diff --git a/clang/test/Rewriter/crash.m b/clang/test/Rewriter/crash.m
@@ -7,7 +7,7 @@ + (id)arrayWithObjects:(id)firstObj, ...;
 @interface NSConstantString {}
 @end
 
-int main() {
+int main(void) {
     id foo = [NSArray arrayWithObjects:@"1", @"2", @"3", @"4", @"5", @"6", @"7", @"8", @"9", @"10", @"11", @"12", 0];
     return 0;
 }
@@ -19,7 +19,7 @@ @protocol A
 @interface Foo
 @end
 
-void func() {
+void func(void) {
   id <A> obj = (id <A>)[Foo bar];
 }
 
diff --git a/clang/test/Rewriter/finally.m b/clang/test/Rewriter/finally.m
@@ -1,6 +1,6 @@
 // RUN: %clang_cc1 -rewrite-objc -fobjc-runtime=macosx-fragile-10.5 -fobjc-exceptions -verify %s -o -
 
-int main() {
+int main(void) {
   @try {
     printf("executing try"); // expected-warning{{implicitly declaring library function 'printf' with type 'int (const char *, ...)'}} \
         // expected-note{{include the header <stdio.h> or explicitly provide a declaration for 'printf'}}
@@ -25,14 +25,14 @@ int main() {
   return 0;
 }
 
-void test_sync_with_implicit_finally() {
+void test_sync_with_implicit_finally(void) {
     id foo;
     @synchronized (foo) {
         return; // The rewriter knows how to generate code for implicit finally
     }
 }
 
-void test2_try_with_implicit_finally() {
+void test2_try_with_implicit_finally(void) {
     @try {
         return; // The rewriter knows how to generate code for implicit finally
     } @catch (id e) {

diff --git a/clang/test/Rewriter/objc-synchronized-1.m b/clang/test/Rewriter/objc-synchronized-1.m
@@ -1,9 +1,9 @@
 // RUN: %clang_cc1 -rewrite-objc -fobjc-runtime=macosx-fragile-10.5  %s -o -
 
-id SYNCH_EXPR();
-void SYNCH_BODY();
-void  SYNCH_BEFORE();
-void  SYNC_AFTER();
+id SYNCH_EXPR(void);
+void SYNCH_BODY(void);
+void  SYNCH_BEFORE(void);
+void  SYNC_AFTER(void);
 
 void foo(id sem)
 {

diff --git a/clang/test/Rewriter/rewrite-captured-nested-bvar.c b/clang/test/Rewriter/rewrite-captured-nested-bvar.c
@@ -6,7 +6,7 @@ void q(void (^p)(void)) {
     p();
 }
 
-void f() {
+void f(void) {
     __block char BYREF_VAR_CHECK = 'a';
     __block char d = 'd';
     q(^{
@@ -25,7 +25,7 @@ void f() {
     });
 }
 
-int main() {
+int main(void) {
     f();
     return 0;
 }

diff --git a/clang/test/Rewriter/rewrite-foreach-1.m b/clang/test/Rewriter/rewrite-foreach-1.m
@@ -16,7 +16,7 @@ @interface MyList (BasicTest)
 - (void)compilerTestAgainst;
 @end
 
-int LOOP();
+int LOOP(void);
 @implementation MyList (BasicTest)
 - (void)compilerTestAgainst {
   id el;

diff --git a/clang/test/Rewriter/rewrite-foreach-2.m b/clang/test/Rewriter/rewrite-foreach-2.m
@@ -16,9 +16,9 @@ @interface MyList (BasicTest)
 - (void)compilerTestAgainst;
 @end
 
-int LOOP();
-int INNERLOOP();
-void END_LOOP();
+int LOOP(void);
+int INNERLOOP(void);
+void END_LOOP(void);
 @implementation MyList (BasicTest)
 - (void)compilerTestAgainst {
   id el;

diff --git a/clang/test/Rewriter/rewrite-foreach-3.m b/clang/test/Rewriter/rewrite-foreach-3.m
@@ -16,7 +16,7 @@ @interface MyList (BasicTest)
 - (void)compilerTestAgainst;
 @end
 
