gdb/testsuite: Explicitly return from main

I've been playing with a board file that forces every testcase to
include a header file that does something like:

  #define main __gdb_testcase_main

and then links an actual main() function that does some
initialization and then jumps to __gdb_testcase_main.

That runs into a number of testcases relying on main not having an
explicit return statement, like e.g.,:

 gdb/build/gdb/testsuite/../../../src/gdb/testsuite/gdb.base/catch-follow-exec.c:27:1: warning: non-void function does not return a value [-Wreturn-type]
 gdb/build/gdb/testsuite/../../../src/gdb/testsuite/gdb.base/catch-signal.c:47:1: warning: non-void function does not return a value [-Wreturn-type]

We don't get those warnings without my board because it is valid to
not explicitly return from main.  There's an implicit "return 0;".

Since it doesn't hurt to be explicit, I've went ahead and added the
explicit return statements.

Also, a couple testcases either don't explicitly specify main's return
type, or return void.  Those are tweaked to explicitly return int.

gdb/testsuite/ChangeLog:

	* gdb.base/catch-follow-exec.c (main): Add explicit return
	statement.
	* gdb.base/catch-signal.c (main): Likewise.
	* gdb.base/condbreak-call-false.c (main): Likewise.
	* gdb.base/consecutive.c (main): Add explicit return
	statement and return type.
	* gdb.base/cursal.c (main): Add explicit return statement.
	* gdb.base/cvexpr.c (main): Likewise.
	* gdb.base/display.c (main): Add explicit return statement and
	return type.
	* gdb.base/dprintf-detach.c (main): Add explicit return statement.
	* gdb.base/endianity.c (main): Likewise.
	* gdb.base/execd-prog.c (main): Likewise.
	* gdb.base/gdb1090.c (main): Likewise.
	* gdb.base/info_qt.c (main): Likewise.
	* gdb.base/lineinc.c (main): Likewise.
	* gdb.base/load-command.c (main): Likewise.
	* gdb.base/macscp1.c (main): Likewise.
	* gdb.base/pr10179-a.c (main): Likewise.
	* gdb.base/quit-live.c (main): Likewise.
	* gdb.base/scope0.c (main): Likewise.
	* gdb.base/settings.c (main): Likewise.
	* gdb.base/stack-checking.c (main): Return int.
	* gdb.base/varargs.c (main): Add explicit return statement.
	* gdb.cp/ambiguous.cc (main): Likewise.
	* gdb.cp/anon-struct.cc (main): Likewise.
	* gdb.cp/anon-union.cc (main): Likewise.
	* gdb.cp/bool.cc (main): Likewise.
	* gdb.cp/bs15503.cc (main): Likewise.
	* gdb.cp/cplusfuncs.cc (main): Likewise.
	* gdb.cp/cttiadd.cc (main): Likewise.
	* gdb.cp/extern-c.cc (main): Likewise.
	* gdb.cp/filename.cc (main): Likewise.
	* gdb.cp/formatted-ref.cc (main): Likewise.
	* gdb.cp/mb-ctor.cc (main): Likewise.
	* gdb.cp/member-ptr.cc (main): Likewise.
	* gdb.cp/minsym-fallback-main.cc (main): Likewise.
	* gdb.cp/overload-const.cc (main): Likewise.
	* gdb.cp/paren-type.cc (main): Likewise.
	* gdb.cp/parse-lang.cc (main): Likewise.
	* gdb.cp/pr-1023.cc (main): Likewise.
	* gdb.cp/psmang1.cc (main): Likewise.
	* gdb.cp/readnow-language.cc (main): Likewise.
	* gdb.cp/ref-params.cc (main): Likewise.
	* gdb.cp/rvalue-ref-params.cc (main): Likewise.
	* gdb.cp/virtbase2.cc (main): Likewise.
	* gdb.dwarf2/dw2-abs-hi-pc.c (main): Likewise.
	* gdb.dwarf2/dw2-namespaceless-anonymous.c (main): Likewise.
	* gdb.dwarf2/dw4-toplevel-types.cc (main): Likewise.
	* gdb.mi/mi-console.c (main): Likewise.
	* gdb.mi/mi-read-memory.c (main): Likewise.
	* gdb.modula2/multidim.c (main): Likewise.
	* gdb.opt/inline-small-func.c (main): Likewise.
	* gdb.python/py-rbreak.c (main): Likewise.
	* gdb.stabs/exclfwd1.c (main): Likewise.
	* gdb.trace/qtro.c (main): Likewise.

