diff --git a/internal/compile.sh b/internal/compile.sh
index ceb3508..b78cf31 100755
--- a/internal/compile.sh
+++ b/internal/compile.sh
@@ -14,7 +14,20 @@
 #  See the License for the specific language governing permissions and
 #  limitations under the License.
 
-g++ -O2 -m64  compact_lang_det_test.cc \
+if [ -z "${CFLAGS}" -a -z "${CXXFLAGS}" -a -z "${CPPFLAGS}" ]; then
+  echo "Warning: None of CFLAGS, CXXFLAGS or CPPFLAGS is set; you probably should enable some options." 1>&2
+fi
+if [ -n "${CFLAGS}" ]; then
+  echo "CFLAGS=${CFLAGS}"
+fi
+if [ -n "${CXXFLAGS}" ]; then
+  echo "CXXFLAGS=${CXXFLAGS}"
+fi
+if [ -n "${CPPFLAGS}" ]; then
+  echo "CPPFLAGS=${CPPFLAGS}"
+fi
+
+g++ $CFLAGS $CPPFLAGS $CXXFLAGS compact_lang_det_test.cc \
   cldutil.cc cldutil_shared.cc compact_lang_det.cc  compact_lang_det_hint_code.cc \
   compact_lang_det_impl.cc  debug.cc fixunicodevalue.cc \
   generated_entities.cc  generated_language.cc generated_ulscript.cc  \
@@ -24,10 +37,10 @@ g++ -O2 -m64  compact_lang_det_test.cc \
   cld_generated_cjk_delta_bi_4.cc generated_distinct_bi_0.cc  \
   cld2_generated_quadchrome_2.cc cld2_generated_deltaoctachrome.cc \
   cld2_generated_distinctoctachrome.cc  cld_generated_score_quad_octa_2.cc  \
-  -o compact_lang_det_test_chrome_2
+  -o compact_lang_det_test_chrome_2 $LDFLAGS
 echo "  compact_lang_det_test_chrome_2 compiled"
 
-g++ -O2 -m64  compact_lang_det_test.cc \
+g++ $CFLAGS $CPPFLAGS $CXXFLAGS compact_lang_det_test.cc \
   cldutil.cc cldutil_shared.cc compact_lang_det.cc  compact_lang_det_hint_code.cc \
   compact_lang_det_impl.cc  debug.cc fixunicodevalue.cc \
   generated_entities.cc  generated_language.cc generated_ulscript.cc  \
@@ -37,11 +50,11 @@ g++ -O2 -m64  compact_lang_det_test.cc \
   cld_generated_cjk_delta_bi_4.cc generated_distinct_bi_0.cc  \
   cld2_generated_quadchrome_16.cc cld2_generated_deltaoctachrome.cc \
   cld2_generated_distinctoctachrome.cc  cld_generated_score_quad_octa_2.cc  \
-  -o compact_lang_det_test_chrome_16
+  -o compact_lang_det_test_chrome_16 $LDFLAGS
 echo "  compact_lang_det_test_chrome_16 compiled"
 
 
-g++ -O2 -m64  cld2_unittest.cc \
+g++ $CFLAGS $CPPFLAGS $CXXFLAGS cld2_unittest.cc \
   cldutil.cc cldutil_shared.cc compact_lang_det.cc  compact_lang_det_hint_code.cc \
   compact_lang_det_impl.cc  debug.cc fixunicodevalue.cc \
   generated_entities.cc  generated_language.cc generated_ulscript.cc  \
@@ -51,10 +64,10 @@ g++ -O2 -m64  cld2_unittest.cc \
   cld_generated_cjk_delta_bi_4.cc generated_distinct_bi_0.cc  \
   cld2_generated_quadchrome_2.cc cld2_generated_deltaoctachrome.cc \
   cld2_generated_distinctoctachrome.cc  cld_generated_score_quad_octa_2.cc  \
-  -o cld2_unittest_chrome_2
+  -o cld2_unittest_chrome_2 $LDFLAGS
 echo "  cld2_unittest_chrome_2 compiled"
 
