Build errors when enabling pcre2 on macOS

[ryandesign]

Building link-grammar 5.12.4 on macOS 12 fails for me:

libtool: compile:  /usr/bin/clang -DPACKAGE_NAME=\"link-grammar\" -DPACKAGE_TARNAME=\"link-grammar\" -DPACKAGE_VERSION=\"5.12.4\" "-DPACKAGE_STRING=\"link-grammar 5.12.4\"" -DPACKAGE_BUGREPORT=\"https://github.com/opencog/link-grammar\" -DPACKAGE_URL=\"https://opencog.github.io/link-grammar-website\" -DPACKAGE=\"link-grammar\" -DVERSION=\"5.12.4\" -DHAVE_STDIO_H=1 -DHAVE_STDLIB_H=1 -DHAVE_STRING_H=1 -DHAVE_INTTYPES_H=1 -DHAVE_STDINT_H=1 -DHAVE_STRINGS_H=1 -DHAVE_SYS_STAT_H=1 -DHAVE_SYS_TYPES_H=1 -DHAVE_UNISTD_H=1 -DSTDC_HEADERS=1 -DHAVE_DLFCN_H=1 -DLT_OBJDIR=\".libs/\" -DYYTEXT_POINTER=1 -DHAVE_STRNDUP=1 -DHAVE_STRTOK_R=1 -DHAVE_SIGACTION=1 -DHAVE_ALIGNED_ALLOC=1 -DHAVE_POSIX_MEMALIGN=1 -DHAVE_ALLOCA_H=1 -DHAVE_ALLOCA=1 -DHAVE_FORK=1 -DHAVE_VFORK=1 -DHAVE_WORKING_VFORK=1 -DHAVE_WORKING_FORK=1 -D__STDC_FORMAT_MACROS=1 -D__STDC_LIMIT_MACROS=1 -DTLS=_Thread_local -DHAVE_PTHREAD_PRIO_INHERIT=1 -DHAVE_PTHREAD=1 -DHAVE_VISIBILITY=1 -DHAVE_LOCALE_T_IN_XLOCALE_H=1 -DHAVE_XLOCALE_H=1 -DHAVE_STDATOMIC_H=1 -DHAVE_MKLIT=1 -DUSE_SAT_SOLVER=1 -DUSE_WORDGRAPH_DISPLAY=1 -DHAVE_SQLITE3=1 -DHAVE_HUNSPELL=1 -DHUNSPELL_DICT_DIR=\"/Library/Spelling\" -DHAVE_EDITLINE=1 -DHAVE_WIDECHAR_EDITLINE=1 -DHAVE_PCRE2_H=1 -DHAVE_DECL_STRERROR_R=1 -DHAVE_STRERROR_R=1 -DVERSION=\"5.12.4\" -DDICTIONARY_DIR=\"/opt/local/share/link-grammar\" -DCC=\"/usr/bin/clang\" -I. -I.. -I.. -I/opt/local/include -isysroot/Library/Developer/CommandLineTools/SDKs/MacOSX12.sdk -Wstrict-prototypes -Wmissing-prototypes -Wnested-externs -Wold-style-definition -Werror-implicit-function-declaration -Wall -Wextra -Wsign-compare -Wpointer-arith -Wwrite-strings -Wmissing-declarations -Wpacked -Wswitch-enum -Wmissing-format-attribute -Wstrict-aliasing -Winit-self -Wshadow -Wno-missing-field-initializers -Wno-unused-parameter -Wno-attributes -Wno-long-long -Winline -I/opt/local/include/hunspell -pthread -D_DEFAULT_SOURCE -std=c11 -D_BSD_SOURCE -D_SVID_SOURCE -D_GNU_SOURCE -D_ISOC11_SOURCE -fvisibility=hidden -pipe -Os -isysroot/Library/Developer/CommandLineTools/SDKs/MacOSX12.sdk -arch x86_64 -MT dict-common/regex-morph.lo -MD -MP -MF dict-common/.deps/regex-morph.Tpo -c dict-common/regex-morph.c  -fno-common -DPIC -o dict-common/.libs/regex-morph.o
dict-common/regex-morph.c:169:8: error: unknown type name 'once_flag'
static once_flag call_once_flag = ONCE_FLAG_INIT;
       ^
dict-common/regex-morph.c:169:35: error: use of undeclared identifier 'ONCE_FLAG_INIT'
static once_flag call_once_flag = ONCE_FLAG_INIT;
                                  ^
dict-common/regex-morph.c:170:8: error: unknown type name 'tss_t'
static tss_t re_md_key;
       ^
dict-common/regex-morph.c:173:11: error: implicit declaration of function 'tss_create' is invalid in C99 [-Werror,-Wimplicit-function-declaration]
        int rc = tss_create(&re_md_key, (tss_dtor_t) pcre2_match_data_free);
                 ^
dict-common/regex-morph.c:173:11: note: did you mean 'Exp_create'?
./dict-ram/dict-ram.h:25:7: note: 'Exp_create' declared here
Exp * Exp_create(Pool_desc *);
      ^
dict-common/regex-morph.c:173:35: error: use of undeclared identifier 'tss_dtor_t'
        int rc = tss_create(&re_md_key, (tss_dtor_t) pcre2_match_data_free);
                                         ^
dict-common/regex-morph.c:174:6: error: use of undeclared identifier 'thrd_success'
        if (thrd_success == rc) return;
            ^
dict-common/regex-morph.c:192:33: error: use of undeclared identifier 'nullptr'
        static pcre2_match_data *pmd = nullptr;
                                       ^
7 errors generated.

I can at least explain the last error: nullptr is a C++11 thing. You can't use C++ things in C code. In C, use NULL.

As for once_flag and ONCE_FLAG_INIT, those seems to be related to C11 threads, and macOS doesn't support C11 threads. The configure script correctly determined that threads.h does not exist.

My configure arguments were --prefix=/opt/local --disable-silent-rules --enable-editline --with-regexlib=pcre2 --disable-aspell --enable-hunspell --disable-java-bindings --disable-perl-bindings --disable-python-bindings --enable-sat-solver=bundled

My compilers are:

% /Library/Developer/CommandLineTools/usr/bin/clang --version
Apple clang version 13.0.0 (clang-1300.0.29.30)
Target: x86_64-apple-darwin21.6.0
Thread model: posix
InstalledDir: /Library/Developer/CommandLineTools/usr/bin

% /Library/Developer/CommandLineTools/usr/bin/clang++ --version
Apple clang version 13.0.0 (clang-1300.0.29.30)
Target: x86_64-apple-darwin21.6.0
Thread model: posix
InstalledDir: /Library/Developer/CommandLineTools/usr/bin

[ryandesign]

If I use --disable-pcre2 --with-regexlib=c instead of --with-regexlib=pcre2 then it builds.

[ryandesign]

Fixed by 34d1a1d, 94eed5c, and 77254ab.