Lots of "comparison of integers of different signs" warnings on install.

[erictaylor]

Installing on Mac OS X 10.10.3 and Node v0.12.5 produces lots of the following warnings (still installs and builds correctly), but is dirty and loud.

Example:

In file included from ../csrc/enc/metablock.cc:21:
../csrc/enc/./cluster.h:129:36: warning: comparison of integers of different signs: 'int' and 'size_type' (aka 'unsigned long') [-Wsign-compare]
    for (int idx2 = idx1 + 1; idx2 < clusters.size(); ++idx2) {
                              ~~~~ ^ ~~~~~~~~~~~~~~~
../csrc/enc/./cluster.h:135:26: warning: comparison of integers of different signs: 'size_type' (aka 'unsigned long') and 'int' [-Wsign-compare]
  while (clusters.size() > min_cluster_size) {
         ~~~~~~~~~~~~~~~ ^ ~~~~~~~~~~~~~~~~
../csrc/enc/./cluster.h:152:27: warning: comparison of integers of different signs: 'int' and 'size_type' (aka 'unsigned long') [-Wsign-compare]
    for (int i = 0; i + 1 < clusters.size(); ++i) {
                    ~~~~~ ^ ~~~~~~~~~~~~~~~
../csrc/enc/./cluster.h:159:23: warning: comparison of integers of different signs: 'int' and 'size_type' (aka 'unsigned long') [-Wsign-compare]
    for (int i = 0; i < pairs.size(); ++i) {
                    ~ ^ ~~~~~~~~~~~~
../csrc/enc/./cluster.h:172:23: warning: comparison of integers of different signs: 'int' and 'size_type' (aka 'unsigned long') [-Wsign-compare]
    for (int i = 0; i < clusters.size(); ++i) {
                    ~ ^ ~~~~~~~~~~~~~~~
../csrc/enc/./cluster.h:234:21: warning: comparison of integers of different signs: 'int' and 'size_type' (aka 'unsigned long') [-Wsign-compare]
  for (int i = 0; i < symbols->size(); ++i) {
                  ~ ^ ~~~~~~~~~~~~~~~
../csrc/enc/./cluster.h:300:3: note: in instantiation of function template specialization 'brotli::HistogramReindex<brotli::Histogram<256> >' requested here
  HistogramReindex(out, histogram_symbols);
  ^
../csrc/enc/metablock.cc:71:5: note: in instantiation of function template specialization 'brotli::ClusterHistograms<brotli::Histogram<256> >' requested here
    ClusterHistograms(literal_histograms,
    ^
In file included from ../csrc/enc/metablock.cc:21:
../csrc/enc/./cluster.h:242:21: warning: comparison of integers of different signs: 'int' and 'size_type' (aka 'unsigned long') [-Wsign-compare]
  for (int i = 0; i < symbols->size(); ++i) {
                  ~ ^ ~~~~~~~~~~~~~~~
../csrc/enc/./cluster.h:128:27: warning: comparison of integers of different signs: 'int' and 'size_type' (aka 'unsigned long') [-Wsign-compare]
  for (int idx1 = 0; idx1 < clusters.size(); ++idx1) {
                     ~~~~ ^ ~~~~~~~~~~~~~~~
../csrc/enc/./cluster.h:285:7: note: in instantiation of function template specialization 'brotli::HistogramCombine<brotli::Histogram<520> >' requested here
      HistogramCombine(&(*out)[0], &cluster_size[0],
      ^
../csrc/enc/metablock.cc:88:5: note: in instantiation of function template specialization 'brotli::ClusterHistograms<brotli::Histogram<520> >' requested here
    ClusterHistograms(distance_histograms,
    ^
In file included from ../csrc/enc/metablock.cc:21:
../csrc/enc/./cluster.h:129:36: warning: comparison of integers of different signs: 'int' and 'size_type' (aka 'unsigned long') [-Wsign-compare]
    for (int idx2 = idx1 + 1; idx2 < clusters.size(); ++idx2) {
                              ~~~~ ^ ~~~~~~~~~~~~~~~
../csrc/enc/./cluster.h:135:26: warning: comparison of integers of different signs: 'size_type' (aka 'unsigned long') and 'int' [-Wsign-compare]
  while (clusters.size() > min_cluster_size) {
         ~~~~~~~~~~~~~~~ ^ ~~~~~~~~~~~~~~~~
../csrc/enc/./cluster.h:152:27: warning: comparison of integers of different signs: 'int' and 'size_type' (aka 'unsigned long') [-Wsign-compare]
    for (int i = 0; i + 1 < clusters.size(); ++i) {
                    ~~~~~ ^ ~~~~~~~~~~~~~~~
../csrc/enc/./cluster.h:159:23: warning: comparison of integers of different signs: 'int' and 'size_type' (aka 'unsigned long') [-Wsign-compare]
    for (int i = 0; i < pairs.size(); ++i) {
                    ~ ^ ~~~~~~~~~~~~
../csrc/enc/./cluster.h:172:23: warning: comparison of integers of different signs: 'int' and 'size_type' (aka 'unsigned long') [-Wsign-compare]
    for (int i = 0; i < clusters.size(); ++i) {
                    ~ ^ ~~~~~~~~~~~~~~~
../csrc/enc/./cluster.h:234:21: warning: comparison of integers of different signs: 'int' and 'size_type' (aka 'unsigned long') [-Wsign-compare]
  for (int i = 0; i < symbols->size(); ++i) {
                  ~ ^ ~~~~~~~~~~~~~~~
../csrc/enc/./cluster.h:300:3: note: in instantiation of function template specialization 'brotli::HistogramReindex<brotli::Histogram<520> >' requested here
  HistogramReindex(out, histogram_symbols);
  ^
../csrc/enc/metablock.cc:88:5: note: in instantiation of function template specialization 'brotli::ClusterHistograms<brotli::Histogram<520> >' requested here
    ClusterHistograms(distance_histograms,
    ^
In file included from ../csrc/enc/metablock.cc:21:
../csrc/enc/./cluster.h:242:21: warning: comparison of integers of different signs: 'int' and 'size_type' (aka 'unsigned long') [-Wsign-compare]
  for (int i = 0; i < symbols->size(); ++i) {
                  ~ ^ ~~~~~~~~~~~~~~~
30 warnings generated.
../csrc/enc/streams.cc:38:16: warning: comparison of integers of different signs: 'unsigned long' and 'int' [-Wsign-compare]
  if (n + pos_ > len_)
      ~~~~~~~~ ^ ~~~~
../csrc/enc/streams.cc:59:24: warning: comparison of integers of different signs: 'unsigned long' and 'int' [-Wsign-compare]
  if (buf_->size() + n > max_size_)
      ~~~~~~~~~~~~~~~~ ^ ~~~~~~~~~
../csrc/enc/streams.cc:81:9: warning: comparison of integers of different signs: 'size_t' (aka 'unsigned long') and 'int' [-Wsign-compare]
  if (n > len_ - pos_)
      ~ ^ ~~~~~~~~~~~
3 warnings generated.

Not sure if we can correct these issues, or possibly suppress the noise if they can safely be ignored.

[nfroidure]

We can probably hide this with a cflag, have to find it though.

[nfroidure]

And, sending an issue to the original woff2 project is also an option, even make a PR if you want.

[vdclouis]

+1

[nfroidure]

I found this https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html

I could mute warnings with the -w option on Linux, can someone confirm it works also for MacOSX?

[nfroidure]

ping @Psiablo

[nfroidure]

Merged and published. Thank you 👍 .