Enable -Wmissing-declarations in development mode.

* m4/gccwarn.m4: Add -Wmissing-declarations.
* iface/ltsmin/ltsmin.cc, iface/ltsmin/modelcheck.cc,
src/bin/common_trans.cc, src/bin/genltl.cc, src/bin/ltlgrind.cc,
src/tests/acc.cc, src/tests/bitvect.cc, src/tests/checkpsl.cc,
src/tests/checkta.cc, src/tests/complementation.cc,
src/tests/consterm.cc, src/tests/emptchk.cc, src/tests/equalsf.cc,
src/tests/graph.cc, src/tests/ikwiad.cc, src/tests/intvcmp2.cc,
src/tests/intvcomp.cc, src/tests/kind.cc, src/tests/length.cc,
src/tests/ltlprod.cc, src/tests/ltlrel.cc, src/tests/ngraph.cc,
src/tests/randtgba.cc, src/tests/readltl.cc, src/tests/reduc.cc,
src/tests/syntimpl.cc, src/tests/tostring.cc, src/tests/twagraph.cc,
src/tl/contain.cc, src/twaalgos/dtgbacomp.cc, src/twaalgos/minimize.cc:
Add "static" and move in anonymous namespace when appropriate.

iface/ltsmin/ltsmin.cc

@@ -943,16 +943,14 @@ namespace spot
       mutable callback_context* state_condition_last_cc_;
     };
 
-  }
 
-
+    //////////////////////////////////////////////////////////////////////////
-  ////////////////////////////////////////////////////////////////////////////
     // LOADER
 
 
     // Call spins to compile "foo.prom" as "foo.prom.spins" if the latter
     // does not exist already or is older.
-  bool
+    static bool
     compile_model(std::string& filename, std::string& ext, bool verbose)
     {
       std::string command;
@@ -972,8 +970,8 @@ namespace spot
 	{
 	  if (verbose)
 	    std::cerr << "Unknown extension `" << ext
-		    << "'.  Use `.prom', `.pm', `.pml', `.dve', `.dve2C' or"\
+		      << ("'.  Use `.prom', `.pm', `.pml', `.dve', `.dve2C' or"
-                    "`.prom.spins'." << std::endl;
+			  "`.prom.spins'.") << std::endl;
 	  return false;
 	}
 
@@ -1014,6 +1012,8 @@ namespace spot
       return false;
     }
 
+  }
+
   kripke_ptr
   load_ltsmin(const std::string& file_arg, const bdd_dict_ptr& dict,
 	      const atomic_prop_set* to_observe,

iface/ltsmin/modelcheck.cc

@@ -60,7 +60,7 @@ Options:\n\
   exit(1);
 }
 
-int
+static int
 checked_main(int argc, char **argv)
 {
   spot::timer_map tm;

m4/gccwarn.m4

@@ -32,7 +32,8 @@ EOF
    Wpointer-arith \
    Wwrite-strings \
    Wcast-qual \
-   Wdocumentation
+   Wdocumentation \
+   Wmissing-declarations
   do
     CXXFLAGS="$cf_save_CXXFLAGS $ac_cv_prog_gxx_warn_flags -$cf_opt"
     if AC_TRY_EVAL(ac_compile); then

src/bin/common_trans.cc

@@ -48,7 +48,7 @@ static struct shorthands_t
     { "spin", " -f %s>%O" },
   };
 
-void show_shorthands()
+static void show_shorthands()
 {
   std::cout
     << ("If a COMMANDFMT does not use any %-sequence, and starts with one of\n"

src/bin/genltl.cc

@@ -321,7 +321,8 @@ phi_n(std::string name, int n)
   return result;
 }
 
-formula N_n(std::string name, int n)
+static formula
+N_n(std::string name, int n)
 {
   return formula::F(phi_n(name, n));
 }

src/bin/ltlgrind.cc

@@ -108,7 +108,7 @@ namespace
   };
 }
 
-int
+static int
 parse_opt(int key, char* arg, struct argp_state*)
 {
   switch (key)

src/tests/acc.cc

@@ -24,7 +24,7 @@
 #include <cstdlib>
 #include "twa/acc.hh"
 
