Re: [PATCH] c++: visibility wrt template and ptrmem targs [PR70413]

2023-12-21 Thread Jason Merrill 

On 12/21/23 14:12, Patrick Palka wrote:

On Sat, 16 Sep 2023, Jason Merrill wrote:


On 9/15/23 12:03, Patrick Palka wrote:

Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for
trunk?


OK.


Thanks a lot.  Testing on cmcstl2 revealed that we don't maintain
visibility flags on alias templates properly, and so we can't trust
them when constraining visibilitiy.  So I went ahead and pushed the
following restricted version of the patch which excludes alias templates
(and adds a couple of alias template targ linkage tests):


OK.


-- >8 --

Subject: [PATCH] c++: visibility wrt template and ptrmem targs [PR70413]

When constraining the visibility of an instantiation, we weren't
properly considering the visibility of PTRMEM_CST and TEMPLATE_DECL
template arguments.

This patch fixes this.  It turns out we don't maintain the relevant
visibility flags for alias templates (e.g. TREE_PUBLIC is never set),
so continue to ignore alias template template arguments for now.

PR c++/70413
PR c++/107906

gcc/cp/ChangeLog:

* decl2.cc (min_vis_expr_r): Handle PTRMEM_CST and TEMPLATE_DECL
other than those for alias templates.

gcc/testsuite/ChangeLog:

* g++.dg/template/linkage2.C: New test.
* g++.dg/template/linkage3.C: New test.
* g++.dg/template/linkage4.C: New test.
* g++.dg/template/linkage4a.C: New test.
---
  gcc/cp/decl2.cc   | 22 ++
  gcc/testsuite/g++.dg/template/linkage2.C  | 13 +
  gcc/testsuite/g++.dg/template/linkage3.C  | 17 +
  gcc/testsuite/g++.dg/template/linkage4.C  | 16 
  gcc/testsuite/g++.dg/template/linkage4a.C | 14 ++
  5 files changed, 78 insertions(+), 4 deletions(-)
  create mode 100644 gcc/testsuite/g++.dg/template/linkage2.C
  create mode 100644 gcc/testsuite/g++.dg/template/linkage3.C
  create mode 100644 gcc/testsuite/g++.dg/template/linkage4.C
  create mode 100644 gcc/testsuite/g++.dg/template/linkage4a.C

diff --git a/gcc/cp/decl2.cc b/gcc/cp/decl2.cc
index 0850d3f5bce..4777ceb8af7 100644
--- a/gcc/cp/decl2.cc
+++ b/gcc/cp/decl2.cc
@@ -2655,7 +2655,10 @@ min_vis_expr_r (tree *tp, int */*walk_subtrees*/, void 
*data)
int *vis_p = (int *)data;
int tpvis = VISIBILITY_DEFAULT;
  
-  switch (TREE_CODE (*tp))

+  tree t = *tp;
+  if (TREE_CODE (t) == PTRMEM_CST)
+t = PTRMEM_CST_MEMBER (t);
+  switch (TREE_CODE (t))
  {
  case CAST_EXPR:
  case IMPLICIT_CONV_EXPR:
@@ -2666,15 +2669,26 @@ min_vis_expr_r (tree *tp, int */*walk_subtrees*/, void 
*data)
  case NEW_EXPR:
  case CONSTRUCTOR:
  case LAMBDA_EXPR:
-  tpvis = type_visibility (TREE_TYPE (*tp));
+  tpvis = type_visibility (TREE_TYPE (t));
break;
  
+case TEMPLATE_DECL:

+  if (DECL_ALIAS_TEMPLATE_P (t))
+   /* FIXME: We don't maintain TREE_PUBLIC / DECL_VISIBILITY for
+  alias templates so we can't trust it here (PR107906).  */
+   break;
+  t = DECL_TEMPLATE_RESULT (t);
+  /* Fall through.  */
  case VAR_DECL:
  case FUNCTION_DECL:
-  if (! TREE_PUBLIC (*tp))
+  if (! TREE_PUBLIC (t))
tpvis = VISIBILITY_ANON;
else
-   tpvis = DECL_VISIBILITY (*tp);
+   tpvis = DECL_VISIBILITY (t);
+  break;
+
+case FIELD_DECL:
+  tpvis = type_visibility (DECL_CONTEXT (t));
break;
  
