Hi Nathan,
Nathan Sidwell <nat...@acm.org> wrote:
> On 1/28/20 11:14 AM, Iain Sandoe wrote:
>> + if (!error_emitted &&
>> + (traits_decl == NULL_TREE || traits_decl == error_mark_node))
>> {
>> error_at (kw, "cannot find %<coroutine traits%> template");
>> + error_emitted = true;
>> return NULL_TREE;
>> }
>
> don't you just want to protect the error_at call with error_emitted?
yes, thanks.
> You might want to pick a canonical 'error' value -- either NULL_TREE or
> error_mark_node, but not both?
done.
Made the function type error recorded per function too.
OK now?
thanks
Iain
coroutines: Fix ICE on invalid (PR93458).
Since coroutine-ness is discovered lazily, we encounter the diagnostics
during each keyword parse. We were not handling the case where a user code
failed to include fundamental information (e.g. the traits) in a graceful
manner.
Once we've emitted an error for this level of fail, then we suppress
additional copies (otherwise the same thing will be reported for every
coroutine keyword seen).
gcc/cp/ChangeLog:
2020-01-29 Iain Sandoe <i...@sandoe.co.uk>
* coroutines.cc (struct coroutine_info): Add a bool flag to note
that we emitted an error for a bad function return type.
(get_coroutine_info): Tolerate an unset info table in case of
missing traits.
(find_coro_traits_template_decl): Note we emitted the error and
suppress duplicates.
(instantiate_coro_traits): Only check for error_mark_node in the
return from lookup_qualified_name.
(find_coro_handle_template_decl): Likewise.
(coro_promise_type_found_p): Reorder initialization so that we check
for the traits and their usability before allocation of the info
table. Check for a suitable return type and emit a diagnostic for
here instead of relying on the lookup machinery. This allows the
error to have a better location, and means we can suppress multiple
copies.
(coro_function_valid_p): Re-check for a valid promise (and thus the
traits) before proceeding. Tolerate missing info as a fatal error.
gcc/testsuite/ChangeLog:
2020-01-29 Iain Sandoe <i...@sandoe.co.uk>
* g++.dg/coroutines/pr93458-1-missing-traits.C: New test.
* g++.dg/coroutines/pr93458-2-bad-coro-type.C: New test.
---
gcc/cp/coroutines.cc | 86 +++++++++++++------
.../coroutines/pr93458-1-missing-traits.C | 10 +++
.../coroutines/pr93458-2-bad-coro-type.C | 12 +++
3 files changed, 84 insertions(+), 24 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/coroutines/pr93458-1-missing-traits.C
create mode 100644 gcc/testsuite/g++.dg/coroutines/pr93458-2-bad-coro-type.C
diff --git a/gcc/cp/coroutines.cc b/gcc/cp/coroutines.cc
index e8a6a4033f6..3ad80699ca0 100644
--- a/gcc/cp/coroutines.cc
+++ b/gcc/cp/coroutines.cc
@@ -91,6 +91,8 @@ struct GTY((for_user)) coroutine_info
tree promise_proxy; /* Likewise, a proxy promise instance. */
location_t first_coro_keyword; /* The location of the keyword that made this
function into a coroutine. */
+ /* Flags to avoid repeated errors for per-function issues. */
+ bool coro_ret_type_error_emitted;
};
struct coroutine_info_hasher : ggc_ptr_hash<coroutine_info>
@@ -169,7 +171,8 @@ get_or_insert_coroutine_info (tree fn_decl)
coroutine_info *
get_coroutine_info (tree fn_decl)
{
- gcc_checking_assert (coroutine_info_table != NULL);
+ if (coroutine_info_table == NULL)
+ return NULL;
coroutine_info **slot = coroutine_info_table->find_slot_with_hash
(fn_decl, coroutine_info_hasher::hash (fn_decl), NO_INSERT);
@@ -257,9 +260,15 @@ find_coro_traits_template_decl (location_t kw)
{
tree traits_decl = lookup_qualified_name (std_node, coro_traits_identifier,
0, true);
- if (traits_decl == NULL_TREE || traits_decl == error_mark_node)
- {
- error_at (kw, "cannot find %<coroutine traits%> template");
+ /* If we are missing fundmental information, such as the traits, then don't
+ emit this for every keyword in a TU. This particular error is per TU
+ so we don't need to keep the indicator per function. */
+ static bool traits_error_emitted = false;
+ if (traits_decl == error_mark_node)
+ {
+ if (!traits_error_emitted)
+ error_at (kw, "cannot find %<coroutine traits%> template");
+ traits_error_emitted = true;
return NULL_TREE;
}
else
@@ -299,7 +308,7 @@ instantiate_coro_traits (tree fndecl, location_t kw)
/*in_decl=*/NULL_TREE, /*context=*/NULL_TREE,
/*entering scope=*/false, tf_warning_or_error);
- if (traits_class == error_mark_node || traits_class == NULL_TREE)
+ if (traits_class == error_mark_node)
{
error_at (kw, "cannot instantiate %<coroutine traits%>");
return NULL_TREE;
@@ -315,7 +324,7 @@ find_coro_handle_template_decl (location_t kw)
{
tree handle_decl = lookup_qualified_name (std_node, coro_handle_identifier,
0, true);
- if (handle_decl == NULL_TREE || handle_decl == error_mark_node)
+ if (handle_decl == error_mark_node)
{
error_at (kw, "cannot find %<coroutine handle%> template");
return NULL_TREE;
@@ -370,34 +379,45 @@ coro_promise_type_found_p (tree fndecl, location_t loc)
{
gcc_assert (fndecl != NULL_TREE);
- /* Save the coroutine data on the side to avoid the overhead on every
- function decl. */
-
- /* We only need one entry per coroutine in a TU, the assumption here is that
- there are typically not 1000s. */
if (!coro_initialized)
{
- gcc_checking_assert (coroutine_info_table == NULL);
- /* A table to hold the state, per coroutine decl. */
- coroutine_info_table =
- hash_table<coroutine_info_hasher>::create_ggc (11);
- /* Set up the identifiers we will use. */
- gcc_checking_assert (coro_traits_identifier == NULL);
+ /* Trees we only need to create once.