-void check(spot::acc_cond& ac, spot::acc_cond::mark_t m)
+static void check(spot::acc_cond& ac, spot::acc_cond::mark_t m)
 {
   std::cout << '#' << m.count() << ": " << ac.format(m);
   if (!m)
@@ -34,7 +34,7 @@ void check(spot::acc_cond& ac, spot::acc_cond::mark_t m)
   std::cout << '\n';
 }
 
-void print(const std::vector<std::vector<int>>& res)
+static void print(const std::vector<std::vector<int>>& res)
 {
   for (auto& v: res)
     {

src/tests/bitvect.cc

@@ -20,7 +20,7 @@
 #include <iostream>
 #include "misc/bitvect.hh"
 
-void ruler()
+static void ruler()
 {
   std::cout << "\n   ";
   for (size_t x = 0; x < 76; ++x)

src/tests/checkpsl.cc

@@ -29,7 +29,7 @@
 #include "twaalgos/product.hh"
 #include "twaalgos/dot.hh"
 
-void
+static void
 syntax(char* prog)
 {
   std::cerr << prog << " file" << std::endl;

src/tests/checkta.cc

@@ -33,14 +33,15 @@
 #include "taalgos/dot.hh"
 #include "taalgos/stats.hh"
 
-void
+static void
 syntax(char* prog)
 {
   std::cerr << prog << " file" << std::endl;
   exit(2);
 }
 
-void stats(std::string title, const spot::ta_ptr& ta)
+static void
+stats(std::string title, const spot::ta_ptr& ta)
 {
   auto s = stats_reachable(ta);
 
@@ -50,7 +51,8 @@ void stats(std::string title, const spot::ta_ptr& ta)
 	    << std::setw(6) << s.acceptance_states << '\n';
 }
 
-void stats(std::string title, const spot::twa_ptr& tg)
+static void
+stats(std::string title, const spot::twa_ptr& tg)
 {
   auto s = stats_reachable(tg);
 

src/tests/complementation.cc

@@ -34,7 +34,7 @@
 
 #include "twa/twasafracomplement.hh"
 
-void usage(const char* prog)
+static void usage(const char* prog)
 {
   std::cout << "usage: " << prog << " [options]" << std::endl;
   std::cout << "with options" << std::endl

src/tests/consterm.cc

@@ -24,7 +24,7 @@
 #include <cstdlib>
 #include "tl/parse.hh"
 
-void
+static void
 syntax(char *prog)
 {
   std::cerr << prog << " formula" << std::endl;

src/tests/emptchk.cc

@@ -32,7 +32,7 @@
 #include "twaalgos/dot.hh"
 #include "twaalgos/emptiness.hh"
 
-void
+static void
 syntax(char* prog)
 {
   std::cerr << prog << " file" << std::endl;

src/tests/equalsf.cc

@@ -32,7 +32,7 @@
 #include "tl/simplify.hh"
 #include "tl/print.hh"
 
-void
+static void
 syntax(char* prog)
 {
   std::cerr << prog << " [-E] file" << std::endl;

src/tests/graph.cc

@@ -70,7 +70,8 @@ dot(std::ostream& out, spot::digraph<SL, TL>& g)
 }
 
 
-bool g1(const spot::digraph<void, void>& g,
+static bool
+g1(const spot::digraph<void, void>& g,
    unsigned s, int e)
 {
   int f = 0;
@@ -82,7 +83,8 @@ bool g1(const spot::digraph<void, void>& g,
   return f == e;
 }
 
-bool f1()
+static bool
+f1()
 {
   spot::digraph<void, void> g(3);
 
@@ -111,7 +113,8 @@ bool f1()
 }
 
 
-bool f2()
+static bool
+f2()
 {
   spot::digraph<int, void> g(3);
 
@@ -133,7 +136,8 @@ bool f2()
   return f == 5;
 }
 
-bool f3()
+static bool
+f3()
 {
   spot::digraph<void, int> g(3);
 
@@ -155,7 +159,8 @@ bool f3()
   return f == 3 && g.states().size() == 3;
 }
 
-bool f4()
+static bool
+f4()
 {
   spot::digraph<int, int> g(3);
 