  default:

diff --git a/gcc/testsuite/g++.dg/template/linkage2.C 
b/gcc/testsuite/g++.dg/template/linkage2.C
new file mode 100644
index 000..08fb6930262
--- /dev/null
+++ b/gcc/testsuite/g++.dg/template/linkage2.C
@@ -0,0 +1,13 @@
+// PR c++/70413
+// { dg-do compile { target c++11 } }
+// { dg-final { scan-assembler-not "(weak|glob)\[^\n\]*_Z" } }
+
+namespace {
+  template struct A;
+}
+
+template class Q> void f() { }
+
+int main() {
+  f();
+}
diff --git a/gcc/testsuite/g++.dg/template/linkage3.C 
b/gcc/testsuite/g++.dg/template/linkage3.C
new file mode 100644
index 000..257aab33b38
--- /dev/null
+++ b/gcc/testsuite/g++.dg/template/linkage3.C
@@ -0,0 +1,17 @@
+// PR c++/70413
+// { dg-final { scan-assembler-not "(weak|glob)\[^\n\]*_Z" } }
+
+namespace {
+  struct A {
+void f();
+int m;
+  };
+}
+
+template void g() { }
+template void h() { }
+
+int main() {
+  g<::f>();
+  h<::m>();
+}
diff --git a/gcc/testsuite/g++.dg/template/linkage4.C 
b/gcc/testsuite/g++.dg/template/linkage4.C
new file mode 100644
index 000..03630eebd3d
--- /dev/null
+++ b/gcc/testsuite/g++.dg/template/linkage4.C
@@ -0,0 +1,16 @@
+// PR c++/107906
+// { dg-do compile { target c++11 } }
+// { dg-final { scan-assembler-not "(weak|glob)\[^\n\]*_Z" { xfail *-*-* } } }
+
+namespace {
+  template using X = int;
+  struct A {
+template using X = int;
+  };
+}
+template class Q> void f() { }
+
+int main() {
+  f();
+  f();
+}
diff --git a/gcc/testsuite/g++.dg/template/linkage4a.C 
b/gcc/testsui

Re: [PATCH] c++: visibility wrt template and ptrmem targs [PR70413]

2023-12-21 Thread Patrick Palka 
On Sat, 16 Sep 2023, Jason Merrill wrote:

> On 9/15/23 12:03, Patrick Palka wrote:
> > Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for
> > trunk?
> 
> OK.

Thanks a lot.  Testing on cmcstl2 revealed that we don't maintain
visibility flags on alias templates properly, and so we can't trust
them when constraining visibilitiy.  So I went ahead and pushed the
following restricted version of the patch which excludes alias templates
(and adds a couple of alias template targ linkage tests):

-- >8 --

Subject: [PATCH] c++: visibility wrt template and ptrmem targs [PR70413]

When constraining the visibility of an instantiation, we weren't
properly considering the visibility of PTRMEM_CST and TEMPLATE_DECL
template arguments.

This patch fixes this.  It turns out we don't maintain the relevant
visibility flags for alias templates (e.g. TREE_PUBLIC is never set),
so continue to ignore alias template template arguments for now.

PR c++/70413
PR c++/107906

gcc/cp/ChangeLog:

* decl2.cc (min_vis_expr_r): Handle PTRMEM_CST and TEMPLATE_DECL
other than those for alias templates.

gcc/testsuite/ChangeLog:

* g++.dg/template/linkage2.C: New test.
* g++.dg/template/linkage3.C: New test.
* g++.dg/template/linkage4.C: New test.
* g++.dg/template/linkage4a.C: New test.
---
 gcc/cp/decl2.cc   | 22 ++
 gcc/testsuite/g++.dg/template/linkage2.C  | 13 +
 gcc/testsuite/g++.dg/template/linkage3.C  | 17 +
 gcc/testsuite/g++.dg/template/linkage4.C  | 16 
 gcc/testsuite/g++.dg/template/linkage4a.C | 14 ++
 5 files changed, 78 insertions(+), 4 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/template/linkage2.C
 create mode 100644 gcc/testsuite/g++.dg/template/linkage3.C
 create mode 100644 gcc/testsuite/g++.dg/template/linkage4.C
 create mode 100644 gcc/testsuite/g++.dg/template/linkage4a.C

diff --git a/gcc/cp/decl2.cc b/gcc/cp/decl2.cc
index 0850d3f5bce..4777ceb8af7 100644
--- a/gcc/cp/decl2.cc
+++ b/gcc/cp/decl2.cc
@@ -2655,7 +2655,10 @@ min_vis_expr_r (tree *tp, int */*walk_subtrees*/, void 
*data)
   int *vis_p = (int *)data;
   int tpvis = VISIBILITY_DEFAULT;
 
