diff a/bindings/ruby/extconf.rb b/bindings/ruby/extconf.rb
--- a/bindings/ruby/extconf.rb
+++ b/bindings/ruby/extconf.rb
@@ -3,6 +3,8 @@
 
 require 'mkmf'
 
+$CFLAGS += ' -Wall '
+
 if /solaris/ =~ RUBY_PLATFORM
    $LDFLAGS += '-R$(EPREFIX)/lib'
 elsif /hpux/ =~ RUBY_PLATFORM
diff a/bindings/ruby/main.c b/bindings/ruby/main.c
--- a/bindings/ruby/main.c
+++ b/bindings/ruby/main.c
@@ -4,6 +4,7 @@
 
 #include <unistd.h>
 #include <ruby.h>
+#include <math.h>
 #include "../../src/rrd_tool.h"
 
 typedef struct string_arr_t {
@@ -19,6 +20,11 @@ typedef int (
     int argc,
     char **argv);
 
+typedef rrd_info_t *(
+    *RRDINFOFUNC) (
+    int argc,
+    char **argv);
+
 #define RRD_CHECK_ERROR  \
     if (rrd_test_error()) \
       rb_raise(rb_eRRDError, rrd_get_error()); \
@@ -142,7 +148,7 @@ VALUE rb_rrd_update(
 /* Calls Returning Data via the Info Interface */
 
 VALUE rb_rrd_infocall(
-    RRDFUNC func,
+    RRDINFOFUNC func,
     VALUE args)
 {
     string_arr a;
@@ -173,9 +179,12 @@ VALUE rb_rrd_infocall(
         case RD_I_STR:
             rb_hash_aset(result, key, rb_str_new2(data->value.u_str));
             break;
+        case RD_I_INT:
+            rb_hash_aset(result, key, INT2FIX(data->value.u_int));
+            break;
         case RD_I_BLO:
             rb_hash_aset(result, key,
-                         rb_str_new(data->value.u_blo.ptr,
+                         rb_str_new((char *)data->value.u_blo.ptr,
                                     data->value.u_blo.size));
             break;
         }
diff a/bindings/tcl/tclrrd.c b/bindings/tcl/tclrrd.c
--- a/bindings/tcl/tclrrd.c
+++ b/bindings/tcl/tclrrd.c
@@ -97,7 +97,7 @@ static void getopt_squieeze(
 
 /* Thread-safe version */
 static int Rrd_Create(
-    ClientData clientData,
+    ClientData __attribute__((unused)) clientData,
     Tcl_Interp *interp,
     int argc,
     CONST84 char *argv[])
@@ -186,7 +186,8 @@ static int Rrd_Create(
         return TCL_ERROR;
     }
 
-    rrd_create_r(argv2[1], pdp_step, last_up, argc - 2, argv2 + 2);
+    rrd_create_r(argv2[1], pdp_step, last_up, argc - 2,
+                 (const char **)argv2 + 2);
 
     getopt_cleanup(argc, argv2);
 
@@ -204,7 +205,7 @@ static int Rrd_Create(
 
 /* Thread-safe version */
 static int Rrd_Dump(
-    ClientData clientData,
+    ClientData __attribute__((unused)) clientData,
     Tcl_Interp *interp,
     int argc,
     CONST84 char *argv[])
@@ -233,7 +234,7 @@ static int Rrd_Dump(
 
 /* Thread-safe version */
 static int Rrd_Last(
-    ClientData clientData,
+    ClientData __attribute__((unused)) clientData,
     Tcl_Interp *interp,
     int argc,
     CONST84 char *argv[])
@@ -264,7 +265,7 @@ static int Rrd_Last(
 
 /* Thread-safe version */
 static int Rrd_Update(
-    ClientData clientData,
+    ClientData __attribute__((unused)) clientData,
     Tcl_Interp *interp,
     int argc,
     CONST84 char *argv[])
@@ -319,7 +320,7 @@ static int Rrd_Update(
         return TCL_ERROR;
     }
 
-    rrd_update_r(argv2[1], template, argc - 2, argv2 + 2);
+    rrd_update_r(argv2[1], template, argc - 2, (const char **)argv2 + 2);
 
     if (template != NULL) {
         free(template);
@@ -337,7 +338,7 @@ static int Rrd_Update(
 }
 
 static int Rrd_Lastupdate(
-    ClientData clientData,
+    ClientData __attribute__((unused)) clientData,
     Tcl_Interp *interp,
     int argc,
     CONST84 char *argv[])
@@ -350,6 +351,12 @@ static int Rrd_Lastupdate(
     Tcl_Obj  *listPtr;
     unsigned long ds_cnt, i;
 