54 files changed, 154 insertions, 11 deletions

diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index 5c37401..230def4 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,5 +1,64 @@
 2020-09-13  Pedro Alves  <pedro@palves.net>
 
+	* gdb.base/catch-follow-exec.c (main): Add explicit return
+	statement.
+	* gdb.base/catch-signal.c (main): Likewise.
+	* gdb.base/condbreak-call-false.c (main): Likewise.
+	* gdb.base/consecutive.c (main): Add explicit return
+	statement and return type.
+	* gdb.base/cursal.c (main): Add explicit return statement.
+	* gdb.base/cvexpr.c (main): Likewise.
+	* gdb.base/display.c (main): Add explicit return statement and
+	return type.
+	* gdb.base/dprintf-detach.c (main): Add explicit return statement.
+	* gdb.base/endianity.c (main): Likewise.
+	* gdb.base/execd-prog.c (main): Likewise.
+	* gdb.base/gdb1090.c (main): Likewise.
+	* gdb.base/info_qt.c (main): Likewise.
+	* gdb.base/lineinc.c (main): Likewise.
+	* gdb.base/load-command.c (main): Likewise.
+	* gdb.base/macscp1.c (main): Likewise.
+	* gdb.base/pr10179-a.c (main): Likewise.
+	* gdb.base/quit-live.c (main): Likewise.
+	* gdb.base/scope0.c (main): Likewise.
+	* gdb.base/settings.c (main): Likewise.
+	* gdb.base/stack-checking.c (main): Return int.
+	* gdb.base/varargs.c (main): Add explicit return statement.
+	* gdb.cp/ambiguous.cc (main): Likewise.
+	* gdb.cp/anon-struct.cc (main): Likewise.
+	* gdb.cp/anon-union.cc (main): Likewise.
+	* gdb.cp/bool.cc (main): Likewise.
+	* gdb.cp/bs15503.cc (main): Likewise.
+	* gdb.cp/cplusfuncs.cc (main): Likewise.
+	* gdb.cp/cttiadd.cc (main): Likewise.
+	* gdb.cp/extern-c.cc (main): Likewise.
+	* gdb.cp/filename.cc (main): Likewise.
+	* gdb.cp/formatted-ref.cc (main): Likewise.
+	* gdb.cp/mb-ctor.cc (main): Likewise.
+	* gdb.cp/member-ptr.cc (main): Likewise.
+	* gdb.cp/minsym-fallback-main.cc (main): Likewise.
+	* gdb.cp/overload-const.cc (main): Likewise.
+	* gdb.cp/paren-type.cc (main): Likewise.
+	* gdb.cp/parse-lang.cc (main): Likewise.
+	* gdb.cp/pr-1023.cc (main): Likewise.
+	* gdb.cp/psmang1.cc (main): Likewise.
+	* gdb.cp/readnow-language.cc (main): Likewise.
+	* gdb.cp/ref-params.cc (main): Likewise.
+	* gdb.cp/rvalue-ref-params.cc (main): Likewise.
+	* gdb.cp/virtbase2.cc (main): Likewise.
+	* gdb.dwarf2/dw2-abs-hi-pc.c (main): Likewise.
+	* gdb.dwarf2/dw2-namespaceless-anonymous.c (main): Likewise.
+	* gdb.dwarf2/dw4-toplevel-types.cc (main): Likewise.
+	* gdb.mi/mi-console.c (main): Likewise.
+	* gdb.mi/mi-read-memory.c (main): Likewise.
+	* gdb.modula2/multidim.c (main): Likewise.
+	* gdb.opt/inline-small-func.c (main): Likewise.
+	* gdb.python/py-rbreak.c (main): Likewise.
+	* gdb.stabs/exclfwd1.c (main): Likewise.
+	* gdb.trace/qtro.c (main): Likewise.
+
+2020-09-13  Pedro Alves  <pedro@palves.net>
+
 	* gdb.base/share-env-with-gdbserver.c (main): Call my_getenv
 	instead of getenv.
 