-  switch (TREE_CODE (*tp))
+  tree t = *tp;
+  if (TREE_CODE (t) == PTRMEM_CST)
+t = PTRMEM_CST_MEMBER (t);
+  switch (TREE_CODE (t))
 {
 case CAST_EXPR:
 case IMPLICIT_CONV_EXPR:
@@ -2666,15 +2669,26 @@ min_vis_expr_r (tree *tp, int */*walk_subtrees*/, void 
*data)
 case NEW_EXPR:
 case CONSTRUCTOR:
 case LAMBDA_EXPR:
-  tpvis = type_visibility (TREE_TYPE (*tp));
+  tpvis = type_visibility (TREE_TYPE (t));
   break;
 
+case TEMPLATE_DECL:
+  if (DECL_ALIAS_TEMPLATE_P (t))
+   /* FIXME: We don't maintain TREE_PUBLIC / DECL_VISIBILITY for
+  alias templates so we can't trust it here (PR107906).  */
+   break;
+  t = DECL_TEMPLATE_RESULT (t);
+  /* Fall through.  */
 case VAR_DECL:
 case FUNCTION_DECL:
-  if (! TREE_PUBLIC (*tp))
+  if (! TREE_PUBLIC (t))
tpvis = VISIBILITY_ANON;
   else
-   tpvis = DECL_VISIBILITY (*tp);
+   tpvis = DECL_VISIBILITY (t);
+  break;
+
+case FIELD_DECL:
+  tpvis = type_visibility (DECL_CONTEXT (t));
   break;
 
 default:
diff --git a/gcc/testsuite/g++.dg/template/linkage2.C 
b/gcc/testsuite/g++.dg/template/linkage2.C
new file mode 100644
index 000..08fb6930262
--- /dev/null
+++ b/gcc/testsuite/g++.dg/template/linkage2.C
@@ -0,0 +1,13 @@
+// PR c++/70413
+// { dg-do compile { target c++11 } }
+// { dg-final { scan-assembler-not "(weak|glob)\[^\n\]*_Z" } }
+
+namespace {
+  template struct A;
+}
+
+template class Q> void f() { }
+
+int main() {
+  f();
+}
diff --git a/gcc/testsuite/g++.dg/template/linkage3.C 
b/gcc/testsuite/g++.dg/template/linkage3.C
new file mode 100644
index 000..257aab33b38
--- /dev/null
+++ b/gcc/testsuite/g++.dg/template/linkage3.C
@@ -0,0 +1,17 @@
+// PR c++/70413
+// { dg-final { scan-assembler-not "(weak|glob)\[^\n\]*_Z" } }
+
+namespace {
+  struct A {
+void f();
+int m;
+  };
+}
+
+template void g() { }
+template void h() { }
+
+int main() {
+  g<::f>();
+  h<::m>();
+}
diff --git a/gcc/testsuite/g++.dg/template/linkage4.C 
b/gcc/testsuite/g++.dg/template/linkage4.C
new file mode 100644
index 000..03630eebd3d
--- /dev/null
+++ b/gcc/testsuite/g++.dg/template/linkage4.C
@@ -0,0 +1,16 @@
+// PR c++/107906
+// { dg-do compile { target c++11 } }
+// { dg-final { scan-assembler-not "(weak|glob)\[^\n\]*_Z" { xfail *-*-* } } }
+
+namespace {
+  template using X = int;
+  struct A {
+template using X = int;
+  };
+}
+template class Q> void f() { }
+
+int main() {
+  f();
+  f();
+}
diff --git a/gcc/testsuite/g++.dg/template/linkage4a.C 
b/gcc/testsuite/g++.dg/template/linkage4a.C
new file mode 100644

Re: [PATCH] c++: visibility wrt template and ptrmem targs [PR70413]

2023-09-16 Thread Jason Merrill via Gcc-patches 

On 9/15/23 12:03, Patrick Palka wrote:

Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for
trunk?