@@ -177,7 +182,8 @@ bool f4()
   return f == 11;
 }
 
-bool f5()
+static bool
+f5()
 {
   spot::digraph<void, std::pair<int, float>> g(3);
 
@@ -199,7 +205,8 @@ bool f5()
   return f == 3 && (h > 2.49 && h < 2.51);
 }
 
-bool f6()
+static bool
+f6()
 {
   spot::digraph<void, std::pair<int, float>> g(3);
 
@@ -221,7 +228,8 @@ bool f6()
   return f == 3 && (h > 2.49 && h < 2.51);
 }
 
-bool f7()
+static bool
+f7()
 {
   spot::digraph<int, int, true> g(3);
   auto s1 = g.new_state(2);
@@ -267,7 +275,8 @@ struct int_pair
 #endif
 };
 
-bool f8()
+static bool
+f8()
 {
   spot::digraph<int_pair, int_pair> g(3);
   auto s1 = g.new_state(2, 4);

src/tests/ikwiad.cc

@@ -71,25 +71,7 @@
 #include "taalgos/dot.hh"
 #include "taalgos/stats.hh"
 
-std::string
+static void
-ltl_defs()
-{
-  std::string s = "\
-X=(0 1 true	   \
-   1 2 $0	   \
-   accept 2)	   \
-U=(0 0 $0	   \
-   0 1 $1	   \
-   accept 1)	   \
-G=(0 0 $0)	   \
-F=U(true, $0)	   \
-W=G($0)|U($0, $1)  \
-R=!U(!$0, !$1)     \
-M=F($0)&R($0, $1)";
-  return s;
-}
-
-void
 syntax(char* prog)
 {
   // Display the supplied name unless it appears to be a libtool wrapper.
@@ -304,7 +286,8 @@ to_int(const char* s)
   return res;
 }
 
-spot::twa_graph_ptr ensure_digraph(const spot::twa_ptr& a)
+static spot::twa_graph_ptr
+ensure_digraph(const spot::twa_ptr& a)
 {
   auto aa = std::dynamic_pointer_cast<spot::twa_graph>(a);
   if (aa)
@@ -312,7 +295,7 @@ spot::twa_graph_ptr ensure_digraph(const spot::twa_ptr& a)
   return spot::make_twa_graph(a, spot::twa::prop_set::all());
 }
 
-int
+static int
 checked_main(int argc, char** argv)
 {
   int exit_code = 0;

src/tests/intvcmp2.cc

@@ -1,5 +1,5 @@
 // -*- coding: utf-8 -*-
-// Copyright (C) 2011, 2014 Laboratoire de Recherche et Developpement
+// Copyright (C) 2011, 2014, 2015 Laboratoire de Recherche et Developpement
 // de l'Epita (LRDE).
 //
 // This file is part of Spot, a model checking library.
@@ -22,7 +22,8 @@
 #include <cstring>
 
 
-int check_aa(int* data, int size, unsigned expected = 0)
+static int
+check_aa(int* data, int size, unsigned expected = 0)
 {
   int* comp = new int[size * 2];
   size_t csize = size * 2;
@@ -67,7 +68,8 @@ int check_aa(int* data, int size, unsigned expected = 0)
   return !!res;
 }
 
-int check(int* comp, int size, unsigned expected = 0)
+static int
+check(int* comp, int size, unsigned expected = 0)
 {
   return
     //check_vv(comp, size, expected) +

src/tests/intvcomp.cc

@@ -1,6 +1,6 @@
 // -*- coding: utf-8 -*-
-// Copyright (C) 2011, 2014 Laboratoire de Recherche et Developpement
+// Copyright (C) 2011, 2014, 2015 Laboratoire de Recherche et
-// de l'Epita (LRDE).
+// Developpement de l'Epita (LRDE).
 //
 // This file is part of Spot, a model checking library.
 //
@@ -21,7 +21,8 @@
 #include "misc/intvcomp.hh"
 #include <cstring>
 
-int check_vv(int* data, int size, unsigned expected = 0)
+static int
+check_vv(int* data, int size, unsigned expected = 0)
 {
 
   std::vector<int> input;
@@ -69,7 +70,8 @@ int check_vv(int* data, int size, unsigned expected = 0)
   return !!res;
 }
 
