ipa-visibility: remove assert in TLS optimization [PR107353]

When upgrading TLS access model based on optimized symbol visibility
status, we attempted to assert that recomputing the model would not
weaken it. It turns out that C, C++, and Fortran front-ends all can
(unintentionally) assign a stronger model than what can be derived
from the declaration.

Let's act conservatively instead of asserting, at least as long as
such pre-existing issues remain.

gcc/ChangeLog:

	PR other/107353
	* ipa-visibility.cc (function_and_variable_visibility):
	Conditionally upgrade TLS model instead of asserting.

diff --git a/gcc/ipa-visibility.cc b/gcc/ipa-visibility.cc
index 3ed2b7cf6797d130dacfbc26c4ec31c5ff1f1dfe..238f7eb84d43009bf2219e7db43dbf9c2d6e505e 100644 (file)
--- a/gcc/ipa-visibility.cc
+++ b/gcc/ipa-visibility.cc
@@ -886,8 +886,12 @@ function_and_variable_visibility (bool whole_program)
              && vnode->ref_list.referring.length ())
            {
              enum tls_model new_model = decl_default_tls_model (decl);
-             gcc_checking_assert (new_model >= decl_tls_model (decl));
-             set_decl_tls_model (decl, new_model);
+             STATIC_ASSERT (TLS_MODEL_GLOBAL_DYNAMIC < TLS_MODEL_LOCAL_DYNAMIC);
+             STATIC_ASSERT (TLS_MODEL_INITIAL_EXEC < TLS_MODEL_LOCAL_EXEC);
+             /* We'd prefer to assert that recomputed model is not weaker than
+                what the front-end assigned, but cannot: see PR 107353.  */
+             if (new_model >= decl_tls_model (decl))
+               set_decl_tls_model (decl, new_model);
            }
        }
     }