re PR tree-optimization/78154 (memcpy et al can be assumed to return non-null)

2016-11-23  Richard Biener  <rguenther@suse.de>
	    Prathamesh Kulkarni  <prathamesh.kulkarni@linaro.rog>

	PR tree-optimization/78154
	* tree-vrp.c (gimple_stmt_nonzero_warnv_p): Return true if function
	returns it's argument and the argument is nonnull.
	* builtin-attrs.def: Define ATTR_RETURNS_NONNULL,
	ATT_RETNONNULL_NOTHROW_LEAF.
	* builtins.def (BUILT_IN_MEMPCPY): Change attribute to
	ATTR_RETNONNULL_NOTHROW_LEAF.
	(BUILT_IN_STPCPY): Likewise.
	(BUILT_IN_STPNCPY): Likewise.
	(BUILT_IN_MEMPCPY_CHK): Likewise.
	(BUILT_IN_STPCPY_CHK): Likewise.
	(BUILT_IN_STPNCPY_CHK): Likewise.
	(BUILT_IN_STRCAT): Change attribute to ATTR_RET1_NOTHROW_NONNULL_LEAF.
	(BUILT_IN_STRNCAT): Likewise.
	(BUILT_IN_STRNCPY): Likewise.
	(BUILT_IN_MEMSET_CHK): Likewise.
	(BUILT_IN_STRCAT_CHK): Likewise.
	(BUILT_IN_STRCPY_CHK): Likewise.
	(BUILT_IN_STRNCAT_CHK): Likewise.
	(BUILT_IN_STRNCPY_CHK): Likewise.

testsuite/
	* gcc.dg/tree-ssa/pr78154.c: New test.

Co-Authored-By: Prathamesh Kulkarni <prathamesh.kulkarni@linaro.org>
From-SVN: r242745

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 30ab26a..7c7ff4c 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,27 @@
+2016-11-23  Richard Biener  <rguenther@suse.de>
+           Prathamesh Kulkarni  <prathamesh.kulkarni@linaro.rog>
+
+       PR tree-optimization/78154
+       * tree-vrp.c (gimple_stmt_nonzero_warnv_p): Return true if function
+       returns it's argument and the argument is nonnull.
+       * builtin-attrs.def: Define ATTR_RETURNS_NONNULL,
+       ATT_RETNONNULL_NOTHROW_LEAF.
+       * builtins.def (BUILT_IN_MEMPCPY): Change attribute to
+       ATTR_RETNONNULL_NOTHROW_LEAF.
+       (BUILT_IN_STPCPY): Likewise.
+       (BUILT_IN_STPNCPY): Likewise.
+       (BUILT_IN_MEMPCPY_CHK): Likewise.
+       (BUILT_IN_STPCPY_CHK): Likewise.
+       (BUILT_IN_STPNCPY_CHK): Likewise.
+       (BUILT_IN_STRCAT): Change attribute to ATTR_RET1_NOTHROW_NONNULL_LEAF.
+       (BUILT_IN_STRNCAT): Likewise.
+       (BUILT_IN_STRNCPY): Likewise.
+       (BUILT_IN_MEMSET_CHK): Likewise.
+       (BUILT_IN_STRCAT_CHK): Likewise.
+       (BUILT_IN_STRCPY_CHK): Likewise.
+       (BUILT_IN_STRNCAT_CHK): Likewise.
+       (BUILT_IN_STRNCPY_CHK): Likewise.
+
 2016-11-23  Naveen H.S  <Naveen.Hurugalawadi@caviumnetworks.com>
 
        * fold-const.c (tree_expr_nonzero_p) : Make non-static.

diff --git a/gcc/builtin-attrs.def b/gcc/builtin-attrs.def
index 8dc59c9..88c9bd1 100644 (file)
--- a/gcc/builtin-attrs.def
+++ b/gcc/builtin-attrs.def
@@ -108,6 +108,7 @@ DEF_ATTR_IDENT (ATTR_TYPEGENERIC, "type generic")
 DEF_ATTR_IDENT (ATTR_TM_REGPARM, "*tm regparm")
 DEF_ATTR_IDENT (ATTR_TM_TMPURE, "transaction_pure")
 DEF_ATTR_IDENT (ATTR_RETURNS_TWICE, "returns_twice")
+DEF_ATTR_IDENT (ATTR_RETURNS_NONNULL, "returns_nonnull")
 