-int check_av(int* data, int size, unsigned expected = 0)
+static int
+check_av(int* data, int size, unsigned expected = 0)
 {
   const std::vector<unsigned int>* v =
     spot::int_array_vector_compress(data, size);
@@ -113,7 +115,8 @@ int check_av(int* data, int size, unsigned expected = 0)
   return !!res;
 }
 
-int check_aa(int* data, int size, unsigned expected = 0)
+static int
+check_aa(int* data, int size, unsigned expected = 0)
 {
   int* comp = new int[size *2];
   size_t csize = size * 2;
@@ -158,7 +161,8 @@ int check_aa(int* data, int size, unsigned expected = 0)
   return !!res;
 }
 
-int check(int* comp, int size, unsigned expected = 0)
+static int
+check(int* comp, int size, unsigned expected = 0)
 {
   return
     check_vv(comp, size, expected) +

src/tests/kind.cc

@@ -24,7 +24,7 @@
 #include <cstdlib>
 #include "tl/parse.hh"
 
-void
+static void
 syntax(char *prog)
 {
   std::cerr << prog << " formula" << std::endl;

src/tests/length.cc

@@ -24,7 +24,7 @@
 #include "tl/parse.hh"
 #include "tl/length.hh"
 
-void
+static void
 syntax(char *prog)
 {
   std::cerr << prog << " formula" << std::endl;

src/tests/ltlprod.cc

@@ -28,7 +28,7 @@
 #include "twaalgos/ltl2tgba_fm.hh"
 #include "twaalgos/dot.hh"
 
-void
+static void
 syntax(char* prog)
 {
   std::cerr << prog << " formula1 formula2" << std::endl;

src/tests/ltlrel.cc

@@ -24,7 +24,7 @@
 #include "tl/relabel.hh"
 #include "tl/print.hh"
 
-void
+static void
 syntax(char *prog)
 {
   std::cerr << prog << " formula" << std::endl;

src/tests/ngraph.cc

@@ -108,8 +108,8 @@ dot(std::ostream& out, const spot::named_graph<G1, G2, G3, G4>& g)
 }
 
 
-bool g1(const spot::digraph<void, void>& g,
+static bool
-	unsigned s, int e)
+g1(const spot::digraph<void, void>& g, unsigned s, int e)
 {
   int f = 0;
   for (auto& t: g.out(s))
@@ -120,7 +120,7 @@ bool g1(const spot::digraph<void, void>& g,
   return f == e;
 }
 
-bool f1()
+static bool f1()
 {
   spot::digraph<void, void> g(3);
   spot::named_graph<spot::digraph<void, void>, std::string> gg(g);
@@ -150,7 +150,7 @@ bool f1()
 }
 
 
-bool f2()
+static bool f2()
 {
   spot::digraph<int, void> g(3);
   spot::named_graph<spot::digraph<int, void>, std::string> gg(g);
@@ -173,7 +173,7 @@ bool f2()
   return f == 5;
 }
 
-bool f3()
+static bool f3()
 {
   spot::digraph<void, int> g(3);
   spot::named_graph<spot::digraph<void, int>, std::string> gg(g);
@@ -196,7 +196,7 @@ bool f3()
   return f == 3 && g.states().size() == 3;
 }
 
-bool f4()
+static bool f4()
 {
   spot::digraph<int, int> g(3);
   spot::named_graph<spot::digraph<int, int>, std::string> gg(g);
@@ -219,7 +219,7 @@ bool f4()
   return f == 11;
 }
 
-bool f5()
+static bool f5()
 {
   typedef spot::digraph<void, std::pair<int, float>> graph_t;
   graph_t g(3);
@@ -243,7 +243,7 @@ bool f5()
   return f == 3 && (h > 2.49 && h < 2.51);
 }
 
-bool f6()
+static bool f6()
 {
   typedef spot::digraph<void, std::pair<int, float>> graph_t;
   graph_t g(3);
@@ -267,7 +267,7 @@ bool f6()
   return f == 3 && (h > 2.49 && h < 2.51);
 }
 
-bool f7()
+static bool f7()
 {
   typedef spot::digraph<int, int, true> graph_t;
   graph_t g(3);
@@ -316,7 +316,7 @@ struct int_pair
 #endif
 };
 
