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.

gdb/testsuite/ChangeLog

@@ -1,3 +1,62 @@
+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

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;
 }

gdb/testsuite/gdb.base/catch-signal.c

@@ -44,5 +44,7 @@ main ()
   raise (SIGHUP);		/* fourth HUP */
 
   raise (SIGINT);		/* first INT */
+
+  return 0;
 }
 

gdb/testsuite/gdb.base/condbreak-call-false.c

@@ -36,4 +36,6 @@ main (void)
 {
   foo ();
   bar ();
+
+  return 0;
 }

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;
 }

gdb/testsuite/gdb.base/cursal.c

@@ -34,4 +34,6 @@ main ()
 {
   int v0 = 0;
   func1 ();
+
+  return 0;
 }

gdb/testsuite/gdb.base/cvexpr.c

@@ -427,4 +427,6 @@ int main ()
 
   use (&v_float_func);
   use (&v_double_func);
+
+  return 0;
 }

gdb/testsuite/gdb.base/display.c

@@ -50,8 +50,10 @@ int do_vars()
     return *p_i;
 }
 
+int
 main()
 {
     do_loops();
     do_vars();    
+    return 0;
 }

gdb/testsuite/gdb.base/dprintf-detach.c

@@ -30,4 +30,6 @@ main (void)
 
   for (i = 0; i < 30; i++)
     function ();
+
+  return 0;
 }

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;
 }

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;
 }

gdb/testsuite/gdb.base/gdb1090.c

@@ -43,4 +43,6 @@ void foo ()
 int main ()
 {
   foo ();
+
+  return 0;
 }

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;
 }

gdb/testsuite/gdb.base/lineinc.c

@@ -27,4 +27,5 @@
 int
 main (int argc, char **argv)
 {
+  return 0;
 }

gdb/testsuite/gdb.base/load-command.c

@@ -19,4 +19,5 @@ int the_variable = 0x1234;
 
 int main ()
 {
+  return 0;
 }

gdb/testsuite/gdb.base/macscp1.c

@@ -111,4 +111,6 @@ main (int argc, char **argv)
   macscp3_2 ();
   macscp1_3 ();
   macscp_expr ();
+
+  return 0;
 }

gdb/testsuite/gdb.base/pr10179-a.c

@@ -17,4 +17,5 @@ bar1()
 int
 main()
 {
+  return 0;
 }

gdb/testsuite/gdb.base/quit-live.c

@@ -24,4 +24,6 @@ main ()
 
   while (secs--)
     sleep (1);
+
+  return 0;
 }

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

gdb/testsuite/gdb.base/settings.c

@@ -20,4 +20,5 @@ int xxx1= 123;
 int
 main ()
 {
+  return 0;
 }

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;
 }

gdb/testsuite/gdb.base/varargs.c

@@ -79,6 +79,8 @@ main (void)
 {
   gdb_unbuffer_output ();
   test ();
+
+  return 0;
 }
 
 /* Integer varargs, 1 declared arg */

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;
 }
-
-
-  

gdb/testsuite/gdb.cp/anon-struct.cc

@@ -54,4 +54,5 @@ t3 v3;
 
 int main()
 {
+  return 0;
 }

gdb/testsuite/gdb.cp/anon-union.cc

@@ -53,4 +53,6 @@ int main()
   w = 45;
 
   int j = 0;
+
+  return 0;
 }

gdb/testsuite/gdb.cp/bool.cc

@@ -34,4 +34,6 @@ main ()
 {
   return_true ();
   return_false ();
+
+  return 0;
 }

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:

gdb/testsuite/gdb.cp/cplusfuncs.cc

@@ -60,6 +60,8 @@ public:
 
 int main () {
    int z=3;
+
+   return 0;
 }
 
 foo::foo  (int i)                  { ifoo = i;}

gdb/testsuite/gdb.cp/cttiadd.cc

@@ -44,4 +44,6 @@ int main()
   add1();
   subr2();
   subr3();
+
+  return 0;
 }

gdb/testsuite/gdb.cp/extern-c.cc

@@ -35,4 +35,6 @@ int main()
   c_func ();
   c_funcs_1 ();
   c_funcs_2 ();
+
+  return 0;
 }

gdb/testsuite/gdb.cp/filename.cc

@@ -52,5 +52,5 @@ int main() {
   D* pd = &d;
   d.m();
 
