* c++: Completeness of typedef structs [PR 99294]
@ 2021-03-01 13:56 Nathan Sidwell
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From: Nathan Sidwell @ 2021-03-01 13:56 UTC (permalink / raw)
To: GCC Patches
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When we read in a class definition, we use fixup_type_variants to
propagate the now-completed fields of the class's TYPE to other
variants. Unfortunately that doesn't propagate all of them, and in this
case we had a typedef to an (incomplete) instantiation. That typedef
ended up with a VOIDmode, which blew up gimple expansion as the type
itself isn't VOID. Without modules, that information is propagated in
finalize_type_size when laying out the class. But that doesn't happen
with stream-in -- we already know the layout. There is already some
overlap between the two functions, now there's a bit more. In
fixup_type_variants, I pay attention to the TYPE_NAME to decide whether
to override a user's TYPE_ALIGN -- variants of the main-variant typedef
just copy the main-variant. Other variants recalculate. Overaligning
is still permitted.
I also added a TYPE_ALIGN_RAW accessor, and fixed a bug in the alignment
streaming I noticed. I did not refactor TYPE_ALIGN beyond using the new
accessor. (It could be written as ((1 << align_raw) >> 1), rather than
use the conditional.)
PR c++/99294
gcc/
* gcc/tree.h (TYPE_ALIGN_RAW): New accessor.
(TYPE_ALIGN): Use it.
gcc/cp/
* class.c (fixup_type_variants): Propagate mode, precision,
alignment & emptiness.
* module.cc (trees_out::type_node): Use TYPE_ALIGN_RAW.
(trees_in::tree_node): Rematerialize alignment here.
gcc/testsuite/
* g++.dg/modules/pr99294.h: New.
* g++.dg/modules/pr99294_a.C: New.
* g++.dg/modules/pr99294_b.C: New.
--
Nathan Sidwell
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diff --git c/gcc/cp/class.c w/gcc/cp/class.c
index 40f5fef7baa..ea007e88e6e 100644
--- c/gcc/cp/class.c
+++ w/gcc/cp/class.c
@@ -2005,35 +2005,45 @@ determine_primary_bases (tree t)
/* Update the variant types of T. */
void
-fixup_type_variants (tree t)
+fixup_type_variants (tree type)
{
- tree variants;
-
- if (!t)
+ if (!type)
return;
- for (variants = TYPE_NEXT_VARIANT (t);
- variants;
- variants = TYPE_NEXT_VARIANT (variants))
+ for (tree variant = TYPE_NEXT_VARIANT (type);
+ variant;
+ variant = TYPE_NEXT_VARIANT (variant))
{
/* These fields are in the _TYPE part of the node, not in
the TYPE_LANG_SPECIFIC component, so they are not shared. */
- TYPE_HAS_USER_CONSTRUCTOR (variants) = TYPE_HAS_USER_CONSTRUCTOR (t);
- TYPE_NEEDS_CONSTRUCTING (variants) = TYPE_NEEDS_CONSTRUCTING (t);
- TYPE_HAS_NONTRIVIAL_DESTRUCTOR (variants)
- = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t);
+ TYPE_HAS_USER_CONSTRUCTOR (variant) = TYPE_HAS_USER_CONSTRUCTOR (type);
+ TYPE_NEEDS_CONSTRUCTING (variant) = TYPE_NEEDS_CONSTRUCTING (type);
+ TYPE_HAS_NONTRIVIAL_DESTRUCTOR (variant)
+ = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type);
- TYPE_POLYMORPHIC_P (variants) = TYPE_POLYMORPHIC_P (t);
- CLASSTYPE_FINAL (variants) = CLASSTYPE_FINAL (t);
+ TYPE_POLYMORPHIC_P (variant) = TYPE_POLYMORPHIC_P (type);
+ CLASSTYPE_FINAL (variant) = CLASSTYPE_FINAL (type);
- TYPE_BINFO (variants) = TYPE_BINFO (t);
+ TYPE_BINFO (variant) = TYPE_BINFO (type);
/* Copy whatever these are holding today. */
- TYPE_VFIELD (variants) = TYPE_VFIELD (t);
- TYPE_FIELDS (variants) = TYPE_FIELDS (t);
+ TYPE_VFIELD (variant) = TYPE_VFIELD (type);
+ TYPE_FIELDS (variant) = TYPE_FIELDS (type);
+
+ TYPE_SIZE (variant) = TYPE_SIZE (type);
+ TYPE_SIZE_UNIT (variant) = TYPE_SIZE_UNIT (type);
+
+ if (!TYPE_USER_ALIGN (variant)