-int LOOP();
+int LOOP(void);
 @implementation MyList (BasicTest)
 - (void)compilerTestAgainst {
   MyList * el;

diff --git a/clang/test/Rewriter/rewrite-foreach-4.m b/clang/test/Rewriter/rewrite-foreach-4.m
@@ -16,7 +16,7 @@ @interface MyList (BasicTest)
 - (void)compilerTestAgainst;
 @end
 
-int LOOP();
+int LOOP(void);
 @implementation MyList (BasicTest)
 - (void)compilerTestAgainst {
   MyList * el;

diff --git a/clang/test/Rewriter/rewrite-foreach-7.m b/clang/test/Rewriter/rewrite-foreach-7.m
@@ -1,7 +1,7 @@
 // RUN: %clang_cc1 -rewrite-objc -fobjc-runtime=macosx-fragile-10.5  %s -o -
 
 @class NSArray;
-int main() {
+int main(void) {
 	NSArray *foo;
 	for (Class c in foo) { }
 }
diff --git a/clang/test/Rewriter/rewrite-modern-synchronized.m b/clang/test/Rewriter/rewrite-modern-synchronized.m
@@ -7,10 +7,10 @@
 
 void *sel_registerName(const char *);
 
-id SYNCH_EXPR();
-void SYNCH_BODY();
-void  SYNCH_BEFORE();
-void  SYNC_AFTER();
+id SYNCH_EXPR(void);
+void SYNCH_BODY(void);
+void  SYNCH_BEFORE(void);
+void  SYNC_AFTER(void);
 
 void foo(id sem)
 {
@@ -26,7 +26,7 @@ void foo(id sem)
  }
 }
 
-void test_sync_with_implicit_finally() {
+void test_sync_with_implicit_finally(void) {
     id foo;
     @synchronized (foo) {
         return; // The rewriter knows how to generate code for implicit finally

diff --git a/clang/test/Rewriter/rewrite-modern-throw.m b/clang/test/Rewriter/rewrite-modern-throw.m
@@ -9,17 +9,17 @@
 void *sel_registerName(const char *);
 
 @interface Foo @end
-void TRY();
-void SPLATCH();
-void MYTRY();
-void MYCATCH();
+void TRY(void);
+void SPLATCH(void);
+void MYTRY(void);
+void MYCATCH(void);
 
-void foo() {
+void foo(void) {
   @try  { TRY(); } 
   @catch (...) { SPLATCH(); @throw; }
 }
 
-int main()
+int main(void)
 {
 
   @try  {

diff --git a/clang/test/Rewriter/rewrite-modern-try-catch-finally.m b/clang/test/Rewriter/rewrite-modern-try-catch-finally.m
@@ -8,7 +8,7 @@
 
 extern int printf(const char *, ...);
 
-int main() {
+int main(void) {
   @try {
   } 
   @finally {
@@ -30,17 +30,17 @@ int main() {
   return 0;
 }
 
-void test2_try_with_implicit_finally() {
+void test2_try_with_implicit_finally(void) {
     @try {
         return;
     } @catch (id e) {
 
     }
 }
 
-void FINALLY();
-void TRY();
-void CATCH();
+void FINALLY(void);
+void TRY(void);
+void CATCH(void);
 
 @interface NSException
 @end

diff --git a/clang/test/Rewriter/rewrite-modern-try-finally.m b/clang/test/Rewriter/rewrite-modern-try-finally.m
@@ -6,11 +6,11 @@
     Class isa;
 } *id;
 
-void FINALLY();
-void TRY();
-void INNER_FINALLY();
-void INNER_TRY();
-void CHECK();
+void FINALLY(void);
+void TRY(void);
+void INNER_FINALLY(void);
+void INNER_TRY(void);
+void CHECK(void);
 
