build: Add checks for compiler supporting constructor

Signed-off-by: Ben Collins <[email protected]>
benmcollins · Dec 23, 2024 · 59531a0 · 59531a0
1 parent 8254046
commit 59531a0
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Showing 7 changed files with 24 additions and 2 deletions.
diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -60,7 +60,15 @@ set_target_properties(jwt_static PROPERTIES OUTPUT_NAME jwt)
 
 target_sources(jwt PRIVATE libjwt/jwt.c libjwt/jwks.c libjwt/base64.c)
 
-generate_export_header(jwt)
+set(COMPILER_CONSTRUCTOR "__attribute__((constructor))")
+_check_c_compiler_attribute(${COMPILER_CONSTRUCTOR} COMPILER_HAS_CONSTRUCTOR)
+if (COMPILER_HAS_CONSTRUCTOR)
+	set(JWT_CUSTOM_CONTENT "\n#define JWT_CONSTRUCTOR ${COMPILER_CONSTRUCTOR}\n")
+else()
+	set(JWT_CUSTOM_CONTENT "\n#define JWT_CONSTRUCTOR\n")
+endif()
+generate_export_header(jwt
+	CUSTOM_CONTENT_FROM_VARIABLE JWT_CUSTOM_CONTENT)
 
 include_directories(${CMAKE_SOURCE_DIR}/include ${CMAKE_BINARY_DIR})
 

diff --git a/Doxyfile b/Doxyfile
@@ -2397,8 +2397,11 @@ INCLUDE_FILE_PATTERNS  =
 
 PREDEFINED             = _DOXYGEN \
                          JWT_EXPORT= \
+			 JWT_NO_EXPORT= \
                          JWT_DEPRECATED= \
 			 JWT_DEPRECATED_EXPORT= \
+			 JWT_DEPRECATED_NO_EXPORT= \
+			 JWT_CONSTRUCTOR= \
                          __attribute__(x)= \
 			 __declspec(x)=
 

diff --git a/configure.ac b/configure.ac
@@ -117,6 +117,7 @@ dnl AX_GCC_FUNC_ATTRIBUTE([deprecated])
 dnl AX_GCC_FUNC_ATTRIBUTE([visibility])
 AC_SUBST([GCC_FUNC_DEPRECATED],["__attribute__((__deprecated__))"])
 AC_SUBST([GCC_EXPORT],["__attribute__((visibility(\"default\")))"])
+AC_SUBST([GCC_CONSTRUCTOR],["__attribute__((constructor))"])
 
 dnl Valgrind defaults
 AX_VALGRIND_DFLT([memcheck], [on])

diff --git a/include/jwt_export.h.in b/include/jwt_export.h.in
@@ -11,9 +11,11 @@
 #      define JWT_EXPORT __declspec(dllimport)
 #    endif
 #  endif
+#  define JWT_CONSTRUCTOR
 #else
 #  define JWT_DEPRECATED @GCC_FUNC_DEPRECATED@
 #  define JWT_EXPORT @GCC_EXPORT@
+#  define JWT_CONSTRUCTOR @GCC_CONSTRUCTOR@
 #endif
 
 #ifndef JWT_DEPRECATED_EXPORT

diff --git a/libjwt/jwt.c b/libjwt/jwt.c
@@ -95,7 +95,7 @@ int jwt_crypto_ops_supports_jwk(void)
 	return jwt_ops->jwk_implemented ? 1 : 0;
 }
 
-__attribute__((constructor))
+JWT_CONSTRUCTOR
 void jwt_init()
 {
 	const char *opname = getenv("JWT_CRYPTO");

diff --git a/tests/jwt_dump.c b/tests/jwt_dump.c
@@ -28,13 +28,15 @@ static int test_set_alloc(void)
 	return jwt_set_alloc(test_malloc, test_realloc, test_free);
 }
 
+#ifdef JWT_CONSTRUCTOR
 START_TEST(test_jwt_crypto_ops)
 {
 	const char *msg = getenv("JWT_CRYPTO");
 
 	ck_assert_str_eq(msg, "NONEXISTENT");
 }
 END_TEST
+#endif
 
 START_TEST(test_alloc_funcs)
 {
@@ -374,7 +376,9 @@ static Suite *libjwt_suite(const char *title)
 
 	tc_core = tcase_create("jwt_dump");
 
+#ifdef JWT_CONSTRUCTOR
 	tcase_add_test(tc_core, test_jwt_crypto_ops);
+#endif
 	tcase_add_loop_test(tc_core, test_alloc_funcs, 0, i);
 	tcase_add_loop_test(tc_core, test_jwt_dump_fp, 0, i);
 	tcase_add_loop_test(tc_core, test_jwt_dump_str, 0, i);

diff --git a/tests/jwt_new.c b/tests/jwt_new.c
@@ -8,13 +8,15 @@
 
 #include "jwt_tests.h"
 
+#ifdef JWT_CONSTRUCTOR
 START_TEST(test_jwt_crypto_ops)
 {
 	const char *msg = getenv("JWT_CRYPTO");
 
 	ck_assert_str_eq(msg, "openssl");
 }
 END_TEST
+#endif
 
 START_TEST(test_jwt_new)
 {
@@ -615,7 +617,9 @@ static Suite *libjwt_suite(const char *title)
 
 	tc_core = tcase_create("jwt_new");
 
+#ifdef JWT_CONSTRUCTOR
 	tcase_add_test(tc_core, test_jwt_crypto_ops);
+#endif
 	tcase_add_loop_test(tc_core, test_jwt_new, 0, i);
 	tcase_add_loop_test(tc_core, test_jwt_dup, 0, i);
 	tcase_add_loop_test(tc_core, test_jwt_dup_signed, 0, i);