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| author | Jason Merrill <jason@redhat.com> | 2014-11-18 22:03:45 -0500 |
|---|---|---|
| committer | Jason Merrill <jason@gcc.gnu.org> | 2014-11-18 22:03:45 -0500 |
| commit | 052beba43fcefe280c617045f03dfe37fcd5b81a (patch) | |
| tree | 791d225ae5241592bde9beb4dcfe27f18935728d /gcc | |
| parent | 58611fb6fa0c1bab4ea0f77df43df67e9a9d19b0 (diff) | |
| download | gcc-052beba43fcefe280c617045f03dfe37fcd5b81a.zip gcc-052beba43fcefe280c617045f03dfe37fcd5b81a.tar.gz gcc-052beba43fcefe280c617045f03dfe37fcd5b81a.tar.bz2 | |
re PR c++/63924 (Constexpr constructible expression "is not constexpr" when used in a template non-type argument)
PR c++/63924
* constexpr.c (cxx_eval_constant_expression) [PARM_DECL]: A load
from a variable of empty class type is constant.
From-SVN: r217749
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/cp/ChangeLog | 4 | ||||
| -rw-r--r-- | gcc/cp/constexpr.c | 6 | ||||
| -rw-r--r-- | gcc/testsuite/g++.dg/cpp0x/constexpr-empty8.C | 7 |
3 files changed, 17 insertions, 0 deletions
diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog index 32f2c6f..5769d2a 100644 --- a/gcc/cp/ChangeLog +++ b/gcc/cp/ChangeLog @@ -1,5 +1,9 @@ 2014-11-18 Jason Merrill <jason@redhat.com> + PR c++/63924 + * constexpr.c (cxx_eval_constant_expression) [PARM_DECL]: A load + from a variable of empty class type is constant. + * constexpr.c (cxx_eval_statement_list): Handle statement-expressions. (potential_constant_expression_1): Handle STMT_EXPR. diff --git a/gcc/cp/constexpr.c b/gcc/cp/constexpr.c index 1b330a0..1303fdc 100644 --- a/gcc/cp/constexpr.c +++ b/gcc/cp/constexpr.c @@ -2845,6 +2845,12 @@ cxx_eval_constant_expression (const constexpr_ctx *ctx, tree t, r = *p; else if (addr) /* Defer in case this is only used for its type. */; + else if (is_empty_class (TREE_TYPE (t))) + { + /* If the class is empty, we aren't actually loading anything. */ + r = build_constructor (TREE_TYPE (t), NULL); + TREE_CONSTANT (r) = true; + } else { if (!ctx->quiet) diff --git a/gcc/testsuite/g++.dg/cpp0x/constexpr-empty8.C b/gcc/testsuite/g++.dg/cpp0x/constexpr-empty8.C new file mode 100644 index 0000000..8c1414a --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp0x/constexpr-empty8.C @@ -0,0 +1,7 @@ +// PR c++/63924 +// { dg-do compile { target c++11 } } + +struct A { }; +constexpr bool f(A a) { return true; } +template <bool B> constexpr bool g() { return true; } +constexpr bool g(A a) { return g<f(a)>(); } |