+ || TYPE_NAME (variant) == TYPE_NAME (type)
+ || TYPE_ALIGN_RAW (variant) < TYPE_ALIGN_RAW (type))
+ {
+ TYPE_ALIGN_RAW (variant) = TYPE_ALIGN_RAW (type);
+ TYPE_USER_ALIGN (variant) = TYPE_USER_ALIGN (type);
+ }
- TYPE_SIZE (variants) = TYPE_SIZE (t);
- TYPE_SIZE_UNIT (variants) = TYPE_SIZE_UNIT (t);
+ TYPE_PRECISION (variant) = TYPE_PRECISION (type);
+ TYPE_MODE_RAW (variant) = TYPE_MODE_RAW (type);
+ TYPE_EMPTY_P (variant) = TYPE_EMPTY_P (type);
}
}
diff --git c/gcc/cp/module.cc w/gcc/cp/module.cc
index 0cb5bd9b644..369a02604fe 100644
--- c/gcc/cp/module.cc
+++ w/gcc/cp/module.cc
@@ -8714,7 +8714,7 @@ trees_out::type_node (tree type)
else
{
if (TYPE_USER_ALIGN (type))
- flags = exact_log2 (TYPE_ALIGN (type));
+ flags = TYPE_ALIGN_RAW (type);
}
if (streaming_p ())
@@ -9510,7 +9510,7 @@ trees_in::tree_node (bool is_use)
}
else
{
- res = build_aligned_type (res, 1u << flags);
+ res = build_aligned_type (res, (1u << flags) >> 1);
TYPE_USER_ALIGN (res) = true;
}
diff --git c/gcc/testsuite/g++.dg/modules/pr99294.h w/gcc/testsuite/g++.dg/modules/pr99294.h
new file mode 100644
index 00000000000..757113c0283
--- /dev/null
+++ w/gcc/testsuite/g++.dg/modules/pr99294.h
@@ -0,0 +1,14 @@
+
+template <typename T>
+class basic_string;
+
+typedef basic_string<char> string;
+
+template <typename T>
+class basic_string
+{
+ public:
+ string Frob ();
+
+ basic_string (int);
+};
diff --git c/gcc/testsuite/g++.dg/modules/pr99294_a.C w/gcc/testsuite/g++.dg/modules/pr99294_a.C
new file mode 100644
index 00000000000..ac8b9a7de5b
--- /dev/null
+++ w/gcc/testsuite/g++.dg/modules/pr99294_a.C
@@ -0,0 +1,18 @@
+// PR 99294, ICE with -fno-module-lazy on class completeness
+// { dg-additional-options -fmodules-ts }
+
+// The instantiation of the *definition* of basic_string is used in
+// importers, *after* they have instantiated a declaration of it *and*
+// created type variants.
+
+module;
+
+#include "pr99294.h"
+
+export module foo;
+// { dg-module-cmi foo }
+
+export inline int greeter (string const &bob)
+{
+ return sizeof (bob); // instantiates string
+}
diff --git c/gcc/testsuite/g++.dg/modules/pr99294_b.C w/gcc/testsuite/g++.dg/modules/pr99294_b.C
new file mode 100644
index 00000000000..30d14d10187
--- /dev/null
+++ w/gcc/testsuite/g++.dg/modules/pr99294_b.C
@@ -0,0 +1,12 @@
+// PR 99294, ICE with -fno-module-lazy on class completeness
+// { dg-additional-options {-fmodules-ts -fno-module-lazy} }
+
+#include "pr99294.h"
+import foo;
+
+string Quux ()
+{
+ return 1;
+}
+
+// ICED complaining about Quux RETURN_DECL during gimple expand
diff --git c/gcc/tree.h w/gcc/tree.h
index 4f33868e8e1..f00ea2ef0af 100644
--- c/gcc/tree.h
+++ w/gcc/tree.h
@@ -2078,12 +2078,16 @@ extern tree vector_element_bits_tree (const_tree);
to this type. */
#define TYPE_ATTRIBUTES(NODE) (TYPE_CHECK (NODE)->type_common.attributes)
+/* Raw access to the alignment field. */
+#define TYPE_ALIGN_RAW(NODE) \
+ (TYPE_CHECK (NODE)->type_common.align)
+
/* The alignment necessary for objects of this type.
The value is an int, measured in bits and must be a power of two.
We support also an "alignment" of zero. */
-#define TYPE_ALIGN(NODE) \
- (TYPE_CHECK (NODE)->type_common.align \
- ? ((unsigned)1) << ((NODE)->type_common.align - 1) : 0)
+#define TYPE_ALIGN(NODE) \
+ (TYPE_ALIGN_RAW (NODE) \
+ ? ((unsigned)1) << (TYPE_ALIGN_RAW(NODE) - 1) : 0)
/* Specify that TYPE_ALIGN(NODE) is X. */
#define SET_TYPE_ALIGN(NODE, X) \
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2021-03-01 13:56 c++: Completeness of typedef structs [PR 99294] Nathan Sidwell
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