-bool f8()
+static bool f8()
 {
   typedef spot::digraph<int_pair, int_pair> graph_t;
   graph_t g(3);
@@ -382,7 +382,7 @@ public:
   }
 };
 
-bool f9()
+static bool f9()
 {
   typedef spot::digraph<my_state, int_pair> graph_t;
   graph_t g(3);

src/tests/randtgba.cc

@@ -82,7 +82,7 @@ const char* default_algos[] = {
 
 std::vector<ec_algo> ec_algos;
 
-spot::emptiness_check_ptr
+static spot::emptiness_check_ptr
 cons_emptiness_check(int num, spot::const_twa_graph_ptr a,
 		     const spot::const_twa_graph_ptr& degen,
 		     unsigned int n_acc)
@@ -96,7 +96,7 @@ cons_emptiness_check(int num, spot::const_twa_graph_ptr a,
   return nullptr;
 }
 
-void
+static void
 syntax(char* prog)
 {
   std::cerr << "Usage: "<< prog << " [OPTIONS...] PROPS..." << std::endl
@@ -173,7 +173,7 @@ syntax(char* prog)
 }
 
 
-int
+static int
 to_int(const char* s)
 {
   char* endptr;
@@ -186,7 +186,7 @@ to_int(const char* s)
   return res;
 }
 
-int
+static int
 to_int_pos(const char* s, const char* arg)
 {
   int res = to_int(s);
@@ -199,7 +199,7 @@ to_int_pos(const char* s, const char* arg)
   return res;
 }
 
-int
+static int
 to_int_nonneg(const char* s, const char* arg)
 {
   int res = to_int(s);
@@ -212,7 +212,7 @@ to_int_nonneg(const char* s, const char* arg)
   return res;
 }
 
-float
+static float
 to_float(const char* s)
 {
   char* endptr;
@@ -226,7 +226,7 @@ to_float(const char* s)
   return res;
 }
 
-float
+static float
 to_float_nonneg(const char* s, const char* arg)
 {
   float res = to_float(s);
@@ -250,7 +250,7 @@ id(const char*, unsigned x)
 
 spot::tgba_statistics prod_stats;
 
-float
+static float
 prod_conv(const char* name, unsigned x)
 {
   float y = static_cast<float>(x);
@@ -418,7 +418,7 @@ ar_stats_type ar_stats;		// Statistics about accepting runs.
 ar_stats_type mar_stats;        // ... about minimized accepting runs.
 
 
-void
+static void
 print_ar_stats(ar_stats_type& ar_stats, const std::string& s)
 {
   std::ios::fmtflags old = std::cout.flags();
@@ -486,7 +486,7 @@ print_ar_stats(ar_stats_type& ar_stats, const std::string& s)
   std::cout << std::setiosflags(old);
 }
 
-spot::formula
+static spot::formula
 generate_formula(const spot::random_ltl& rl,
 		 spot::ltl_simplifier& simp,
 		 int opt_f, int opt_s,

src/tests/readltl.cc

@@ -27,7 +27,7 @@
 #include "tl/parse.hh"
 #include "tl/dot.hh"
 
-void
+static void
 syntax(char* prog)
 {
   std::cerr << prog << " [-d] formula" << std::endl;

src/tests/reduc.cc

@@ -31,7 +31,7 @@
 #include "tl/simplify.hh"
 #include "tl/length.hh"
 
-void
+static void
 syntax(char* prog)
 {
   std::cerr << prog << " option formula1 (formula2)?" << std::endl;

src/tests/syntimpl.cc

@@ -28,7 +28,7 @@
 #include "tl/simplify.hh"
 #include "tl/nenoform.hh"
 
-void
+static void
 syntax(char* prog)
 {
   std::cerr << prog << " formula1 formula2?" << std::endl;

src/tests/tostring.cc

@@ -26,7 +26,7 @@
 #include "tl/parse.hh"
 #include "tl/print.hh"
 
-void
+static void
 syntax(char *prog)
 {
   std::cerr << prog << " formula1" << std::endl;

src/tests/twagraph.cc

@@ -23,7 +23,7 @@
 #include "twaalgos/dot.hh"
 #include "tl/defaultenv.hh"
 