diff --git a/gdb/testsuite/gdb.base/catch-follow-exec.c b/gdb/testsuite/gdb.base/catch-follow-exec.c
index 3168b02..1e33adc 100644
--- a/gdb/testsuite/gdb.base/catch-follow-exec.c
+++ b/gdb/testsuite/gdb.base/catch-follow-exec.c
@@ -24,4 +24,6 @@ main (void)
 {
   char *exec_args[] = { "/bin/ls", "ppp", NULL };
   execve (exec_args[0], exec_args, NULL);
+
+  return 0;
 }
diff --git a/gdb/testsuite/gdb.base/catch-signal.c b/gdb/testsuite/gdb.base/catch-signal.c
index ecec9fe..e6c6d56 100644
--- a/gdb/testsuite/gdb.base/catch-signal.c
+++ b/gdb/testsuite/gdb.base/catch-signal.c
@@ -44,5 +44,7 @@ main ()
   raise (SIGHUP);		/* fourth HUP */
 
   raise (SIGINT);		/* first INT */
+
+  return 0;
 }
 
diff --git a/gdb/testsuite/gdb.base/condbreak-call-false.c b/gdb/testsuite/gdb.base/condbreak-call-false.c
index 2d6112e..92e1164 100644
--- a/gdb/testsuite/gdb.base/condbreak-call-false.c
+++ b/gdb/testsuite/gdb.base/condbreak-call-false.c
@@ -36,4 +36,6 @@ main (void)
 {
   foo ();
   bar ();
+
+  return 0;
 }
diff --git a/gdb/testsuite/gdb.base/consecutive.c b/gdb/testsuite/gdb.base/consecutive.c
index 7d0cea9..869a88c 100644
--- a/gdb/testsuite/gdb.base/consecutive.c
+++ b/gdb/testsuite/gdb.base/consecutive.c
@@ -10,7 +10,9 @@ int foo ()
   return a[0] + a[1] + a[2] + a[3] + a[4] + a[5] + a[6];
 }
 
-main()
+int
+main ()
 {
   foo ();
+  return 0;
 }
diff --git a/gdb/testsuite/gdb.base/cursal.c b/gdb/testsuite/gdb.base/cursal.c
index 9e14982..3c3ba72 100644
--- a/gdb/testsuite/gdb.base/cursal.c
+++ b/gdb/testsuite/gdb.base/cursal.c
@@ -34,4 +34,6 @@ main ()
 {
   int v0 = 0;
   func1 ();
+
+  return 0;
 }
diff --git a/gdb/testsuite/gdb.base/cvexpr.c b/gdb/testsuite/gdb.base/cvexpr.c
index 042c331..9cfdd90 100644
--- a/gdb/testsuite/gdb.base/cvexpr.c
+++ b/gdb/testsuite/gdb.base/cvexpr.c
@@ -427,4 +427,6 @@ int main ()
 
   use (&v_float_func);
   use (&v_double_func);
+
+  return 0;
 }
diff --git a/gdb/testsuite/gdb.base/display.c b/gdb/testsuite/gdb.base/display.c
index cd833e2..67f205a 100644
--- a/gdb/testsuite/gdb.base/display.c
+++ b/gdb/testsuite/gdb.base/display.c
@@ -50,8 +50,10 @@ int do_vars()
     return *p_i;
 }
 
+int
 main()
 {
     do_loops();
     do_vars();    
+    return 0;
 }
diff --git a/gdb/testsuite/gdb.base/dprintf-detach.c b/gdb/testsuite/gdb.base/dprintf-detach.c
index 8b0fe3e..9728c87 100644
--- a/gdb/testsuite/gdb.base/dprintf-detach.c
+++ b/gdb/testsuite/gdb.base/dprintf-detach.c
@@ -30,4 +30,6 @@ main (void)
 
   for (i = 0; i < 30; i++)
     function ();
+
+  return 0;
 }
diff --git a/gdb/testsuite/gdb.base/endianity.c b/gdb/testsuite/gdb.base/endianity.c
index a376a58..ef3b6d4 100644
--- a/gdb/testsuite/gdb.base/endianity.c
+++ b/gdb/testsuite/gdb.base/endianity.c
@@ -46,4 +46,6 @@ main (void)
   struct otherendian o = {3, 2, 7, 23.5, 1.25 + 7.25i, 75};
 
