From: Iain Sandoe Date: Sat, 10 May 2025 16:22:55 +0000 (+0100) Subject: c++, coroutines: Allow NVRO in more cases for ramp functions. X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d87caa9d3595ca845c9282cef8b0c9a656d8def0;p=thirdparty%2Fgcc.git c++, coroutines: Allow NVRO in more cases for ramp functions. The constraints of the c++ coroutines specification require the ramp to construct a return object early in the function. This will be returned at some later time. This is implemented as NVRO but requires that copying be well-formed even though it will be elided. Special-case ramp functions to allow this. gcc/cp/ChangeLog: * typeck.cc (check_return_expr): Suppress conversions for NVRO in coroutine ramp functions. Signed-off-by: Iain Sandoe --- diff --git a/gcc/cp/typeck.cc b/gcc/cp/typeck.cc index 1b9fdf5b21d..af2cbaff8fd 100644 --- a/gcc/cp/typeck.cc +++ b/gcc/cp/typeck.cc @@ -11463,6 +11463,12 @@ check_return_expr (tree retval, bool *no_warning, bool *dangling) && call_from_lambda_thunk_p (retval)) converted = true; + /* Don't check copy-initialization for NRV in a coroutine ramp; we + implement this case as NRV, but it's specified as directly + initializing the return value from get_return_object(). */ + if (DECL_RAMP_FN (current_function_decl) && named_return_value_okay_p) + converted = true; + /* First convert the value to the function's return type, then to the type of return value's location to handle the case that functype is smaller than the valtype. */