diff options
| author | Jakub Jelinek <jakub@redhat.com> | 2019-02-26 15:37:39 +0100 |
|---|---|---|
| committer | Jakub Jelinek <jakub@gcc.gnu.org> | 2019-02-26 15:37:39 +0100 |
| commit | c7f7c313c0da09232ced316ebb9806bd0f70405c (patch) | |
| tree | 042a5de16a25d6b84a493f189ce6d45b60833c41 /gcc | |
| parent | 01c3ddcffb38e92e0f59aeb270e4848a5b8941f0 (diff) | |
| download | gcc-c7f7c313c0da09232ced316ebb9806bd0f70405c.zip gcc-c7f7c313c0da09232ced316ebb9806bd0f70405c.tar.gz gcc-c7f7c313c0da09232ced316ebb9806bd0f70405c.tar.bz2 | |
re PR c++/89481 (constexpr function allows writing one active union member and reading another)
PR c++/89481
* constexpr.c (cxx_eval_store_expression): When changing active union
member, set no_zero_init.
* g++.dg/cpp1y/constexpr-89481.C: New test.
From-SVN: r269213
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/cp/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/cp/constexpr.c | 1 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/testsuite/g++.dg/cpp1y/constexpr-89481.C | 24 |
4 files changed, 36 insertions, 0 deletions
diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog index 2da2e3d..6344e4e 100644 --- a/gcc/cp/ChangeLog +++ b/gcc/cp/ChangeLog @@ -1,3 +1,9 @@ +2019-02-26 Jakub Jelinek <jakub@redhat.com> + + PR c++/89481 + * constexpr.c (cxx_eval_store_expression): When changing active union + member, set no_zero_init. + 2019-02-23 Marek Polacek <polacek@redhat.com> PR c++/88294 - ICE with non-constant noexcept-specifier. diff --git a/gcc/cp/constexpr.c b/gcc/cp/constexpr.c index 4008027..5bc5efe 100644 --- a/gcc/cp/constexpr.c +++ b/gcc/cp/constexpr.c @@ -3860,6 +3860,7 @@ cxx_eval_store_expression (const constexpr_ctx *ctx, tree t, } /* Changing active member. */ vec_safe_truncate (CONSTRUCTOR_ELTS (*valp), 0); + no_zero_init = true; } for (idx = 0; diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 3f76c45..4317ad8 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2019-02-26 Jakub Jelinek <jakub@redhat.com> + + PR c++/89481 + * g++.dg/cpp1y/constexpr-89481.C: New test. + 2019-02-26 Richard Biener <rguenther@suse.de> PR tree-optimization/89505 diff --git a/gcc/testsuite/g++.dg/cpp1y/constexpr-89481.C b/gcc/testsuite/g++.dg/cpp1y/constexpr-89481.C new file mode 100644 index 0000000..8ac4ef0 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp1y/constexpr-89481.C @@ -0,0 +1,24 @@ +// PR c++/89481 +// { dg-do compile { target c++14 } } + +constexpr int +foo () +{ + union U { long long a; int b[2]; } u { 5LL }; + u.b[1] = 4; // { dg-error "change of the active member of a union from" "" { target c++17_down } } + return u.b[0]; +} + +constexpr int +bar () +{ + union U { long long a; int b[2]; } u { 5LL }; + u.b[1] = 4; // { dg-error "change of the active member of a union from" "" { target c++17_down } } + return u.b[1]; +} + +static_assert (foo () == 0, ""); // { dg-error "non-constant condition for static assertion" } + // { dg-message "in 'constexpr' expansion of" "" { target *-*-* } .-1 } + // { dg-error "accessing uninitialized array element" "" { target c++2a } .-2 } +static_assert (bar () == 4, ""); // { dg-error "non-constant condition for static assertion" "" { target c++17_down } } + // { dg-message "in 'constexpr' expansion of" "" { target c++17_down } .-1 } |