 @interface Foo
 @end

diff --git a/clang/test/Rewriter/rewrite-try-catch.m b/clang/test/Rewriter/rewrite-try-catch.m
@@ -3,12 +3,12 @@
 @interface Foo @end
 @interface GARF @end
 
-void foo() {
+void foo(void) {
   @try  { TRY(); } 
   @catch (...) { SPLATCH(); @throw; }
 }
 
-int main()
+int main(void)
 {
 
   @try  {

diff --git a/clang/test/Rewriter/rewrite-weak-attr.m b/clang/test/Rewriter/rewrite-weak-attr.m
@@ -1,10 +1,10 @@
 // RUN: %clang_cc1 -triple i686-pc-win32 -fms-extensions -fblocks -Dnil=0 -rewrite-objc -fobjc-runtime=macosx-fragile-10.5   -o - %s
-int main() {
+int main(void) {
         __weak __block id foo = nil;
         __block id foo2 = nil;
         id foo3 = nil;
 
-        void (^myblock)() = ^{
+        void (^myblock)(void) = ^{
                 foo = nil;
                 foo2 = nil;
                 [foo3 bar];

diff --git a/clang/test/Rewriter/undef-field-reference-1.m b/clang/test/Rewriter/undef-field-reference-1.m
@@ -8,7 +8,7 @@ @interface MyDerived
 @end
 
 MyDerived *pd;
-int main() {
+int main(void) {
 	return pd->IVAR;
 }
 

diff --git a/clang/test/Rewriter/weak_byref_objects.m b/clang/test/Rewriter/weak_byref_objects.m
@@ -1,12 +1,12 @@
 // RUN: %clang_cc1 -fblocks -triple i386-apple-darwin9 -fobjc-gc -rewrite-objc -fobjc-runtime=macosx-fragile-10.5  %s -o -
 
 #define nil 0
-int main() {
+int main(void) {
         __weak __block id foo = nil;
         __block id foo2 = nil;
         id foo3 = nil;
 
-        void (^myblock)() = ^{
+        void (^myblock)(void) = ^{
                 foo = nil;
                 foo2 = nil;
                 [foo3 bar];

diff --git a/clang/test/VFS/framework-import.m b/clang/test/VFS/framework-import.m
@@ -3,6 +3,6 @@
 
 #import <SomeFramework/public_header.h>
 
-void foo() {
+void foo(void) {
   from_framework();
 }
diff --git a/clang/test/VFS/implicit-include.c b/clang/test/VFS/implicit-include.c
@@ -1,6 +1,6 @@
 // RUN: sed -e "s@INPUT_DIR@%{/S:regex_replacement}/Inputs@g" -e "s@OUT_DIR@%{/t:regex_replacement}@g" %S/Inputs/vfsoverlay.yaml > %t.yaml
 // RUN: %clang_cc1 -Werror -ivfsoverlay %t.yaml -I %t -include "not_real.h" -fsyntax-only %s
 
-void foo() {
+void foo(void) {
   bar();
 }
diff --git a/clang/test/VFS/include-mixed-real-and-virtual.c b/clang/test/VFS/include-mixed-real-and-virtual.c
@@ -7,7 +7,7 @@
 #include "not_real.h"
 #include "real.h"
 
-void foo() {
+void foo(void) {
   bar();
   baz();
 }
diff --git a/clang/test/VFS/include-real-from-virtual.c b/clang/test/VFS/include-real-from-virtual.c
@@ -6,6 +6,6 @@
 
 #include "include_real.h"
 
-void foo() {
+void foo(void) {
   baz();
 }
diff --git a/clang/test/VFS/include-virtual-from-real.c b/clang/test/VFS/include-virtual-from-real.c
@@ -6,6 +6,6 @@
 
 #include "include_not_real.h"
 