OK.


-- >8 --

When constraining the visibility of an instantiation, we weren't
properly considering the visibility of PTRMEM_CST and TEMPLATE_DECL
template arguments.

PR c++/70413

gcc/cp/ChangeLog:

* decl2.cc (min_vis_expr_r): Handle PTRMEM_CST and TEMPLATE_DECL.

gcc/testsuite/ChangeLog:

* g++.dg/abi/no-linkage-expr2.C: New test.
* g++.dg/abi/no-linkage-expr3.C: New test.
---
  gcc/cp/decl2.cc | 18 ++
  gcc/testsuite/g++.dg/abi/no-linkage-expr2.C | 15 +++
  gcc/testsuite/g++.dg/abi/no-linkage-expr3.C | 17 +
  3 files changed, 46 insertions(+), 4 deletions(-)
  create mode 100644 gcc/testsuite/g++.dg/abi/no-linkage-expr2.C
  create mode 100644 gcc/testsuite/g++.dg/abi/no-linkage-expr3.C

diff --git a/gcc/cp/decl2.cc b/gcc/cp/decl2.cc
index b402befba6d..5006372a646 100644
--- a/gcc/cp/decl2.cc
+++ b/gcc/cp/decl2.cc
@@ -2582,7 +2582,10 @@ min_vis_expr_r (tree *tp, int */*walk_subtrees*/, void 
*data)
int *vis_p = (int *)data;
int tpvis = VISIBILITY_DEFAULT;
  
-  switch (TREE_CODE (*tp))

+  tree t = *tp;
+  if (TREE_CODE (t) == PTRMEM_CST)
+t = PTRMEM_CST_MEMBER (t);
+  switch (TREE_CODE (t))
  {
  case CAST_EXPR:
  case IMPLICIT_CONV_EXPR:
@@ -2593,15 +2596,22 @@ min_vis_expr_r (tree *tp, int */*walk_subtrees*/, void 
*data)
  case NEW_EXPR:
  case CONSTRUCTOR:
  case LAMBDA_EXPR:
-  tpvis = type_visibility (TREE_TYPE (*tp));
+  tpvis = type_visibility (TREE_TYPE (t));
break;
  
+case TEMPLATE_DECL:

+  t = DECL_TEMPLATE_RESULT (t);
+  /* Fall through.  */
  case VAR_DECL:
  case FUNCTION_DECL:
-  if (! TREE_PUBLIC (*tp))
+  if (! TREE_PUBLIC (t))
tpvis = VISIBILITY_ANON;
else
-   tpvis = DECL_VISIBILITY (*tp);
+   tpvis = DECL_VISIBILITY (t);
+  break;
+
+case FIELD_DECL:
+  tpvis = type_visibility (DECL_CONTEXT (t));
break;
  
  default:

diff --git a/gcc/testsuite/g++.dg/abi/no-linkage-expr2.C 
b/gcc/testsuite/g++.dg/abi/no-linkage-expr2.C
new file mode 100644
index 000..db23570bb08
--- /dev/null
+++ b/gcc/testsuite/g++.dg/abi/no-linkage-expr2.C
@@ -0,0 +1,15 @@
+// PR c++/70413
+// { dg-do compile { target c++11 } }
+// { dg-final { scan-assembler-not "weak.*_Z" } }
+
+namespace {
+  template struct A;
+  template using B = int;
+}
+
+template class Q> void f() { }
+
+int main() {
+  f();
+  f();
+}
diff --git a/gcc/testsuite/g++.dg/abi/no-linkage-expr3.C 
b/gcc/testsuite/g++.dg/abi/no-linkage-expr3.C
new file mode 100644
index 000..a2db1a45c74
--- /dev/null
+++ b/gcc/testsuite/g++.dg/abi/no-linkage-expr3.C
@@ -0,0 +1,17 @@
+// PR c++/70413
+// { dg-final { scan-assembler-not "weak.*_Z" } }
+
+namespace {
+  struct A {
+void f();
+int m;
+  };
+}
+
+template void g() { }
+template void h() { }
+
+int main() {
+  g<::f>();
+  h<::m>();
+}

[PATCH] c++: visibility wrt template and ptrmem targs [PR70413]

2023-09-15 Thread Patrick Palka via Gcc-patches 
Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for
trunk?

