[pushed,1/2] c++: always check consteval address
Checks
Commit Message
Tested x86_64-pc-linux-gnu, applying to trunk.
-- 8< --
The restriction on the "permitted result of a constant expression" to not
refer to an immediate function applies regardless of context. The previous
code tried to only check in cases where we wouldn't get the check in
cp_fold_r, but with the next patch I would need to add another case and it
shouldn't be a problem to always check.
We also shouldn't talk about immediate evaluation when we aren't dealing
with one.
gcc/cp/ChangeLog:
* constexpr.cc (cxx_eval_outermost_constant_expr): Always check
for address of immediate fn.
(maybe_constant_init_1): Evaluate PTRMEM_CST.
gcc/testsuite/ChangeLog:
* g++.dg/DRs/dr2478.C: Handle -fimplicit-constexpr.
* g++.dg/cpp23/consteval-if12.C: Adjust diagnostics.
* g++.dg/cpp2a/consteval20.C: Likewise.
* g++.dg/cpp2a/consteval24.C: Likewise.
* g++.dg/cpp2a/srcloc20.C: Likewise.
---
gcc/cp/constexpr.cc | 22 ++++++++++++++-------
gcc/testsuite/g++.dg/DRs/dr2478.C | 17 +++++++++-------
gcc/testsuite/g++.dg/cpp23/consteval-if12.C | 8 ++++----
gcc/testsuite/g++.dg/cpp2a/consteval20.C | 4 ++--
gcc/testsuite/g++.dg/cpp2a/consteval24.C | 8 ++++----
gcc/testsuite/g++.dg/cpp2a/srcloc20.C | 4 ++--
6 files changed, 37 insertions(+), 26 deletions(-)
base-commit: 204303c81e82ddd01e7dc5a5a63719d476f9043c
@@ -8353,7 +8353,8 @@ cxx_eval_outermost_constant_expr (tree t, bool allow_non_constant,
non_constant_p = true;
}
- if (!global_ctx.heap_vars.is_empty ())
+ if (!non_constant_p && cxx_dialect >= cxx20
+ && !global_ctx.heap_vars.is_empty ())
{
tree heap_var = cp_walk_tree_without_duplicates (&r, find_heap_var_refs,
NULL);
@@ -8384,15 +8385,22 @@ cxx_eval_outermost_constant_expr (tree t, bool allow_non_constant,
/* Check that immediate invocation does not return an expression referencing
any immediate function decls. */
- if (is_consteval || in_immediate_context ())
+ if (!non_constant_p && cxx_dialect >= cxx20)
if (tree immediate_fndecl
= cp_walk_tree_without_duplicates (&r, find_immediate_fndecl,
NULL))
{
if (!allow_non_constant && !non_constant_p)
- error_at (cp_expr_loc_or_input_loc (t),
- "immediate evaluation returns address of immediate "
- "function %qD", immediate_fndecl);
+ {
+ if (is_consteval)
+ error_at (cp_expr_loc_or_input_loc (t),
+ "immediate evaluation returns address of immediate "
+ "function %qD", immediate_fndecl);
+ else
+ error_at (cp_expr_loc_or_input_loc (t),
+ "constant evaluation returns address of immediate "
+ "function %qD", immediate_fndecl);
+ }
r = t;
non_constant_p = true;
}
@@ -8795,8 +8803,8 @@ maybe_constant_init_1 (tree t, tree decl, bool allow_non_constant,
t = TARGET_EXPR_INITIAL (t);
if (!is_nondependent_static_init_expression (t))
/* Don't try to evaluate it. */;
- else if (CONSTANT_CLASS_P (t) && allow_non_constant)
- /* No evaluation needed. */;
+ else if (CONSTANT_CLASS_P (t) && TREE_CODE (t) != PTRMEM_CST)
+ /* No evaluation needed. PTRMEM_CST needs the immediate fn check. */;
else
{
/* [basic.start.static] allows constant-initialization of variables with
@@ -1,11 +1,14 @@
// DR 2478 - Properties of explicit specializations of implicitly-instantiated class templates
// { dg-do compile { target c++20 } }
+// Defeat -fimplicit-constexpr
+int ii;
+
template <typename T>
struct S {
- int foo () { return 0; }
+ int foo () { return ii; }
constexpr int bar () { return 0; }
- int baz () { return 0; }
+ int baz () { return ii; }
consteval int qux () { return 0; }
constexpr S () {}
static constinit T x;
@@ -14,7 +17,7 @@ struct S {
template <typename T>
T S<T>::x = S<T> ().foo (); // { dg-error "'constinit' variable 'S<char>::x' does not have a constant initializer" }
- // { dg-error "call to non-'constexpr' function" "" { target *-*-* } .-1 }
+ // { dg-error "call to non-'constexpr' function|called in a constant expression" "" { target *-*-* } .-1 }
template <typename T>
T S<T>::y = S<T> ().foo ();
@@ -49,14 +52,14 @@ S<char>::qux ()
template <>
long S<long>::x = S<long> ().foo (); // { dg-bogus "'constinit' variable 'S<long int>::x' does not have a constant initializer" "" { xfail *-*-* } }
- // { dg-bogus "call to non-'constexpr' function" "" { xfail *-*-* } .-1 }
+ // { dg-bogus "call to non-'constexpr' function|called in a constant expression" "" { xfail *-*-* } .-1 }
template <>
constinit long S<long>::y = S<long> ().foo (); // { dg-error "'constinit' variable 'S<long int>::y' does not have a constant initializer" }
- // { dg-error "call to non-'constexpr' function" "" { target *-*-* } .-1 }
+ // { dg-error "call to non-'constexpr' function|called in a constant expression" "" { target *-*-* } .-1 }
constinit auto a = S<char> ().foo (); // { dg-error "'constinit' variable 'a' does not have a constant initializer" }
- // { dg-error "call to non-'constexpr' function" "" { target *-*-* } .-1 }
+ // { dg-error "call to non-'constexpr' function|called in a constant expression" "" { target *-*-* } .-1 }