-void foo() {
+void foo(void) {
   bar();
 }
diff --git a/clang/test/VFS/include.c b/clang/test/VFS/include.c
@@ -3,6 +3,6 @@
 
 #include "not_real.h"
 
-void foo() {
+void foo(void) {
   bar();
 }
diff --git a/clang/test/VFS/module-import.m b/clang/test/VFS/module-import.m
@@ -4,7 +4,7 @@
 
 @import not_real;
 
-void foo() {
+void foo(void) {
   bar();
 }
 

diff --git a/clang/test/VFS/relative-path.c b/clang/test/VFS/relative-path.c
@@ -5,6 +5,6 @@
 
 #include "not_real.h"
 
-void foo() {
+void foo(void) {
   bar();
 }
diff --git a/clang/test/VFS/vfsroot-with-overlay.c b/clang/test/VFS/vfsroot-with-overlay.c
@@ -6,6 +6,6 @@
 
 #include "not_real.h"
 
-void foo() {
+void foo(void) {
   bar();
 }
diff --git a/clang/test/utils/update_cc_test_checks/Inputs/check-globals.c b/clang/test/utils/update_cc_test_checks/Inputs/check-globals.c
@@ -2,9 +2,9 @@
 // RUN: true
 // RUN: %clang_cc1 -triple x86_64-pc-linux-gnu -emit-llvm -o - %s | FileCheck %s
 
-void foo() {
+void foo(void) {
   static int i, j;
 }
-void bar() {
+void bar(void) {
   static int i, j;
 }
diff --git a/clang/test/utils/update_cc_test_checks/Inputs/def-and-decl.c b/clang/test/utils/update_cc_test_checks/Inputs/def-and-decl.c
@@ -5,7 +5,7 @@ int foo(int arg);
 
 void empty_function(void);
 
-int main() {
+int main(void) {
   empty_function();
   return foo(1);
 }

diff --git a/clang/test/utils/update_cc_test_checks/Inputs/def-and-decl.c.expected b/clang/test/utils/update_cc_test_checks/Inputs/def-and-decl.c.expected
@@ -14,7 +14,7 @@ void empty_function(void);
 // CHECK-NEXT:    [[CALL:%.*]] = call i32 @foo(i32 noundef 1)
 // CHECK-NEXT:    ret i32 [[CALL]]
 //
-int main() {
+int main(void) {
   empty_function();
   return foo(1);
 }

diff --git a/clang/test/utils/update_cc_test_checks/Inputs/generated-funcs-regex.c b/clang/test/utils/update_cc_test_checks/Inputs/generated-funcs-regex.c
@@ -1,6 +1,6 @@
 // RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fopenmp %s -emit-llvm -o - | FileCheck %s
 
-void __test_offloading_42_abcdef_bar_l123();
+void __test_offloading_42_abcdef_bar_l123(void);
 void use(int);
 
 void foo(int a)

diff --git a/clang/test/utils/update_cc_test_checks/Inputs/generated-funcs-regex.c.expected b/clang/test/utils/update_cc_test_checks/Inputs/generated-funcs-regex.c.expected
@@ -1,7 +1,7 @@
 // NOTE: Assertions have been autogenerated by utils/update_cc_test_checks.py UTC_ARGS: --include-generated-funcs --replace-value-regex "__([a-z]+)_offloading_[a-z0-9]+_[a-z0-9]+_(.*)_l[0-9]+" "somevar_[a-z0-9]+_"
 // RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fopenmp %s -emit-llvm -o - | FileCheck %s
 