-g++ -O2 -m64  -Davoid_utf8_string_constants cld2_unittest.cc \
+g++ $CFLAGS $CPPFLAGS $CXXFLAGS -Davoid_utf8_string_constants cld2_unittest.cc \
   cldutil.cc cldutil_shared.cc compact_lang_det.cc  compact_lang_det_hint_code.cc \
   compact_lang_det_impl.cc  debug.cc fixunicodevalue.cc \
   generated_entities.cc  generated_language.cc generated_ulscript.cc  \
@@ -64,7 +77,7 @@ g++ -O2 -m64  -Davoid_utf8_string_constants cld2_unittest.cc \
   cld_generated_cjk_delta_bi_4.cc generated_distinct_bi_0.cc  \
   cld2_generated_quadchrome_2.cc cld2_generated_deltaoctachrome.cc \
   cld2_generated_distinctoctachrome.cc  cld_generated_score_quad_octa_2.cc  \
-  -o cld2_unittest_avoid_chrome_2
+  -o cld2_unittest_avoid_chrome_2 $LDFLAGS
 echo "  cld2_unittest_avoid_chrome_2 compiled"
 
 
diff --git a/internal/compile_dynamic.sh b/internal/compile_dynamic.sh
index d1c8f17..6973163 100755
--- a/internal/compile_dynamic.sh
+++ b/internal/compile_dynamic.sh
@@ -14,8 +14,21 @@
 #  See the License for the specific language governing permissions and
 #  limitations under the License.
 
+if [ -z "${CFLAGS}" -a -z "${CXXFLAGS}" -a -z "${CPPFLAGS}" ]; then
+  echo "Warning: None of CFLAGS, CXXFLAGS or CPPFLAGS is set; you probably should enable some options." 1>&2
+fi
+if [ -n "${CFLAGS}" ]; then
+  echo "CFLAGS=${CFLAGS}"
+fi
+if [ -n "${CXXFLAGS}" ]; then
+  echo "CXXFLAGS=${CXXFLAGS}"
+fi
+if [ -n "${CPPFLAGS}" ]; then
+  echo "CPPFLAGS=${CPPFLAGS}"
+fi
+
 # The data tool, which can be used to read and write CLD2 dynamic data files
-g++ -O2 -m64 cld2_dynamic_data_tool.cc \
+g++ $CFLAGS $CPPFLAGS $CXXFLAGS cld2_dynamic_data_tool.cc \
   cld2_dynamic_data.h cld2_dynamic_data.cc \
   cld2_dynamic_data_extractor.h cld2_dynamic_data_extractor.cc \
   cld2_dynamic_data_loader.h  cld2_dynamic_data_loader.cc \
@@ -28,11 +41,11 @@ g++ -O2 -m64 cld2_dynamic_data_tool.cc \
   cld_generated_cjk_delta_bi_4.cc generated_distinct_bi_0.cc  \
   cld2_generated_quadchrome_2.cc cld2_generated_deltaoctachrome.cc \
   cld2_generated_distinctoctachrome.cc  cld_generated_score_quad_octa_2.cc  \
-  -o cld2_dynamic_data_tool
+  -o cld2_dynamic_data_tool $LDFLAGS
 echo "  cld2_dynamic_data_tool compiled"
 
 # Tests for Chromium flavored dynamic CLD2
-g++ -O2 -m64 -D CLD2_DYNAMIC_MODE compact_lang_det_test.cc \
+g++ $CFLAGS $CPPFLAGS $CXXFLAGS -D CLD2_DYNAMIC_MODE compact_lang_det_test.cc \
   cld2_dynamic_data.h cld2_dynamic_data.cc \
   cld2_dynamic_data_extractor.h cld2_dynamic_data_extractor.cc \
   cld2_dynamic_data_loader.h  cld2_dynamic_data_loader.cc \
@@ -41,12 +54,12 @@ g++ -O2 -m64 -D CLD2_DYNAMIC_MODE compact_lang_det_test.cc \
   generated_entities.cc  generated_language.cc generated_ulscript.cc  \
   getonescriptspan.cc lang_script.cc offsetmap.cc  scoreonescriptspan.cc \
   tote.cc utf8statetable.cc  \
-  -o compact_lang_det_dynamic_test_chrome
+  -o compact_lang_det_dynamic_test_chrome $LDFLAGS
 echo "  compact_lang_det_dynamic_test_chrome compiled"
 
