#include "tree-ssa-propagate.h"
#include "target.h"
+/* Return true when DECL is static object in other partition.
+ In that case we must prevent folding as we can't refer to
+ the symbol.
+
+ We can get into it in two ways:
+ 1) When analyzing C++ virtual tables.
+ C++ virtual tables do have known constructors even
+ when they are keyed to other compilation unit.
+ Those tables can contain pointers to methods and vars
+ in other units. Those methods have both STATIC and EXTERNAL
+ set.
+ 2) In WHOPR mode devirtualization might lead to reference
+ to method that was partitioned elsehwere.
+ In this case we have static VAR_DECL or FUNCTION_DECL
+ that has no corresponding callgraph/varpool node
+ declaring the body. */
+
+static bool
+static_object_in_other_unit_p (tree decl)
+{
+ struct varpool_node *vnode;
+ struct cgraph_node *node;
+
+ if (!TREE_STATIC (decl)
+ || TREE_PUBLIC (decl) || DECL_COMDAT (decl))
+ return false;
+ /* External flag is set, so we deal with C++ reference
+ to static object from other file. */
+ if (DECL_EXTERNAL (decl))
+ {
+ /* Just be sure it is not big in frontend setting
+ flags incorrectly. Those variables should never
+ be finalized. */
+ gcc_checking_assert (!(vnode = varpool_get_node (decl))
+ || !vnode->finalized);
+ return true;
+ }
+ /* We are not at ltrans stage; so don't worry about WHOPR. */
+ if (!flag_ltrans)
+ return false;
+ if (TREE_CODE (decl) == FUNCTION_DECL)
+ {
+ node = cgraph_get_node (decl);
+ if (!node || !node->analyzed)
+ return true;
+ }
+ else if (TREE_CODE (decl) == VAR_DECL)
+ {
+ vnode = varpool_get_node (decl);
+ if (!vnode || !vnode->finalized)
+ return true;
+ }
+ return false;
+}
+
/* CVAL is value taken from DECL_INITIAL of variable. Try to transorm it into
acceptable form for is_gimple_min_invariant. */
if (TREE_CODE (cval) == ADDR_EXPR)
{
tree base = get_base_address (TREE_OPERAND (cval, 0));
+ if (base
+ && (TREE_CODE (base) == VAR_DECL
+ || TREE_CODE (base) == FUNCTION_DECL)
+ && static_object_in_other_unit_p (base))
+ return NULL_TREE;
if (base && TREE_CODE (base) == VAR_DECL)
add_referenced_var (base);
}
if (val)
{
val = canonicalize_constructor_val (val);
- if (is_gimple_min_invariant (val))
+ if (val && is_gimple_min_invariant (val))
return val;
+ else
+ return NULL_TREE;
}
/* Variables declared 'const' without an initializer
have zero as the initializer if they may not be
{
HOST_WIDE_INT i;
tree v, fndecl;
- struct cgraph_node *node;
v = BINFO_VIRTUALS (known_binfo);
i = 0;
}
fndecl = TREE_VALUE (v);
- node = cgraph_get_node (fndecl);
/* When cgraph node is missing and function is not public, we cannot
devirtualize. This can happen in WHOPR when the actual method
ends up in other partition, because we found devirtualization
possibility too late. */
- if ((!node || (!node->analyzed && !node->in_other_partition))
- && (!TREE_PUBLIC (fndecl) || DECL_COMDAT (fndecl)))
+ if (static_object_in_other_unit_p (fndecl))
return NULL;
return build_fold_addr_expr (fndecl);
}