-void __test_offloading_42_abcdef_bar_l123();
+void __test_offloading_42_abcdef_bar_l123(void);
 void use(int);
 
 void foo(int a)
@@ -23,7 +23,7 @@ void foo(int a)
 // CHECK-NEXT:    store i32 [[TMP0]], i32* [[CONV]], align 4
 // CHECK-NEXT:    [[TMP1:%.*]] = load i64, i64* [[A_CASTED]], align 8
 // CHECK-NEXT:    call void @{{__omp_offloading_[a-z0-9]+_[a-z0-9]+_foo_l[0-9]+}}(i64 [[TMP1]]) #[[ATTR3:[0-9]+]]
-// CHECK-NEXT:    call void (...) @{{__test_offloading_[a-z0-9]+_[a-z0-9]+_bar_l[0-9]+}}()
+// CHECK-NEXT:    call void @{{__test_offloading_[a-z0-9]+_[a-z0-9]+_bar_l[0-9]+}}()
 // CHECK-NEXT:    ret void
 //
 //

diff --git a/clang/test/utils/update_cc_test_checks/Inputs/generated-funcs.c b/clang/test/utils/update_cc_test_checks/Inputs/generated-funcs.c
@@ -8,7 +8,7 @@ double A[size];
 
 void foo(void);
 
-int main() {
+int main(void) {
   int i = 0;
 
 #pragma omp parallel for

diff --git a/clang/test/utils/update_cc_test_checks/Inputs/generated-funcs.c.generated.expected b/clang/test/utils/update_cc_test_checks/Inputs/generated-funcs.c.generated.expected
@@ -9,7 +9,7 @@ double A[size];
 
 void foo(void);
 
-int main() {
+int main(void) {
   int i = 0;
 
 #pragma omp parallel for

diff --git a/clang/test/utils/update_cc_test_checks/Inputs/generated-funcs.c.no-generated.expected b/clang/test/utils/update_cc_test_checks/Inputs/generated-funcs.c.no-generated.expected
@@ -46,7 +46,7 @@ void foo(void);
 // NOOMP-NEXT:    call void @foo()
 // NOOMP-NEXT:    ret i32 0
 //
-int main() {
+int main(void) {
   int i = 0;
 
 #pragma omp parallel for

diff --git a/clang/test/utils/update_cc_test_checks/Inputs/global-hex-value-regex.c b/clang/test/utils/update_cc_test_checks/Inputs/global-hex-value-regex.c
@@ -1,10 +1,10 @@
 // RUN: %clang_cc1 -triple x86_64-pc-linux-gnu -emit-llvm -o - %s | FileCheck %s
 
-void foo() {
+void foo(void) {
   static int hex = 0x10;
   static int dec = 10;
 }
-void bar() {
+void bar(void) {
   static int hex = 0x20;
   static int dec = 20;
 }
diff --git a/clang/test/utils/update_cc_test_checks/Inputs/global-hex-value-regex.c.expected b/clang/test/utils/update_cc_test_checks/Inputs/global-hex-value-regex.c.expected
@@ -11,15 +11,15 @@
 // CHECK-NEXT:  entry:
 // CHECK-NEXT:    ret void
 //
-void foo() {
+void foo(void) {
   static int hex = 0x10;
   static int dec = 10;
 }
 // CHECK-LABEL: @bar(
 // CHECK-NEXT:  entry:
 // CHECK-NEXT:    ret void
 //
-void bar() {
+void bar(void) {
   static int hex = 0x20;
   static int dec = 20;
 }
diff --git a/clang/test/utils/update_cc_test_checks/Inputs/global-value-regex.c b/clang/test/utils/update_cc_test_checks/Inputs/global-value-regex.c
@@ -1,8 +1,8 @@
 // RUN: %clang_cc1 -triple x86_64-pc-linux-gnu -emit-llvm -o - %s | FileCheck %s
 
