PR tree-optimization/81384 - built-in form of strnlen missing

gcc/ChangeLog:

	PR tree-optimization/81384
	* builtin-types.def (BT_FN_SIZE_CONST_STRING_SIZE): New.
	* builtins.c (expand_builtin_strnlen): New function.
	(expand_builtin): Call it.
	(fold_builtin_n): Avoid setting TREE_NO_WARNING.
	* builtins.def (BUILT_IN_STRNLEN): New.
	* calls.c (maybe_warn_nonstring_arg): Handle BUILT_IN_STRNLEN.
	Warn for bounds in excess of maximum object size.
	* tree-ssa-strlen.c (maybe_set_strlen_range): Return tree representing
	single-value ranges.  Handle strnlen.
	(handle_builtin_strlen): Handle strnlen.
	(strlen_check_and_optimize_stmt): Same.
	* doc/extend.texi (Other Builtins): Document strnlen.

gcc/testsuite/ChangeLog:

	PR tree-optimization/81384
	* gcc.c-torture/execute/builtins/lib/strnlen.c: New test.
	* gcc.c-torture/execute/builtins/strnlen-lib.c: New test.
	* gcc.c-torture/execute/builtins/strnlen.c: New test.
	* gcc.dg/attr-nonstring-2.c: New test.
	* gcc.dg/attr-nonstring-3.c: New test.
	* gcc.dg/attr-nonstring-4.c: New test.
	* gcc.dg/strlenopt-45.c: New test.
	* gcc.dg/strlenopt.h (strnlen):  Declare.

From-SVN: r261705

1 files changed, 115 insertions, 0 deletions

diff --git a/gcc/testsuite/gcc.dg/attr-nonstring-2.c b/gcc/testsuite/gcc.dg/attr-nonstring-2.c
new file mode 100644
index 0000000..e9edb66
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/attr-nonstring-2.c
@@ -0,0 +1,115 @@
+/* PR middle-end/81384 - built-in form of strnlen missing
+   { dg-do compile }
+   { dg-options "-O2 -Wall -ftrack-macro-expansion=0" } */
+
+#include "range.h"
+
+extern void* memcpy (void*, const void*, size_t);
+extern size_t strnlen (const char*, size_t);
+
+#define NONSTRING __attribute__ ((nonstring))
+
+#define _CAT(s, n)   s ## n
+#define CAT(s, n)    _CAT (s, n)
+#define UNIQ(n)      CAT (n, __LINE__)
+
+void sink (size_t, ...);
+
+#define T(expr)   sink (expr)
+
+void test_strnlen_array_cst (void)
+{
+  NONSTRING char ns3[3];
+  sink (0, ns3);    // "initialize" ns3
+
+  T (strnlen (ns3, 0));
+  T (strnlen (ns3, 1));
+  T (strnlen (ns3, 2));
+  T (strnlen (ns3, 3));
+  T (strnlen (ns3, 4));             /* { dg-warning "argument 1 declared attribute .nonstring. is smaller than the specified bound 4" } */
+  T (strnlen (ns3, DIFF_MAX));      /* { dg-warning "argument 1 declared attribute .nonstring. is smaller than the specified bound \[0-9\]+" } */
+  T (strnlen (ns3, SIZE_MAX));      /* { dg-warning "specified bound \[0-9\]+ exceeds maximum object size \[0-9\]+" } */
+
+  NONSTRING char ns5[5];
+  sink (0, ns5);
+
+  T (strnlen (ns5, 0));
+  T (strnlen (ns5, 1));
+  T (strnlen (ns5, 2));
+  T (strnlen (ns5, 3));
+  T (strnlen (ns5, 6));             /* { dg-warning "argument 1 declared attribute .nonstring. is smaller than the specified bound 6" } */
+  T (strnlen (ns5, DIFF_MAX));      /* { dg-warning "argument 1 declared attribute .nonstring. is smaller than the specified bound \[0-9\]+" } */
+  T (strnlen (ns5, SIZE_MAX));      /* { dg-warning "specified bound \[0-9\]+ exceeds maximum object size \[0-9\]+" } */
+}
+
+
+void test_strnlen_array_range (void)
+{
+  NONSTRING char ns3[3];
+  sink (0, ns3);    // "initialize" ns3
+
+  T (strnlen (ns3, UR (0, 3)));
+  T (strnlen (ns3, UR (0, 9)));
+  T (strnlen (ns3, UR (3, 4)));
+  T (strnlen (ns3, UR (3, DIFF_MAX)));
+  T (strnlen (ns3, UR (4, 5)));     /* { dg-warning "argument 1 declared attribute .nonstring. is smaller than the specified bound \[0-9\]+" } */
+  T (strnlen (ns3, UR (DIFF_MAX, SIZE_MAX)));  /* { dg-warning "argument 1 declared attribute .nonstring. is smaller " } */
+}
+
+
+#undef T
+#define T(N, init, nelts, bound)			\
+  do {							\
+    extern NONSTRING char UNIQ (arr)[N];		\
+    memcpy (UNIQ (arr), init, nelts);			\
+    sink (strnlen (UNIQ (arr), bound), UNIQ (arr));	\
+  } while (0)
+
+void test_strnlen_string_cst (void)
+{
+  T (3, "1",   2, 1);
+  T (3, "1",   2, 2);
+  T (3, "1",   2, 3);
+  T (3, "12",  3, 1);
+  T (3, "12",  3, 9);
+  T (3, "123", 3, 1);
+  T (3, "123", 3, 4);               /* { dg-warning "argument 1 declared attribute .nonstring. is smaller than the specified bound 4" } */
+  T (3, "123", 3, 9);               /* { dg-warning "argument 1 declared attribute .nonstring. is smaller than the specified bound 9" } */
+
+  T (5, "1",   2, 1);
+  T (5, "1",   2, 2);
+  T (5, "1",   2, 9);
+
+  T (5, "12",  3, 1);
+  T (5, "12",  3, 9);
+  T (5, "123", 3, 1);
+  T (5, "123", 3, 5);
+  T (5, "123", 3, 6);               /* { dg-warning "argument 1 declared attribute .nonstring. is smaller than the specified bound 6" } */
+
+  /* Strnlen shouldn't trigger a warning for arrays of unknown size
+     (except for accesses to uninitialized elements when those are
+     detected).  */
+  T (/* [] */, "1", 1, 1);
+  T (/* [] */, "1", 1, 2);
+  T (/* [] */, "1", 2, 1);
+  T (/* [] */, "1", 2, 2);
+  T (/* [] */, "1", 2, 3);
+  T (/* [] */, "1", 2, 9);
+  T (/* [] */, "1", 2, DIFF_MAX);
+  T (/* [] */, "1", 2, SIZE_MAX);
+
+  size_t n = DIFF_MAX;
+  T (/* [] */, "123", 3, n);
+  T (/* [] */, "123", 3, n + 1);    /* { dg-warning "specified bound \[0-9\]+ exceeds maximum object size " } */
+  n = SIZE_MAX;
+  T (/* [] */, "123", 3, n);        /* { dg-warning "specified bound \[0-9\]+ exceeds maximum object size " } */
+}
+
+
+void test_strnlen_string_range (void)
+{
+  T (3, "1",   2, UR (0, 1));
+  T (3, "1",   2, UR (3, 9));
+  T (3, "123", 3, UR (4, 5));       /* { dg-warning "argument 1 declared attribute .nonstring. is smaller than the specified bound 4" } */
+  T (3, "123", 3, UR (5, 9));       /* { dg-warning "argument 1 declared attribute .nonstring. is smaller than the specified bound 5" } */
+}