-  /* stop outside */
+  return 0; /* stop outside */
 }

gdb/testsuite/gdb.cp/formatted-ref.cc

@@ -40,4 +40,5 @@ int main(void)
 
   f1 (s1, e1, i1);
 
+  return 0;
 }

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;
 }

gdb/testsuite/gdb.cp/member-ptr.cc

@@ -230,4 +230,5 @@ int main ()
 
   k += b.s;
   
+  return 0;
 }

gdb/testsuite/gdb.cp/minsym-fallback-main.cc

@@ -24,4 +24,6 @@ main ()
 {
   c.f ();
   c ();
+
+  return 0;
 }

gdb/testsuite/gdb.cp/overload-const.cc

@@ -25,4 +25,6 @@ int
 main ()
 {
   myclass::func (42);
+
+  return 0;
 }

gdb/testsuite/gdb.cp/paren-type.cc

@@ -30,4 +30,6 @@ int
 main ()
 {
   C::f(1);
+
+  return 0;
 }

gdb/testsuite/gdb.cp/parse-lang.cc

@@ -37,4 +37,6 @@ main ()
 
   c.m ();
   marker ();
+
+  return 0;
 }

gdb/testsuite/gdb.cp/pr-1023.cc

@@ -16,5 +16,6 @@ int main ()
   myClass mc;
   mc.performBlocking (0);
   mc.performUnblocking (0);
-}
 
+  return 0;
+}

gdb/testsuite/gdb.cp/psmang1.cc

@@ -37,6 +37,8 @@ main (int argc, char **argv)
 
   si.method1 ();
   si.method2 ();
+
+  return 0;
 }
 
 

gdb/testsuite/gdb.cp/readnow-language.cc

@@ -18,4 +18,5 @@
 int
 main ()
 {
+  return 0;
 }

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;
 }

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;
 }

gdb/testsuite/gdb.cp/virtbase2.cc

@@ -46,4 +46,6 @@ int main()
 {
   derived().func_d();
   foo().func_f();
+
+  return 0;
 }

gdb/testsuite/gdb.dwarf2/dw2-abs-hi-pc.c

@@ -25,4 +25,6 @@ main (void)
 {
   hello ();
   world ();
+
+  return 0;
 }

gdb/testsuite/gdb.dwarf2/dw2-namespaceless-anonymous.c

@@ -19,4 +19,5 @@ char _ZN12_GLOBAL__N_11vE = 1;
 
 int main ()
 {
+  return 0;
 }

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; }

gdb/testsuite/gdb.mi/mi-console.c

@@ -13,4 +13,6 @@ int
 main ()
 {
   hello ();
-} /* after-hello */
+
+  return 0;  /* after-hello */
+}

gdb/testsuite/gdb.mi/mi-read-memory.c

@@ -17,4 +17,5 @@ int
 main ()
 {
   initialize ();
+  return 0;
 }

gdb/testsuite/gdb.modula2/multidim.c

@@ -36,4 +36,6 @@ main ()
 	count += 1;
       }
   here ();
+
+  return 0;
 }

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.  */
+}

gdb/testsuite/gdb.python/py-rbreak.c

@@ -67,4 +67,6 @@ main()
   func5 ();
   func6 ();
   outside_scope ();
+
+  return 0;
 }

gdb/testsuite/gdb.stabs/exclfwd1.c

@@ -30,4 +30,5 @@ a_t v1;
 int
 main ()
 {
+  return 0;
 }

gdb/testsuite/gdb.trace/qtro.c

@@ -30,4 +30,6 @@ main ()
 {
   subr (1);
   end ();
+
+  return 0;
 }