 
 # Unit tests, in dynamic mode
-g++ -O2 -m64 -g3 -D CLD2_DYNAMIC_MODE cld2_unittest.cc \
+g++ $CFLAGS $CPPFLAGS $CXXFLAGS -g3 -D CLD2_DYNAMIC_MODE cld2_unittest.cc \
   cld2_dynamic_data.h cld2_dynamic_data.cc \
   cld2_dynamic_data_loader.h  cld2_dynamic_data_loader.cc \
   cldutil.cc cldutil_shared.cc compact_lang_det.cc  compact_lang_det_hint_code.cc \
@@ -54,11 +67,11 @@ g++ -O2 -m64 -g3 -D CLD2_DYNAMIC_MODE cld2_unittest.cc \
   generated_entities.cc  generated_language.cc generated_ulscript.cc  \
   getonescriptspan.cc lang_script.cc offsetmap.cc  scoreonescriptspan.cc \
   tote.cc utf8statetable.cc  \
-  -o cld2_dynamic_unittest
+  -o cld2_dynamic_unittest $LDFLAGS
 echo "  cld2_dynamic_unittest compiled"
 
 # Shared library, in dynamic mode
-g++ -shared -fPIC -O2 -m64 -D CLD2_DYNAMIC_MODE \
+g++ $CFLAGS $CPPFLAGS $CXXFLAGS -shared -fPIC -D CLD2_DYNAMIC_MODE \
   cld2_dynamic_data.h cld2_dynamic_data.cc \
   cld2_dynamic_data_loader.h  cld2_dynamic_data_loader.cc \
   cldutil.cc cldutil_shared.cc compact_lang_det.cc compact_lang_det_hint_code.cc \
@@ -66,6 +79,6 @@ g++ -shared -fPIC -O2 -m64 -D CLD2_DYNAMIC_MODE \
   generated_entities.cc  generated_language.cc generated_ulscript.cc  \
   getonescriptspan.cc lang_script.cc offsetmap.cc  scoreonescriptspan.cc \
   tote.cc utf8statetable.cc  \
-  -o libcld2_dynamic.so
+  -o libcld2_dynamic.so -Wl,-soname=libcld2_dynamic.so $LDFLAGS
 echo "  libcld2_dynamic.so compiled"
 
diff --git a/internal/compile_full.sh b/internal/compile_full.sh
index c58ba2c..4736506 100755
--- a/internal/compile_full.sh
+++ b/internal/compile_full.sh
@@ -14,7 +14,20 @@
 #  See the License for the specific language governing permissions and
 #  limitations under the License.
 
-g++ -O2 -m64  compact_lang_det_test.cc \
+if [ -z "${CFLAGS}" -a -z "${CXXFLAGS}" -a -z "${CPPFLAGS}" ]; then
+  echo "Warning: None of CFLAGS, CXXFLAGS or CPPFLAGS is set; you probably should enable some options." 1>&2
+fi
+if [ -n "${CFLAGS}" ]; then
+  echo "CFLAGS=${CFLAGS}"
+fi
+if [ -n "${CXXFLAGS}" ]; then
+  echo "CXXFLAGS=${CXXFLAGS}"
+fi
+if [ -n "${CPPFLAGS}" ]; then
+  echo "CPPFLAGS=${CPPFLAGS}"
+fi
+
+g++ $CFLAGS $CPPFLAGS $CXXFLAGS compact_lang_det_test.cc \
   cldutil.cc cldutil_shared.cc compact_lang_det.cc  compact_lang_det_hint_code.cc \
   compact_lang_det_impl.cc  debug.cc fixunicodevalue.cc \
   generated_entities.cc  generated_language.cc generated_ulscript.cc  \
@@ -24,10 +37,10 @@ g++ -O2 -m64  compact_lang_det_test.cc \
   cld_generated_cjk_delta_bi_32.cc generated_distinct_bi_0.cc  \
   cld2_generated_quad0122.cc cld2_generated_deltaocta0122.cc \
   cld2_generated_distinctocta0122.cc  cld_generated_score_quad_octa_0122.cc  \
-  -o compact_lang_det_test_full
+  -o compact_lang_det_test_full $LDFLAGS
 echo "  compact_lang_det_test_full compiled"
 
-g++ -O2 -m64  cld2_unittest_full.cc \
+g++ $CFLAGS $CPPFLAGS $CXXFLAGS cld2_unittest_full.cc \
   cldutil.cc cldutil_shared.cc compact_lang_det.cc  compact_lang_det_hint_code.cc \
   compact_lang_det_impl.cc  debug.cc fixunicodevalue.cc \
   generated_entities.cc  generated_language.cc generated_ulscript.cc  \
@@ -37,10 +50,10 @@ g++ -O2 -m64  cld2_unittest_full.cc \
   cld_generated_cjk_delta_bi_32.cc generated_distinct_bi_0.cc  \
   cld2_generated_quad0122.cc cld2_generated_deltaocta0122.cc \
   cld2_generated_distinctocta0122.cc  cld_generated_score_quad_octa_0122.cc  \
-  -o cld2_unittest_full
+  -o cld2_unittest_full $LDFLAGS
 echo "  cld2_unittest_full compiled"
 