-- >8 --

When constraining the visibility of an instantiation, we weren't
properly considering the visibility of PTRMEM_CST and TEMPLATE_DECL
template arguments.

PR c++/70413

gcc/cp/ChangeLog:

* decl2.cc (min_vis_expr_r): Handle PTRMEM_CST and TEMPLATE_DECL.

gcc/testsuite/ChangeLog:

* g++.dg/abi/no-linkage-expr2.C: New test.
* g++.dg/abi/no-linkage-expr3.C: New test.
---
 gcc/cp/decl2.cc | 18 ++
 gcc/testsuite/g++.dg/abi/no-linkage-expr2.C | 15 +++
 gcc/testsuite/g++.dg/abi/no-linkage-expr3.C | 17 +
 3 files changed, 46 insertions(+), 4 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/abi/no-linkage-expr2.C
 create mode 100644 gcc/testsuite/g++.dg/abi/no-linkage-expr3.C

diff --git a/gcc/cp/decl2.cc b/gcc/cp/decl2.cc
index b402befba6d..5006372a646 100644
--- a/gcc/cp/decl2.cc
+++ b/gcc/cp/decl2.cc
@@ -2582,7 +2582,10 @@ min_vis_expr_r (tree *tp, int */*walk_subtrees*/, void 
*data)
   int *vis_p = (int *)data;
   int tpvis = VISIBILITY_DEFAULT;
 
-  switch (TREE_CODE (*tp))
+  tree t = *tp;
+  if (TREE_CODE (t) == PTRMEM_CST)
+t = PTRMEM_CST_MEMBER (t);
+  switch (TREE_CODE (t))
 {
 case CAST_EXPR:
 case IMPLICIT_CONV_EXPR:
@@ -2593,15 +2596,22 @@ min_vis_expr_r (tree *tp, int */*walk_subtrees*/, void 
*data)
 case NEW_EXPR:
 case CONSTRUCTOR:
 case LAMBDA_EXPR:
-  tpvis = type_visibility (TREE_TYPE (*tp));
+  tpvis = type_visibility (TREE_TYPE (t));
   break;
 
+case TEMPLATE_DECL:
+  t = DECL_TEMPLATE_RESULT (t);
+  /* Fall through.  */
 case VAR_DECL:
 case FUNCTION_DECL:
-  if (! TREE_PUBLIC (*tp))
+  if (! TREE_PUBLIC (t))
tpvis = VISIBILITY_ANON;
   else
-   tpvis = DECL_VISIBILITY (*tp);
+   tpvis = DECL_VISIBILITY (t);
+  break;
+
+case FIELD_DECL:
+  tpvis = type_visibility (DECL_CONTEXT (t));
   break;
 
 default:
diff --git a/gcc/testsuite/g++.dg/abi/no-linkage-expr2.C 
b/gcc/testsuite/g++.dg/abi/no-linkage-expr2.C
new file mode 100644
index 000..db23570bb08
--- /dev/null
+++ b/gcc/testsuite/g++.dg/abi/no-linkage-expr2.C
@@ -0,0 +1,15 @@
+// PR c++/70413
+// { dg-do compile { target c++11 } }
+// { dg-final { scan-assembler-not "weak.*_Z" } }
+
+namespace {
+  template struct A;
+  template using B = int;
+}
+
+template class Q> void f() { }
+
+int main() {
+  f();
+  f();
+}
diff --git a/gcc/testsuite/g++.dg/abi/no-linkage-expr3.C 
b/gcc/testsuite/g++.dg/abi/no-linkage-expr3.C
new file mode 100644
index 000..a2db1a45c74
--- /dev/null
+++ b/gcc/testsuite/g++.dg/abi/no-linkage-expr3.C
@@ -0,0 +1,17 @@
+// PR c++/70413
+// { dg-final { scan-assembler-not "weak.*_Z" } }
+
+namespace {
+  struct A {
+void f();
+int m;
+  };
+}
+
+template void g() { }
+template void h() { }
+
+int main() {
+  g<::f>();
+  h<::m>();
+}
-- 
2.42.0.158.g94e83dcf5b