[CMake] Remove some always-true HAVE_XXX_H

These are unneeded even on AIX, PURE_WINDOWS, and ZOS (per #104706)

* HAVE_ERRNO_H: introduced by 1a93330 (2009) but unneeded.
  The guarded ABI is unconditionally used by lldb.
* HAVE_FCNTL_H
* HAVE_FENV_H
* HAVE_SYS_STAT_H

Pull Request: #123087

Author: MaskRay

llvm/cmake/config-ix.cmake

@@ -59,8 +59,6 @@ endif()
 
 # include checks
 check_include_file(dlfcn.h HAVE_DLFCN_H)
-check_include_file(errno.h HAVE_ERRNO_H)
-check_include_file(fcntl.h HAVE_FCNTL_H)
 check_include_file(malloc/malloc.h HAVE_MALLOC_MALLOC_H)
 if( NOT PURE_WINDOWS )
   check_include_file(pthread.h HAVE_PTHREAD_H)
@@ -69,13 +67,11 @@ check_include_file(signal.h HAVE_SIGNAL_H)
 check_include_file(sys/ioctl.h HAVE_SYS_IOCTL_H)
 check_include_file(sys/mman.h HAVE_SYS_MMAN_H)
 check_include_file(sys/resource.h HAVE_SYS_RESOURCE_H)
-check_include_file(sys/stat.h HAVE_SYS_STAT_H)
 check_include_file(sys/time.h HAVE_SYS_TIME_H)
 check_include_file(sysexits.h HAVE_SYSEXITS_H)
 check_include_file(termios.h HAVE_TERMIOS_H)
 check_include_file(unistd.h HAVE_UNISTD_H)
 check_include_file(valgrind/valgrind.h HAVE_VALGRIND_VALGRIND_H)
-check_include_file(fenv.h HAVE_FENV_H)
 check_symbol_exists(FE_ALL_EXCEPT "fenv.h" HAVE_DECL_FE_ALL_EXCEPT)
 check_symbol_exists(FE_INEXACT "fenv.h" HAVE_DECL_FE_INEXACT)
 check_c_source_compiles("

llvm/include/llvm/Config/config.h.cmake

@@ -72,15 +72,6 @@
 /* Define if __unw_add_dynamic_fde() is available on this platform. */
 #cmakedefine HAVE_UNW_ADD_DYNAMIC_FDE ${HAVE_UNW_ADD_DYNAMIC_FDE}
 
-/* Define to 1 if you have the <errno.h> header file. */
-#cmakedefine HAVE_ERRNO_H ${HAVE_ERRNO_H}
-
-/* Define to 1 if you have the <fcntl.h> header file. */
-#cmakedefine HAVE_FCNTL_H ${HAVE_FCNTL_H}
-
-/* Define to 1 if you have the <fenv.h> header file. */
-#cmakedefine HAVE_FENV_H ${HAVE_FENV_H}
-
 /* Define if libffi is available on this platform. */
 #cmakedefine HAVE_FFI_CALL ${HAVE_FFI_CALL}
 
@@ -198,9 +189,6 @@
 /* Define to 1 if you have the <sys/resource.h> header file. */
 #cmakedefine HAVE_SYS_RESOURCE_H ${HAVE_SYS_RESOURCE_H}
 
-/* Define to 1 if you have the <sys/stat.h> header file. */
-#cmakedefine HAVE_SYS_STAT_H ${HAVE_SYS_STAT_H}
-
 /* Define to 1 if you have the <sys/time.h> header file. */
 #cmakedefine HAVE_SYS_TIME_H ${HAVE_SYS_TIME_H}
 

llvm/include/llvm/Support/FileSystem.h

@@ -44,9 +44,7 @@
 #include <system_error>
 #include <vector>
 
-#ifdef HAVE_SYS_STAT_H
 #include <sys/stat.h>
-#endif
 
 namespace llvm {
 namespace sys {

llvm/lib/Analysis/ConstantFolding.cpp

@@ -1885,7 +1885,7 @@ Constant *GetConstantFoldFPValue128(float128 V, Type *Ty) {
 
