[PATCH] Fix ICE: in function_and_variable_visibility, at ipa-visibility.c:795 (PR99466)

[Iain Buclaw via Gcc-patches]

Hi,

This patch fixes an ICE caused by emutls routines generating a weak,
non-public symbol for storing the initializer of a weak TLS variable.

In get_emutls_init_templ_addr, only declarations that were DECL_ONE_ONLY
would get a public initializer symbol, ignoring variables that were
declared with __attribute__((weak)).

Because DECL_VISIBILITY is also copied to the emutls initializer, a
second test is included which checks that the expected visibility is
emitted too.

Tested on x86_64-apple-darwin10, OK for mainline?

The oldest version of gcc I've checked is 7.5.0, and the ICE is present
there too.  Is this OK for backporting, and if so which versions should
it be backported to?

Regards,
Iain.

---
gcc/ChangeLog:

        PR ipa/99466
        * tree-emutls.c (get_emutls_init_templ_addr): Mark initializer of weak
        TLS declarations as public.

gcc/testsuite/ChangeLog:

        * gcc.dg/tls/pr98607-1.c: New test.
        * gcc.dg/tls/pr98607-2.c: New test.
---
 gcc/testsuite/gcc.dg/tls/pr98607-1.c |  8 ++++++++
 gcc/testsuite/gcc.dg/tls/pr98607-2.c | 10 ++++++++++
 gcc/tree-emutls.c                    |  6 ++++--
 3 files changed, 22 insertions(+), 2 deletions(-)
 create mode 100644 gcc/testsuite/gcc.dg/tls/pr98607-1.c
 create mode 100644 gcc/testsuite/gcc.dg/tls/pr98607-2.c

diff --git a/gcc/testsuite/gcc.dg/tls/pr98607-1.c 
b/gcc/testsuite/gcc.dg/tls/pr98607-1.c
new file mode 100644
index 00000000000..446850e148b
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tls/pr98607-1.c
@@ -0,0 +1,8 @@
+/* { dg-do compile } */
+/* { dg-require-weak "" } */
+/* { dg-require-effective-target tls_emulated } */
+/* { dg-add-options tls } */
+__attribute__((weak))
+__thread int tlsvar = 3;
+/* { dg-final { scan-assembler ".weak_definition ___emutls_t.tlsvar" { target 
*-*-darwin* } } } */
+/* { dg-final { scan-assembler-not ".private_extern ___emutls_t.tlsvar" { 
target *-*-darwin* } } } */
diff --git a/gcc/testsuite/gcc.dg/tls/pr98607-2.c 
b/gcc/testsuite/gcc.dg/tls/pr98607-2.c
new file mode 100644
index 00000000000..86ffaad7f48
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tls/pr98607-2.c
@@ -0,0 +1,10 @@
+/* { dg-do compile } */
+/* { dg-require-weak "" } */
+/* { dg-require-visibility "" } */
+/* { dg-require-effective-target tls_emulated } */
+/* { dg-add-options tls } */
+__attribute__((weak))
+__attribute__((visibility ("hidden")))
+__thread int tlsvar = 3;
+/* { dg-final { scan-assembler ".weak_definition ___emutls_t.tlsvar" { target 
*-*-darwin* } } } */
+/* { dg-final { scan-assembler ".private_extern ___emutls_t.tlsvar" { target 
*-*-darwin* } } } */
diff --git a/gcc/tree-emutls.c b/gcc/tree-emutls.c
index f1053385944..1c9c5d5aee1 100644
--- a/gcc/tree-emutls.c
+++ b/gcc/tree-emutls.c
@@ -242,16 +242,18 @@ get_emutls_init_templ_addr (tree decl)
   DECL_PRESERVE_P (to) = DECL_PRESERVE_P (decl);
 
   DECL_WEAK (to) = DECL_WEAK (decl);
-  if (DECL_ONE_ONLY (decl))
+  if (DECL_ONE_ONLY (decl) || DECL_WEAK (decl))
     {
       TREE_STATIC (to) = TREE_STATIC (decl);
       TREE_PUBLIC (to) = TREE_PUBLIC (decl);
       DECL_VISIBILITY (to) = DECL_VISIBILITY (decl);
-      make_decl_one_only (to, DECL_ASSEMBLER_NAME (to));
     }
   else
     TREE_STATIC (to) = 1;
 
+  if (DECL_ONE_ONLY (decl))
+    make_decl_one_only (to, DECL_ASSEMBLER_NAME (to));
+
   DECL_VISIBILITY_SPECIFIED (to) = DECL_VISIBILITY_SPECIFIED (decl);
   DECL_INITIAL (to) = DECL_INITIAL (decl);
   DECL_INITIAL (decl) = NULL;
-- 
2.27.0