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| author | Marek Polacek <mpolacek@gcc.gnu.org> | 2016-05-23 15:37:09 +0000 |
|---|---|---|
| committer | Marek Polacek <mpolacek@gcc.gnu.org> | 2016-05-23 15:37:09 +0000 |
| commit | a7dc5980e91d758905750a5c0a533f689eca355e (patch) | |
| tree | d51176bb0505d6371f073a25030266ac0a853be1 /gcc/gimplify.c | |
| parent | 7e5a3c96db2383a41587d6525b4ac9ea1fafe091 (diff) | |
| download | gcc-a7dc5980e91d758905750a5c0a533f689eca355e.zip gcc-a7dc5980e91d758905750a5c0a533f689eca355e.tar.gz gcc-a7dc5980e91d758905750a5c0a533f689eca355e.tar.bz2 | |
re PR c/49859 (gcc could warn about statements between "switch" and first "case")
PR c/49859
* common.opt (Wswitch-unreachable): New option.
* doc/invoke.texi: Document -Wswitch-unreachable.
* gimplify.c (gimplify_switch_expr): Implement the -Wswitch-unreachable
warning.
* c-c++-common/Wswitch-unreachable-1.c: New test.
* gcc.dg/Wswitch-unreachable-1.c: New test.
* c-c++-common/goacc/sb-2.c (void foo): Add dg-warning.
* g++.dg/cpp0x/lambda/lambda-switch.C (main): Likewise.
* g++.dg/gomp/block-10.C: Likewise.
* gcc.dg/gomp/block-10.c: Likewise.
* g++.dg/gomp/block-9.C: Likewise.
* gcc.dg/gomp/block-9.c: Likewise.
* g++.dg/gomp/target-1.C: Likewise.
* g++.dg/gomp/target-2.C: Likewise.
* gcc.dg/gomp/target-1.c: Likewise.
* gcc.dg/gomp/target-2.c: Likewise.
* g++.dg/gomp/taskgroup-1.C: Likewise.
* gcc.dg/gomp/taskgroup-1.c: Likewise.
* gcc.dg/gomp/teams-1.c: Likewise.
* g++.dg/gomp/teams-1.C: Likewise.
* g++.dg/overload/error3.C: Likewise.
* g++.dg/tm/jump1.C: Likewise.
* g++.dg/torture/pr40335.C: Likewise.
* gcc.dg/c99-vla-jump-5.c: Likewise.
* gcc.dg/switch-warn-1.c: Likewise.
* gcc.dg/Wjump-misses-init-1.c: Use -Wno-switch-unreachable.
* gcc.dg/nested-func-1.c: Likewise.
* gcc.dg/pr67784-4.c: Likewise.
From-SVN: r236597
Diffstat (limited to 'gcc/gimplify.c')
| -rw-r--r-- | gcc/gimplify.c | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/gcc/gimplify.c b/gcc/gimplify.c index 4a544e3..6473544 100644 --- a/gcc/gimplify.c +++ b/gcc/gimplify.c @@ -1595,6 +1595,32 @@ gimplify_switch_expr (tree *expr_p, gimple_seq *pre_p) gimplify_ctxp->case_labels.create (8); gimplify_stmt (&SWITCH_BODY (switch_expr), &switch_body_seq); + + /* Possibly warn about unreachable statements between switch's + controlling expression and the first case. */ + if (warn_switch_unreachable + /* This warning doesn't play well with Fortran when optimizations + are on. */ + && !lang_GNU_Fortran () + && switch_body_seq != NULL) + { + gimple_seq seq = switch_body_seq; + if (gimple_code (switch_body_seq) == GIMPLE_BIND) + seq = gimple_bind_body (as_a <gbind *> (switch_body_seq)); + gimple *stmt = gimple_seq_first_stmt (seq); + enum gimple_code code = gimple_code (stmt); + if (code != GIMPLE_LABEL && code != GIMPLE_TRY) + { + if (code == GIMPLE_GOTO + && TREE_CODE (gimple_goto_dest (stmt)) == LABEL_DECL + && DECL_ARTIFICIAL (gimple_goto_dest (stmt))) + /* Don't warn for compiler-generated gotos. These occur + in Duff's devices, for example. */; + else + warning_at (gimple_location (stmt), OPT_Wswitch_unreachable, + "statement will never be executed"); + } + } labels = gimplify_ctxp->case_labels; gimplify_ctxp->case_labels = saved_labels; |