 DEF_ATTR_TREE_LIST (ATTR_NOVOPS_LIST, ATTR_NOVOPS, ATTR_NULL, ATTR_NULL)
 
@@ -197,6 +198,10 @@ DEF_ATTR_TREE_LIST (ATTR_CONST_NOTHROW_NONNULL, ATTR_CONST, ATTR_NULL, \
    and which return their first argument.  */
 DEF_ATTR_TREE_LIST (ATTR_RET1_NOTHROW_NONNULL_LEAF, ATTR_FNSPEC, ATTR_LIST_STR1, \
                        ATTR_NOTHROW_NONNULL_LEAF)
+/* Nothrow leaf functions whose pointer parameter(s) are all nonnull,
+   and return value is also nonnull.  */
+DEF_ATTR_TREE_LIST (ATTR_RETNONNULL_NOTHROW_LEAF, ATTR_RETURNS_NONNULL, ATTR_NULL, \
+                       ATTR_NOTHROW_NONNULL_LEAF)
 /* Nothrow const leaf functions whose pointer parameter(s) are all nonnull.  */
 DEF_ATTR_TREE_LIST (ATTR_CONST_NOTHROW_NONNULL_LEAF, ATTR_CONST, ATTR_NULL, \
                        ATTR_NOTHROW_NONNULL_LEAF)

