On 1/17/26 8:46 AM, Marek Polacek wrote:
Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk?
-- >8 --
This came up during Reflection review:
<https://gcc.gnu.org/pipermail/gcc-patches/2026-January/705175.html>
Certain entities, e.g. vars in public inline functions or template
functions should be exported. But entities defined within TU-local
should not be exported.
This patch adjusts min_vis_expr_r to that effect as per the Reflection
discussion.
gcc/cp/ChangeLog:
* decl2.cc (min_vis_expr_r): For _DECLs with no linkage refer to the
linkage of the containing entity that does have a name with linkage.
gcc/testsuite/ChangeLog:
* g++.dg/reflect/visibility1.C: Adjust dg-final.
---
gcc/cp/decl2.cc | 13 ++++++-------
gcc/testsuite/g++.dg/reflect/visibility1.C | 18 +++++++++---------
2 files changed, 15 insertions(+), 16 deletions(-)
diff --git a/gcc/cp/decl2.cc b/gcc/cp/decl2.cc
index 4de6345135f..3a2326b4a1d 100644
--- a/gcc/cp/decl2.cc
+++ b/gcc/cp/decl2.cc
@@ -3114,8 +3114,10 @@ min_vis_expr_r (tree *tp, int *walk_subtrees, void *data)
break;
}
addressable:
+ /* For _DECLs with no linkage refer to the linkage of the containing
+ entity that does have a name with linkage. */
if (decl_linkage (t) == lk_none)
- tpvis = type_visibility (TREE_TYPE (t));
+ tpvis = expr_visibility (DECL_CONTEXT (t));
/* Decls that have had their visibility constrained will report
as external linkage, but we still want to transitively constrain
if we refer to them, so just check TREE_PUBLIC instead. */
@@ -3170,13 +3172,10 @@ min_vis_expr_r (tree *tp, int *walk_subtrees, void
*data)
*walk_subtrees = 0;
break;
}
- if ((VAR_P (r) && decl_function_context (r))
- || TREE_CODE (r) == PARM_DECL)
+ if (VAR_P (r) || TREE_CODE (r) == PARM_DECL)
{
- /* Block scope variables are local to the TU. */
- tpvis = VISIBILITY_ANON;
- *walk_subtrees = 0;
- break;
+ t = r;
+ goto addressable;
}
break;
}
diff --git a/gcc/testsuite/g++.dg/reflect/visibility1.C
b/gcc/testsuite/g++.dg/reflect/visibility1.C
index c47817b9b4e..738edce5fa8 100644
--- a/gcc/testsuite/g++.dg/reflect/visibility1.C
+++ b/gcc/testsuite/g++.dg/reflect/visibility1.C
@@ -49,8 +49,8 @@ inline void
qux (int x)
{
int v = 42;
- foo <106, ^^x> (); // { dg-final { scan-assembler-not
"\t.weak\t_Z3fooILi106EL" } } - var in inline fn - TODO, shall this be exported?
- foo <107, ^^v> (); // { dg-final { scan-assembler-not
"\t.weak\t_Z3fooILi107EL" } } - var in inline fn - TODO, shall this be exported?
+ foo <106, ^^x> (); // { dg-final { scan-assembler
"\t.weak\t_Z3fooILi106EL" } } - var in inline fn
+ foo <107, ^^v> (); // { dg-final { scan-assembler
"\t.weak\t_Z3fooILi107EL" } } - var in inline fn
}
template <int N>
@@ -58,8 +58,8 @@ void
plugh (int x)
{
int v = 42;
- foo <132, ^^x> (); // { dg-final { scan-assembler-not
"\t.weak\t_Z3fooILi132EL" } } - var in public fn template instantiation - TODO, shall
this be exported?
- foo <133, ^^v> (); // { dg-final { scan-assembler-not
"\t.weak\t_Z3fooILi133EL" } } - var in public fn template instantiation - TODO, shall
this be exported?
+ foo <132, ^^x> (); // { dg-final { scan-assembler
"\t.weak\t_Z3fooILi132EL" } } - var in public fn template instantiation
+ foo <133, ^^v> (); // { dg-final { scan-assembler
"\t.weak\t_Z3fooILi133EL" } } - var in public fn template instantiation
foo <134, parameters_of (parent_of (^^v))[0]> (); // { dg-final { scan-assembler
"\t.weak\t_Z3fooILi134EL" { target *-*-linux* } } } - fn parm of public fn template
instantiation
}
@@ -80,9 +80,9 @@ void
fred (int x)
{
int v = 42;
- foo <138, ^^x> (); // { dg-final { scan-assembler-not
"\t.weak\t_Z3fooILi138EL" } } - var in TU-local fn template instantiation
- foo <139, ^^v> (); // { dg-final { scan-assembler-not
"\t.weak\t_Z3fooILi139EL" } } - var in Tu-local fn template instantiation
- foo <140, parameters_of (parent_of (^^v))[0]> (); // { dg-final { scan-assembler-not
"\t.weak\t_Z3fooILi140EL" { xfail *-*-* } } } - fn parm of TU-local fn template
instantiation - TODO, I think this shouldn't be exported and the mangling of these 3 doesn't
include the template parameter
+ foo <138, ^^x> (); // { dg-final { scan-assembler
"\t.weak\t_Z3fooILi138EL" } } - var in fn template instantiation
+ foo <139, ^^v> (); // { dg-final { scan-assembler
"\t.weak\t_Z3fooILi139EL" } } - var in fn template instantiation
+ foo <140, parameters_of (parent_of (^^v))[0]> (); // { dg-final { scan-assembler-not
"\t.weak\t_Z3fooILi140EL" { xfail *-*-* } } } - fn parm of fn template instantiation
- TODO, I think this shouldn't be exported and the mangling of these 3 doesn't include the
template parameter
Why isn't this line changed with the others?
}
[[=1]] void
@@ -108,8 +108,8 @@ xyzzy (int x)
foo <122, ^^G <int>> (); // { dg-final { scan-assembler-not
"\t.weak\t_Z3fooILi122EL" } } - specialization of TU-local template
foo <123, ^^G <A>> (); // { dg-final { scan-assembler-not
"\t.weak\t_Z3fooILi123EL" } } - specialization of TU-local template
foo <124, ^^G <B>> (); // { dg-final { scan-assembler-not
"\t.weak\t_Z3fooILi124EL" } } - specialization of TU-local template
- foo <125, ^^x> (); // { dg-final { scan-assembler-not
"\t.weak\t_Z3fooILi125EL" } } - var in public fn but non-comdat - TODO, shall this be
exported?
- foo <126, ^^v> (); // { dg-final { scan-assembler-not
"\t.weak\t_Z3fooILi126EL" } } - var in public fn but non-comdat - TODO, shall this be
exported?
+ foo <125, ^^x> (); // { dg-final { scan-assembler
"\t.weak\t_Z3fooILi125EL" } } - var in public fn but non-comdat
+ foo <126, ^^v> (); // { dg-final { scan-assembler
"\t.weak\t_Z3fooILi126EL" } } - var in public fn but non-comdat
foo <127, std::meta::info {}> (); // { dg-final { scan-assembler
"\t.weak\t_Z3fooILi127EL" { target *-*-linux* } } } - null reflection
foo <128, ^^b> (); // { dg-final { scan-assembler
"\t.weak\t_Z3fooILi128EL" { target *-*-linux* } } } - public variable
foo <129, ^^c> (); // { dg-final { scan-assembler-not
"\t.weak\t_Z3fooILi129EL" } } - TU-local variable
base-commit: f0c9201c1f3003f35fa764fa9ebe864f6e123859
