https://gcc.gnu.org/g:5457388f58262bee41ae1d744ff6f3da34119e2d
commit r14-11611-g5457388f58262bee41ae1d744ff6f3da34119e2d
Author: Eric Botcazou <ebotca...@adacore.com>
Date: Mon Apr 14 23:35:43 2025 +0200
Revert very recent backport of changes to the type system
The backport of the change made for PR c/113688 onto the 14 branch a couple
of weeks ago has seriously broken the LTO compiler for the Ada language on
the 14 branch, because it changes the GCC type system for the sake of C in
a way that is not compatible with simple discriminated types in Ada. To be
more precise, useless_type_conversion_p now returns true for some (view-)
conversions that are needed by the rest of the compiler.
gcc/
PR lto/119792
Revert
Backported from master:
2024-12-12 Martin Uecker <uec...@tugraz.at>
PR c/113688
PR c/114014
PR c/114713
PR c/117724
* tree.cc (gimple_canonical_types_compatible_p): Add exception.
(verify_type): Add exception.
gcc/lto/
PR lto/119792
Revert
Backported from master:
2024-12-12 Martin Uecker <uec...@tugraz.at>
* lto-common.cc (hash_canonical_type): Add exception.
gcc/testsuite/
* gcc.dg/pr113688.c: Delete.
* gcc.dg/pr114014.c: Likewise.
* gcc.dg/pr114713.c: Likewise.
* gcc.dg/pr117724.c: Likewise
Diff:
---
gcc/lto/lto-common.cc | 9 ++------
gcc/testsuite/gcc.dg/pr113688.c | 8 -------
gcc/testsuite/gcc.dg/pr114014.c | 14 ------------
gcc/testsuite/gcc.dg/pr114713.c | 35 -----------------------------
gcc/testsuite/gcc.dg/pr117724.c | 16 --------------
gcc/tree.cc | 49 +++++++++--------------------------------
6 files changed, 12 insertions(+), 119 deletions(-)
diff --git a/gcc/lto/lto-common.cc b/gcc/lto/lto-common.cc
index 7697a7d6ea02..2ce94cc32828 100644
--- a/gcc/lto/lto-common.cc
+++ b/gcc/lto/lto-common.cc
@@ -254,8 +254,7 @@ hash_canonical_type (tree type)
checked. */
code = tree_code_for_canonical_type_merging (TREE_CODE (type));
hstate.add_int (code);
- if (!RECORD_OR_UNION_TYPE_P (type))
- hstate.add_int (TYPE_MODE (type));
+ hstate.add_int (TYPE_MODE (type));
/* Incorporate common features of numerical types. */
if (INTEGRAL_TYPE_P (type)
@@ -333,11 +332,7 @@ hash_canonical_type (tree type)
&& (! DECL_SIZE (f)
|| ! integer_zerop (DECL_SIZE (f))))
{
- tree t = TREE_TYPE (f);
- if (!TREE_CHAIN (f)
- && TREE_CODE (t) == ARRAY_TYPE)
- t = TREE_TYPE (t);
- iterative_hash_canonical_type (t, hstate);
+ iterative_hash_canonical_type (TREE_TYPE (f), hstate);
nf++;
}
diff --git a/gcc/testsuite/gcc.dg/pr113688.c b/gcc/testsuite/gcc.dg/pr113688.c
deleted file mode 100644
index 8dee8c86f1bf..000000000000
--- a/gcc/testsuite/gcc.dg/pr113688.c
+++ /dev/null
@@ -1,8 +0,0 @@
-/* { dg-do compile } */
-/* { dg-options "-g" } */
-
-struct S{int x,y[1];}*a;
-int main(void){
- struct S{int x,y[];};
-}
-
diff --git a/gcc/testsuite/gcc.dg/pr114014.c b/gcc/testsuite/gcc.dg/pr114014.c
deleted file mode 100644
index 1531ffab1b75..000000000000
--- a/gcc/testsuite/gcc.dg/pr114014.c
+++ /dev/null
@@ -1,14 +0,0 @@
-/* PR c/114014
- * { dg-do compile }
- * { dg-options "-std=gnu23 -g" } */
-
-struct r {
- int a;
- char b[];
-};
-struct r {
- int a;
- char b[0];
-};
-
-
diff --git a/gcc/testsuite/gcc.dg/pr114713.c b/gcc/testsuite/gcc.dg/pr114713.c
deleted file mode 100644
index 78e3237de948..000000000000
--- a/gcc/testsuite/gcc.dg/pr114713.c
+++ /dev/null
@@ -1,35 +0,0 @@
-/* { dg-do run } */
-/* { dg-require-effective-target lto } */
-/* { dg-options "-std=c23 -flto -O2" } */
-
