https://gcc.gnu.org/g:77772f8a3da8ea30066d2201f8148714a8e89da5
commit r14-9356-g77772f8a3da8ea30066d2201f8148714a8e89da5
Author: Nathaniel Shead <nathanielosh...@gmail.com>
Date: Tue Mar 5 15:17:09 2024 +1100
c++: Stream DECL_CONTEXT for template template parms [PR98881]
When streaming in a nested template-template parameter as in the
attached testcase, we end up reaching the containing template-template
parameter in 'tpl_parms_fini'. We should not set the DECL_CONTEXT to
this (nested) template-template parameter, as it should already be the
struct that the outer template-template parameter is declared on.
The precise logic for what DECL_CONTEXT should be for a template
template parameter in various situations seems rather obscure. Rather
than trying to determine the assumptions that need to hold, it seems
simpler to just always re-stream the DECL_CONTEXT as needed for now.
PR c++/98881
gcc/cp/ChangeLog:
* module.cc (trees_out::tpl_parms_fini): Stream out DECL_CONTEXT
for template template parameters.
(trees_in::tpl_parms_fini): Read it.
gcc/testsuite/ChangeLog:
* g++.dg/modules/tpl-tpl-parm-3.h: New test.
* g++.dg/modules/tpl-tpl-parm-3_a.H: New test.
* g++.dg/modules/tpl-tpl-parm-3_b.C: New test.
* g++.dg/modules/tpl-tpl-parm-3_c.C: New test.
Signed-off-by: Nathaniel Shead <nathanielosh...@gmail.com>
Reviewed-by: Patrick Palka <ppa...@redhat.com>
Reviewed-by: Jason Merrill <ja...@redhat.com>
Diff:
---
gcc/cp/module.cc | 41 ++++++-------------------
gcc/testsuite/g++.dg/modules/tpl-tpl-parm-3.h | 12 ++++++++
gcc/testsuite/g++.dg/modules/tpl-tpl-parm-3_a.H | 5 +++
gcc/testsuite/g++.dg/modules/tpl-tpl-parm-3_b.C | 5 +++
gcc/testsuite/g++.dg/modules/tpl-tpl-parm-3_c.C | 15 +++++++++
5 files changed, 47 insertions(+), 31 deletions(-)
diff --git a/gcc/cp/module.cc b/gcc/cp/module.cc
index 80b63a70a62..f7e8b357fc2 100644
--- a/gcc/cp/module.cc
+++ b/gcc/cp/module.cc
@@ -10126,23 +10126,12 @@ trees_out::tpl_parms_fini (tree tmpl, unsigned
tpl_levels)
tree dflt = TREE_PURPOSE (parm);
tree_node (dflt);
- if (streaming_p ())
- {
- tree decl = TREE_VALUE (parm);
- if (TREE_CODE (decl) == TEMPLATE_DECL)
- {
- tree ctx = DECL_CONTEXT (decl);
- tree inner = DECL_TEMPLATE_RESULT (decl);
- tree tpi = (TREE_CODE (inner) == TYPE_DECL
- ? TEMPLATE_TYPE_PARM_INDEX (TREE_TYPE (decl))
- : DECL_INITIAL (inner));
- bool original = (TEMPLATE_PARM_LEVEL (tpi)
- == TEMPLATE_PARM_ORIG_LEVEL (tpi));
- /* Original template template parms have a context
- of their owning template. Reduced ones do not. */
- gcc_checking_assert (original ? ctx == tmpl : !ctx);
- }
- }
+ /* Template template parameters need a context of their owning
+ template. This is quite tricky to infer correctly on stream-in
+ (see PR c++/98881) so we'll just provide it directly. */
+ tree decl = TREE_VALUE (parm);
+ if (TREE_CODE (decl) == TEMPLATE_DECL)
+ tree_node (DECL_CONTEXT (decl));
}
}
}
@@ -10160,24 +10149,14 @@ trees_in::tpl_parms_fini (tree tmpl, unsigned
tpl_levels)
{
tree parm = TREE_VEC_ELT (vec, ix);
tree dflt = tree_node ();
- if (get_overrun ())
- return false;
TREE_PURPOSE (parm) = dflt;
tree decl = TREE_VALUE (parm);
if (TREE_CODE (decl) == TEMPLATE_DECL)
- {
- tree inner = DECL_TEMPLATE_RESULT (decl);
- tree tpi = (TREE_CODE (inner) == TYPE_DECL
- ? TEMPLATE_TYPE_PARM_INDEX (TREE_TYPE (decl))
- : DECL_INITIAL (inner));
- bool original = (TEMPLATE_PARM_LEVEL (tpi)
- == TEMPLATE_PARM_ORIG_LEVEL (tpi));
- /* Original template template parms have a context
- of their owning template. Reduced ones do not. */
- if (original)
- DECL_CONTEXT (decl) = tmpl;
- }
+ DECL_CONTEXT (decl) = tree_node ();
+
+ if (get_overrun ())
+ return false;
}
}
return true;
diff --git a/gcc/testsuite/g++.dg/modules/tpl-tpl-parm-3.h
b/gcc/testsuite/g++.dg/modules/tpl-tpl-parm-3.h
new file mode 100644
index 00000000000..b0dcf353c23
--- /dev/null
+++ b/gcc/testsuite/g++.dg/modules/tpl-tpl-parm-3.h
@@ -0,0 +1,12 @@
+// PR c++/98881
+
+template <typename P> struct X {};
+
+template<template <typename> typename TT>
+struct X<TT<int>> {
+ template<template <typename> typename UU>
+ void f (X<UU<int>>&);
+};
+
+template<template<class> class TT> struct Y;
+template<template<class> class UU> struct Y { };
diff --git a/gcc/testsuite/g++.dg/modules/tpl-tpl-parm-3_a.H
b/gcc/testsuite/g++.dg/modules/tpl-tpl-parm-3_a.H
new file mode 100644
index 00000000000..47464081f25
--- /dev/null
+++ b/gcc/testsuite/g++.dg/modules/tpl-tpl-parm-3_a.H
@@ -0,0 +1,5 @@
+// PR c++/98881
+// { dg-additional-options "-fmodule-header" }
+// { dg-module-cmi {} }
+
+#include "tpl-tpl-parm-3.h"
diff --git a/gcc/testsuite/g++.dg/modules/tpl-tpl-parm-3_b.C
b/gcc/testsuite/g++.dg/modules/tpl-tpl-parm-3_b.C
new file mode 100644
index 00000000000..1e3cc6c444f
--- /dev/null
+++ b/gcc/testsuite/g++.dg/modules/tpl-tpl-parm-3_b.C
@@ -0,0 +1,5 @@
+// PR c++/98881
+// { dg-additional-options "-fmodules-ts -fno-module-lazy" }
+
+#include "tpl-tpl-parm-3.h"
+import "tpl-tpl-parm-3_a.H";
diff --git a/gcc/testsuite/g++.dg/modules/tpl-tpl-parm-3_c.C
b/gcc/testsuite/g++.dg/modules/tpl-tpl-parm-3_c.C
new file mode 100644
index 00000000000..5edba6cc64f
--- /dev/null
+++ b/gcc/testsuite/g++.dg/modules/tpl-tpl-parm-3_c.C
@@ -0,0 +1,15 @@
+// PR c++/98881
+// { dg-additional-options "-fmodules-ts" }
+
+import "tpl-tpl-parm-3_a.H";
+
+template <typename T> struct A {};
+template <typename T> struct B {};
+
+void foo() {
+ X<A<int>> a;
+ X<B<int>> b;
+ a.f(b);
+
+ Y<A> y;
+}
