--- gcc/opts.c.jj	2015-01-05 19:52:17.151813267 +0100
+++ gcc/opts.c	2015-01-05 22:48:11.738814380 +0100
@@ -1588,6 +1588,7 @@ common_handle_option (struct gcc_options
 		sizeof "returns-nonnull-attribute" - 1 },
 	      { "object-size", SANITIZE_OBJECT_SIZE,
 		sizeof "object-size" - 1 },
+	      { "all", ~0, sizeof "all" - 1 },
 	      { NULL, 0, 0 }
 	    };
 	    const char *comma;
@@ -1611,7 +1612,15 @@ common_handle_option (struct gcc_options
 		  && memcmp (p, spec[i].name, len) == 0)
 		{
 		  /* Handle both -fsanitize and -fno-sanitize cases.  */
-		  if (value)
+		  if (value && spec[i].flag == ~0U)
+		    {
+		      if (code == OPT_fsanitize_)
+			error_at (loc, "-fsanitize=all option is not valid");
+		      else
+			*flag |= ~(SANITIZE_USER_ADDRESS | SANITIZE_THREAD
+				   | SANITIZE_LEAK);
+		    }
+		  else if (value)
 		    *flag |= spec[i].flag;
 		  else
 		    *flag &= ~spec[i].flag;
--- gcc/doc/invoke.texi.jj	2015-01-05 22:44:36.000000000 +0100
+++ gcc/doc/invoke.texi	2015-01-05 22:58:23.600292158 +0100
@@ -5683,6 +5683,8 @@ be a legitimate way of obtaining infinit
 @opindex fsanitize=float-cast-overflow
 This option enables floating-point type to integer conversion checking.
 We check that the result of the conversion does not overflow.
+Unlike other similar options, @option{-fsanitize=float-cast-overflow} is
+not enabled by @option{-fsanitize=undefined}.
 This option does not work well with @code{FE_INVALID} exceptions enabled.
 
 @item -fsanitize=nonnull-attribute
@@ -5718,6 +5720,13 @@ While @option{-ftrapv} causes traps for
 @option{-fsanitize=undefined} gives a diagnostic message.
 This currently works only for the C family of languages.
 
+@item -fno-sanitize=all
+@opindex fno-sanitize=all
+
+This option disables all previously enabled sanitizers.
+@option{-fsanitize=all} is not allowed, as some sanitizers cannot be used
+together.
+
 @item -fasan-shadow-offset=@var{number}
 @opindex fasan-shadow-offset
 This option forces GCC to use custom shadow offset in AddressSanitizer checks.
@@ -5741,11 +5750,14 @@ Currently this feature only works for @o
 except for @option{-fsanitize=unreachable} and @option{-fsanitize=return}),
 @option{-fsanitize=float-cast-overflow}, @option{-fsanitize=float-divide-by-zero} and
 @option{-fsanitize=kernel-address}.  For these sanitizers error recovery is turned on by default.
+@option{-fsanitize-recover=all} and @option{-fno-sanitize-recover=all} is also
+accepted, the former enables recovery for all sanitizers that support it,
+the latter disables recovery for all sanitizers that support it.
 
 Syntax without explicit @var{opts} parameter is deprecated.  It is equivalent to
-@option{-fsanitize-recover=undefined,float-cast-overflow,float-divide-by-zero,kernel-address}.
+@option{-fsanitize-recover=undefined,float-cast-overflow,float-divide-by-zero}.
 Similarly @option{-fno-sanitize-recover} is equivalent to
-@option{-fno-sanitize-recover=undefined,float-cast-overflow,float-divide-by-zero,kernel-address}.
+@option{-fno-sanitize-recover=undefined,float-cast-overflow,float-divide-by-zero}.
 
