diff options
Diffstat (limited to 'gcc/cp/constexpr.cc')
| -rw-r--r-- | gcc/cp/constexpr.cc | 55 |
1 files changed, 43 insertions, 12 deletions
diff --git a/gcc/cp/constexpr.cc b/gcc/cp/constexpr.cc index 7e37582..f56c5c4 100644 --- a/gcc/cp/constexpr.cc +++ b/gcc/cp/constexpr.cc @@ -307,7 +307,14 @@ is_valid_constexpr_fn (tree fun, bool complain) { ret = false; if (complain) - error ("%q#T has virtual base classes", DECL_CONTEXT (fun)); + { + if (DECL_CONSTRUCTOR_P (fun)) + error ("%<constexpr%> constructor in %q#T that has " + "virtual base classes", DECL_CONTEXT (fun)); + else + error ("%<constexpr%> destructor in %q#T that has " + "virtual base classes", DECL_CONTEXT (fun)); + } } return ret; @@ -1048,6 +1055,12 @@ explain_invalid_constexpr_fn (tree fun) { static hash_set<tree> *diagnosed; tree body; + + /* Don't try to explain a function we already complained about. */ + if (function *f = DECL_STRUCT_FUNCTION (fun)) + if (f->language->erroneous) + return; + /* In C++23, a function marked 'constexpr' may not actually be a constant expression. We haven't diagnosed the problem yet: -Winvalid-constexpr wasn't enabled. The function was called, so diagnose why it cannot be @@ -3079,6 +3092,7 @@ cxx_eval_call_expression (const constexpr_ctx *ctx, tree t, } constexpr_ctx new_ctx = *ctx; + ctx = &new_ctx; if (DECL_CONSTRUCTOR_P (fun) && !ctx->object && TREE_CODE (t) == AGGR_INIT_EXPR) { @@ -3088,21 +3102,20 @@ cxx_eval_call_expression (const constexpr_ctx *ctx, tree t, tree ctor = new_ctx.ctor = build_constructor (DECL_CONTEXT (fun), NULL); CONSTRUCTOR_NO_CLEARING (ctor) = true; ctx->global->put_value (new_ctx.object, ctor); - ctx = &new_ctx; } /* An immediate invocation is manifestly constant evaluated including the arguments of the call, so use mce_true even for the argument evaluation. */ if (DECL_IMMEDIATE_FUNCTION_P (fun)) - { - new_ctx.manifestly_const_eval = mce_true; - ctx = &new_ctx; - } + new_ctx.manifestly_const_eval = mce_true; /* We used to shortcut trivial constructor/op= here, but nowadays we can only get a trivial function here with -fno-elide-constructors. */ gcc_checking_assert (!trivial_fn_p (fun) || !flag_elide_constructors + /* Or it's a call from maybe_thunk_body (111075). */ + || (TREE_CODE (t) == CALL_EXPR ? CALL_FROM_THUNK_P (t) + : AGGR_INIT_FROM_THUNK_P (t)) /* We don't elide constructors when processing a noexcept-expression. */ || cp_noexcept_operand); @@ -3182,6 +3195,11 @@ cxx_eval_call_expression (const constexpr_ctx *ctx, tree t, } } + /* Don't complain about problems evaluating an ill-formed function. */ + if (function *f = DECL_STRUCT_FUNCTION (fun)) + if (f->language->erroneous) + new_ctx.quiet = true; + int depth_ok = push_cx_call_context (t); /* Remember the object we are constructing or destructing. */ @@ -9127,6 +9145,15 @@ cxx_eval_outermost_constant_expr (tree t, bool allow_non_constant, tree fndecl = cp_get_callee_fndecl_nofold (x); if (fndecl && DECL_IMMEDIATE_FUNCTION_P (fndecl)) is_consteval = true; + /* Don't try to evaluate a std::vector constructor taking an integer, it + will fail in the 'if (heap_var)' block below after doing all the work + (c++/113835). This will need adjustment if P3554 is accepted. Note + that evaluation of e.g. the vector default constructor can succeed, so + we don't shortcut all vector constructors. */ + if (fndecl && DECL_CONSTRUCTOR_P (fndecl) && allow_non_constant + && is_std_class (type, "vector") && call_expr_nargs (x) > 1 + && TREE_CODE (TREE_TYPE (get_nth_callarg (x, 1))) == INTEGER_TYPE) + return t; } if (AGGREGATE_TYPE_P (type) || VECTOR_TYPE_P (type)) { @@ -9242,9 +9269,11 @@ cxx_eval_outermost_constant_expr (tree t, bool allow_non_constant, if (heap_var) { if (!allow_non_constant && !non_constant_p) - error_at (DECL_SOURCE_LOCATION (heap_var), - "%qE is not a constant expression because it refers to " - "a result of %<operator new%>", t); + { + error ("%qE is not a constant expression because it refers to " + "a result of %<operator new%>", t); + inform (DECL_SOURCE_LOCATION (heap_var), "allocated here"); + } r = t; non_constant_p = true; } @@ -9253,9 +9282,11 @@ cxx_eval_outermost_constant_expr (tree t, bool allow_non_constant, if (DECL_NAME (heap_var) != heap_deleted_identifier) { if (!allow_non_constant && !non_constant_p) - error_at (DECL_SOURCE_LOCATION (heap_var), - "%qE is not a constant expression because allocated " - "storage has not been deallocated", t); + { + error ("%qE is not a constant expression because allocated " + "storage has not been deallocated", t); + inform (DECL_SOURCE_LOCATION (heap_var), "allocated here"); + } r = t; non_constant_p = true; } |