Merge remote branch 'sebastian/bug2696' into maint-0.2.2

3 files changed, 37 insertions, 10 deletions

diff --git a/changes/bug2696 b/changes/bug2696
new file mode 100644
index 0000000000..6ea41d4a6a
--- /dev/null
+++ b/changes/bug2696
@@ -0,0 +1,5 @@
+  o Minor features:
+    - Make compilation with clang possible when using
+      --enable-gcc-warnings by removing two warnings that clang hasn't
+      implemented yet and by fixing a few warnings. Implements ticket
+      2696.
diff --git a/configure.in b/configure.in
index f30402d5b5..4436fe2075 100644
--- a/configure.in
+++ b/configure.in
@@ -865,12 +865,13 @@ fi
 # Set CFLAGS _after_ all the above checks, since our warnings are stricter
 # than autoconf's macros like.
 if test "$GCC" = yes; then
-  CFLAGS="$CFLAGS -Wall -g -O2"
   # Disable GCC's strict aliasing checks.  They are an hours-to-debug
   # accident waiting to happen.
-  CFLAGS="$CFLAGS -fno-strict-aliasing"
+  CFLAGS="$CFLAGS -Wall -fno-strict-aliasing"
 else
-  CFLAGS="$CFLAGS -g -O"
+  # Autoconf sets -g -O2 by default. Override optimization level
+  # for non-gcc compilers
+  CFLAGS="$CFLAGS -O"
   enable_gcc_warnings=no
   enable_gcc_warnings_advisory=no
 fi
@@ -894,6 +895,11 @@ if test x$enable_gcc_warnings = xyes || test x$enable_gcc_warnings_advisory = xy
 #error
 #endif])], have_gcc43=yes, have_gcc43=no)
 
+  AC_COMPILE_IFELSE([AC_LANG_PROGRAM([], [
+#if !defined(__clang__) || (__clang_major__ > 2) || (__clang_major__ == 2 && __clang_minor__ > 9)
+#error
+#endif])], have_clang29orlower=yes, have_clang29orlower=no)
+
   save_CFLAGS="$CFLAGS"
   CFLAGS="$CFLAGS -Wshorten-64-to-32"
   AC_COMPILE_IFELSE([AC_LANG_PROGRAM([], [])], have_shorten64_flag=yes,
@@ -924,11 +930,19 @@ if test x$enable_gcc_warnings = xyes || test x$enable_gcc_warnings_advisory = xy
   if test x$have_gcc42 = xyes ; then 
     # These warnings break gcc 4.0.2 and work on gcc 4.2
     # XXXX020 See if any of these work with earlier versions.
-    CFLAGS="$CFLAGS -Waddress -Wmissing-noreturn -Wnormalized=id -Woverride-init -Wstrict-overflow=1"
+    CFLAGS="$CFLAGS -Waddress -Wmissing-noreturn -Wstrict-overflow=1"
+
     # We used to use -Wstrict-overflow=5, but that breaks us heavily under 4.3.
   fi
 
-  if test x$have_gcc43 = xyes ; then 
+  if test x$have_gcc42 = xyes && test x$have_clang29orlower = xno; then
+    # These warnings break gcc 4.0.2 and clang, but work on gcc 4.2
+    # We only disable these for clang 2.9 and lower, in case they are
+    # supported in later versions.
+    CFLAGS="$CFLAGS -Wnormalized=id -Woverride-init"
+  fi
+
+  if test x$have_gcc43 = xyes ; then
     # These warnings break gcc 4.2 and work on gcc 4.3
     # XXXX020 See if any of these work with earlier versions.
     CFLAGS="$CFLAGS -Wextra -Warray-bounds"
diff --git a/src/or/geoip.c b/src/or/geoip.c
index e5694b9618..a99165488a 100644
--- a/src/or/geoip.c
+++ b/src/or/geoip.c
@@ -284,11 +284,18 @@ geoip_is_loaded(void)
 typedef struct clientmap_entry_t {
   HT_ENTRY(clientmap_entry_t) node;
   uint32_t ipaddr;
+  /** Time when we last saw this IP address, in MINUTES since the epoch.
+   *
+   * (This will run out of space around 4011 CE.  If Tor is still in use around
+   * 4000 CE, please remember to add more bits to last_seen_in_minutes.) */
   unsigned int last_seen_in_minutes:30;
   unsigned int action:2;
 } clientmap_entry_t;
 
-#define ACTION_MASK 3
+/** Largest allowable value for last_seen_in_minutes.  (It's a 30-bit field,
+ * so it can hold up to (1u<<30)-1, or 0x3fffffffu.
+ */
+#define MAX_LAST_SEEN_IN_MINUTES 0X3FFFFFFFu
 
 /** Map from client IP address to last time seen. */
 static HT_HEAD(clientmap, clientmap_entry_t) client_history =
@@ -413,15 +420,16 @@ geoip_note_client_seen(geoip_client_action_t action,
   lookup.ipaddr = addr;
   lookup.action = (int)action;
   ent = HT_FIND(clientmap, &client_history, &lookup);
-  if (ent) {
-    ent->last_seen_in_minutes = now / 60;
-  } else {
+  if (! ent) {
     ent = tor_malloc_zero(sizeof(clientmap_entry_t));
     ent->ipaddr = addr;
-    ent->last_seen_in_minutes = now / 60;
     ent->action = (int)action;
     HT_INSERT(clientmap, &client_history, ent);
   }
+  if (now / 60 <= MAX_LAST_SEEN_IN_MINUTES && now >= 0)
+    ent->last_seen_in_minutes = (unsigned)(now/60);
+  else
+    ent->last_seen_in_minutes = 0;
 
   if (action == GEOIP_CLIENT_NETWORKSTATUS ||
       action == GEOIP_CLIENT_NETWORKSTATUS_V2) {