Don’t print to stderr unless a standalone binary

We will use woff2 code from OTS and it is undesirable for a library to
print messages to stderr.

Makefile

@@ -5,7 +5,7 @@ CPPFLAGS = -I./brotli/dec/ -I./brotli/enc/ -I./src
 CC ?= gcc
 CXX ?= g++
 
-COMMON_FLAGS = -fno-omit-frame-pointer -no-canonical-prefixes
+COMMON_FLAGS = -fno-omit-frame-pointer -no-canonical-prefixes -DFONT_COMPRESSION_BIN
 
 ifeq ($(OS), Darwin)
   CPPFLAGS += -DOS_MACOSX

src/normalize.cc

@@ -286,8 +286,10 @@ bool NormalizeFontCollection(FontCollection* font_collection) {
     font_collection->fonts.size());
   for (auto& font : font_collection->fonts) {
     if (!NormalizeWithoutFixingChecksums(&font)) {
+#ifdef FONT_COMPRESSION_BIN
       fprintf(stderr, "Font normalization failed.\n");
-      return false;
+#endif
+      return FONT_COMPRESSION_FAILURE();
     }
     offset += kSfntHeaderSize + kSfntEntrySize * font.num_tables;
   }
@@ -308,8 +310,10 @@ bool NormalizeFontCollection(FontCollection* font_collection) {
   // Now we can fix the checksums
   for (auto& font : font_collection->fonts) {
     if (!FixChecksums(&font)) {
+#ifdef FONT_COMPRESSION_BIN
       fprintf(stderr, "Failed to fix checksums\n");
-      return false;
+#endif
+      return FONT_COMPRESSION_FAILURE();
     }
   }
 

src/woff2_dec.cc

@@ -901,7 +901,9 @@ bool ConvertWOFF2ToTTF(uint8_t* result, size_t result_length,
       }
 
       if (PREDICT_FALSE((glyf_table == NULL) != (loca_table == NULL))) {
+#ifdef FONT_COMPRESSION_BIN
         fprintf(stderr, "Cannot have just one of glyf/loca\n");
+#endif
         return FONT_COMPRESSION_FAILURE();
       }
 
@@ -936,9 +938,11 @@ bool ConvertWOFF2ToTTF(uint8_t* result, size_t result_length,
     dst_offset = Round4(dst_offset);
   }
   if (PREDICT_FALSE(src_offset > length || dst_offset != result_length)) {
+#ifdef FONT_COMPRESSION_BIN
     fprintf(stderr, "offset fail; src_offset %" PRIu64 " length %lu "
       "dst_offset %" PRIu64 " result_length %lu\n",
       src_offset, length, dst_offset, result_length);
+#endif
     return FONT_COMPRESSION_FAILURE();
   }
 

src/woff2_enc.cc

@@ -216,8 +216,10 @@ uint32_t CompressedBufferSize(uint32_t original_size) {
 bool TransformFontCollection(FontCollection* font_collection) {
   for (auto& font : font_collection->fonts) {
     if (!TransformGlyfAndLocaTables(&font)) {
+#ifdef FONT_COMPRESSION_BIN
       fprintf(stderr, "Font transformation failed.\n");
-      return false;
+#endif
+      return FONT_COMPRESSION_FAILURE();
     }
   }
 
@@ -236,16 +238,18 @@ bool ConvertTTFToWOFF2(const uint8_t *data, size_t length,
                        const WOFF2Params& params) {
   FontCollection font_collection;
   if (!ReadFontCollection(data, length, &font_collection)) {
+#ifdef FONT_COMPRESSION_BIN
     fprintf(stderr, "Parsing of the input font failed.\n");
-    return false;
+#endif
+    return FONT_COMPRESSION_FAILURE();
   }
 
   if (!NormalizeFontCollection(&font_collection)) {
-    return false;
+    return FONT_COMPRESSION_FAILURE();
   }
 
   if (!TransformFontCollection(&font_collection)) {
-    return false;
+    return FONT_COMPRESSION_FAILURE();
   }
 
   // Although the compressed size of each table in the final woff2 file won't
@@ -281,8 +285,10 @@ bool ConvertTTFToWOFF2(const uint8_t *data, size_t length,
                      &compression_buf[0],
                      &total_compressed_length,
                      params.brotli_quality)) {
+#ifdef FONT_COMPRESSION_BIN
     fprintf(stderr, "Compression of combined table failed.\n");
-    return false;
+#endif
+    return FONT_COMPRESSION_FAILURE();
   }
 
   // Compress the extended metadata
@@ -297,8 +303,10 @@ bool ConvertTTFToWOFF2(const uint8_t *data, size_t length,
                       compressed_metadata_buf.data(),
                       &compressed_metadata_buf_length,
                       params.brotli_quality)) {
+#ifdef FONT_COMPRESSION_BIN
       fprintf(stderr, "Compression of extended metadata failed.\n");
-      return false;
+#endif
+      return FONT_COMPRESSION_FAILURE();
     }
   } else {
     compressed_metadata_buf_length = 0;
@@ -348,9 +356,11 @@ bool ConvertTTFToWOFF2(const uint8_t *data, size_t length,
   size_t woff2_length = ComputeWoff2Length(font_collection, tables,
       index_by_offset, compressed_metadata_buf_length);
   if (woff2_length > *result_length) {
+#ifdef FONT_COMPRESSION_BIN
     fprintf(stderr, "Result allocation was too small (%zd vs %zd bytes).\n",
            *result_length, woff2_length);
-    return false;
+#endif
+    return FONT_COMPRESSION_FAILURE();
   }
   *result_length = woff2_length;
 
@@ -419,9 +429,11 @@ bool ConvertTTFToWOFF2(const uint8_t *data, size_t length,
         uint32_t table_length =
           table.IsReused() ? table.reuse_of->length : table.length;
         if (index_by_offset.find(table_offset) == index_by_offset.end()) {
+#ifdef FONT_COMPRESSION_BIN
           fprintf(stderr, "Missing table index for offset 0x%08x\n",
                   table_offset);
-          return false;
+#endif
+          return FONT_COMPRESSION_FAILURE();
         }
         uint16_t index = index_by_offset[table_offset];
         Store255UShort(index, &offset, result);
@@ -440,9 +452,11 @@ bool ConvertTTFToWOFF2(const uint8_t *data, size_t length,
              &offset, result);
 
   if (*result_length != offset) {
+#ifdef FONT_COMPRESSION_BIN
     fprintf(stderr, "Mismatch between computed and actual length "
             "(%zd vs %zd)\n", *result_length, offset);
-    return false;
+#endif
+    return FONT_COMPRESSION_FAILURE();
   }
   return true;
 }