#include "gimple-fold.h"
/* Return true when DECL can be referenced from current unit.
- We can get declarations that are not possible to reference for
- various reasons:
+ FROM_DECL (if non-null) specify constructor of variable DECL was taken from.
+ We can get declarations that are not possible to reference for various
+ reasons:
1) When analyzing C++ virtual tables.
C++ virtual tables do have known constructors even
directly. */
static bool
-can_refer_decl_in_current_unit_p (tree decl)
+can_refer_decl_in_current_unit_p (tree decl, tree from_decl)
{
struct varpool_node *vnode;
struct cgraph_node *node;
-
- if (!TREE_STATIC (decl) && !DECL_EXTERNAL (decl))
+ symtab_node snode;
+
+ /* We will later output the initializer, so we can reffer to it.
+ So we are concerned only when DECL comes from initializer of
+ external var. */
+ if (!from_decl
+ || TREE_CODE (from_decl) != VAR_DECL
+ || !DECL_EXTERNAL (from_decl)
+ || (symtab_get_node (from_decl)->symbol.in_other_partition))
+ return true;
+ /* We are concerned ony about static/external vars and functions. */
+ if ((!TREE_STATIC (decl) && !DECL_EXTERNAL (decl))
+ || (TREE_CODE (decl) != VAR_DECL && TREE_CODE (decl) != FUNCTION_DECL))
return true;
- /* External flag is set, so we deal with C++ reference
- to static object from other file.
- We also may see weakref that is always safe. */
- if (DECL_EXTERNAL (decl) && TREE_STATIC (decl)
- && TREE_CODE (decl) == VAR_DECL)
- return lookup_attribute ("weakref", DECL_ATTRIBUTES (decl)) != NULL;
+ /* Weakrefs have somewhat confusing DECL_EXTERNAL flag set; they are always safe. */
+ if (DECL_EXTERNAL (decl)
+ && lookup_attribute ("weakref", DECL_ATTRIBUTES (decl)))
+ return true;
+ /* We are folding reference from external vtable. The vtable may reffer
+ to a symbol keyed to other compilation unit. The other compilation
+ unit may be in separate DSO and the symbol may be hidden. */
+ if (DECL_VISIBILITY_SPECIFIED (decl)
+ && DECL_EXTERNAL (decl)
+ && (!(snode = symtab_get_node (decl)) || !snode->symbol.in_other_partition))
+ return false;
/* When function is public, we always can introduce new reference.
Exception are the COMDAT functions where introducing a direct
reference imply need to include function body in the curren tunit. */
/* We are not at ltrans stage; so don't worry about WHOPR.
Also when still gimplifying all referred comdat functions will be
produced.
- ??? as observed in PR20991 for already optimized out comdat virtual functions
- we may not neccesarily give up because the copy will be output elsewhere when
- corresponding vtable is output. */
+
+ As observed in PR20991 for already optimized out comdat virtual functions
+ it may be tempting to not neccesarily give up because the copy will be
+ output elsewhere when corresponding vtable is output.
+ This is however not possible - ABI specify that COMDATs are output in
+ units where they are used and when the other unit was compiled with LTO
+ it is possible that vtable was kept public while the function itself
+ was privatized. */
if (!flag_ltrans && (!DECL_COMDAT (decl) || !cgraph_function_flags_ready))
return true;
- /* If we already output the function body, we are safe. */
- if (TREE_ASM_WRITTEN (decl))
- return true;
+
+ /* OK we are seeing either COMDAT or static variable. In this case we must
+ check that the definition is still around so we can refer it. */
if (TREE_CODE (decl) == FUNCTION_DECL)
{
node = cgraph_get_node (decl);
compilation stage when making a new reference no longer makes callee
to be compiled. */
if (!node || !node->analyzed || node->global.inlined_to)
- return false;
+ {
+ gcc_checking_assert (!TREE_ASM_WRITTEN (decl));
+ return false;
+ }
}
else if (TREE_CODE (decl) == VAR_DECL)
{
vnode = varpool_get_node (decl);
- if (!vnode || !vnode->finalized)
- return false;
+ if (!vnode || !vnode->analyzed)
+ {
+ gcc_checking_assert (!TREE_ASM_WRITTEN (decl));
+ return false;
+ }
}
return true;
}
/* CVAL is value taken from DECL_INITIAL of variable. Try to transform it into
- acceptable form for is_gimple_min_invariant. */
+ acceptable form for is_gimple_min_invariant.
+ FROM_DECL (if non-NULL) specify variable whose constructor contains CVAL. */
tree
-canonicalize_constructor_val (tree cval)
+canonicalize_constructor_val (tree cval, tree from_decl)
{
STRIP_NOPS (cval);
if (TREE_CODE (cval) == POINTER_PLUS_EXPR
if ((TREE_CODE (base) == VAR_DECL
|| TREE_CODE (base) == FUNCTION_DECL)
- && !can_refer_decl_in_current_unit_p (base))
+ && !can_refer_decl_in_current_unit_p (base, from_decl))
return NULL_TREE;
if (TREE_CODE (base) == VAR_DECL)
{
tree val = DECL_INITIAL (sym);
if (val)
{
- val = canonicalize_constructor_val (val);
+ val = canonicalize_constructor_val (val, sym);
if (val && is_gimple_min_invariant (val))
return val;
else
static tree fold_ctor_reference (tree type, tree ctor,
unsigned HOST_WIDE_INT offset,
- unsigned HOST_WIDE_INT size);
+ unsigned HOST_WIDE_INT size, tree);
/* See if we can find constructor defining value of BASE.