diff --git a/gcc/builtins.def b/gcc/builtins.def
index e2c5828..151836a 100644 (file)
--- a/gcc/builtins.def
+++ b/gcc/builtins.def
@@ -646,13 +646,13 @@ DEF_LIB_BUILTIN        (BUILT_IN_MEMCHR, "memchr", BT_FN_PTR_CONST_PTR_INT_SIZE,
 DEF_LIB_BUILTIN        (BUILT_IN_MEMCMP, "memcmp", BT_FN_INT_CONST_PTR_CONST_PTR_SIZE, ATTR_PURE_NOTHROW_NONNULL_LEAF)
 DEF_LIB_BUILTIN_CHKP   (BUILT_IN_MEMCPY, "memcpy", BT_FN_PTR_PTR_CONST_PTR_SIZE, ATTR_RET1_NOTHROW_NONNULL_LEAF)
 DEF_LIB_BUILTIN_CHKP   (BUILT_IN_MEMMOVE, "memmove", BT_FN_PTR_PTR_CONST_PTR_SIZE, ATTR_RET1_NOTHROW_NONNULL_LEAF)
-DEF_EXT_LIB_BUILTIN_CHKP (BUILT_IN_MEMPCPY, "mempcpy", BT_FN_PTR_PTR_CONST_PTR_SIZE, ATTR_NOTHROW_NONNULL_LEAF)
+DEF_EXT_LIB_BUILTIN_CHKP (BUILT_IN_MEMPCPY, "mempcpy", BT_FN_PTR_PTR_CONST_PTR_SIZE, ATTR_RETNONNULL_NOTHROW_LEAF)
 DEF_LIB_BUILTIN_CHKP   (BUILT_IN_MEMSET, "memset", BT_FN_PTR_PTR_INT_SIZE, ATTR_RET1_NOTHROW_NONNULL_LEAF)
 DEF_EXT_LIB_BUILTIN    (BUILT_IN_RINDEX, "rindex", BT_FN_STRING_CONST_STRING_INT, ATTR_PURE_NOTHROW_NONNULL_LEAF)
-DEF_EXT_LIB_BUILTIN_CHKP (BUILT_IN_STPCPY, "stpcpy", BT_FN_STRING_STRING_CONST_STRING, ATTR_NOTHROW_NONNULL_LEAF)
-DEF_EXT_LIB_BUILTIN    (BUILT_IN_STPNCPY, "stpncpy", BT_FN_STRING_STRING_CONST_STRING_SIZE, ATTR_NOTHROW_NONNULL_LEAF)
+DEF_EXT_LIB_BUILTIN_CHKP (BUILT_IN_STPCPY, "stpcpy", BT_FN_STRING_STRING_CONST_STRING, ATTR_RETNONNULL_NOTHROW_LEAF)
+DEF_EXT_LIB_BUILTIN    (BUILT_IN_STPNCPY, "stpncpy", BT_FN_STRING_STRING_CONST_STRING_SIZE, ATTR_RETNONNULL_NOTHROW_LEAF)
 DEF_EXT_LIB_BUILTIN    (BUILT_IN_STRCASECMP, "strcasecmp", BT_FN_INT_CONST_STRING_CONST_STRING, ATTR_PURE_NOTHROW_NONNULL_LEAF)
-DEF_LIB_BUILTIN_CHKP   (BUILT_IN_STRCAT, "strcat", BT_FN_STRING_STRING_CONST_STRING, ATTR_NOTHROW_NONNULL_LEAF)
+DEF_LIB_BUILTIN_CHKP   (BUILT_IN_STRCAT, "strcat", BT_FN_STRING_STRING_CONST_STRING, ATTR_RET1_NOTHROW_NONNULL_LEAF)
 DEF_LIB_BUILTIN_CHKP   (BUILT_IN_STRCHR, "strchr", BT_FN_STRING_CONST_STRING_INT, ATTR_PURE_NOTHROW_NONNULL_LEAF)
 DEF_LIB_BUILTIN        (BUILT_IN_STRCMP, "strcmp", BT_FN_INT_CONST_STRING_CONST_STRING, ATTR_PURE_NOTHROW_NONNULL_LEAF)
 DEF_LIB_BUILTIN_CHKP   (BUILT_IN_STRCPY, "strcpy", BT_FN_STRING_STRING_CONST_STRING, ATTR_RET1_NOTHROW_NONNULL_LEAF)
@@ -661,9 +661,9 @@ DEF_EXT_LIB_BUILTIN    (BUILT_IN_STRDUP, "strdup", BT_FN_STRING_CONST_STRING, AT
 DEF_EXT_LIB_BUILTIN    (BUILT_IN_STRNDUP, "strndup", BT_FN_STRING_CONST_STRING_SIZE, ATTR_MALLOC_NOTHROW_NONNULL_LEAF)
 DEF_LIB_BUILTIN_CHKP   (BUILT_IN_STRLEN, "strlen", BT_FN_SIZE_CONST_STRING, ATTR_PURE_NOTHROW_NONNULL_LEAF)
 DEF_EXT_LIB_BUILTIN    (BUILT_IN_STRNCASECMP, "strncasecmp", BT_FN_INT_CONST_STRING_CONST_STRING_SIZE, ATTR_PURE_NOTHROW_NONNULL_LEAF)
-DEF_LIB_BUILTIN        (BUILT_IN_STRNCAT, "strncat", BT_FN_STRING_STRING_CONST_STRING_SIZE, ATTR_NOTHROW_NONNULL_LEAF)
+DEF_LIB_BUILTIN        (BUILT_IN_STRNCAT, "strncat", BT_FN_STRING_STRING_CONST_STRING_SIZE, ATTR_RET1_NOTHROW_NONNULL_LEAF)
 DEF_LIB_BUILTIN        (BUILT_IN_STRNCMP, "strncmp", BT_FN_INT_CONST_STRING_CONST_STRING_SIZE, ATTR_PURE_NOTHROW_NONNULL_LEAF)
-DEF_LIB_BUILTIN        (BUILT_IN_STRNCPY, "strncpy", BT_FN_STRING_STRING_CONST_STRING_SIZE, ATTR_NOTHROW_NONNULL_LEAF)
+DEF_LIB_BUILTIN        (BUILT_IN_STRNCPY, "strncpy", BT_FN_STRING_STRING_CONST_STRING_SIZE, ATTR_RET1_NOTHROW_NONNULL_LEAF)