+ Set up the identifiers we will use. */
coro_init_identifiers ();
- /* Trees we only need to create once. */
+
/* Coroutine traits template. */
coro_traits_templ = find_coro_traits_template_decl (loc);
- gcc_checking_assert (coro_traits_templ != NULL);
+ if (coro_traits_templ == NULL_TREE
+ || coro_traits_templ == error_mark_node)
+ return false;
+
/* coroutine_handle<> template. */
coro_handle_templ = find_coro_handle_template_decl (loc);
- gcc_checking_assert (coro_handle_templ != NULL);
+ if (coro_handle_templ == NULL_TREE
+ || coro_handle_templ == error_mark_node)
+ return false;
+
/* We can also instantiate the void coroutine_handle<> */
void_coro_handle_type =
instantiate_coro_handle_for_promise_type (loc, NULL_TREE);
- gcc_checking_assert (void_coro_handle_type != NULL);
+ if (void_coro_handle_type == NULL_TREE
+ || void_coro_handle_type == error_mark_node)
+ return false;
+
+ /* A table to hold the state, per coroutine decl. */
+ gcc_checking_assert (coroutine_info_table == NULL);
+ coroutine_info_table =
+ hash_table<coroutine_info_hasher>::create_ggc (11);
+
+ if (coroutine_info_table == NULL)
+ return false;
+
coro_initialized = true;
}
+ /* Save the coroutine data on the side to avoid the overhead on every
+ function decl tree. */
+
coroutine_info *coro_info = get_or_insert_coroutine_info (fndecl);
/* Without this, we cannot really proceed. */
gcc_checking_assert (coro_info);
@@ -407,6 +427,18 @@ coro_promise_type_found_p (tree fndecl, location_t loc)
{
/* Get the coroutine traits template class instance for the function
signature we have - coroutine_traits <R, ...> */
+ if (!CLASS_TYPE_P (TREE_TYPE (TREE_TYPE (fndecl))))
+ {
+ /* It makes more sense to show the function header for this, even
+ though we will have encountered it when processing a keyword.
+ Only emit the error once, not for every keyword we encounter. */
+ if (!coro_info->coro_ret_type_error_emitted)
+ error_at (DECL_SOURCE_LOCATION (fndecl), "a coroutine must have a"
+ " class or struct return type");
+ coro_info->coro_ret_type_error_emitted = true;
+ return false;
+ }
+
tree templ_class = instantiate_coro_traits (fndecl, loc);
/* Find the promise type for that. */
@@ -422,7 +454,7 @@ coro_promise_type_found_p (tree fndecl, location_t loc)
/* Try to find the handle type for the promise. */
tree handle_type =
instantiate_coro_handle_for_promise_type (loc, coro_info->promise_type);
- if (handle_type == NULL_TREE)
+ if (handle_type == NULL_TREE || handle_type == error_mark_node)
return false;
/* Complete this, we're going to use it. */
@@ -597,11 +629,17 @@ coro_function_valid_p (tree fndecl)
{
location_t f_loc = DECL_SOURCE_LOCATION (fndecl);
+ /* For cases where fundamental information cannot be found, e.g. the
+ coroutine traits are missing, we need to punt early. */
+ if (!coro_promise_type_found_p (fndecl, f_loc))
+ return false;
+
/* Since we think the function is a coroutine, that implies we parsed
a keyword that triggered this. Keywords check promise validity for
their context and thus the promise type should be known at this point. */
- gcc_checking_assert (get_coroutine_handle_type (fndecl) != NULL_TREE
- && get_coroutine_promise_type (fndecl) != NULL_TREE);
+ if (get_coroutine_handle_type (fndecl) == NULL_TREE
+ || get_coroutine_promise_type (fndecl) == NULL_TREE)
+ return false;
if (current_function_returns_value || current_function_returns_null)
{
diff --git a/gcc/testsuite/g++.dg/coroutines/pr93458-1-missing-traits.C
b/gcc/testsuite/g++.dg/coroutines/pr93458-1-missing-traits.C
new file mode 100644
index 00000000000..46adccded98
--- /dev/null
+++ b/gcc/testsuite/g++.dg/coroutines/pr93458-1-missing-traits.C
@@ -0,0 +1,10 @@
+// { dg-additional-options "-fsyntax-only -fexceptions -w" }
+
+// Diagose missing traits (fail to include <coroutine>).
+
+int
+bad_coroutine (void)
+{
+ co_yield 5; // { dg-error {cannot find 'coroutine traits' template} }
+ co_return;
+}
diff --git a/gcc/testsuite/g++.dg/coroutines/pr93458-2-bad-coro-type.C
b/gcc/testsuite/g++.dg/coroutines/pr93458-2-bad-coro-type.C
new file mode 100644
index 00000000000..aab9b34b69a
--- /dev/null
+++ b/gcc/testsuite/g++.dg/coroutines/pr93458-2-bad-coro-type.C
@@ -0,0 +1,12 @@
+// { dg-additional-options "-fsyntax-only -fexceptions -w" }
+
+// Diagose bad coroutine function type.
+
+#include "coro.h"
+
+int
+bad_coroutine (void) // { dg-error {a coroutine must have a class or struct
return type} }
+{
+ co_yield 5;
+ co_return;
+}
--
2.24.1