When we know the consructor with constant offset (such as
static tree
fold_array_ctor_reference (tree type, tree ctor,
unsigned HOST_WIDE_INT offset,
- unsigned HOST_WIDE_INT size)
+ unsigned HOST_WIDE_INT size,
+ tree from_decl)
{
unsigned HOST_WIDE_INT cnt;
tree cfield, cval;
/* Do we have match? */
if (double_int_cmp (access_index, index, 1) >= 0
&& double_int_cmp (access_index, max_index, 1) <= 0)
- return fold_ctor_reference (type, cval, inner_offset, size);
+ return fold_ctor_reference (type, cval, inner_offset, size,
+ from_decl);
}
/* When memory is not explicitely mentioned in constructor,
it is 0 (or out of range). */
static tree
fold_nonarray_ctor_reference (tree type, tree ctor,
unsigned HOST_WIDE_INT offset,
- unsigned HOST_WIDE_INT size)
+ unsigned HOST_WIDE_INT size,
+ tree from_decl)
{
unsigned HOST_WIDE_INT cnt;
tree cfield, cval;
if (double_int_cmp (uhwi_to_double_int (offset), bitoffset, 0) < 0)
return NULL_TREE;
return fold_ctor_reference (type, cval,
- double_int_to_uhwi (inner_offset), size);
+ double_int_to_uhwi (inner_offset), size,
+ from_decl);
}
}
/* When memory is not explicitely mentioned in constructor, it is 0. */
static tree
fold_ctor_reference (tree type, tree ctor, unsigned HOST_WIDE_INT offset,
- unsigned HOST_WIDE_INT size)
+ unsigned HOST_WIDE_INT size, tree from_decl)
{
tree ret;
/* We found the field with exact match. */
if (useless_type_conversion_p (type, TREE_TYPE (ctor))
&& !offset)
- return canonicalize_constructor_val (ctor);
+ return canonicalize_constructor_val (ctor, from_decl);
/* We are at the end of walk, see if we can view convert the
result. */
&& operand_equal_p (TYPE_SIZE (type),
TYPE_SIZE (TREE_TYPE (ctor)), 0))
{
- ret = canonicalize_constructor_val (ctor);
+ ret = canonicalize_constructor_val (ctor, from_decl);
ret = fold_unary (VIEW_CONVERT_EXPR, type, ret);
if (ret)
STRIP_NOPS (ret);
if (TREE_CODE (TREE_TYPE (ctor)) == ARRAY_TYPE
|| TREE_CODE (TREE_TYPE (ctor)) == VECTOR_TYPE)
- return fold_array_ctor_reference (type, ctor, offset, size);
+ return fold_array_ctor_reference (type, ctor, offset, size,
+ from_decl);
else
- return fold_nonarray_ctor_reference (type, ctor, offset, size);
+ return fold_nonarray_ctor_reference (type, ctor, offset, size,
+ from_decl);
}
return NULL_TREE;
return NULL_TREE;
return fold_ctor_reference (TREE_TYPE (t), ctor, offset,
TREE_INT_CST_LOW (unit_size)
- * BITS_PER_UNIT);
+ * BITS_PER_UNIT,
+ base);
}
}
/* Fallthru. */
if (offset < 0)
return NULL_TREE;
- return fold_ctor_reference (TREE_TYPE (t), ctor, offset, size);
+ return fold_ctor_reference (TREE_TYPE (t), ctor, offset, size,
+ base);
case REALPART_EXPR:
case IMAGPART_EXPR:
gimple_get_virt_method_for_binfo (HOST_WIDE_INT token, tree known_binfo)
{
unsigned HOST_WIDE_INT offset, size;
- tree v, fn;
+ tree v, fn, vtable;
- v = BINFO_VTABLE (known_binfo);
+ vtable = v = BINFO_VTABLE (known_binfo);
/* If there is no virtual methods table, leave the OBJ_TYPE_REF alone. */
if (!v)
return NULL_TREE;
size = tree_low_cst (TYPE_SIZE (TREE_TYPE (TREE_TYPE (v))), 1);
offset += token * size;
fn = fold_ctor_reference (TREE_TYPE (TREE_TYPE (v)), DECL_INITIAL (v),
- offset, size);
+ offset, size, vtable);
if (!fn || integer_zerop (fn))
return NULL_TREE;
gcc_assert (TREE_CODE (fn) == ADDR_EXPR
devirtualize. This can happen in WHOPR when the actual method
ends up in other partition, because we found devirtualization
possibility too late. */
- if (!can_refer_decl_in_current_unit_p (fn))
+ if (!can_refer_decl_in_current_unit_p (fn, vtable))
return NULL_TREE;
/* Make sure we create a cgraph node for functions we'll reference.
projects / thirdparty / gcc.git / commitdiff
