gcc compilation broken with SVN r264042

[David Chisnall]

Hi,

I'm trying to reproduce this, but I don't seem to be able to get the same error as you.  I do get a warning with GCC about a cast to an anonymous struct, which the attached patch fixes, but even without this I'm able to build both with the gcc in 9 and the gcc in ports.  Can you let me know your gcc version?  Unfortunately, the gcc error reporting isn't very helpful, so I don't know what it thinks it can't convert to a pointer type.  It would be great if you could try this patch, and if that doesn't fix it then try splitting the casts and dereferences into separate lines and see which part of this it is the gcc doesn't like.  

David

Index: include/block_abi.h
===================================================================
--- include/block_abi.h	(revision 264042)
+++ include/block_abi.h	(working copy)
@@ -50,14 +50,16 @@
 	} *name
 #define CALL_BLOCK(name, ...) (name)->invoke(name, __VA_ARGS__)
 #endif // __BLOCKS__
+struct generic_block
+{
+	void *isa;
+	int flags;
+	int reserved;
+	void (*invoke)(void *, ...);
+};
 /**
  * Returns the pointer to the block-invoke function.  This is used for passing
  * blocks to functions that want a function pointer and a data pointer.
  */
 #define GET_BLOCK_FUNCTION(x) \
-	(((struct {\
-		void *isa;\
-		int flags;\
-		int reserved;\
-		void (*invoke)(void *, ...);\
-	}*)x)->invoke)
+	(((struct generic_block*)x)->invoke)


On 2 Apr 2014, at 20:15, Michael Butler <imb at protected-networks.net> wrote:

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> Seems that GCC doesn't like/understand the cast ..
> 
> imb at mail:/usr/src/lib/libc> sudo make
> cc  -O2 -pipe -march=pentium4  -I/usr/src/lib/libc/include
> - -I/usr/src/lib/libc/../../include -I/usr/src/lib/libc/i386 -DNLS
> - -D__DBINTERFACE_PRIVATE -I/usr/src/lib/libc/../../contrib/gdtoa
> - -I/usr/src/lib/libc/../../contrib/libc-vis -DINET6
> - -I/usr/obj/usr/src/lib/libc -I/usr/src/lib/libc/resolv -D_ACL_PRIVATE
> - -DPOSIX_MISTAKE -I/usr/src/lib/libc/../../contrib/jemalloc/include
> - -DMALLOC_PRODUCTION -I/usr/src/lib/libc/../../contrib/tzcode/stdtime
> - -I/usr/src/lib/libc/stdtime  -I/usr/src/lib/libc/locale -DBROKEN_DES
> - -DPORTMAP -DDES_BUILTIN -I/usr/src/lib/libc/rpc -DYP -DNS_CACHING
> - -DSYMBOL_VERSIONING -std=gnu99  -fstack-protector -Wsystem-headers
> - -Werror -Wall -Wno-format-y2k -Wno-uninitialized -Wno-pointer-sign -c
> /usr/src/lib/libc/stdlib/atexit.c -o atexit.o
> /usr/src/lib/libc/stdlib/atexit.c: In function 'atexit_b':
> /usr/src/lib/libc/stdlib/atexit.c:157: error: cannot convert to a
> pointer type
> *** Error code 1
> 
> Stop.
> make: stopped in /usr/src/lib/libc
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