Hi!
C++ before 2a says that constexpr constructors may not have function-try-block
body, for other constexpr functions it instead says that the function body
can be (=delete, =default or compound-statement), but that rules out
function-try-block as well.
For ctors we were diagnostic this in
build_constexpr_constructor_member_initializers, but with worse locus, so
this patch diagnoses it for both ctors and other constexpr functions in the
same place.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
Or would you prefer to have P1002R1 implemented and thus make this perhaps a
pedwarn before cxx2a, similarly for the error on try block in the body and
tweak build_constexpr_constructor_member_initializers? I think constexpr
evaluation handles TRY_BLOCK already.
2019-02-27 Jakub Jelinek <ja...@redhat.com>
PR c++/89513
* parser.c (cp_parser_ctor_initializer_opt_and_function_body):
Diagnose constexpr ctor or function with function-try-block.
Formatting fix.
* constexpr.c (build_constexpr_constructor_member_initializers):
Don't diagnose constexpr ctor with function-try-block here.
* g++.dg/cpp0x/constexpr-89513.C: New test.
--- gcc/cp/parser.c.jj 2019-02-23 11:32:45.705614155 +0100
+++ gcc/cp/parser.c 2019-02-27 14:18:26.211248671 +0100
@@ -22589,11 +22589,22 @@ cp_parser_ctor_initializer_opt_and_funct
bool in_function_try_block)
{
tree body, list;
- const bool check_body_p =
- DECL_CONSTRUCTOR_P (current_function_decl)
- && DECL_DECLARED_CONSTEXPR_P (current_function_decl);
+ const bool check_body_p
+ = (DECL_CONSTRUCTOR_P (current_function_decl)
+ && DECL_DECLARED_CONSTEXPR_P (current_function_decl));
tree last = NULL;
+ if (in_function_try_block
+ && DECL_DECLARED_CONSTEXPR_P (current_function_decl))
+ {
+ if (DECL_CONSTRUCTOR_P (current_function_decl))
+ error ("body of %<constexpr%> constructor cannot be "
+ "a function-try-block");
+ else
+ error ("body of %<constexpr%> function cannot be "
+ "a function-try-block");
+ }
+
/* Begin the function body. */
body = begin_function_body ();
/* Parse the optional ctor-initializer. */
--- gcc/cp/constexpr.c.jj 2019-02-26 15:37:06.475371073 +0100
+++ gcc/cp/constexpr.c 2019-02-27 14:17:34.434096156 +0100
@@ -627,11 +627,8 @@ build_constexpr_constructor_member_initi
}
}
else if (TREE_CODE (body) == TRY_BLOCK)
- {
- error ("body of %<constexpr%> constructor cannot be "
- "a function-try-block");
- return error_mark_node;
- }
+ /* This should have been diagnosed earlier. */
+ return error_mark_node;
else if (EXPR_P (body))
ok = build_data_member_initialization (body, &vec);
else
--- gcc/testsuite/g++.dg/cpp0x/constexpr-89513.C.jj 2019-02-27
14:28:50.280033938 +0100
+++ gcc/testsuite/g++.dg/cpp0x/constexpr-89513.C 2019-02-27
14:34:51.585120108 +0100
@@ -0,0 +1,48 @@
+// PR c++/89513
+// { dg-do compile { target c++11 } }
+// { dg-options "" }
+
+constexpr bool foo ()
+try { // { dg-error "body of 'constexpr' function cannot be a
function-try-block" }
+ return true;
+} catch (...) {
+ return false;
+} // { dg-error "body of 'constexpr' function" "" {
target c++11_only } }
+
+#if __cplusplus > 201103L
+constexpr bool bar ()
+try { // { dg-error "body of 'constexpr' function cannot be a
function-try-block" "" { target c++14 } }
+ try { // { dg-error "'try' in 'constexpr' function"
"" { target c++14 } }
+ return true;
+ } catch (int) {
+ return false;
+ }
+} catch (...) {
+ return false;
+}
+
+constexpr bool baz ()
+{
+ try { return true; } catch (...) { return false; } // { dg-error "'try' in
'constexpr' function" "" { target c++14 } }
+}
+#endif
+
+struct S {
+ constexpr S () try : m (1) // { dg-error "body of 'constexpr' constructor
cannot be a function-try-block" }
+ {
+#if __cplusplus > 201103L
+ try { // { dg-error "'try' in 'constexpr' function" "" {
target c++14 } }
+ } catch (int) {
+ }
+#endif
+ } catch (...) {
+ }
+ int m;
+};
+
+struct T {
+ constexpr T ()
+ try { // { dg-error "body of 'constexpr' constructor
cannot be a function-try-block" }
+ } catch (...) {
+ }
+};
Jakub
