Don't redefine a bunch of defines from llvm-config.h in config.h.

[thakis]

Summary

r210144 made config.h include llvm-config.h and deduplicated defines. Then rL239987 later added back some of the duplication. http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20150914/300329.html suggests this was done for the configure/make build, which no longer exists.

A prior attempt at this was apparently at https://reviews.llvm.org/D41371

[thakis]

missed one

[bogner]

include/llvm/Config/config.h.cmake

296–297

The one in llvm-config.h doesn't have this comment and does use cmakedefine. Please make sure we're still doing the right thing when this is empty (that is, build with -DLLVM_DEFAULT_TARGET_TRIPLE="")

[thakis]

include/llvm/Config/config.h.cmake

296–297

Since config.h includes llvm-config.h, when it's undefined in config.h the one in llvm-config.h won. So this is behavior-preserving, and since this doesn't work it looks like the comment is outdated.

[thakis]

bogner, rnk, chapuni: ping

include/llvm/Config/config.h.cmake

296–297

Did this make sense?

[bogner]

include/llvm/Config/config.h.cmake

296–297

No, I think you have this backwards. Today, if LLVM_DEFAULT_TARGET_TRIPLE is blank, llvm-config.h has a comment like so:

/* #undef LLVM_DEFAULT_TARGET_TRIPLE */

Whereas config.h defines the value to an empty string:

#define LLVM_DEFAULT_TARGET_TRIPLE ""

So removing this from config.h will make it so that it's neither #defined nor #undef'd in either file, which is not behaviour preserving. In fact, if you build this way you'll probably get a compile error in lib/Support/Unix/Host.inc when it tries to call updateTripleOSVersion with no parameter. This is what I was asking you to check here.

Moving the explicit define from here to llvm-config.h is also technically not behaviour preserving, since external projects that use these headers will see a #define of "" instead of no symbol at all, but I think that's at least a change that is arguably correct.

[thakis]

Address comment.

include/llvm/Config/config.h.cmake

296–297

Got it, thanks! I removed LLVM_DEFAULT_TARGET_TRIPLE from this change.

[rnk]

+1

[thakis]

r331987, thanks!

include/llvm/Config/config.h.cmake

 #cmakedefine HAVE____CHKSTK ${HAVE____CHKSTK}
 
 /* Have host's ___chkstk_ms */
 #cmakedefine HAVE____CHKSTK_MS ${HAVE____CHKSTK_MS}
 
 /* Linker version detected at compile time. */
 #cmakedefine HOST_LINK_VERSION "${HOST_LINK_VERSION}"
 
-/* Define if we link Polly to the tools */
-#cmakedefine LINK_POLLY_INTO_TOOLS
-
 /* Target triple LLVM will generate code for by default */
 /* Doesn't use `cmakedefine` because it is allowed to be empty. */
 #define LLVM_DEFAULT_TARGET_TRIPLE "${LLVM_DEFAULT_TARGET_TRIPLE}"
 
-/* Define if threads enabled */
-#cmakedefine01 LLVM_ENABLE_THREADS
-
 /* Define if zlib compression is available */
 #cmakedefine01 LLVM_ENABLE_ZLIB
 
-/* Has gcc/MSVC atomic intrinsics */
-#cmakedefine01 LLVM_HAS_ATOMICS
-
-/* Host triple LLVM will be executed on */
-#cmakedefine LLVM_HOST_TRIPLE "${LLVM_HOST_TRIPLE}"
-
-/* Define if this is Unixish platform */
-#cmakedefine LLVM_ON_UNIX ${LLVM_ON_UNIX}
-
 /* Define if overriding target triple is enabled */
 #cmakedefine LLVM_TARGET_TRIPLE_ENV "${LLVM_TARGET_TRIPLE_ENV}"
 
-/* Define if we have the Intel JIT API runtime support library */
-#cmakedefine01 LLVM_USE_INTEL_JITEVENTS
-
-/* Define if we have the oprofile JIT-support library */
-#cmakedefine01 LLVM_USE_OPROFILE
-
 /* LLVM version information */
 #cmakedefine LLVM_VERSION_INFO "${LLVM_VERSION_INFO}"
 
 /* Whether tools show host and target info when invoked with --version */
 #cmakedefine01 LLVM_VERSION_PRINTER_SHOW_HOST_TARGET_INFO
 
-/* Major version of the LLVM API */
-#define LLVM_VERSION_MAJOR ${LLVM_VERSION_MAJOR}
-
-/* Minor version of the LLVM API */
-#define LLVM_VERSION_MINOR ${LLVM_VERSION_MINOR}
-
-/* Patch version of the LLVM API */
-#define LLVM_VERSION_PATCH ${LLVM_VERSION_PATCH}
-
-/* LLVM version string */
-#define LLVM_VERSION_STRING "${PACKAGE_VERSION}"
-
 /* Define if libxml2 is supported on this platform. */
 #cmakedefine LLVM_LIBXML2_ENABLED ${LLVM_LIBXML2_ENABLED}
 
 /* Define to the extension used for shared libraries, say, ".so". */
 #cmakedefine LTDL_SHLIB_EXT "${LTDL_SHLIB_EXT}"
 
 /* Define to the address where bug reports for this package should be sent. */
 #cmakedefine PACKAGE_BUGREPORT "${PACKAGE_BUGREPORT}"