   do_nothing (&o); /* START */
+
+  return 0;
 }
diff --git a/gdb/testsuite/gdb.base/execd-prog.c b/gdb/testsuite/gdb.base/execd-prog.c
index ac9928f..39cb210 100644
--- a/gdb/testsuite/gdb.base/execd-prog.c
+++ b/gdb/testsuite/gdb.base/execd-prog.c
@@ -25,4 +25,6 @@ int main (int argc, char **argv)
     }
   s = argv[1];
   printf ("argument received: %s\n", s);
+
+  return 0;
 }
diff --git a/gdb/testsuite/gdb.base/gdb1090.c b/gdb/testsuite/gdb.base/gdb1090.c
index 453f98f..cb8fb76 100644
--- a/gdb/testsuite/gdb.base/gdb1090.c
+++ b/gdb/testsuite/gdb.base/gdb1090.c
@@ -43,4 +43,6 @@ void foo ()
 int main ()
 {
   foo ();
+
+  return 0;
 }
diff --git a/gdb/testsuite/gdb.base/info_qt.c b/gdb/testsuite/gdb.base/info_qt.c
index 2a3893e..10c011d 100644
--- a/gdb/testsuite/gdb.base/info_qt.c
+++ b/gdb/testsuite/gdb.base/info_qt.c
@@ -75,4 +75,6 @@ main (int argc, char **argv, char **envp)
   (void) info_fun2bis ('b');
   (void) info_fun2xxx ('c', 1, 2);
   (void) info_fun2yyy ('d', 3, 4);
+
+  return 0;
 }
diff --git a/gdb/testsuite/gdb.base/lineinc.c b/gdb/testsuite/gdb.base/lineinc.c
index 91784e7..655ba54 100644
--- a/gdb/testsuite/gdb.base/lineinc.c
+++ b/gdb/testsuite/gdb.base/lineinc.c
@@ -27,4 +27,5 @@
 int
 main (int argc, char **argv)
 {
+  return 0;
 }
diff --git a/gdb/testsuite/gdb.base/load-command.c b/gdb/testsuite/gdb.base/load-command.c
index d185f27..15d6de3 100644
--- a/gdb/testsuite/gdb.base/load-command.c
+++ b/gdb/testsuite/gdb.base/load-command.c
@@ -19,4 +19,5 @@ int the_variable = 0x1234;
 
 int main ()
 {
+  return 0;
 }
diff --git a/gdb/testsuite/gdb.base/macscp1.c b/gdb/testsuite/gdb.base/macscp1.c
index 09a4c0d..a42666e 100644
--- a/gdb/testsuite/gdb.base/macscp1.c
+++ b/gdb/testsuite/gdb.base/macscp1.c
@@ -111,4 +111,6 @@ main (int argc, char **argv)
   macscp3_2 ();
   macscp1_3 ();
   macscp_expr ();
+
+  return 0;
 }
diff --git a/gdb/testsuite/gdb.base/pr10179-a.c b/gdb/testsuite/gdb.base/pr10179-a.c
index 584b1bc..1d67d07 100644
--- a/gdb/testsuite/gdb.base/pr10179-a.c
+++ b/gdb/testsuite/gdb.base/pr10179-a.c
@@ -17,4 +17,5 @@ bar1()
 int
 main()
 {
+  return 0;
 }
diff --git a/gdb/testsuite/gdb.base/quit-live.c b/gdb/testsuite/gdb.base/quit-live.c
index aa0a7a2..bbbef6e 100644
--- a/gdb/testsuite/gdb.base/quit-live.c
+++ b/gdb/testsuite/gdb.base/quit-live.c
@@ -24,4 +24,6 @@ main ()
 
   while (secs--)
     sleep (1);
+
+  return 0;
 }
diff --git a/gdb/testsuite/gdb.base/scope0.c b/gdb/testsuite/gdb.base/scope0.c
index e7f4724..3aad48d 100644
--- a/gdb/testsuite/gdb.base/scope0.c
+++ b/gdb/testsuite/gdb.base/scope0.c
@@ -24,6 +24,8 @@ int main ()
   foo ();
   autovars (5, 6);
   localscopes (0);
+
+  return 0;
 }
 
