Message ID | FC9FAA1A-0566-4DFE-9FC5-D326DEF867F2@sandoe.co.uk |
---|---|
State | New |
Headers | show |
Series | coroutines: Pass class ref to traits lookup and promise allocator [PR94760] | expand |
On 4/25/20 11:08 AM, Iain Sandoe wrote: > (WAS [PATCH] coroutines: Handle lambda capture objects in the way as clang.) > > I am sorry to mess you around on this. It wasn't you who wasn't focussing :) > We changed the argument passed to the promise parameter preview > to match a reference to *this. However to be consistent with the > other ports, we do need to match the reference transformation in > the traits lookup and the promise allocator lookup. A few comments ... > > gcc/cp/ChangeLog: > > 2020-04-25 Iain Sandoe <iain@sandoe.co.uk> > > PR c++/94760 > * coroutines.cc (instantiate_coro_traits): Pass a reference to > object type rather than a pointer type for 'this', for method > coroutines. > (struct param_info): Add a field to hold that the parm is a lambda > closure pointer. > (morph_fn_to_coro): Check for lambda closure pointers in the > args. Use a reference to *this when building the args list for the > promise allocator lookup. > > gcc/testsuite/ChangeLog: > > 2020-04-25 Iain Sandoe <iain@sandoe.co.uk> > > PR c++/94760 > * g++.dg/coroutines/pr94760-mismatched-traits-and-promise-prev.C: New test. > --- > gcc/cp/coroutines.cc | 52 +++++++++++++++++-- > ...9xxxx-mismatched-traits-and-promise-prev.C | 29 +++++++++++ > 2 files changed, 77 insertions(+), 4 deletions(-) > create mode 100644 gcc/testsuite/g++.dg/coroutines/pr9xxxx-mismatched-traits-and-promise-prev.C > > diff --git a/gcc/cp/coroutines.cc b/gcc/cp/coroutines.cc > index 4f254b7fd10..c80a3b716b2 100644 > --- a/gcc/cp/coroutines.cc > +++ b/gcc/cp/coroutines.cc > @@ -296,14 +296,25 @@ instantiate_coro_traits (tree fndecl, location_t kw) > type. */ > > tree functyp = TREE_TYPE (fndecl); > + tree arg = DECL_ARGUMENTS (fndecl); > + bool lambda_p = LAMBDA_TYPE_P (DECL_CONTEXT (fndecl)); I think LAMBDA_FUNCTION_P (fndecl) expresses intent better. > @@ -3652,6 +3664,7 @@ morph_fn_to_coro (tree orig, tree *resumer, tree *destroyer) > The second two entries start out empty - and only get populated > when we see uses. */ > param_uses = new hash_map<tree, param_info>; > + bool lambda_p = LAMBDA_TYPE_P (DECL_CONTEXT (orig)); Likewise. > > for (tree arg = DECL_ARGUMENTS (orig); arg != NULL; > arg = DECL_CHAIN (arg)) > @@ -3691,7 +3704,17 @@ morph_fn_to_coro (tree orig, tree *resumer, tree *destroyer) > } > else > parm.frame_type = actual_type; > + > parm.this_ptr = is_this_parameter (arg); > + if (lambda_p) > + { > + parm.lambda_cobj = parm.this_ptr > + || (DECL_NAME (arg) == closure_identifier); i'm confused by the need for || here. Why isn't just the DECL_NAME test needed? The parser appears to give the object parameter that name. (If you do need the parm.this_ptr piece, it suggests somewhere else outside of coro is not being consistent, but ICBW.) > @@ -3831,9 +3854,28 @@ morph_fn_to_coro (tree orig, tree *resumer, tree *destroyer) > those of the original function. */ > vec<tree, va_gc> *args = make_tree_vector (); > vec_safe_push (args, resizeable); /* Space needed. */ > + > for (tree arg = DECL_ARGUMENTS (orig); arg != NULL; > arg = DECL_CHAIN (arg)) > - vec_safe_push (args, arg); > + { > + param_info *parm_i = param_uses->get (arg); > + gcc_checking_assert (parm_i); > + if (parm_i->lambda_cobj) > + vec_safe_push (args, arg); > + else if (0 && parm_i->this_ptr) ^^ looks like now-disabled experimental code?
