https://gcc.gnu.org/g:450dc448eabaaf14a3401788028049b27991213c
commit r14-11477-g450dc448eabaaf14a3401788028049b27991213c
Author: Martin Uecker <uec...@tugraz.at>
Date: Mon Dec 9 12:07:57 2024 +0100
Fix type compatibility for types with flexible array member 1/2
[PR113688,PR114713,PR117724]
Allow the TYPE_MODE of a type with an array as last member to differ from
another compatible type.
gcc/ChangeLog:
* tree.cc (gimple_canonical_types_compatible_p): Add exception.
(verify_type): Add exception.
gcc/lto/ChangeLog:
* lto-common.cc (hash_canonical_type): Add exception.
(cherry picked from commit 1f48225a0ddfaf74a229105343b22f3086c4b8cb)
Diff:
---
gcc/lto/lto-common.cc | 3 ++-
gcc/tree.cc | 12 +++++++++---
2 files changed, 11 insertions(+), 4 deletions(-)
diff --git a/gcc/lto/lto-common.cc b/gcc/lto/lto-common.cc
index 2ce94cc32828..f6e08b51dcaf 100644
--- a/gcc/lto/lto-common.cc
+++ b/gcc/lto/lto-common.cc
@@ -254,7 +254,8 @@ hash_canonical_type (tree type)
checked. */
code = tree_code_for_canonical_type_merging (TREE_CODE (type));
hstate.add_int (code);
- hstate.add_int (TYPE_MODE (type));
+ if (!RECORD_OR_UNION_TYPE_P (type))
+ hstate.add_int (TYPE_MODE (type));
/* Incorporate common features of numerical types. */
if (INTEGRAL_TYPE_P (type)
diff --git a/gcc/tree.cc b/gcc/tree.cc
index d716d7ccfe31..f202187754a6 100644
--- a/gcc/tree.cc
+++ b/gcc/tree.cc
@@ -13846,8 +13846,11 @@ gimple_canonical_types_compatible_p (const_tree t1,
const_tree t2,
|| TREE_CODE (t1) == NULLPTR_TYPE)
return true;
- /* Can't be the same type if they have different mode. */
- if (TYPE_MODE (t1) != TYPE_MODE (t2))
+ /* Can't be compatible types if they have different mode. Because of
+ flexible array members, we allow mismatching modes for structures or
+ unions. */
+ if (!RECORD_OR_UNION_TYPE_P (t1)
+ && TYPE_MODE (t1) != TYPE_MODE (t2))
return false;
/* Non-aggregate types can be handled cheaply. */
@@ -14150,8 +14153,11 @@ verify_type (const_tree t)
debug_tree (ct);
error_found = true;
}
-
if (COMPLETE_TYPE_P (t) && TYPE_CANONICAL (t)
+ /* We allow a mismatch for structure or union because of
+ flexible array members. */
+ && !RECORD_OR_UNION_TYPE_P (t)
+ && !RECORD_OR_UNION_TYPE_P (TYPE_CANONICAL (t))
&& TYPE_MODE (t) != TYPE_MODE (TYPE_CANONICAL (t)))
{
error ("%<TYPE_MODE%> of %<TYPE_CANONICAL%> is not compatible");
