helper/compiler: fix build on MacOS

On MacOS, clang defines [1]: #define __nonnull _Nonnull that creates incompatibility with GCC and with the macro __nonnull defined in some libc. Detect clang on MacOS and undefine __nonnull. Change-Id: I64fcf51b102ea91c196e657debd8c267943a2b08 Signed-off-by: Antonio Borneo <[email protected]> Links: [1] https://github.com/llvm/llvm-project/blob/llvmorg-16.0.0/clang/lib/Frontend/InitPreprocessor.cpp#L1226 Reviewed-on: https://review.openocd.org/c/openocd/+/7544 Tested-by: jenkins
riscv-collab · Mar 25, 2023 · 9ce6b08 · 9ce6b08
1 parent b6b4f9d
commit 9ce6b08
Showing 1 changed file with 8 additions and 0 deletions.
diff --git a/src/helper/compiler.h b/src/helper/compiler.h
@@ -32,7 +32,15 @@
 /*
  * The __nonnull function attribute marks pointer parameters that
  * must not be NULL.
+ *
+ * clang for Apple defines
+ * #define __nonnull _Nonnull
+ * that is a per argument attribute, incompatible with the gcc per function attribute __nonnull__.
+ * Undefine it to keep compatibility among compilers.
  */
+#if defined(__clang__) && defined(__APPLE__)
+# undef __nonnull
+#endif
 #ifndef __nonnull
 # if __has_attribute(__nonnull__)
 #  define __nonnull(params) __attribute__ ((__nonnull__ params))