merge bitcoin#24337: Do not define PROVIDE_FUZZ_MAIN_FUNCTION macro…

… unconditionally

configure.ac

@@ -1363,22 +1363,6 @@ if test "x$enable_fuzz" = "xyes"; then
   enable_fuzz_binary=yes
 
   AX_CHECK_PREPROC_FLAG([-DABORT_ON_FAILED_ASSUME],[[DEBUG_CPPFLAGS="$DEBUG_CPPFLAGS -DABORT_ON_FAILED_ASSUME"]],,[[$CXXFLAG_WERROR]])
-
-  AC_MSG_CHECKING([whether main function is needed for fuzz binary])
-  AX_CHECK_LINK_FLAG(
-    [[-fsanitize=$use_sanitizers]],
-    [AC_MSG_RESULT([no])],
-    [AC_MSG_RESULT([yes])
-     CORE_CPPFLAGS="$CORE_CPPFLAGS -DPROVIDE_FUZZ_MAIN_FUNCTION"],
-    [],
-    [AC_LANG_PROGRAM([[
-      #include <cstdint>
-      #include <cstddef>
-      extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) { return 0; }
-      /* comment to remove the main function ...
-     ]],[[
-      */ int not_main() {
-     ]])])
 else
     BITCOIN_QT_INIT
 
@@ -1392,8 +1376,25 @@ else
       QT_DBUS_INCLUDES=SUPPRESS_WARNINGS($QT_DBUS_INCLUDES)
       QT_TEST_INCLUDES=SUPPRESS_WARNINGS($QT_TEST_INCLUDES)
     fi
+fi
+
+if test x$enable_fuzz_binary = xyes; then
+  AC_MSG_CHECKING([whether main function is needed for fuzz binary])
+  AX_CHECK_LINK_FLAG(
+    [],
+    [AC_MSG_RESULT([no])],
+    [AC_MSG_RESULT([yes]); CORE_CPPFLAGS="$CORE_CPPFLAGS -DPROVIDE_FUZZ_MAIN_FUNCTION"],
+    [$SANITIZER_LDFLAGS],
+    [AC_LANG_PROGRAM([[
+      #include <cstdint>
+      #include <cstddef>
+      extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) { return 0; }
+      /* comment to remove the main function ...
+     ]],[[
+      */ int not_main() {
+     ]])])
 
-    CORE_CPPFLAGS="$CORE_CPPFLAGS -DPROVIDE_FUZZ_MAIN_FUNCTION"
+  CHECK_RUNTIME_LIB
 fi
 
 if test x$enable_wallet != xno; then
@@ -1817,10 +1818,6 @@ if test x$build_bitcoin_wallet$build_bitcoin_cli$build_bitcoin_tx$build_bitcoind
   AC_MSG_ERROR([No targets! Please specify at least one of: --with-utils --with-libs --with-daemon --with-gui --enable-bench or --enable-tests])
 fi
 
-if test x$enable_fuzz_binary = xyes; then
-  CHECK_RUNTIME_LIB
-fi
-
 AM_CONDITIONAL([TARGET_DARWIN], [test x$TARGET_OS = xdarwin])
 AM_CONDITIONAL([BUILD_DARWIN], [test x$BUILD_OS = xdarwin])
 AM_CONDITIONAL([TARGET_LINUX], [test x$TARGET_OS = xlinux])