update diagnostic messages

Author: a-tarasyuk

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -7409,11 +7409,11 @@ def warn_c23_compat_utf8_string : Warning<
 def note_cxx20_c23_compat_utf8_string_remove_u8 : Note<
   "remove 'u8' prefix to avoid a change of behavior; "
   "Clang encodes unprefixed narrow string literals as UTF-8">;
-def warn_c23_compat_restrict_pointers_to_array : Warning<
-  "'restrict' qualifier on pointers to arrays is incompatible with C17 and earlier">,
+def warn_c23_compat_restrict_on_array_of_pointers : Warning<
+  "'restrict' qualifier on an array of pointers is incompatible with C standards before C23">,
   InGroup<CPre23Compat>, DefaultIgnore;
-def ext_restrict_pointers_to_array_c23 : Extension<
-  "'restrict' qualifier on pointers to arrays is a C23 extension">, InGroup<C23>;
+def ext_restrict_on_array_of_pointers_c23 : Extension<
+  "'restrict' qualifier on an array of pointers is a C23 extension">, InGroup<C23>;
 def err_array_init_different_type : Error<
   "cannot initialize array %diff{of type $ with array of type $|"
   "with different type of array}0,1">;

clang/lib/Sema/SemaType.cpp

@@ -1621,9 +1621,9 @@ QualType Sema::BuildQualifiedType(QualType T, SourceLocation Loc,
       Diag(Loc, DiagID) << EltTy;
       Qs.removeRestrict();
     } else {
-      if (!getLangOpts().C23 && (T->isArrayType() || EltTy->isArrayType())) {
-        Diag(Loc, diag::ext_restrict_pointers_to_array_c23);
-        Diag(Loc, diag::warn_c23_compat_restrict_pointers_to_array);
+      if (!getLangOpts().C23 && T->isArrayType()) {
+        Diag(Loc, diag::ext_restrict_on_array_of_pointers_c23);
+        Diag(Loc, diag::warn_c23_compat_restrict_on_array_of_pointers);
       }
     }
   }

clang/test/Sema/pre-c2x-restrict-qualifier.c

@@ -3,16 +3,15 @@
 // RUN: %clang_cc1 -std=c17 -fsyntax-only -Wpre-c2x-compat -verify=pre-c2x-compat %s
 
 typedef int (*T1)[2];
-restrict T1 t1;         // pedantic-warning {{'restrict' qualifier on pointers to arrays is a C23 extension}} \
-                        // pre-c2x-compat-warning {{'restrict' qualifier on pointers to arrays is incompatible with C17 and earlier}}
+restrict T1 t1;
 
 typedef int *T2[2];
-restrict T2 t2;         // pedantic-warning {{'restrict' qualifier on pointers to arrays is a C23 extension}} \
-                        // pre-c2x-compat-warning {{'restrict' qualifier on pointers to arrays is incompatible with C17 and earlier}}
+restrict T2 t2;         // pedantic-warning {{'restrict' qualifier on an array of pointers is a C23 extension}} \
+                        // pre-c2x-compat-warning {{'restrict' qualifier on an array of pointers is incompatible with C standards before C23}}
 
 typedef int *T3[2][2];
-restrict T3 t3;         // pedantic-warning {{'restrict' qualifier on pointers to arrays is a C23 extension}} \
-                        // pre-c2x-compat-warning {{'restrict' qualifier on pointers to arrays is incompatible with C17 and earlier}}
+restrict T3 t3;         // pedantic-warning {{'restrict' qualifier on an array of pointers is a C23 extension}} \
+                        // pre-c2x-compat-warning {{'restrict' qualifier on an array of pointers is incompatible with C standards before C23}}
 
 typedef int (*t4)();    // pedantic-warning {{a function declaration without a prototype is deprecated in all versions of C}}
 typedef t4 t5[2];

clang/test/Sema/types.c

@@ -6,10 +6,10 @@
 // RUN: %clang_cc1 %s -fblocks -pedantic -verify -triple=powerpc64-ibm-aix-xcoff
 
 typedef int (*T)[2];
-restrict T x; // expected-warning {{'restrict' qualifier on pointers to arrays is a C23 extension}}
+restrict T x;
 
 typedef int *S[2];
-restrict S y; // expected-warning {{'restrict' qualifier on pointers to arrays is a C23 extension}}
+restrict S y; // expected-warning {{'restrict' qualifier on an array of pointers is a C23 extension}}
 
 // int128_t is available.
 int a(void) {