 /* On some systems, such as AIX, unreferenced variables are deleted
diff --git a/gdb/testsuite/gdb.base/settings.c b/gdb/testsuite/gdb.base/settings.c
index 204224e..e9eeb28 100644
--- a/gdb/testsuite/gdb.base/settings.c
+++ b/gdb/testsuite/gdb.base/settings.c
@@ -20,4 +20,5 @@ int xxx1= 123;
 int
 main ()
 {
+  return 0;
 }
diff --git a/gdb/testsuite/gdb.base/stack-checking.c b/gdb/testsuite/gdb.base/stack-checking.c
index e11b5c4..772ce90 100644
--- a/gdb/testsuite/gdb.base/stack-checking.c
+++ b/gdb/testsuite/gdb.base/stack-checking.c
@@ -40,10 +40,11 @@ void big_frame ()
   small_frame ();
 }
 
-void
+int
 main ()
 {
   small_frame ();
   medium_frame ();
   big_frame ();
+  return 0;
 }
diff --git a/gdb/testsuite/gdb.base/varargs.c b/gdb/testsuite/gdb.base/varargs.c
index 4c0f165..cacb29d 100644
--- a/gdb/testsuite/gdb.base/varargs.c
+++ b/gdb/testsuite/gdb.base/varargs.c
@@ -79,6 +79,8 @@ main (void)
 {
   gdb_unbuffer_output ();
   test ();
+
+  return 0;
 }
 
 /* Integer varargs, 1 declared arg */
diff --git a/gdb/testsuite/gdb.cp/ambiguous.cc b/gdb/testsuite/gdb.cp/ambiguous.cc
index 6ee7bc1..93fba1c 100644
--- a/gdb/testsuite/gdb.cp/ambiguous.cc
+++ b/gdb/testsuite/gdb.cp/ambiguous.cc
@@ -103,8 +103,6 @@ int main()
   i += k.i + m.w + a1.x + a2.x + a3.x + x.z + l.z + n.r + j.j;
 
   marker1();
-  
-}
-
 
-  
+  return 0;
+}
diff --git a/gdb/testsuite/gdb.cp/anon-struct.cc b/gdb/testsuite/gdb.cp/anon-struct.cc
index 5bcfaf2..0460425 100644
--- a/gdb/testsuite/gdb.cp/anon-struct.cc
+++ b/gdb/testsuite/gdb.cp/anon-struct.cc
@@ -54,4 +54,5 @@ t3 v3;
 
 int main()
 {
+  return 0;
 }
diff --git a/gdb/testsuite/gdb.cp/anon-union.cc b/gdb/testsuite/gdb.cp/anon-union.cc
index fa75251..2a2a1c5 100644
--- a/gdb/testsuite/gdb.cp/anon-union.cc
+++ b/gdb/testsuite/gdb.cp/anon-union.cc
@@ -53,4 +53,6 @@ int main()
   w = 45;
 
   int j = 0;
+
+  return 0;
 }
diff --git a/gdb/testsuite/gdb.cp/bool.cc b/gdb/testsuite/gdb.cp/bool.cc
index c6860a4..9144380 100644
--- a/gdb/testsuite/gdb.cp/bool.cc
+++ b/gdb/testsuite/gdb.cp/bool.cc
@@ -34,4 +34,6 @@ main ()
 {
   return_true ();
   return_false ();
+
+  return 0;
 }
diff --git a/gdb/testsuite/gdb.cp/bs15503.cc b/gdb/testsuite/gdb.cp/bs15503.cc
index dae0479..4a13578 100644
--- a/gdb/testsuite/gdb.cp/bs15503.cc
+++ b/gdb/testsuite/gdb.cp/bs15503.cc
@@ -59,6 +59,8 @@ void StringTest <T>::testFunction() {
 int main() {
    StringTest<wchar_t> ts;
    ts.runTest();
+
+   return 0;
 }
 