-struct foo { int x; char a[]; };
-
-void test_bar(void* b);
-
-__attribute__((noinline))
-int test_foo(struct foo* a, void* b)
-{
- a->x = 1;
- test_bar(b);
- return a->x;
-}
-
-int main()
-{
- struct foo y;
-
- if (2 != test_foo(&y, &y))
- __builtin_abort();
-
- return 0;
-}
-
-// TU2
-struct foo { int x; char a[0]; };
-
-void test_bar(void* b)
-{
- struct foo *p = b;
- p->x = 2;
-}
-
diff --git a/gcc/testsuite/gcc.dg/pr117724.c b/gcc/testsuite/gcc.dg/pr117724.c
deleted file mode 100644
index d631daeb644d..000000000000
--- a/gcc/testsuite/gcc.dg/pr117724.c
+++ /dev/null
@@ -1,16 +0,0 @@
-/* { dg-do compile } */
-/* { dg-options "-g" } */
-
-struct {
- unsigned long len;
- unsigned long size;
- char data[];
-}; /* { dg-warning "unnamed struct" } */
-struct {
- struct {
- unsigned long len;
- unsigned long size;
- char data[6];
- };
-}; /* { dg-warning "unnamed struct" } */
-
diff --git a/gcc/tree.cc b/gcc/tree.cc
index a4c62e1f0681..d716d7ccfe31 100644
--- a/gcc/tree.cc
+++ b/gcc/tree.cc
@@ -13846,11 +13846,8 @@ gimple_canonical_types_compatible_p (const_tree t1,
const_tree t2,
|| TREE_CODE (t1) == NULLPTR_TYPE)
return true;
- /* 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))
+ /* Can't be the same type if they have different mode. */
+ if (TYPE_MODE (t1) != TYPE_MODE (t2))
return false;
/* Non-aggregate types can be handled cheaply. */
@@ -13901,7 +13898,7 @@ gimple_canonical_types_compatible_p (const_tree t1,
const_tree t2,
{
case ARRAY_TYPE:
/* Array types are the same if the element types are the same and
- minimum and maximum index are the same. */
+ the number of elements are the same. */
if (!gimple_canonical_types_compatible_p (TREE_TYPE (t1), TREE_TYPE (t2),
trust_type_canonical)
|| TYPE_STRING_FLAG (t1) != TYPE_STRING_FLAG (t2)
@@ -13995,46 +13992,23 @@ gimple_canonical_types_compatible_p (const_tree t1,
const_tree t2,
f1 || f2;
f1 = TREE_CHAIN (f1), f2 = TREE_CHAIN (f2))
{
- /* Skip non-fields and zero-sized fields, except zero-sized
- arrays at the end. */
+ /* Skip non-fields and zero-sized fields. */
while (f1 && (TREE_CODE (f1) != FIELD_DECL
|| (DECL_SIZE (f1)
- && integer_zerop (DECL_SIZE (f1))
- && (TREE_CHAIN (f1)
- || TREE_CODE (TREE_TYPE (f1))
- != ARRAY_TYPE))))
+ && integer_zerop (DECL_SIZE (f1)))))
f1 = TREE_CHAIN (f1);
while (f2 && (TREE_CODE (f2) != FIELD_DECL
|| (DECL_SIZE (f2)
- && integer_zerop (DECL_SIZE (f2))
- && (TREE_CHAIN (f2)
- || TREE_CODE (TREE_TYPE (f2))
- != ARRAY_TYPE))))
+ && integer_zerop (DECL_SIZE (f2)))))
f2 = TREE_CHAIN (f2);
if (!f1 || !f2)
break;
-
- tree t1 = TREE_TYPE (f1);
- tree t2 = TREE_TYPE (f2);
-
- /* If the last element are arrays, we only compare the element
- types. */
- if (TREE_CHAIN (f1) == NULL_TREE && TREE_CODE (t1) == ARRAY_TYPE
- && TREE_CHAIN (f2) == NULL_TREE && TREE_CODE (t2) == ARRAY_TYPE)
- {
- /* If both arrays have zero size, this is a match. */
- if (DECL_SIZE (f1) && integer_zerop (DECL_SIZE (f1))
- && DECL_SIZE (f2) && integer_zerop (DECL_SIZE (f2)))
- return true;
-
- t1 = TREE_TYPE (t1);
- t2 = TREE_TYPE (t2);
- }
-
+ /* The fields must have the same name, offset and type. */
if (DECL_NONADDRESSABLE_P (f1) != DECL_NONADDRESSABLE_P (f2)
|| !gimple_compare_field_offset (f1, f2)
|| !gimple_canonical_types_compatible_p
- (t1, t2, trust_type_canonical))
+ (TREE_TYPE (f1), TREE_TYPE (f2),
+ trust_type_canonical))
return false;
}
@@ -14176,11 +14150,8 @@ 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");