 DEF_LIB_BUILTIN        (BUILT_IN_STRPBRK, "strpbrk", BT_FN_STRING_CONST_STRING_CONST_STRING, ATTR_PURE_NOTHROW_NONNULL_LEAF)
 DEF_LIB_BUILTIN        (BUILT_IN_STRRCHR, "strrchr", BT_FN_STRING_CONST_STRING_INT, ATTR_PURE_NOTHROW_NONNULL_LEAF)
 DEF_LIB_BUILTIN        (BUILT_IN_STRSPN, "strspn", BT_FN_SIZE_CONST_STRING_CONST_STRING, ATTR_PURE_NOTHROW_NONNULL_LEAF)
@@ -904,14 +904,14 @@ DEF_BUILTIN_STUB (BUILT_IN_MEMCMP_EQ, "__builtin_memcmp_eq")
 DEF_GCC_BUILTIN               (BUILT_IN_OBJECT_SIZE, "object_size", BT_FN_SIZE_CONST_PTR_INT, ATTR_PURE_NOTHROW_LEAF_LIST)
 DEF_EXT_LIB_BUILTIN_CHKP (BUILT_IN_MEMCPY_CHK, "__memcpy_chk", BT_FN_PTR_PTR_CONST_PTR_SIZE_SIZE, ATTR_RET1_NOTHROW_NONNULL_LEAF)
 DEF_EXT_LIB_BUILTIN_CHKP (BUILT_IN_MEMMOVE_CHK, "__memmove_chk", BT_FN_PTR_PTR_CONST_PTR_SIZE_SIZE, ATTR_RET1_NOTHROW_NONNULL_LEAF)
-DEF_EXT_LIB_BUILTIN_CHKP (BUILT_IN_MEMPCPY_CHK, "__mempcpy_chk", BT_FN_PTR_PTR_CONST_PTR_SIZE_SIZE, ATTR_NOTHROW_NONNULL_LEAF)
-DEF_EXT_LIB_BUILTIN_CHKP (BUILT_IN_MEMSET_CHK, "__memset_chk", BT_FN_PTR_PTR_INT_SIZE_SIZE, ATTR_NOTHROW_NONNULL_LEAF)
-DEF_EXT_LIB_BUILTIN_CHKP (BUILT_IN_STPCPY_CHK, "__stpcpy_chk", BT_FN_STRING_STRING_CONST_STRING_SIZE, ATTR_NOTHROW_NONNULL_LEAF)
-DEF_EXT_LIB_BUILTIN    (BUILT_IN_STPNCPY_CHK, "__stpncpy_chk", BT_FN_STRING_STRING_CONST_STRING_SIZE_SIZE, ATTR_NOTHROW_NONNULL_LEAF)
-DEF_EXT_LIB_BUILTIN_CHKP (BUILT_IN_STRCAT_CHK, "__strcat_chk", BT_FN_STRING_STRING_CONST_STRING_SIZE, ATTR_NOTHROW_NONNULL_LEAF)
-DEF_EXT_LIB_BUILTIN_CHKP (BUILT_IN_STRCPY_CHK, "__strcpy_chk", BT_FN_STRING_STRING_CONST_STRING_SIZE, ATTR_NOTHROW_NONNULL_LEAF)
-DEF_EXT_LIB_BUILTIN    (BUILT_IN_STRNCAT_CHK, "__strncat_chk", BT_FN_STRING_STRING_CONST_STRING_SIZE_SIZE, ATTR_NOTHROW_NONNULL_LEAF)
-DEF_EXT_LIB_BUILTIN    (BUILT_IN_STRNCPY_CHK, "__strncpy_chk", BT_FN_STRING_STRING_CONST_STRING_SIZE_SIZE, ATTR_NOTHROW_NONNULL_LEAF)
+DEF_EXT_LIB_BUILTIN_CHKP (BUILT_IN_MEMPCPY_CHK, "__mempcpy_chk", BT_FN_PTR_PTR_CONST_PTR_SIZE_SIZE, ATTR_RETNONNULL_NOTHROW_LEAF)
+DEF_EXT_LIB_BUILTIN_CHKP (BUILT_IN_MEMSET_CHK, "__memset_chk", BT_FN_PTR_PTR_INT_SIZE_SIZE, ATTR_RET1_NOTHROW_NONNULL_LEAF)
+DEF_EXT_LIB_BUILTIN_CHKP (BUILT_IN_STPCPY_CHK, "__stpcpy_chk", BT_FN_STRING_STRING_CONST_STRING_SIZE, ATTR_RETNONNULL_NOTHROW_LEAF)
+DEF_EXT_LIB_BUILTIN    (BUILT_IN_STPNCPY_CHK, "__stpncpy_chk", BT_FN_STRING_STRING_CONST_STRING_SIZE_SIZE, ATTR_RETNONNULL_NOTHROW_LEAF)
+DEF_EXT_LIB_BUILTIN_CHKP (BUILT_IN_STRCAT_CHK, "__strcat_chk", BT_FN_STRING_STRING_CONST_STRING_SIZE, ATTR_RET1_NOTHROW_NONNULL_LEAF)
+DEF_EXT_LIB_BUILTIN_CHKP (BUILT_IN_STRCPY_CHK, "__strcpy_chk", BT_FN_STRING_STRING_CONST_STRING_SIZE, ATTR_RET1_NOTHROW_NONNULL_LEAF)
+DEF_EXT_LIB_BUILTIN    (BUILT_IN_STRNCAT_CHK, "__strncat_chk", BT_FN_STRING_STRING_CONST_STRING_SIZE_SIZE, ATTR_RET1_NOTHROW_NONNULL_LEAF)
+DEF_EXT_LIB_BUILTIN    (BUILT_IN_STRNCPY_CHK, "__strncpy_chk", BT_FN_STRING_STRING_CONST_STRING_SIZE_SIZE, ATTR_RET1_NOTHROW_NONNULL_LEAF)
 DEF_EXT_LIB_BUILTIN    (BUILT_IN_SNPRINTF_CHK, "__snprintf_chk", BT_FN_INT_STRING_SIZE_INT_SIZE_CONST_STRING_VAR, ATTR_FORMAT_PRINTF_NOTHROW_5_6)
 DEF_EXT_LIB_BUILTIN    (BUILT_IN_SPRINTF_CHK, "__sprintf_chk", BT_FN_INT_STRING_INT_SIZE_CONST_STRING_VAR, ATTR_FORMAT_PRINTF_NOTHROW_4_5)
 DEF_EXT_LIB_BUILTIN    (BUILT_IN_VSNPRINTF_CHK, "__vsnprintf_chk", BT_FN_INT_STRING_SIZE_INT_SIZE_CONST_STRING_VALIST_ARG, ATTR_FORMAT_PRINTF_NOTHROW_5_0)