 /* output:
diff --git a/gdb/testsuite/gdb.cp/cplusfuncs.cc b/gdb/testsuite/gdb.cp/cplusfuncs.cc
index 021d7c1..7d2e274 100644
--- a/gdb/testsuite/gdb.cp/cplusfuncs.cc
+++ b/gdb/testsuite/gdb.cp/cplusfuncs.cc
@@ -60,6 +60,8 @@ public:
 
 int main () {
    int z=3;
+
+   return 0;
 }
 
 foo::foo  (int i)                  { ifoo = i;}
diff --git a/gdb/testsuite/gdb.cp/cttiadd.cc b/gdb/testsuite/gdb.cp/cttiadd.cc
index c728766..0d417c7 100644
--- a/gdb/testsuite/gdb.cp/cttiadd.cc
+++ b/gdb/testsuite/gdb.cp/cttiadd.cc
@@ -44,4 +44,6 @@ int main()
   add1();
   subr2();
   subr3();
+
+  return 0;
 }
diff --git a/gdb/testsuite/gdb.cp/extern-c.cc b/gdb/testsuite/gdb.cp/extern-c.cc
index 2260d71..b03d53d 100644
--- a/gdb/testsuite/gdb.cp/extern-c.cc
+++ b/gdb/testsuite/gdb.cp/extern-c.cc
@@ -35,4 +35,6 @@ int main()
   c_func ();
   c_funcs_1 ();
   c_funcs_2 ();
+
+  return 0;
 }
diff --git a/gdb/testsuite/gdb.cp/filename.cc b/gdb/testsuite/gdb.cp/filename.cc
index 30aca72..834d4ea 100644
--- a/gdb/testsuite/gdb.cp/filename.cc
+++ b/gdb/testsuite/gdb.cp/filename.cc
@@ -52,5 +52,5 @@ int main() {
   D* pd = &d;
   d.m();
 
-  /* stop outside */
+  return 0; /* stop outside */
 }
diff --git a/gdb/testsuite/gdb.cp/formatted-ref.cc b/gdb/testsuite/gdb.cp/formatted-ref.cc
index 7f1cb37..343293e 100644
--- a/gdb/testsuite/gdb.cp/formatted-ref.cc
+++ b/gdb/testsuite/gdb.cp/formatted-ref.cc
@@ -40,4 +40,5 @@ int main(void)
 
   f1 (s1, e1, i1);
 
+  return 0;
 }
diff --git a/gdb/testsuite/gdb.cp/mb-ctor.cc b/gdb/testsuite/gdb.cp/mb-ctor.cc
index c299260..c54b4fe 100644
--- a/gdb/testsuite/gdb.cp/mb-ctor.cc
+++ b/gdb/testsuite/gdb.cp/mb-ctor.cc
@@ -63,4 +63,6 @@ int main()
      Derived. Base is constructed separately by
      DeeplyDerived's ctor.  */
   DeeplyDerived dd(15);
+
+  return 0;
 }
diff --git a/gdb/testsuite/gdb.cp/member-ptr.cc b/gdb/testsuite/gdb.cp/member-ptr.cc
index a3780de..31ded58 100644
--- a/gdb/testsuite/gdb.cp/member-ptr.cc
+++ b/gdb/testsuite/gdb.cp/member-ptr.cc
@@ -230,4 +230,5 @@ int main ()
 
   k += b.s;
   
+  return 0;
 }
diff --git a/gdb/testsuite/gdb.cp/minsym-fallback-main.cc b/gdb/testsuite/gdb.cp/minsym-fallback-main.cc
index 628fe78..8263588 100644
--- a/gdb/testsuite/gdb.cp/minsym-fallback-main.cc
+++ b/gdb/testsuite/gdb.cp/minsym-fallback-main.cc
@@ -24,4 +24,6 @@ main ()
 {
   c.f ();
   c ();
+
+  return 0;
 }
diff --git a/gdb/testsuite/gdb.cp/overload-const.cc b/gdb/testsuite/gdb.cp/overload-const.cc
index 255ed81..16c5f38 100644
--- a/gdb/testsuite/gdb.cp/overload-const.cc
+++ b/gdb/testsuite/gdb.cp/overload-const.cc
@@ -25,4 +25,6 @@ int
 main ()
 {
   myclass::func (42);
+
+  return 0;
 }
diff --git a/gdb/testsuite/gdb.cp/paren-type.cc b/gdb/testsuite/gdb.cp/paren-type.cc
index 226d003..179bb10 100644
--- a/gdb/testsuite/gdb.cp/paren-type.cc
+++ b/gdb/testsuite/gdb.cp/paren-type.cc
@@ -30,4 +30,6 @@ int
 main ()
 {
   C::f(1);
+
+  return 0;
 }
diff --git a/gdb/testsuite/gdb.cp/parse-lang.cc b/gdb/testsuite/gdb.cp/parse-lang.cc
index 50db4ac..14ecf57 100644
--- a/gdb/testsuite/gdb.cp/parse-lang.cc
+++ b/gdb/testsuite/gdb.cp/parse-lang.cc
@@ -37,4 +37,6 @@ main ()
 