Nathan Sidwell <nathan@acm.org> wrote: > On 4/25/20 11:08 AM, Iain Sandoe wrote: >> + tree arg = DECL_ARGUMENTS (fndecl); >> + bool lambda_p = LAMBDA_TYPE_P (DECL_CONTEXT (fndecl)); > > I think LAMBDA_FUNCTION_P (fndecl) expresses intent better. done in both places. >> + >> parm.this_ptr = is_this_parameter (arg); >> + if (lambda_p) >> + { >> + parm.lambda_cobj = parm.this_ptr >> + || (DECL_NAME (arg) == closure_identifier); > > i'm confused by the need for || here. Why isn't just the DECL_NAME test needed? The parser appears to give the object parameter that name. (If you do need the parm.this_ptr piece, it suggests somewhere else outside of coro is not being consistent, but ICBW.) It seems that, when a lambda is part of a class, the closure object gets the name ‘this’. When a lambda is defined outside a class context, the closure object is named __closure. I added a comment as to why we make the two checks (also, why we can’t just use is_this_parameter() as the test elsewhere) >> + vec_safe_push (args, arg); >> + else if (0 && parm_i->this_ptr) > > ^^ looks like now-disabled experimental code? well caught, now enabled as intended. thanks for the review is the revised below OK (testing now) thanks iain === We changed the argument passed to the promise parameter preview to match a reference to *this. However to be consistent with the other ports, we do need to match the reference transformation in the traits lookup and the promise allocator lookup. gcc/cp/ChangeLog: 2020-04-27 Iain Sandoe <iain@sandoe.co.uk> PR c++/94760 * coroutines.cc (instantiate_coro_traits): Pass a reference to object type rather than a pointer type for 'this', for method coroutines. (struct param_info): Add a field to hold that the parm is a lambda closure pointer. (morph_fn_to_coro): Check for lambda closure pointers in the args. Use a reference to *this when building the args list for the promise allocator lookup. gcc/testsuite/ChangeLog: 2020-04-27 Iain Sandoe <iain@sandoe.co.uk> PR c++/94760 * g++.dg/coroutines/pr94760-mismatched-traits-and-promise-prev.C: New test. --- gcc/cp/coroutines.cc | 54 +++++++++++++++++-- ...9xxxx-mismatched-traits-and-promise-prev.C | 29 ++++++++++ 2 files changed, 79 insertions(+), 4 deletions(-) create mode 100644 gcc/testsuite/g++.dg/coroutines/pr9xxxx-mismatched-traits-and-promise-prev.C diff --git a/gcc/cp/coroutines.cc b/gcc/cp/coroutines.cc index 0a5a0c9b1d2..cfaa018c551 100644 --- a/gcc/cp/coroutines.cc +++ b/gcc/cp/coroutines.cc @@ -296,14 +296,25 @@ instantiate_coro_traits (tree fndecl, location_t kw) type. */ tree functyp = TREE_TYPE (fndecl); + tree arg = DECL_ARGUMENTS (fndecl); + bool lambda_p = LAMBDA_FUNCTION_P (fndecl); tree arg_node = TYPE_ARG_TYPES (functyp); tree argtypes = make_tree_vec (list_length (arg_node)-1); unsigned p = 0; while (arg_node != NULL_TREE && !VOID_TYPE_P (TREE_VALUE (arg_node))) { - TREE_VEC_ELT (argtypes, p++) = TREE_VALUE (arg_node); + if (is_this_parameter (arg) && !lambda_p) + { + /* We pass a reference to *this to the param preview. */ + tree ct = TREE_TYPE (TREE_TYPE (arg)); + TREE_VEC_ELT (argtypes, p++) = cp_build_reference_type (ct, false); + } + else + TREE_VEC_ELT (argtypes, p++) = TREE_VALUE (arg_node); + arg_node = TREE_CHAIN (arg_node); + arg = DECL_CHAIN (arg); } tree argtypepack = cxx_make_type (TYPE_ARGUMENT_PACK); @@ -1766,6 +1777,7 @@ struct param_info bool pt_ref; /* Was a pointer to object. */ bool trivial_dtor; /* The frame type has a trivial DTOR. */ bool this_ptr; /* Is 'this' */ + bool lambda_cobj; /* Lambda capture object */ }; struct local_var_info @@ -3652,6 +3664,7 @@ morph_fn_to_coro (tree orig, tree *resumer, tree *destroyer) The second two entries start out empty - and only get populated when we see uses. */ param_uses = new hash_map<tree, param_info>; + bool lambda_p = LAMBDA_FUNCTION_P (orig); unsigned no_name_parm = 0; for (tree arg = DECL_ARGUMENTS (orig); arg != NULL; @@ -3692,7 +3705,19 @@ morph_fn_to_coro (tree orig, tree *resumer, tree *destroyer) } else parm.frame_type = actual_type; + + /* The closure object pointer is called 'this' when a lambda is + part of a class, and __closure when it is not. */ parm.this_ptr = is_this_parameter (arg); + if (lambda_p) + { + parm.lambda_cobj = parm.this_ptr + || (DECL_NAME (arg) == closure_identifier); + parm.this_ptr = false; + } + else + parm.lambda_cobj = false; + parm.trivial_dtor = TYPE_HAS_TRIVIAL_DESTRUCTOR (parm.frame_type); char *buf; if (DECL_NAME (arg)) @@ -3838,9 +3863,28 @@ morph_fn_to_coro (tree orig, tree *resumer, tree *destroyer) those of the original function. */ vec<tree, va_gc> *args = make_tree_vector (); vec_safe_push (args, resizeable); /* Space needed. */ + for (tree arg = DECL_ARGUMENTS (orig); arg != NULL; arg = DECL_CHAIN (arg)) - vec_safe_push (args, arg); + { + param_info *parm_i = param_uses->get (arg); + gcc_checking_assert (parm_i); + if (parm_i->lambda_cobj) + vec_safe_push (args, arg); + else if (parm_i->this_ptr) + { + /* We pass a reference to *this to the allocator lookup. */ + tree tt = TREE_TYPE (TREE_TYPE (arg)); + tree this_ref = build1 (INDIRECT_REF, tt, arg); + tt = cp_build_reference_type (tt, false); + this_ref = convert_to_reference (tt, this_ref, CONV_STATIC, + LOOKUP_NORMAL , NULL_TREE, + tf_warning_or_error); + vec_safe_push (args, this_ref); + } + else + vec_safe_push (args, arg); + } /* We might need to check that the provided function is nothrow. */ tree func; @@ -4036,8 +4080,10 @@ morph_fn_to_coro (tree orig, tree *resumer, tree *destroyer) false, tf_warning_or_error); /* Add this to the promise CTOR arguments list, accounting for - refs and this ptr. */ - if (parm.this_ptr) + refs and special handling for method this ptr. */ + if (parm.lambda_cobj) + vec_safe_push (promise_args, arg); + else if (parm.this_ptr) { /* We pass a reference to *this to the param preview. */ tree tt = TREE_TYPE (arg); diff --git a/gcc/testsuite/g++.dg/coroutines/pr9xxxx-mismatched-traits-and-promise-prev.C b/gcc/testsuite/g++.dg/coroutines/pr9xxxx-mismatched-traits-and-promise-prev.C new file mode 100644 index 00000000000..235b5e757be --- /dev/null +++ b/gcc/testsuite/g++.dg/coroutines/pr9xxxx-mismatched-traits-and-promise-prev.C @@ -0,0 +1,29 @@ +// { dg-do compile { target c++17 } } + +#include "coro.h" + +// Test that we get matching types to traits and promise param +// preview. + +// A separate issue from allowing non-class return types. +struct Fake {} ; + +template<typename R, typename CallOp, typename ...T> +struct std::coroutine_traits<R, CallOp, T...> { + struct promise_type { + promise_type (CallOp op, T ...args) {} + Fake get_return_object() { return {}; } + std::suspend_always initial_suspend() { return {}; } + std::suspend_never final_suspend() { return {}; } + void return_void() {} + void unhandled_exception() {} + }; +}; + + +struct Foo +{ + Fake operator() (int a) { + co_return; + } +};
