Check for strlcpy/strlcat

Some newer builds of glibc have strlcpy and strlcat defined, resulting
in build failures on newer Linux distros. Rather than try to hard-code
whether or not each version of each platform has strlcat and strlcpy,
this patch has CMake check to see if it's available after including
string.h. If they are, then we should not redefine them.

This is a targeted change pulling the fix from the patch set merged in
5a1db79.

Author: etcwilde

CoreFoundation/Base.subproj/CoreFoundation_Prefix.h

@@ -189,7 +189,8 @@ static dispatch_queue_t __ ## PREFIX ## Queue(void) {			\
 #define CF_RETAIN_BALANCED_ELSEWHERE(obj, identified_location) do { } while (0)
 #endif
 
-#if (TARGET_OS_LINUX && !TARGET_OS_ANDROID && !TARGET_OS_CYGWIN) || TARGET_OS_WIN32
+#if !TARGET_OS_MAC
+#ifndef HAVE_STRLCPY
 CF_INLINE size_t
 strlcpy(char * dst, const char * src, size_t maxlen) {
     const size_t srclen = strlen(src);
@@ -201,7 +202,9 @@ strlcpy(char * dst, const char * src, size_t maxlen) {
     }
     return srclen;
 }
+#endif // !HAVE_STRLCPY
 
+#ifndef HAVE_STRLCAT
 CF_INLINE size_t
 strlcat(char * dst, const char * src, size_t maxlen) {
     const size_t srclen = strlen(src);
@@ -215,7 +218,8 @@ strlcat(char * dst, const char * src, size_t maxlen) {
     }
     return dstlen + srclen;
 }
-#endif
+#endif // !HAVE_STRLCAT
+#endif // !TARGET_OS_MAC
 
 #if TARGET_OS_WIN32
 // Compatibility with boolean.h

CoreFoundation/CMakeLists.txt

@@ -6,6 +6,8 @@ project(CoreFoundation
   VERSION 1338
   LANGUAGES ASM C)
 
+include(CheckSymbolExists)
+
 set(CMAKE_C_STANDARD 99)
 set(CMAKE_C_STANDARD_REQUIRED YES)
 
@@ -62,6 +64,16 @@ if(NOT "${CMAKE_C_SIMULATE_ID}" STREQUAL "MSVC")
   add_compile_options($<$<COMPILE_LANGUAGE:C>:-Werror=implicit-function-declaration>)
 endif()
 
+check_symbol_exists("strlcat" "string.h" HAVE_STRLCAT)
+check_symbol_exists("strlcpy" "string.h" HAVE_STRLCPY)
+
+if(HAVE_STRLCAT)
+  add_compile_definitions($<$<COMPILE_LANGUAGE:C>:HAVE_STRLCAT>)
+endif()
+if(HAVE_STRLCPY)
+  add_compile_definitions($<$<COMPILE_LANGUAGE:C>:HAVE_STRLCPY>)
+endif()
+
 if(CF_DEPLOYMENT_SWIFT)
   add_compile_options($<$<COMPILE_LANGUAGE:C>:$<$<STREQUAL:${CMAKE_C_SIMULATE_ID},MSVC>:/clang:>-fcf-runtime-abi=swift>)
 endif()