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 47dadd8..bb502ba 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,9 @@
+2016-11-23  Richard Biener  <rguenther@suse.de>
+           Prathamesh Kulkarni  <prathamesh.kulkarni@linaro.rog>
+
+           PR tree-optimization/78154
+           * gcc.dg/tree-ssa/pr78154.c: New test.
+
 2016-11-23  Naveen H.S  <Naveen.Hurugalawadi@caviumnetworks.com>
 
        * gcc.dg/pr31096.c: New testcase.

diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr78154.c b/gcc/testsuite/gcc.dg/tree-ssa/pr78154.c
new file mode 100644 (file)
index 0000000..d908a39
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/pr78154.c
@@ -0,0 +1,43 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-evrp-slim" } */
+
+void f(void *d, const void *s, __SIZE_TYPE__ n)
+{
+  void *t1 = __builtin_memcpy (d, s, n);
+  if (t1 == 0)
+    __builtin_abort ();
+
+  void *t2 = __builtin_memmove (d, s, n);
+  if (t2 == 0)
+    __builtin_abort ();
+
+  void *t3 = __builtin_memset (d, 0, n);
+  if (t3 == 0)
+    __builtin_abort ();
+
+  void *t4 = __builtin_strcpy (d, s);
+  if (t4 == 0)
+    __builtin_abort ();
+
+  void *t5 = __builtin_strncpy (d, s, n);
+  if (t5 == 0)
+    __builtin_abort ();
+
+  void *t6 = __builtin_strcat (d, s);
+  if (t6 == 0)
+    __builtin_abort ();
+
+  void *t7 = __builtin_strncat (d, s, n);
+  if (t7 == 0)
+    __builtin_abort ();
+
+  void *t8 = __builtin_stpcpy (d, s);
+  if (t8 == 0)
+    __builtin_abort ();
+
+  void *t9 = __builtin_stpncpy (d, s, n);
+  if (t9 == 0)
+    __builtin_abort ();
+}
+
+/* { dg-final { scan-tree-dump-not "__builtin_abort" "evrp" } } */

diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c
index c2a4133..5bd4418 100644 (file)
--- a/gcc/tree-vrp.c
+++ b/gcc/tree-vrp.c
@@ -1097,6 +1097,20 @@ gimple_stmt_nonzero_warnv_p (gimple *stmt, bool *strict_overflow_p)
            lookup_attribute ("returns_nonnull",
                              TYPE_ATTRIBUTES (gimple_call_fntype (stmt))))
          return true;
+
+       gcall *call_stmt = as_a<gcall *> (stmt);
+       unsigned rf = gimple_call_return_flags (call_stmt);
+       if (rf & ERF_RETURNS_ARG)
+         {
+           unsigned argnum = rf & ERF_RETURN_ARG_MASK;
+           if (argnum < gimple_call_num_args (call_stmt))
+             {
+               tree arg = gimple_call_arg (call_stmt, argnum);
+               if (SSA_VAR_P (arg)
+                   && infer_nonnull_range_by_attribute (stmt, arg))
+                 return true;
+             }
+         }
        return gimple_alloca_call_p (stmt);
       }
     default: