diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -7780,7 +7780,8 @@
   "|%diff{sending $ to parameter of type $|"
   "sending to parameter of different type}0,1"
   "|%diff{casting $ to type $|casting between types}0,1}2"
-  " converts between pointers to integer types with different sign">,
+  " converts between pointers to integer types that differ by"
+  " signed/unsigned/plain variation">,
   InGroup<DiagGroup<"pointer-sign">>;
 def err_typecheck_convert_incompatible_pointer_sign : Error<
   "%select{%diff{assigning to $ from $|assigning to different types}0,1"
@@ -7794,7 +7795,8 @@
   "|%diff{sending $ to parameter of type $|"
   "sending to parameter of different type}0,1"
   "|%diff{casting $ to type $|casting between types}0,1}2"
-  " converts between pointers to integer types with different sign">;
+  " converts between pointers to integer types that differ by"
+  " signed/unsigned/plain variation">;
 def ext_typecheck_convert_incompatible_pointer : ExtWarn<
   "incompatible pointer types "
   "%select{%diff{assigning to $ from $|assigning to different types}0,1"
diff --git a/clang/test/Sema/incompatible-sign.c b/clang/test/Sema/incompatible-sign.c
--- a/clang/test/Sema/incompatible-sign.c
+++ b/clang/test/Sema/incompatible-sign.c
@@ -1,5 +1,23 @@
 // RUN: %clang_cc1 %s -verify -fsyntax-only
+// RUN: %clang_cc1 %s -verify -fsyntax-only -fno-signed-char
 
 int a(int* x); // expected-note{{passing argument to parameter 'x' here}}
-int b(unsigned* y) { return a(y); } // expected-warning {{passing 'unsigned int *' to parameter of type 'int *' converts between pointers to integer types with different sign}}
+int b(unsigned* y) { return a(y); } // expected-warning {{passing 'unsigned int *' to parameter of type 'int *' converts between pointers to integer types that differ by signed/unsigned/plain variation}}
 
+signed char *plainCharToSignedChar(signed char *arg) { // expected-note{{passing argument to parameter}}
+  extern char c;
+  signed char *p = &c; // expected-warning {{converts between pointers to integer types that differ by signed/unsigned/plain variation}}
+  struct { signed char *p; } s = { &c }; // expected-warning {{converts between pointers to integer types that differ by signed/unsigned/plain variation}}
+  p = &c; // expected-warning {{converts between pointers to integer types that differ by signed/unsigned/plain variation}}
+  plainCharToSignedChar(&c); // expected-warning {{converts between pointers to integer types that differ by signed/unsigned/plain variation}}
+  return &c; // expected-warning {{converts between pointers to integer types that differ by signed/unsigned/plain variation}}
+}
+
+char *unsignedCharToPlainChar(char *arg) { // expected-note{{passing argument to parameter}}
+  extern unsigned char uc;
+  char *p = &uc; // expected-warning {{converts between pointers to integer types that differ by signed/unsigned/plain variation}}
+  (void) (char *[]){ [42] = &uc }; // expected-warning {{converts between pointers to integer types that differ by signed/unsigned/plain variation}}
+  p = &uc; // expected-warning {{converts between pointers to integer types that differ by signed/unsigned/plain variation}}
+  unsignedCharToPlainChar(&uc); // expected-warning {{converts between pointers to integer types that differ by signed/unsigned/plain variation}}
+  return &uc; // expected-warning {{converts between pointers to integer types that differ by signed/unsigned/plain variation}}
+}
diff --git a/clang/test/Sema/incompatible-sign.cpp b/clang/test/Sema/incompatible-sign.cpp
new file mode 100644
--- /dev/null
+++ b/clang/test/Sema/incompatible-sign.cpp
@@ -0,0 +1,14 @@
+// RUN: %clang_cc1 %s -verify -fsyntax-only
+// RUN: %clang_cc1 %s -verify -fsyntax-only -fno-signed-char
+
+void plainToSigned() {
+  extern char c;
+  signed char *p;
+  p = &c; // expected-error {{converts between pointers to integer types that differ by signed/unsigned/plain variation}}
+}
+
+void unsignedToPlain() {
+  extern unsigned char uc;
+  char *p;
+  p = &uc; // expected-error {{converts between pointers to integer types that differ by signed/unsigned/plain variation}}
+}
diff --git a/clang/test/Sema/vector-ops.c b/clang/test/Sema/vector-ops.c
--- a/clang/test/Sema/vector-ops.c
+++ b/clang/test/Sema/vector-ops.c
@@ -24,7 +24,7 @@
 
   v2u *v2u_ptr = 0;
   v2s *v2s_ptr;
-  v2s_ptr = v2u_ptr; // expected-warning{{converts between pointers to integer types with different sign}}
+  v2s_ptr = v2u_ptr; // expected-warning{{converts between pointers to integer types that differ by signed/unsigned/plain variation}}
 }
 
 void testLogicalVecVec(v2u v2ua, v2s v2sa, v2f v2fa) {
diff --git a/clang/test/SemaObjC/objc-cf-audited-warning.m b/clang/test/SemaObjC/objc-cf-audited-warning.m
--- a/clang/test/SemaObjC/objc-cf-audited-warning.m
+++ b/clang/test/SemaObjC/objc-cf-audited-warning.m
@@ -20,5 +20,5 @@
 
 void saveImageToJPG(const char *filename)
 {
-    CFURLRef url = CFURLCreateFromFileSystemRepresentation(kCFAllocatorDefault, filename, 10, 0); // expected-warning {{passing 'const char *' to parameter of type 'const UInt8 *' (aka 'const unsigned char *') converts between pointers to integer types with different sign}}
+    CFURLRef url = CFURLCreateFromFileSystemRepresentation(kCFAllocatorDefault, filename, 10, 0); // expected-warning {{passing 'const char *' to parameter of type 'const UInt8 *' (aka 'const unsigned char *') converts between pointers to integer types that differ by signed/unsigned/plain variation}}
 }
diff --git a/clang/test/SemaOpenCL/builtins-amdgcn-error.cl b/clang/test/SemaOpenCL/builtins-amdgcn-error.cl
--- a/clang/test/SemaOpenCL/builtins-amdgcn-error.cl
+++ b/clang/test/SemaOpenCL/builtins-amdgcn-error.cl
@@ -156,7 +156,7 @@
   const char ptr[] = "workgroup";
   val = __builtin_amdgcn_atomic_inc32(&val, val, __ATOMIC_ACQUIRE, ptr); // expected-error {{expression is not a string literal}}
   int signedVal = 15;
-  signedVal = __builtin_amdgcn_atomic_inc32(&signedVal, signedVal, __ATOMIC_ACQUIRE, ""); // expected-warning {{passing '__private int *' to parameter of type 'volatile __private unsigned int *' converts between pointers to integer types with different sign}}
+  signedVal = __builtin_amdgcn_atomic_inc32(&signedVal, signedVal, __ATOMIC_ACQUIRE, ""); // expected-warning {{passing '__private int *' to parameter of type 'volatile __private unsigned int *' converts between pointers to integer types that differ by signed/unsigned/plain variation}}
 }
 
 void test_atomic_inc64() {
@@ -170,7 +170,7 @@
   const char ptr[] = "workgroup";
   val = __builtin_amdgcn_atomic_inc64(&val, val, __ATOMIC_ACQUIRE, ptr); // expected-error {{expression is not a string literal}}
   __INT64_TYPE__ signedVal = 15;
-  signedVal = __builtin_amdgcn_atomic_inc64(&signedVal, signedVal, __ATOMIC_ACQUIRE, ""); // expected-warning {{passing '__private long *' to parameter of type 'volatile __private unsigned long *' converts between pointers to integer types with different sign}}
+  signedVal = __builtin_amdgcn_atomic_inc64(&signedVal, signedVal, __ATOMIC_ACQUIRE, ""); // expected-warning {{passing '__private long *' to parameter of type 'volatile __private unsigned long *' converts between pointers to integer types that differ by signed/unsigned/plain variation}}
 }
 
 void test_atomic_dec32() {
@@ -184,7 +184,7 @@
   const char ptr[] = "workgroup";
   val = __builtin_amdgcn_atomic_dec32(&val, val, __ATOMIC_ACQUIRE, ptr); // expected-error {{expression is not a string literal}}
   int signedVal = 15;
-  signedVal = __builtin_amdgcn_atomic_dec32(&signedVal, signedVal, __ATOMIC_ACQUIRE, ""); // expected-warning {{passing '__private int *' to parameter of type 'volatile __private unsigned int *' converts between pointers to integer types with different sign}}
+  signedVal = __builtin_amdgcn_atomic_dec32(&signedVal, signedVal, __ATOMIC_ACQUIRE, ""); // expected-warning {{passing '__private int *' to parameter of type 'volatile __private unsigned int *' converts between pointers to integer types that differ by signed/unsigned/plain variation}}
 }
 
 void test_atomic_dec64() {
@@ -198,5 +198,5 @@
   const char ptr[] = "workgroup";
   val = __builtin_amdgcn_atomic_dec64(&val, val, __ATOMIC_ACQUIRE, ptr); // expected-error {{expression is not a string literal}}
   __INT64_TYPE__ signedVal = 15;
-  signedVal = __builtin_amdgcn_atomic_dec64(&signedVal, signedVal, __ATOMIC_ACQUIRE, ""); // expected-warning {{passing '__private long *' to parameter of type 'volatile __private unsigned long *' converts between pointers to integer types with different sign}}
+  signedVal = __builtin_amdgcn_atomic_dec64(&signedVal, signedVal, __ATOMIC_ACQUIRE, ""); // expected-warning {{passing '__private long *' to parameter of type 'volatile __private unsigned long *' converts between pointers to integer types that differ by signed/unsigned/plain variation}}
 }