ICU-20839 Add ICU4C header test to check for including utypes.h when using U_SHOW_CPL...

diff --git a/icu4c/source/test/hdrtst/Makefile.in b/icu4c/source/test/hdrtst/Makefile.in
index 60a8e72a67734c8ee208de660deda7173a1494da..af0e8485843e40a03ec33782ac1456eb331b6111 100644 (file)
--- a/icu4c/source/test/hdrtst/Makefile.in
+++ b/icu4c/source/test/hdrtst/Makefile.in
@@ -16,9 +16,12 @@
 ##  unicode/ucnv.h -   0
 ##
 ##    .. etc.  Anything other than zero is an error. (except for the deprecation tests, where '1' is the correct value)
-##              
+##
 ##  If a header fails the C compile test it is likely because the header is a
-##  C++ header and isn't properly guarded by the U_SHOW_CPLUSPLUS_API macro.
+##  C++ header and it isn't properly guarded by the U_SHOW_CPLUSPLUS_API macro.
+##
+##  If a header fails the cppguardtest test it is likely because the header doesn't
+##  include the utypes.h header first *before* using the macro U_SHOW_CPLUSPLUS_API.
 ##
 ##  If a header fails because it is deprecated, add it to the 'dfiles.txt'
 ##
@@ -37,7 +40,7 @@ all:
        @echo Please read this Makefile for more information.
        @echo run \'$(MAKE) check\' to run the test "(use -k if you don't want to stop on errs)"
 
-check: dtest ctest cpptest drafttest deprtest internaltest obsoletetest
+check: dtest ctest cpptest drafttest deprtest internaltest obsoletetest cppguardtest
 
 headertest:
        @FAIL=0;stub=ht_stub_$(NAME.headers).$(SUFFIX.headers); for file in "$(prefix)/include/unicode"/*.h ; do \
@@ -108,6 +111,24 @@ dtest:
        echo "$@: $$NONE - exit status $$FAIL" ; \
        exit $$FAIL
 
+cppguardtest:
+       @FAIL=0;stub=ht_stub_cppguardtest.cpp; for file in "$(prefix)/include/unicode"/*.h ; do \
+               incfile=`basename $$file` ; \
+               if grep -q "U_SHOW_CPLUSPLUS_API" $$file ; then \
+                       echo "$@ unicode/$$incfile" ; \
+                       echo "#include <unicode/$$incfile>" > $$stub ; \
+                       echo 'void junk(){}' >> $$stub ; \
+                       echo '#if !defined(U_SHOW_CPLUSPLUS_API)' >> $$stub ; \
+                       echo "#error The header '$$incfile' refers to the macro U_SHOW_CPLUSPLUS_API (defined in utypes.h) but either does not include utypes.h or does so incorrectly." >> $$stub ; \
+                       echo '#endif' >> $$stub ; \
+                       $(COMPILE.cc) $(cppflags) $$stub || FAIL=1 ; \
+                       rm -f $$stub; \
+               else \
+                       echo "$@ skipping unicode/$$incfile" ; \
+               fi ; \
+       done ; \
+       exit $$FAIL
+
 clean:
        -@rm -f ht_*
 
@@ -118,4 +139,4 @@ Makefile: $(srcdir)/Makefile.in  $(top_builddir)/config.status
        cd $(top_builddir) \
        && CONFIG_FILES=$(subdir)/$@ CONFIG_HEADERS= $(SHELL) ./config.status
 
-.PHONY:        doclean check all headertest cpptest dtest ctest clean distclean
+.PHONY:        doclean check all headertest cpptest dtest cppguardtest ctest clean distclean