 /// Clear the floating-point exception state.
 inline void llvm_fenv_clearexcept() {
-#if defined(HAVE_FENV_H) && HAVE_DECL_FE_ALL_EXCEPT
+#if HAVE_DECL_FE_ALL_EXCEPT
   feclearexcept(FE_ALL_EXCEPT);
 #endif
   errno = 0;
@@ -1896,7 +1896,7 @@ inline bool llvm_fenv_testexcept() {
   int errno_val = errno;
   if (errno_val == ERANGE || errno_val == EDOM)
     return true;
-#if defined(HAVE_FENV_H) && HAVE_DECL_FE_ALL_EXCEPT && HAVE_DECL_FE_INEXACT
+#if HAVE_DECL_FE_ALL_EXCEPT && HAVE_DECL_FE_INEXACT
   if (fetestexcept(FE_ALL_EXCEPT & ~FE_INEXACT))
     return true;
 #endif

llvm/lib/ExecutionEngine/RuntimeDyld/RTDyldMemoryManager.cpp

@@ -20,11 +20,9 @@
 #ifdef __linux__
   // These includes used by RTDyldMemoryManager::getPointerToNamedFunction()
   // for Glibc trickery. See comments in this function for more information.
-  #ifdef HAVE_SYS_STAT_H
-    #include <sys/stat.h>
-  #endif
-  #include <fcntl.h>
-  #include <unistd.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <unistd.h>
 #endif
 
 namespace llvm {

llvm/lib/Support/Errno.cpp

@@ -13,10 +13,7 @@
 #include "llvm/Support/Errno.h"
 #include "llvm/Config/config.h"
 #include <cstring>
-
-#if HAVE_ERRNO_H
 #include <errno.h>
-#endif
 
 //===----------------------------------------------------------------------===//
 //=== WARNING: Implementation here must contain only TRULY operating system
@@ -26,11 +23,9 @@
 namespace llvm {
 namespace sys {
 
-#if HAVE_ERRNO_H
 std::string StrError() {
   return StrError(errno);
 }
-#endif  // HAVE_ERRNO_H
 
 std::string StrError(int errnum) {
   std::string str;

llvm/lib/Support/Unix/Path.inc

@@ -18,12 +18,8 @@
 #include "Unix.h"
 #include <limits.h>
 #include <stdio.h>
-#if HAVE_SYS_STAT_H
 #include <sys/stat.h>
-#endif
-#if HAVE_FCNTL_H
 #include <fcntl.h>
-#endif
 #ifdef HAVE_UNISTD_H
 #include <unistd.h>
 #endif

llvm/lib/Support/Unix/Process.inc

@@ -17,18 +17,14 @@
 #include "llvm/Config/llvm-config.h" // for LLVM_ENABLE_THREADS
 #include <mutex>
 #include <optional>
-#if HAVE_FCNTL_H
 #include <fcntl.h>
-#endif
 #ifdef HAVE_SYS_TIME_H
 #include <sys/time.h>
 #endif
 #ifdef HAVE_SYS_RESOURCE_H
 #include <sys/resource.h>
 #endif
-#ifdef HAVE_SYS_STAT_H
 #include <sys/stat.h>
-#endif
 #if HAVE_SIGNAL_H
 #include <signal.h>
 #endif

llvm/lib/Support/Unix/Program.inc

@@ -28,18 +28,14 @@
 #include "llvm/Support/StringSaver.h"
 #include "llvm/Support/SystemZ/zOSSupport.h"
 #include "llvm/Support/raw_ostream.h"
-#if HAVE_SYS_STAT_H
 #include <sys/stat.h>
-#endif
 #if HAVE_SYS_RESOURCE_H
 #include <sys/resource.h>
 #endif
 #if HAVE_SIGNAL_H
 #include <signal.h>
 #endif
-#if HAVE_FCNTL_H
 #include <fcntl.h>
-#endif
 #if HAVE_UNISTD_H
 #include <unistd.h>
 #endif

llvm/lib/Support/Unix/Signals.inc

@@ -53,9 +53,7 @@
 #if HAVE_SIGNAL_H
 #include <signal.h>
 #endif
-#if HAVE_SYS_STAT_H
 #include <sys/stat.h>
-#endif
 #if HAVE_DLFCN_H
 #include <dlfcn.h>
 #endif