+    if (argc != 2) {
+        Tcl_AppendResult(interp, "RRD Error: needs a single rrd filename",
+                         (char *) NULL);
+        return TCL_ERROR;
+    }
+
     argv2 = getopt_init(argc, argv);
     if (rrd_lastupdate(argc - 1, argv2, &last_update,
                        &ds_cnt, &ds_namv, &last_ds) == 0) {
@@ -379,7 +386,7 @@ static int Rrd_Lastupdate(
 }
 
 static int Rrd_Fetch(
-    ClientData clientData,
+    ClientData __attribute__((unused)) clientData,
     Tcl_Interp *interp,
     int argc,
     CONST84 char *argv[])
@@ -424,7 +431,7 @@ static int Rrd_Fetch(
 
 
 static int Rrd_Graph(
-    ClientData clientData,
+    ClientData __attribute__((unused)) clientData,
     Tcl_Interp *interp,
     int argc,
     CONST84 char *argv[])
@@ -534,7 +541,7 @@ static int Rrd_Graph(
 
 
 static int Rrd_Tune(
-    ClientData clientData,
+    ClientData __attribute__((unused)) clientData,
     Tcl_Interp *interp,
     int argc,
     CONST84 char *argv[])
@@ -558,7 +565,7 @@ static int Rrd_Tune(
 
 
 static int Rrd_Resize(
-    ClientData clientData,
+    ClientData __attribute__((unused)) clientData,
     Tcl_Interp *interp,
     int argc,
     CONST84 char *argv[])
@@ -582,7 +589,7 @@ static int Rrd_Resize(
 
 
 static int Rrd_Restore(
-    ClientData clientData,
+    ClientData __attribute__((unused)) clientData,
     Tcl_Interp *interp,
     int argc,
     CONST84 char *argv[])
diff a/src/Makefile.am b/src/Makefile.am
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -12,6 +12,8 @@ endif
 INCLUDES = -DLOCALEDIR="\"$(datadir)/locale\""
 RRD_DEFAULT_FONT=@RRD_DEFAULT_FONT@
 AM_CPPFLAGS = -DRRD_DEFAULT_FONT=\"$(RRD_DEFAULT_FONT)\" -DNUMVERS=@NUMVERS@
+AM_CFLAGS = @CFLAGS@
+## no including this by default @WERROR@
 
 UPD_C_FILES =		\
 	rrd_parsetime.c	\
@@ -77,7 +79,7 @@ librrd_la_LDFLAGS         += -export-symbols librrd.sym
 
 librrd_th_la_SOURCES         = $(UPD_C_FILES) $(RRD_C_FILES) rrd_thread_safe.c
 librrd_th_la_DEPENDENCIES    = librrd.sym
-librrd_th_la_CFLAGS          = $(MULTITHREAD_CFLAGS)
+librrd_th_la_CFLAGS          = $(AM_CFLAGS) $(MULTITHREAD_CFLAGS)
 librrd_th_la_LDFLAGS         = $(MULTITHREAD_LDFLAGS) -version-info @LIBVERS@
 librrd_th_la_LDFLAGS         += -export-symbols librrd.sym
 librrd_th_la_LIBADD          = $(ALL_LIBS)
diff a/src/rrd_dump.c b/src/rrd_dump.c
--- a/src/rrd_dump.c
+++ b/src/rrd_dump.c
@@ -58,8 +58,7 @@
 extern char *tzname[2];
 #endif
 
-
-int rrd_dump_opt_r(
+static int rrd_dump_opt_r(
     const char *filename,
     char *outname,
     int opt_noheader)
diff a/src/rrd_gfx.c b/src/rrd_gfx.c
--- a/src/rrd_gfx.c
+++ b/src/rrd_gfx.c
@@ -124,7 +124,7 @@ static PangoLayout *gfx_prep_text(
     const char *text)
 {
     PangoLayout  *layout = im->layout;
-    PangoFontDescription *pfd;
+    const PangoFontDescription *pfd;
     cairo_t  *cr = im->cr;
 
     static double last_tabwidth = -1;
diff a/src/rrd_open.c b/src/rrd_open.c
--- a/src/rrd_open.c
+++ b/src/rrd_open.c
@@ -389,9 +389,9 @@ void rrd_dontneed(
     rrd_t *rrd)
 {
 #if defined USE_MADVISE || defined HAVE_POSIX_FADVISE
-    unsigned long dontneed_start;
-    unsigned long rra_start;
-    unsigned long active_block;
+    off_t dontneed_start;
+    off_t rra_start;
+    off_t active_block;
     unsigned long i;
     ssize_t   _page_size = sysconf(_SC_PAGESIZE);
 
diff a/src/rrd_xport.c b/src/rrd_xport.c
--- a/src/rrd_xport.c
+++ b/src/rrd_xport.c
@@ -228,7 +228,7 @@ int rrd_xport_fn(
             ref_list[xport_counter++] = i;
             *step_list_ptr = im->gdes[im->gdes[i].vidx].step;
             /* printf("%s:%lu\n",im->gdes[i].legend,*step_list_ptr); */
-            *step_list_ptr++;
+            step_list_ptr++;
             /* reserve room for one legend entry */
             /* is FMT_LEG_LEN + 5 the correct size? */
             if ((legend_list[j] =