-void foo() {
+void foo(void) {
   static int i, j;
 }
-void bar() {
+void bar(void) {
   static int i, j;
 }
diff --git a/clang/test/utils/update_cc_test_checks/Inputs/global-value-regex.c.expected b/clang/test/utils/update_cc_test_checks/Inputs/global-value-regex.c.expected
@@ -9,13 +9,13 @@
 // CHECK-NEXT:  entry:
 // CHECK-NEXT:    ret void
 //
-void foo() {
+void foo(void) {
   static int i, j;
 }
 // CHECK-LABEL: @bar(
 // CHECK-NEXT:  entry:
 // CHECK-NEXT:    ret void
 //
-void bar() {
+void bar(void) {
   static int i, j;
 }
diff --git a/clang/test/utils/update_cc_test_checks/Inputs/on_the_fly_arg_change.c b/clang/test/utils/update_cc_test_checks/Inputs/on_the_fly_arg_change.c
@@ -1,12 +1,12 @@
 // RUN: %clang_cc1 -triple=x86_64-unknown-linux-gnu -emit-llvm -o - %s | FileCheck %s
 
-int checks_please() {
+int checks_please(void) {
   return 1;
 }
 
 // UTC_ARGS: --disable
 
-int no_checks_please() {
+int no_checks_please(void) {
   // Manual CHECK line should be retained:
   // CHECK: manual check line
   return -1;
@@ -15,6 +15,6 @@ int no_checks_please() {
 // UTC_ARGS: --enable
 
 
-int checks_again() {
+int checks_again(void) {
   return 2;
 }
diff --git a/clang/test/utils/update_cc_test_checks/Inputs/on_the_fly_arg_change.c.expected b/clang/test/utils/update_cc_test_checks/Inputs/on_the_fly_arg_change.c.expected
@@ -5,13 +5,13 @@
 // CHECK-NEXT:  entry:
 // CHECK-NEXT:    ret i32 1
 //
-int checks_please() {
+int checks_please(void) {
   return 1;
 }
 
 // UTC_ARGS: --disable
 
-int no_checks_please() {
+int no_checks_please(void) {
   // Manual CHECK line should be retained:
   // CHECK: manual check line
   return -1;
@@ -24,6 +24,6 @@ int no_checks_please() {
 // CHECK-NEXT:  entry:
 // CHECK-NEXT:    ret i32 2
 //
-int checks_again() {
+int checks_again(void) {
   return 2;
 }
diff --git a/clang/test/utils/update_cc_test_checks/check-globals.test b/clang/test/utils/update_cc_test_checks/check-globals.test
@@ -44,10 +44,10 @@ END.
  BOTH-NEXT:// RUN: true
  BOTH-NEXT:// RUN: %clang_cc1 -triple x86_64-pc-linux-gnu -emit-llvm -o - %s | FileCheck %s
 BOTH-EMPTY:
-  IGF-NEXT:void foo() {
+  IGF-NEXT:void foo(void) {
   IGF-NEXT:  static int i, j;
   IGF-NEXT:}
-  IGF-NEXT:void bar() {
+  IGF-NEXT:void bar(void) {
   IGF-NEXT:  static int i, j;
   IGF-NEXT:}
  BOTH-NEXT://.
@@ -60,15 +60,15 @@ BOTH-EMPTY:
  BOTH-NEXT:// CHECK-NEXT:  entry:
  BOTH-NEXT:// CHECK-NEXT:    ret void
  BOTH-NEXT://
-  NRM-NEXT:void foo() {
+  NRM-NEXT:void foo(void) {
   NRM-NEXT:  static int i, j;
   NRM-NEXT:}
   IGF-NEXT://
  BOTH-NEXT:// CHECK-LABEL: @bar(
  BOTH-NEXT:// CHECK-NEXT:  entry:
  BOTH-NEXT:// CHECK-NEXT:    ret void
  BOTH-NEXT://
-  NRM-NEXT:void bar() {
+  NRM-NEXT:void bar(void) {
   NRM-NEXT:  static int i, j;
   NRM-NEXT:}
  BOTH-NEXT://.
-Original file line number
+Diff line change
@@ Expand Up / @@ -4,7 +4,7 @@ @@
     @import not_real;
-    void foo() {
+    void foo(void) {
       bar();
     }
@@ Expand Down @@