-04-01 Joseph S. Myers + + PR c/17855 + * gimplify.c (gimplify_expr): Create a temporary for lvalue + COND_EXPR and CALL_EXPR. + 2005-03-31 Vladimir Makarov PR target/20632 diff --git a/gcc/gimplify.c b/gcc/gimplify.c index 9191baea26a..bd15e045a16 100644 --- a/gcc/gimplify.c +++ b/gcc/gimplify.c @@ -3810,10 +3810,28 @@ gimplify_expr (tree *expr_p, tree *pre_p, tree *post_p, case COND_EXPR: ret = gimplify_cond_expr (expr_p, pre_p, post_p, NULL_TREE, fallback); + /* C99 code may assign to an array in a structure value of a + conditional expression, and this has undefined behavior + only on execution, so create a temporary if an lvalue is + required. */ + if (fallback == fb_lvalue) + { + *expr_p = get_initialized_tmp_var (*expr_p, pre_p, post_p); + lang_hooks.mark_addressable (*expr_p); + } break; case CALL_EXPR: ret = gimplify_call_expr (expr_p, pre_p, fallback != fb_none); + /* C99 code may assign to an array in a structure returned + from a function, and this has undefined behavior only on + execution, so create a temporary if an lvalue is + required. */ + if (fallback == fb_lvalue) + { + *expr_p = get_initialized_tmp_var (*expr_p, pre_p, post_p); + lang_hooks.mark_addressable (*expr_p); + } break; case TREE_LIST: diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 6e6601dfe65..f3c26176915 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,10 @@ +2005-04-01 Joseph S. Myers + + PR c/17855 + * gcc.c-torture/compile/struct-non-lval-1.c, + gcc.c-torture/compile/struct-non-lval-2.c, + gcc.c-torture/compile/struct-non-lval-3.c: New tests. + 2005-03-31 Janis Johnson * gcc.dg/tls/tls.exp: Remove temporary file. diff --git a/gcc/testsuite/gcc.c-torture/compile/struct-non-lval-1.c b/gcc/testsuite/gcc.c-torture/compile/struct-non-lval-1.c new file mode 100644 index 00000000000..0924f5cc02d --- /dev/null +++ b/gcc/testsuite/gcc.c-torture/compile/struct-non-lval-1.c @@ -0,0 +1,7 @@ +/* Bug c/17855. */ +struct foo {char x, y, z[2];}; +struct foo f(); +void bar(int baz) +{ + f().z[baz] = 1; +} diff --git a/gcc/testsuite/gcc.c-torture/compile/struct-non-lval-2.c b/gcc/testsuite/gcc.c-torture/compile/struct-non-lval-2.c new file mode 100644 index 00000000000..daa0d17492d --- /dev/null +++ b/gcc/testsuite/gcc.c-torture/compile/struct-non-lval-2.c @@ -0,0 +1,7 @@ +/* Bug c/17855, using conditional expression for non-lvalue. */ +struct foo {char x, y, z[2];}; +struct foo p, q; int r; +void bar(int baz) +{ + (r ? p : q).z[baz] = 1; +} diff --git a/gcc/testsuite/gcc.c-torture/compile/struct-non-lval-3.c b/gcc/testsuite/gcc.c-torture/compile/struct-non-lval-3.c new file mode 100644 index 00000000000..3020194cae0 --- /dev/null +++ b/gcc/testsuite/gcc.c-torture/compile/struct-non-lval-3.c @@ -0,0 +1,7 @@ +/* Bug c/17855, using assignment for non-lvalue. */ +struct foo {char x, y, z[2];}; +struct foo p, q; +void bar(int baz) +{ + (p = q).z[baz] = 1; +} -- 2.30.2