On 4/27/20 2:41 PM, Iain Sandoe wrote: > Nathan Sidwell <nathan@acm.org> wrote: > >> On 4/25/20 11:08 AM, Iain Sandoe wrote: > >>> + tree arg = DECL_ARGUMENTS (fndecl); >>> + bool lambda_p = LAMBDA_TYPE_P (DECL_CONTEXT (fndecl)); >> >> I think LAMBDA_FUNCTION_P (fndecl) expresses intent better. > done in both places. > >>> + >>> parm.this_ptr = is_this_parameter (arg); >>> + if (lambda_p) >>> + { >>> + parm.lambda_cobj = parm.this_ptr >>> + || (DECL_NAME (arg) == closure_identifier); >> >> i'm confused by the need for || here. Why isn't just the DECL_NAME test needed? The parser appears to give the object parameter that name. (If you do need the parm.this_ptr piece, it suggests somewhere else outside of coro is not being consistent, but ICBW.) > > It seems that, when a lambda is part of a class, the closure object gets the name ‘this’. > When a lambda is defined outside a class context, the closure object is named __closure. > > I added a comment as to why we make the two checks (also, why we can’t just use > is_this_parameter() as the test elsewhere) > >>> + vec_safe_push (args, arg); >>> + else if (0 && parm_i->this_ptr) >> >> ^^ looks like now-disabled experimental code? > well caught, now enabled as intended. > > thanks for the review is the revised below OK (testing now) > > thanks > iain > > === > > We changed the argument passed to the promise parameter preview > to match a reference to *this. However to be consistent with the > other ports, we do need to match the reference transformation in > the traits lookup and the promise allocator lookup. > > gcc/cp/ChangeLog: > > 2020-04-27 Iain Sandoe <iain@sandoe.co.uk> > > PR c++/94760 > * coroutines.cc (instantiate_coro_traits): Pass a reference to > object type rather than a pointer type for 'this', for method > coroutines. > (struct param_info): Add a field to hold that the parm is a lambda > closure pointer. > (morph_fn_to_coro): Check for lambda closure pointers in the > args. Use a reference to *this when building the args list for the > promise allocator lookup. > > gcc/testsuite/ChangeLog: > > 2020-04-27 Iain Sandoe <iain@sandoe.co.uk> > > PR c++/94760 > * g++.dg/coroutines/pr94760-mismatched-traits-and-promise-prev.C: New test. > --- > gcc/cp/coroutines.cc | 54 +++++++++++++++++-- > ...9xxxx-mismatched-traits-and-promise-prev.C | 29 ++++++++++ > 2 files changed, 79 insertions(+), 4 deletions(-) > create mode 100644 gcc/testsuite/g++.dg/coroutines/pr9xxxx-mismatched-traits-and-promise-prev.C > > diff --git a/gcc/cp/coroutines.cc b/gcc/cp/coroutines.cc > index 0a5a0c9b1d2..cfaa018c551 100644 > --- a/gcc/cp/coroutines.cc > +++ b/gcc/cp/coroutines.cc > @@ -296,14 +296,25 @@ instantiate_coro_traits (tree fndecl, location_t kw) > type. */ > > tree functyp = TREE_TYPE (fndecl); > + tree arg = DECL_ARGUMENTS (fndecl); > + bool lambda_p = LAMBDA_FUNCTION_P (fndecl); > tree arg_node = TYPE_ARG_TYPES (functyp); > tree argtypes = make_tree_vec (list_length (arg_node)-1); > unsigned p = 0; > > while (arg_node != NULL_TREE && !VOID_TYPE_P (TREE_VALUE (arg_node))) > { > - TREE_VEC_ELT (argtypes, p++) = TREE_VALUE (arg_node); > + if (is_this_parameter (arg) && !lambda_p) > + { > + /* We pass a reference to *this to the param preview. */ > + tree ct = TREE_TYPE (TREE_TYPE (arg)); > + TREE_VEC_ELT (argtypes, p++) = cp_build_reference_type (ct, false); > + } > + else > + TREE_VEC_ELT (argtypes, p++) = TREE_VALUE (arg_node); > + > arg_node = TREE_CHAIN (arg_node); > + arg = DECL_CHAIN (arg); > } > > tree argtypepack = cxx_make_type (TYPE_ARGUMENT_PACK); > @@ -1766,6 +1777,7 @@ struct param_info > bool pt_ref; /* Was a pointer to object. */ > bool trivial_dtor; /* The frame type has a trivial DTOR. */ > bool this_ptr; /* Is 'this' */ > + bool lambda_cobj; /* Lambda capture object */ > }; > > struct local_var_info > @@ -3652,6 +3664,7 @@ morph_fn_to_coro (tree orig, tree *resumer, tree *destroyer) > The second two entries start out empty - and only get populated > when we see uses. */ > param_uses = new hash_map<tree, param_info>; > + bool lambda_p = LAMBDA_FUNCTION_P (orig); > > unsigned no_name_parm = 0; > for (tree arg = DECL_ARGUMENTS (orig); arg != NULL; > @@ -3692,7 +3705,19 @@ morph_fn_to_coro (tree orig, tree *resumer, tree *destroyer) > } > else > parm.frame_type = actual_type; > + > + /* The closure object pointer is called 'this' when a lambda is > + part of a class, and __closure when it is not. */ It turns out this occurs when tsubsting a lambda. I.e. whenever the lambda is inside a templated function (real or pseudo). IMHO that;s a bug in the template machinery, but let's not fix that right now, I have filed 94807. Just update the comment to describe this as occurring during instantiation. your patch is ok otherwise, thanks. nathan
diff --git a/gcc/cp/coroutines.cc b/gcc/cp/coroutines.cc index 4f254b7fd10..c80a3b716b2 100644 --- a/gcc/cp/coroutines.cc +++ b/gcc/cp/coroutines.cc @@ -296,14 +296,25 @@ instantiate_coro_traits (tree fndecl, location_t kw) type. */ tree functyp = TREE_TYPE (fndecl); + tree arg = DECL_ARGUMENTS (fndecl); + bool lambda_p = LAMBDA_TYPE_P (DECL_CONTEXT (fndecl)); tree arg_node = TYPE_ARG_TYPES (functyp); tree argtypes = make_tree_vec (list_length (arg_node)-1); unsigned p = 0; while (arg_node != NULL_TREE && !VOID_TYPE_P (TREE_VALUE (arg_node))) { - TREE_VEC_ELT (argtypes, p++) = TREE_VALUE (arg_node); + if (is_this_parameter (arg) && !lambda_p) + { + /* We pass a reference to *this to the param preview. */ + tree ct = TREE_TYPE (TREE_TYPE (arg)); + TREE_VEC_ELT (argtypes, p++) = cp_build_reference_type (ct, false); + } + else + TREE_VEC_ELT (argtypes, p++) = TREE_VALUE (arg_node); + arg_node = TREE_CHAIN (arg_node); + arg = DECL_CHAIN (arg); } tree argtypepack = cxx_make_type (TYPE_ARGUMENT_PACK); @@ -1766,6 +1777,7 @@ struct param_info bool pt_ref; /* Was a pointer to object. */ bool trivial_dtor; /* The frame type has a trivial DTOR. */ bool this_ptr; /* Is 'this' */ + bool lambda_cobj; /* Lambda capture object */ }; struct local_var_info @@ -3652,6 +3664,7 @@ morph_fn_to_coro (tree orig, tree *resumer, tree *destroyer) The second two entries start out empty - and only get populated when we see uses. */ param_uses = new hash_map<tree, param_info>; + bool lambda_p = LAMBDA_TYPE_P (DECL_CONTEXT (orig)); for (tree arg = DECL_ARGUMENTS (orig); arg != NULL; arg = DECL_CHAIN (arg)) @@ -3691,7 +3704,17 @@ morph_fn_to_coro (tree orig, tree *resumer, tree *destroyer) } else parm.frame_type = actual_type; + parm.this_ptr = is_this_parameter (arg); + if (lambda_p) + { + parm.lambda_cobj = parm.this_ptr + || (DECL_NAME (arg) == closure_identifier); + parm.this_ptr = false; + } + else + parm.lambda_cobj = false; + parm.trivial_dtor = TYPE_HAS_TRIVIAL_DESTRUCTOR (parm.frame_type); tree pname = DECL_NAME (arg); char *buf = xasprintf ("__parm.%s", IDENTIFIER_POINTER (pname)); @@ -3831,9 +3854,28 @@ morph_fn_to_coro (tree orig, tree *resumer, tree *destroyer) those of the original function. */ vec<tree, va_gc> *args = make_tree_vector (); vec_safe_push (args, resizeable); /* Space needed. */ + for (tree arg = DECL_ARGUMENTS (orig); arg != NULL; arg = DECL_CHAIN (arg)) - vec_safe_push (args, arg); + { + param_info *parm_i = param_uses->get (arg); + gcc_checking_assert (parm_i); + if (parm_i->lambda_cobj) + vec_safe_push (args, arg); + else if (0 && parm_i->this_ptr) + { + /* We pass a reference to *this to the allocator lookup. */ + tree tt = TREE_TYPE (TREE_TYPE (arg)); + tree this_ref = build1 (INDIRECT_REF, tt, arg); + tt = cp_build_reference_type (tt, false); + this_ref = convert_to_reference (tt, this_ref, CONV_STATIC, + LOOKUP_NORMAL , NULL_TREE, + tf_warning_or_error); + vec_safe_push (args, this_ref); + } + else + vec_safe_push (args, arg); + } /* We might need to check that the provided function is nothrow. */ tree func; @@ -4029,8 +4071,10 @@ morph_fn_to_coro (tree orig, tree *resumer, tree *destroyer) false, tf_warning_or_error); /* Add this to the promise CTOR arguments list, accounting for - refs and this ptr. */ - if (parm.this_ptr) + refs and special handling for method this ptr. */ + if (parm.lambda_cobj) + vec_safe_push (promise_args, arg); + else if (parm.this_ptr) { /* We pass a reference to *this to the param preview. */ tree tt = TREE_TYPE (arg); diff --git a/gcc/testsuite/g++.dg/coroutines/pr9xxxx-mismatched-traits-and-promise-prev.C b/gcc/testsuite/g++.dg/coroutines/pr9xxxx-mismatched-traits-and-promise-prev.C new file mode 100644 index 00000000000..235b5e757be --- /dev/null +++ b/gcc/testsuite/g++.dg/coroutines/pr9xxxx-mismatched-traits-and-promise-prev.C @@ -0,0 +1,29 @@ +// { dg-do compile { target c++17 } } + +#include "coro.h" + +// Test that we get matching types to traits and promise param +// preview. + +// A separate issue from allowing non-class return types. +struct Fake {} ; + +template<typename R, typename CallOp, typename ...T> +struct std::coroutine_traits<R, CallOp, T...> { + struct promise_type { + promise_type (CallOp op, T ...args) {} + Fake get_return_object() { return {}; } + std::suspend_always initial_suspend() { return {}; } + std::suspend_never final_suspend() { return {}; } + void return_void() {} + void unhandled_exception() {} + }; +}; + + +struct Foo +{ + Fake operator() (int a) { + co_return; + } +};