   c.m ();
   marker ();
+
+  return 0;
 }
diff --git a/gdb/testsuite/gdb.cp/pr-1023.cc b/gdb/testsuite/gdb.cp/pr-1023.cc
index 7583084..156f486 100644
--- a/gdb/testsuite/gdb.cp/pr-1023.cc
+++ b/gdb/testsuite/gdb.cp/pr-1023.cc
@@ -16,5 +16,6 @@ int main ()
   myClass mc;
   mc.performBlocking (0);
   mc.performUnblocking (0);
-}
 
+  return 0;
+}
diff --git a/gdb/testsuite/gdb.cp/psmang1.cc b/gdb/testsuite/gdb.cp/psmang1.cc
index 12d120f..088f32d 100644
--- a/gdb/testsuite/gdb.cp/psmang1.cc
+++ b/gdb/testsuite/gdb.cp/psmang1.cc
@@ -37,6 +37,8 @@ main (int argc, char **argv)
 
   si.method1 ();
   si.method2 ();
+
+  return 0;
 }
 
 
diff --git a/gdb/testsuite/gdb.cp/readnow-language.cc b/gdb/testsuite/gdb.cp/readnow-language.cc
index fcd7958..72f039a 100644
--- a/gdb/testsuite/gdb.cp/readnow-language.cc
+++ b/gdb/testsuite/gdb.cp/readnow-language.cc
@@ -18,4 +18,5 @@
 int
 main ()
 {
+  return 0;
 }
diff --git a/gdb/testsuite/gdb.cp/ref-params.cc b/gdb/testsuite/gdb.cp/ref-params.cc
index 5948001..e68418e 100644
--- a/gdb/testsuite/gdb.cp/ref-params.cc
+++ b/gdb/testsuite/gdb.cp/ref-params.cc
@@ -69,4 +69,6 @@ int main(void)
   MultiChild& MQR = MQ;
 
   mf2(MQ);			/* Set breakpoint MQ here.  */
+
+  return 0;
 }
diff --git a/gdb/testsuite/gdb.cp/rvalue-ref-params.cc b/gdb/testsuite/gdb.cp/rvalue-ref-params.cc
index b23afbf..62caed9 100644
--- a/gdb/testsuite/gdb.cp/rvalue-ref-params.cc
+++ b/gdb/testsuite/gdb.cp/rvalue-ref-params.cc
@@ -80,4 +80,6 @@ main ()
   MultiChild &MQR = MQ;
 
   mf2 (std::move (MQ));			/* Set breakpoint MQ here.  */
+
+  return 0;
 }
diff --git a/gdb/testsuite/gdb.cp/virtbase2.cc b/gdb/testsuite/gdb.cp/virtbase2.cc
index 058484f..62f4d86 100644
--- a/gdb/testsuite/gdb.cp/virtbase2.cc
+++ b/gdb/testsuite/gdb.cp/virtbase2.cc
@@ -46,4 +46,6 @@ int main()
 {
   derived().func_d();
   foo().func_f();
+
+  return 0;
 }
diff --git a/gdb/testsuite/gdb.dwarf2/dw2-abs-hi-pc.c b/gdb/testsuite/gdb.dwarf2/dw2-abs-hi-pc.c
index 9994ed5..4f0b81f 100644
--- a/gdb/testsuite/gdb.dwarf2/dw2-abs-hi-pc.c
+++ b/gdb/testsuite/gdb.dwarf2/dw2-abs-hi-pc.c
@@ -25,4 +25,6 @@ main (void)
 {
   hello ();
   world ();
+
+  return 0;
 }
diff --git a/gdb/testsuite/gdb.dwarf2/dw2-namespaceless-anonymous.c b/gdb/testsuite/gdb.dwarf2/dw2-namespaceless-anonymous.c
index 3c5e258..3d6b4a4 100644
--- a/gdb/testsuite/gdb.dwarf2/dw2-namespaceless-anonymous.c
+++ b/gdb/testsuite/gdb.dwarf2/dw2-namespaceless-anonymous.c
@@ -19,4 +19,5 @@ char _ZN12_GLOBAL__N_11vE = 1;
 