-void f1()
+static void f1()
 {
   auto d = spot::make_bdd_dict();
   auto tg = make_twa_graph(d);

src/tl/contain.cc

@@ -120,17 +120,4 @@ namespace spot
     r.translation = e;
     return &r;
   }
-
-
-  formula
-  reduce_tau03(formula f, bool stronger)
-  {
-    if (!f.is_psl_formula())
-      return f;
-
-    ltl_simplifier_options opt(false, false, false,
-			       true, stronger);
-    ltl_simplifier simpl(opt);
-    return simpl.simplify(f);
-  }
 }

src/twaalgos/dtgbacomp.cc

@@ -24,7 +24,10 @@
 
 namespace spot
 {
-  twa_graph_ptr dtgba_complement_nonweak(const const_twa_graph_ptr& aut)
+  namespace
+  {
+    static twa_graph_ptr
+    dtgba_complement_nonweak(const const_twa_graph_ptr& aut)
     {
       // Clone the original automaton.
       auto res = make_twa_graph(aut,
@@ -112,7 +115,8 @@ namespace spot
       return res;
     }
 
-  twa_graph_ptr dtgba_complement_weak(const const_twa_graph_ptr& aut)
+    static twa_graph_ptr
+    dtgba_complement_weak(const const_twa_graph_ptr& aut)
     {
       // Clone the original automaton.
       auto res = make_twa_graph(aut,
@@ -159,6 +163,7 @@ namespace spot
       //res->merge_edges();
       return res;
     }
+  }
 
   twa_graph_ptr dtgba_complement(const const_twa_graph_ptr& aut)
   {

src/twaalgos/minimize.cc

@@ -80,10 +80,10 @@ namespace spot
       dump_hash_set(hs, aut, s);
       return s.str();
     }
-  }
 
     // Find all states of an automaton.
-  void build_state_set(const const_twa_ptr& a, hash_set* seen)
+    static void
+    build_state_set(const const_twa_ptr& a, hash_set* seen)
     {
       std::queue<const state*> tovisit;
       // Perform breadth-first traversal.
@@ -113,7 +113,8 @@ namespace spot
 
     // From the base automaton and the list of sets, build the minimal
     // resulting automaton
-  twa_graph_ptr build_result(const const_twa_ptr& a,
+    static twa_graph_ptr
+    build_result(const const_twa_ptr& a,
 		 std::list<hash_set*>& sets,
 		 hash_set* final)
     {
@@ -174,10 +175,6 @@ namespace spot
       return res;
     }
 
-
-  namespace
-  {
-
     struct wdba_search_acc_loop : public bfs_steps
     {
       wdba_search_acc_loop(const const_twa_ptr& det_a,
@@ -265,9 +262,7 @@ namespace spot
       return accepting;
     }
 
-  }
+    static twa_graph_ptr minimize_dfa(const const_twa_graph_ptr& det_a,
-
-  twa_graph_ptr minimize_dfa(const const_twa_graph_ptr& det_a,
 				      hash_set* final, hash_set* non_final)
     {
       typedef std::list<hash_set*> partition_t;
@@ -332,8 +327,8 @@ namespace spot
 	  delete non_final;
 	}
 
-    // A bdd_states_map is a list of formulae (in a BDD form) associated with a
+      // A bdd_states_map is a list of formulae (in a BDD form)
-    // destination set of states.
+      // associated with a destination set of states.
       typedef std::map<bdd, hash_set*, bdd_less_than> bdd_states_map;
 
       bool did_split = true;
@@ -347,7 +342,8 @@ namespace spot
 	      hash_set* cur = cur_run.front();
 	      cur_run.pop_front();
 
-	    trace << "processing " << format_hash_set(cur, det_a) << std::endl;
+	      trace << "processing " << format_hash_set(cur, det_a)
+		    << std::endl;
 
 	      hash_set::iterator hi;
 	      bdd_states_map bdd_map;
@@ -471,7 +467,7 @@ namespace spot
 
       return res;
     }
-
+  }
 
   twa_graph_ptr minimize_monitor(const const_twa_graph_ptr& a)
   {