constinit auto b = S<char> ().bar ();
constinit auto c = S<int> ().foo ();
constinit auto d = S<int> ().bar (); // { dg-error "'constinit' variable 'd' does not have a constant initializer" }
@@ -65,7 +68,7 @@ constinit auto e = S<char> ().baz ();
constinit auto f = S<char> ().qux (); // { dg-error "'constinit' variable 'f' does not have a constant initializer" }
// { dg-error "call to non-'constexpr' function" "" { target *-*-* } .-1 }
constinit auto g = S<int> ().baz (); // { dg-error "'constinit' variable 'g' does not have a constant initializer" }
- // { dg-error "call to non-'constexpr' function" "" { target *-*-* } .-1 }
+ // { dg-error "call to non-'constexpr' function|called in a constant expression" "" { target *-*-* } .-1 }
constinit auto h = S<int> ().qux ();
auto i = S<char>::x;
auto j = S<int>::x;
@@ -19,10 +19,10 @@ bar ()
{
S s;
if consteval { // { dg-warning "'if consteval' only available with" "" { target c++20_only } }
- constexpr auto fn1 = foo; // { dg-error "immediate evaluation returns address of immediate function" }
- constexpr auto fn2 = &foo; // { dg-error "immediate evaluation returns address of immediate function" }
- constexpr auto fn3 = &S::foo; // { dg-error "immediate evaluation returns address of immediate function" }
- constexpr auto fn4 = &S::bar; // { dg-error "immediate evaluation returns address of immediate function" }
+ constexpr auto fn1 = foo; // { dg-error "constant evaluation returns address of immediate function" }
+ constexpr auto fn2 = &foo; // { dg-error "constant evaluation returns address of immediate function" }
+ constexpr auto fn3 = &S::foo; // { dg-error "constant evaluation returns address of immediate function" }
+ constexpr auto fn4 = &S::bar; // { dg-error "constant evaluation returns address of immediate function" }
constexpr auto fn5 = baz (); // { dg-error "immediate evaluation returns address of immediate function" }
constexpr auto fn6 = qux (); // { dg-error "immediate evaluation returns address of immediate function" }
constexpr auto fn7 = corge (); // { dg-error "immediate evaluation returns address of immediate function" }
@@ -11,12 +11,12 @@ int
bar ()
{
auto c = &S::foo; // { dg-error "taking address of an immediate function" }
- constexpr auto d = &S::foo; // { dg-error "taking address of an immediate function" }
+ constexpr auto d = &S::foo; // { dg-error "constant evaluation returns address of immediate function" }
static auto e = &S::foo; // { dg-error "taking address of an immediate function" }
return (s.*&S::foo) (); // { dg-error "taking address of an immediate function" }
}
-constexpr auto a = &S::foo; // { dg-error "taking address of an immediate function" }
+constexpr auto a = &S::foo; // { dg-error "constant evaluation returns address of immediate function" }
auto b = &S::foo; // { dg-error "taking address of an immediate function" }
consteval int
@@ -17,10 +17,10 @@ consteval int
bar ()
{
S s;
- constexpr auto fn1 = foo; // { dg-error "immediate evaluation returns address of immediate function" }
- constexpr auto fn2 = &foo; // { dg-error "immediate evaluation returns address of immediate function" }
- constexpr auto fn3 = &S::foo; // { dg-error "immediate evaluation returns address of immediate function" }
- constexpr auto fn4 = &S::bar; // { dg-error "immediate evaluation returns address of immediate function" }
+ constexpr auto fn1 = foo; // { dg-error "constant evaluation returns address of immediate function" }
+ constexpr auto fn2 = &foo; // { dg-error "constant evaluation returns address of immediate function" }
+ constexpr auto fn3 = &S::foo; // { dg-error "constant evaluation returns address of immediate function" }
+ constexpr auto fn4 = &S::bar; // { dg-error "constant evaluation returns address of immediate function" }
constexpr auto fn5 = baz (); // { dg-error "immediate evaluation returns address of immediate function" }
constexpr auto fn6 = qux (); // { dg-error "immediate evaluation returns address of immediate function" }
constexpr auto fn7 = corge (); // { dg-error "immediate evaluation returns address of immediate function" }
@@ -33,12 +33,12 @@ namespace std {
using namespace std;
auto a = source_location::current; // { dg-error "taking address of an immediate function" }
-constexpr auto b = &source_location::current; // { dg-error "taking address of an immediate function" }
+constexpr auto b = &source_location::current; // { dg-error "constant evaluation returns address of immediate function" }
void
foo ()
{
auto c = &source_location::current; // { dg-error "taking address of an immediate function" }
- constexpr auto d = source_location::current; // { dg-error "taking address of an immediate function" }
+ constexpr auto d = source_location::current; // { dg-error "constant evaluation returns address of immediate function" }
static auto e = source_location::current; // { dg-error "taking address of an immediate function" }
}