 int main ()
 {
+  return 0;
 }
diff --git a/gdb/testsuite/gdb.dwarf2/dw4-toplevel-types.cc b/gdb/testsuite/gdb.dwarf2/dw4-toplevel-types.cc
index c47598c..da8e90b 100644
--- a/gdb/testsuite/gdb.dwarf2/dw4-toplevel-types.cc
+++ b/gdb/testsuite/gdb.dwarf2/dw4-toplevel-types.cc
@@ -18,4 +18,4 @@
 struct X {} x;
 struct Y {} y;
 struct Z {} z;
-int main() {}
+int main() { return 0; }
diff --git a/gdb/testsuite/gdb.mi/mi-console.c b/gdb/testsuite/gdb.mi/mi-console.c
index 5ca046f..ba63454 100644
--- a/gdb/testsuite/gdb.mi/mi-console.c
+++ b/gdb/testsuite/gdb.mi/mi-console.c
@@ -13,4 +13,6 @@ int
 main ()
 {
   hello ();
-} /* after-hello */
+
+  return 0;  /* after-hello */
+}
diff --git a/gdb/testsuite/gdb.mi/mi-read-memory.c b/gdb/testsuite/gdb.mi/mi-read-memory.c
index 7a87c64..27ae25e 100644
--- a/gdb/testsuite/gdb.mi/mi-read-memory.c
+++ b/gdb/testsuite/gdb.mi/mi-read-memory.c
@@ -17,4 +17,5 @@ int
 main ()
 {
   initialize ();
+  return 0;
 }
diff --git a/gdb/testsuite/gdb.modula2/multidim.c b/gdb/testsuite/gdb.modula2/multidim.c
index b0ce848..e6c7934 100644
--- a/gdb/testsuite/gdb.modula2/multidim.c
+++ b/gdb/testsuite/gdb.modula2/multidim.c
@@ -36,4 +36,6 @@ main ()
 	count += 1;
       }
   here ();
+
+  return 0;
 }
diff --git a/gdb/testsuite/gdb.opt/inline-small-func.c b/gdb/testsuite/gdb.opt/inline-small-func.c
index 902674e..bd79c3a 100644
--- a/gdb/testsuite/gdb.opt/inline-small-func.c
+++ b/gdb/testsuite/gdb.opt/inline-small-func.c
@@ -19,4 +19,5 @@ int
 main ()
 {		/* caller: before call.  */
   callee ();	/* caller: the call.  */
-}		/* caller: after call.  */
+  return 0;	/* caller: after call.  */
+}
diff --git a/gdb/testsuite/gdb.python/py-rbreak.c b/gdb/testsuite/gdb.python/py-rbreak.c
index 1e02a42..da28cff 100644
--- a/gdb/testsuite/gdb.python/py-rbreak.c
+++ b/gdb/testsuite/gdb.python/py-rbreak.c
@@ -67,4 +67,6 @@ main()
   func5 ();
   func6 ();
   outside_scope ();
+
+  return 0;
 }
diff --git a/gdb/testsuite/gdb.stabs/exclfwd1.c b/gdb/testsuite/gdb.stabs/exclfwd1.c
index a0642d0..ef53601 100644
--- a/gdb/testsuite/gdb.stabs/exclfwd1.c
+++ b/gdb/testsuite/gdb.stabs/exclfwd1.c
@@ -30,4 +30,5 @@ a_t v1;
 int
 main ()
 {
+  return 0;
 }
diff --git a/gdb/testsuite/gdb.trace/qtro.c b/gdb/testsuite/gdb.trace/qtro.c
index f9d7ea5..0c95f7c 100644
--- a/gdb/testsuite/gdb.trace/qtro.c
+++ b/gdb/testsuite/gdb.trace/qtro.c
@@ -30,4 +30,6 @@ main ()
 {
   subr (1);
   end ();
+
+  return 0;
 }