 @item -fsanitize-undefined-trap-on-error
 @opindex fsanitize-undefined-trap-on-error
--- gcc/testsuite/c-c++-common/asan/sanitize-all-1.c.jj	2015-01-05 22:48:11.739814363 +0100
+++ gcc/testsuite/c-c++-common/asan/sanitize-all-1.c	2015-01-05 22:48:11.739814363 +0100
@@ -0,0 +1,12 @@
+/* { dg-do compile } */
+/* { dg-options "-fno-sanitize=all" } */
+
+volatile int ten = 10;
+
+int main() {
+  volatile char x[10];
+  x[ten];
+  return 0;
+}
+
+/* { dg-final { scan-assembler-not "__asan_load" } } */
--- gcc/testsuite/c-c++-common/ubsan/sanitize-all-1.c.jj	2015-01-05 22:48:11.739814363 +0100
+++ gcc/testsuite/c-c++-common/ubsan/sanitize-all-1.c	2015-01-05 22:48:11.739814363 +0100
@@ -0,0 +1,8 @@
+/* Test -f*sanitize*=all */
+/* { dg-do compile } */
+/* { dg-skip-if "" { *-*-* } { "*" } { "-O2" } } */
+/* { dg-options "-fsanitize=all" } */
+
+int i;
+
+/* { dg-error "-fsanitize=all option is not valid" "" { target *-*-* } 0 } */
--- gcc/testsuite/c-c++-common/ubsan/sanitize-all-2.c.jj	2015-01-05 22:48:11.739814363 +0100
+++ gcc/testsuite/c-c++-common/ubsan/sanitize-all-2.c	2015-01-05 22:48:11.739814363 +0100
@@ -0,0 +1,41 @@
+/* Test -f*sanitize*=all */
+/* { dg-do run } */
+/* { dg-skip-if "" { *-*-* } { "*" } { "-O2" } } */
+/* { dg-skip-if "" { *-*-* } { "-flto -fno-fat-lto-objects" } } */
+/* { dg-options "-fsanitize=undefined,float-cast-overflow,float-divide-by-zero -fno-sanitize=all -fdump-tree-optimized" } */
+
+int a[4];
+
+int
+f1 (int x, int y, int z)
+{
+  return a[x] + (1 << y) + (100 / z);
+}
+
+char *
+f2 (int x)
+{
+  char *p = (char *) __builtin_calloc (64, 1);
+  p[x] = 3;
+  return p;
+}
+
+int
+f3 (int x, int *y, double z, double w)
+{
+  int a[*y];
+  if (x)
+    __builtin_unreachable ();
+  asm volatile ("" : : "r" (&a[0]));
+  return z / w;
+}
+
+int
+main ()
+{
+  return 0;
+}
+
+/* { dg-final { scan-tree-dump-not "__ubsan_" "optimized" } } */
+/* { dg-final { scan-tree-dump-not "UBSAN_CHECK_" "optimized" } } */
+/* { dg-final { cleanup-tree-dump "optimized" } } */
--- gcc/testsuite/c-c++-common/ubsan/sanitize-all-3.c.jj	2015-01-05 22:48:11.740814345 +0100
+++ gcc/testsuite/c-c++-common/ubsan/sanitize-all-3.c	2015-01-05 22:48:11.740814345 +0100
@@ -0,0 +1,42 @@
+/* Test -f*sanitize*=all */
+/* { dg-do run } */
+/* { dg-skip-if "" { *-*-* } { "*" } { "-O2" } } */
+/* { dg-skip-if "" { *-*-* } { "-flto -fno-fat-lto-objects" } } */
+/* { dg-options "-fsanitize=undefined -fsanitize-recover=all -fdump-tree-optimized" } */
+
+int a[4];
+
+int
+f1 (int x, int y, int z)
+{
+  return a[x] + (1 << y) + (100 / z);
+}
+
+char *
+f2 (int x)
+{
+  char *p = (char *) __builtin_calloc (64, 1);
+  p[x] = 3;
+  return p;
+}
+
+int
+f3 (int x, int *y, double z, double w)
+{
+  int a[*y];
+  if (x)
+    __builtin_unreachable ();
+  asm volatile ("" : : "r" (&a[0]));
+  return z / w;
+}
+
+int
+main ()
+{
+  return 0;
+}
+
+/* { dg-final { scan-tree-dump "__ubsan_" "optimized" } } */
+/* { dg-final { scan-tree-dump-not "__ubsan_\[a-z_\]*_abort" "optimized" } } */
+/* { dg-final { scan-tree-dump "UBSAN_CHECK_" "optimized" } } */
+/* { dg-final { cleanup-tree-dump "optimized" } } */
--- gcc/testsuite/c-c++-common/ubsan/sanitize-all-4.c.jj	2015-01-05 22:48:11.740814345 +0100
+++ gcc/testsuite/c-c++-common/ubsan/sanitize-all-4.c	2015-01-05 22:48:11.740814345 +0100
@@ -0,0 +1,42 @@
+/* Test -f*sanitize*=all */
+/* { dg-do run } */
+/* { dg-skip-if "" { *-*-* } { "*" } { "-O2" } } */
+/* { dg-skip-if "" { *-*-* } { "-flto -fno-fat-lto-objects" } } */
+/* { dg-options "-fsanitize=undefined -fno-sanitize-recover=all -fdump-tree-optimized" } */
+
+int a[4];
+
+int
+f1 (int x, int y, int z)
+{
+  return a[x] + (1 << y) + (100 / z);
+}
+
+char *
+f2 (int x)
+{
+  char *p = (char *) __builtin_calloc (64, 1);
+  p[x] = 3;
+  return p;
+}
+
+int
+f3 (int x, int *y, double z, double w)
+{
+  int a[*y];
+  if (x)
+    __builtin_unreachable ();
+  asm volatile ("" : : "r" (&a[0]));
+  return z / w;
+}
+
+int
+main ()
+{
+  return 0;
+}
+
+/* { dg-final { scan-tree-dump "__ubsan_\[a-z_\]*_abort" "optimized" } } */
+/* { dg-final { scan-tree-dump-not "__ubsan_\[a-z_\]*\[^et\] " "optimized" } } */
+/* { dg-final { scan-tree-dump "UBSAN_CHECK_" "optimized" } } */
+/* { dg-final { cleanup-tree-dump "optimized" } } */
