Recognize the __builtin_dynamic_object_size builtin, but simply
replace it with -1 or 0 for now.
gcc/ChangeLog:
* builtins.c (expand_builtin, fold_builtin_2): Add
BUILT_IN_DYN_OBJECT_SIZE.
(fold_builtin_dyn_object_size): New function.
(valid_object_size_args): New function.
(fold_builtin_object_size): Use it.
* builtins.def (BUILT_IN_DYN_OBJECT_SIZE): New builtin.
---
gcc/builtins.c | 63 +++++++++++++++++++++++++++++++++++++++---------
gcc/builtins.def | 1 +
2 files changed, 53 insertions(+), 11 deletions(-)
diff --git a/gcc/builtins.c b/gcc/builtins.c
index 3e57eb03af0..894d62359b4 100644
--- a/gcc/builtins.c
+++ b/gcc/builtins.c
@@ -180,6 +180,7 @@ static rtx expand_builtin_memory_chk (tree, rtx,
machine_mode,
static void maybe_emit_chk_warning (tree, enum built_in_function);
static void maybe_emit_sprintf_chk_warning (tree, enum built_in_function);
static tree fold_builtin_object_size (tree, tree);
+static tree fold_builtin_dyn_object_size (tree, tree);
unsigned HOST_WIDE_INT target_newline;
unsigned HOST_WIDE_INT target_percent;
@@ -7910,6 +7911,7 @@ expand_builtin (tree exp, rtx target, rtx subtarget,
machine_mode mode,
return const0_rtx;
case BUILT_IN_OBJECT_SIZE:
+ case BUILT_IN_DYN_OBJECT_SIZE:
return expand_builtin_object_size (exp);
case BUILT_IN_MEMCPY_CHK:
@@ -9318,6 +9320,9 @@ fold_builtin_2 (location_t loc, tree expr, tree fndecl,
tree arg0, tree arg1)
case BUILT_IN_OBJECT_SIZE:
return fold_builtin_object_size (arg0, arg1);
+ case BUILT_IN_DYN_OBJECT_SIZE:
+ return fold_builtin_dyn_object_size (arg0, arg1);
+
case BUILT_IN_ATOMIC_ALWAYS_LOCK_FREE:
return fold_builtin_atomic_always_lock_free (arg0, arg1);
@@ -9964,7 +9969,10 @@ fold_builtin_next_arg (tree exp, bool va_start_p)
}
-/* Expand a call EXP to __builtin_object_size. */
+/* Expand a call EXP to __builtin_object_size or
+ __builtin_dynamic_object_size. If the builtin survived up to this point
+ then it means we have failed to get an object size, so replace the call with
+ 0 or -1 depending on the object size type argument. */
static rtx
expand_builtin_object_size (tree exp)
@@ -10250,27 +10258,40 @@ maybe_emit_sprintf_chk_warning (tree exp, enum
built_in_function fcode)
access_write_only);
}
-/* Fold a call to __builtin_object_size with arguments PTR and OST,
- if possible. */
+/* Validate arguments to __builtin_object_size and
+ __builtin_dynamic_object_size. If both arguments are valid, return the
+ object size type in OSTP. */
-static tree
-fold_builtin_object_size (tree ptr, tree ost)
+static bool
+valid_object_size_args (const tree ptr, tree ost, int *ostp)
{
- unsigned HOST_WIDE_INT bytes;
- int object_size_type;
-
if (!validate_arg (ptr, POINTER_TYPE)
|| !validate_arg (ost, INTEGER_TYPE))
- return NULL_TREE;
+ return false;
STRIP_NOPS (ost);
if (TREE_CODE (ost) != INTEGER_CST
|| tree_int_cst_sgn (ost) < 0
|| compare_tree_int (ost, 3) > 0)
- return NULL_TREE;
+ return false;
- object_size_type = tree_to_shwi (ost);
+ *ostp = tree_to_shwi (ost);
+
+ return true;
+}
+
+/* Fold a call to __builtin_object_size with arguments PTR and OST,
+ if possible. */
+
+static tree
+fold_builtin_object_size (tree ptr, tree ost)
+{
+ unsigned HOST_WIDE_INT bytes;
+ int object_size_type;
+
+ if (!valid_object_size_args (ptr, ost, &object_size_type))
+ return NULL_TREE;
/* __builtin_object_size doesn't evaluate side-effects in its arguments;
if there are any side-effects, it returns (size_t) -1 for types 0 and 1
@@ -10297,6 +10318,26 @@ fold_builtin_object_size (tree ptr, tree ost)
return NULL_TREE;
}
+/* Fold a call to __builtin_dynamic_object_size with arguments PTR and OST,
+ if possible. */
+
+static tree
+fold_builtin_dyn_object_size (tree ptr, tree ost)
+{
+ int object_size_type;
+
+ if (!valid_object_size_args (ptr, ost, &object_size_type))
+ return NULL_TREE;
+
+ /* __builtin_dynamic_object_size doesn't evaluate side-effects in its
+ arguments; if there are any side-effects, it returns (size_t) -1 for types
+ 0 and 1 and (size_t) 0 for types 2 and 3. */
+ if (TREE_SIDE_EFFECTS (ptr))
+ return build_int_cst_type (size_type_node, object_size_type < 2 ? -1 : 0);
+
+ return NULL_TREE;
+}
+
/* Builtins with folding operations that operate on "..." arguments
need special handling; we need to store the arguments in a convenient
data structure before attempting any folding. Fortunately there are
diff --git a/gcc/builtins.def b/gcc/builtins.def
index 45a09b4d42d..ae94caab921 100644
--- a/gcc/builtins.def
+++ b/gcc/builtins.def
@@ -972,6 +972,7 @@ DEF_BUILTIN_STUB (BUILT_IN_STRNCMP_EQ,
"__builtin_strncmp_eq")
/* Object size checking builtins. */
DEF_GCC_BUILTIN (BUILT_IN_OBJECT_SIZE, "object_size",
BT_FN_SIZE_CONST_PTR_INT, ATTR_CONST_NOTHROW_LEAF_LIST)
+DEF_GCC_BUILTIN (BUILT_IN_DYN_OBJECT_SIZE,
"dynamic_object_size", BT_FN_SIZE_CONST_PTR_INT, ATTR_NOTHROW_LEAF_LIST)
DEF_EXT_LIB_BUILTIN (BUILT_IN_MEMCPY_CHK, "__memcpy_chk",
BT_FN_PTR_PTR_CONST_PTR_SIZE_SIZE, ATTR_NOTHROW_NONNULL_LEAF)
DEF_EXT_LIB_BUILTIN (BUILT_IN_MEMMOVE_CHK, "__memmove_chk",
BT_FN_PTR_PTR_CONST_PTR_SIZE_SIZE, ATTR_NOTHROW_NONNULL_LEAF)
DEF_EXT_LIB_BUILTIN (BUILT_IN_MEMPCPY_CHK, "__mempcpy_chk",
BT_FN_PTR_PTR_CONST_PTR_SIZE_SIZE, ATTR_RETNONNULL_NOTHROW_LEAF)
--
2.31.1