-g++ -O2 -m64  -Davoid_utf8_string_constants cld2_unittest_full.cc \
+g++ $CFLAGS $CPPFLAGS $CXXFLAGS -Davoid_utf8_string_constants cld2_unittest_full.cc \
   cldutil.cc cldutil_shared.cc compact_lang_det.cc  compact_lang_det_hint_code.cc \
   compact_lang_det_impl.cc  debug.cc fixunicodevalue.cc \
   generated_entities.cc  generated_language.cc generated_ulscript.cc  \
@@ -50,6 +63,6 @@ g++ -O2 -m64  -Davoid_utf8_string_constants cld2_unittest_full.cc \
   cld_generated_cjk_delta_bi_32.cc generated_distinct_bi_0.cc  \
   cld2_generated_quad0122.cc cld2_generated_deltaocta0122.cc \
   cld2_generated_distinctocta0122.cc  cld_generated_score_quad_octa_0122.cc  \
-  -o cld2_unittest_full_avoid
+  -o cld2_unittest_full_avoid $LDFLAGS
 echo "  cld2_unittest_full_avoid compiled"
 
diff --git a/internal/compile_libs.sh b/internal/compile_libs.sh
index 6173402..38c6655 100755
--- a/internal/compile_libs.sh
+++ b/internal/compile_libs.sh
@@ -14,7 +14,20 @@
 #  See the License for the specific language governing permissions and
 #  limitations under the License.
 
-g++ -shared -fPIC -O2 -m64 \
+if [ -z "${CFLAGS}" -a -z "${CXXFLAGS}" -a -z "${CPPFLAGS}" ]; then
+  echo "Warning: None of CFLAGS, CXXFLAGS or CPPFLAGS is set; you probably should enable some options." 1>&2
+fi
+if [ -n "${CFLAGS}" ]; then
+  echo "CFLAGS=${CFLAGS}"
+fi
+if [ -n "${CXXFLAGS}" ]; then
+  echo "CXXFLAGS=${CXXFLAGS}"
+fi
+if [ -n "${CPPFLAGS}" ]; then
+  echo "CPPFLAGS=${CPPFLAGS}"
+fi
+
+g++ $CFLAGS $CPPFLAGS $CXXFLAGS -shared -fPIC \
   cldutil.cc cldutil_shared.cc compact_lang_det.cc compact_lang_det_hint_code.cc \
   compact_lang_det_impl.cc  debug.cc fixunicodevalue.cc \
   generated_entities.cc  generated_language.cc generated_ulscript.cc  \
@@ -24,9 +37,9 @@ g++ -shared -fPIC -O2 -m64 \
   cld_generated_cjk_delta_bi_4.cc generated_distinct_bi_0.cc  \
   cld2_generated_quadchrome_2.cc cld2_generated_deltaoctachrome.cc \
   cld2_generated_distinctoctachrome.cc  cld_generated_score_quad_octa_2.cc  \
-  -o libcld2.so
+  -o libcld2.so $LDFLAGS -Wl,-soname=libcld2.so
 
-g++ -shared -fPIC -O2 -m64 \
+g++ $CFLAGS $CPPFLAGS $CXXFLAGS -shared -fPIC \
   cldutil.cc cldutil_shared.cc compact_lang_det.cc compact_lang_det_hint_code.cc \
   compact_lang_det_impl.cc  debug.cc fixunicodevalue.cc \
   generated_entities.cc  generated_language.cc generated_ulscript.cc  \
@@ -36,5 +49,5 @@ g++ -shared -fPIC -O2 -m64 \
   cld_generated_cjk_delta_bi_32.cc generated_distinct_bi_0.cc  \
   cld2_generated_quad0122.cc cld2_generated_deltaocta0122.cc \
   cld2_generated_distinctocta0122.cc  cld_generated_score_quad_octa_0122.cc  \
-  -o libcld2_full.so
+  -o libcld2_full.so $LDFLAGS -Wl,-soname=libcld2_full.so