The build system is currently miss-identifying GNU/kFreeBSD as FreeBSD.

This kind of simplification is sometimes useful, but in general it's not correct. 

As GNU/kFreeBSD is an hybrid system, for kernel-related issues we want to match the
build definitions used for FreeBSD, whereas for userland-related issues we want to
match the definitions used for other systems with Glibc.

The current modification adjusts the build system so that they can be distinguished,
and explicitly adds GNU/kFreeBSD to the build checks in which it belongs.

Fixes bug #16444.

Patch by Robert Millan in the context of Debian.

llvm-svn: 185311

llvm/Makefile.rules

@@ -275,10 +275,12 @@ ifeq ($(ENABLE_OPTIMIZED),1)
   BuildMode := Release
   # Don't use -fomit-frame-pointer on Darwin or FreeBSD.
   ifneq ($(HOST_OS),FreeBSD)
+  ifneq ($(HOST_OS),GNU/kFreeBSD)
   ifneq ($(HOST_OS),Darwin)
     OmitFramePointer := -fomit-frame-pointer
   endif
   endif
+  endif
 
   CXX.Flags += $(OPTIMIZE_OPTION) $(OmitFramePointer)
   C.Flags   += $(OPTIMIZE_OPTION) $(OmitFramePointer)
@@ -1451,7 +1453,7 @@ LD.Flags += -Wl,-exported_symbol,_main
 endif
 endif
 
-ifeq ($(HOST_OS), $(filter $(HOST_OS), Linux NetBSD FreeBSD GNU))
+ifeq ($(HOST_OS), $(filter $(HOST_OS), Linux NetBSD FreeBSD GNU/kFreeBSD GNU))
 ifneq ($(ARCH), Mips)
   LD.Flags += -Wl,--version-script=$(LLVM_SRC_ROOT)/autoconf/ExportMap.map
 endif

llvm/autoconf/configure.ac

@@ -222,11 +222,16 @@ AC_CACHE_CHECK([type of operating system we're going to host on],
     llvm_cv_no_link_all_option="-Wl,-noall_load"
     llvm_cv_os_type="Minix"
     llvm_cv_platform_type="Unix" ;;
-  *-*-freebsd* | *-*-kfreebsd-gnu)
+  *-*-freebsd*)
     llvm_cv_link_all_option="-Wl,--whole-archive"
     llvm_cv_no_link_all_option="-Wl,--no-whole-archive"
     llvm_cv_os_type="FreeBSD"
     llvm_cv_platform_type="Unix" ;;
+  *-*-kfreebsd-gnu)
+    llvm_cv_link_all_option="-Wl,--whole-archive"
+    llvm_cv_no_link_all_option="-Wl,--no-whole-archive"
+    llvm_cv_os_type="GNU/kFreeBSD"
+    llvm_cv_platform_type="Unix" ;;
   *-*-openbsd*)
     llvm_cv_link_all_option="-Wl,--whole-archive"
     llvm_cv_no_link_all_option="-Wl,--no-whole-archive"
@@ -317,8 +322,10 @@ AC_CACHE_CHECK([type of operating system we're going to target],
     llvm_cv_target_os_type="Darwin" ;;
   *-*-minix*)
     llvm_cv_target_os_type="Minix" ;;
-  *-*-freebsd* | *-*-kfreebsd-gnu)
+  *-*-freebsd*)
     llvm_cv_target_os_type="FreeBSD" ;;
+  *-*-kfreebsd-gnu)
+    llvm_cv_target_os_type="GNU/kFreeBSD" ;;
   *-*-openbsd*)
     llvm_cv_target_os_type="OpenBSD" ;;
   *-*-netbsd*)

llvm/configure

@@ -3826,11 +3826,16 @@ else
     llvm_cv_no_link_all_option="-Wl,-noall_load"
     llvm_cv_os_type="Minix"
     llvm_cv_platform_type="Unix" ;;
-  *-*-freebsd* | *-*-kfreebsd-gnu)
+  *-*-freebsd*)
     llvm_cv_link_all_option="-Wl,--whole-archive"
     llvm_cv_no_link_all_option="-Wl,--no-whole-archive"
     llvm_cv_os_type="FreeBSD"
     llvm_cv_platform_type="Unix" ;;
+  *-*-kfreebsd-gnu)
+    llvm_cv_link_all_option="-Wl,--whole-archive"
+    llvm_cv_no_link_all_option="-Wl,--no-whole-archive"
+    llvm_cv_os_type="GNU/kFreeBSD"
+    llvm_cv_platform_type="Unix" ;;
   *-*-openbsd*)
     llvm_cv_link_all_option="-Wl,--whole-archive"
     llvm_cv_no_link_all_option="-Wl,--no-whole-archive"
@@ -3927,8 +3932,10 @@ else
     llvm_cv_target_os_type="Darwin" ;;
   *-*-minix*)
     llvm_cv_target_os_type="Minix" ;;
-  *-*-freebsd* | *-*-kfreebsd-gnu)
+  *-*-freebsd*)
     llvm_cv_target_os_type="FreeBSD" ;;
+  *-*-kfreebsd-gnu)
+    llvm_cv_target_os_type="GNU/kFreeBSD" ;;
   *-*-openbsd*)
     llvm_cv_target_os_type="OpenBSD" ;;
   *-*-netbsd*)

llvm/projects/sample/Makefile.llvm.rules

@@ -208,10 +208,12 @@ ifeq ($(ENABLE_OPTIMIZED),1)
   BuildMode := Release
   # Don't use -fomit-frame-pointer on Darwin or FreeBSD.
   ifneq ($(HOST_OS),FreeBSD)
+  ifneq ($(HOST_OS),GNU/kFreeBSD)
   ifneq ($(HOST_OS),Darwin)
     OmitFramePointer := -fomit-frame-pointer
   endif
   endif
+  endif
 
   # Darwin requires -fstrict-aliasing to be explicitly enabled.
   # Avoid -fstrict-aliasing on Darwin for now, there are unresolved issues
@@ -1372,7 +1374,7 @@ LD.Flags += -Wl,-exported_symbol,_main
 endif
 endif
 
-ifeq ($(HOST_OS), $(filter $(HOST_OS), Linux NetBSD FreeBSD))
+ifeq ($(HOST_OS), $(filter $(HOST_OS), Linux NetBSD FreeBSD GNU/kFreeBSD))
 ifneq ($(ARCH), Mips)
   LD.Flags += -Wl,--version-script=$(PROJ_SRC_ROOT)/autoconf/ExportMap.map
 endif

llvm/tools/llvm-shlib/Makefile

@@ -62,18 +62,18 @@ ifeq ($(HOST_OS),Darwin)
     endif
 endif
 
-ifeq ($(HOST_OS), $(filter $(HOST_OS), Linux FreeBSD OpenBSD GNU Bitrig))
+ifeq ($(HOST_OS), $(filter $(HOST_OS), Linux FreeBSD GNU/kFreeBSD OpenBSD GNU Bitrig))
     # Include everything from the .a's into the shared library.
     LLVMLibsOptions := -Wl,--whole-archive $(LLVMLibsOptions) \
                        -Wl,--no-whole-archive
 endif
 
-ifeq ($(HOST_OS), $(filter $(HOST_OS), Linux FreeBSD GNU))
+ifeq ($(HOST_OS), $(filter $(HOST_OS), Linux FreeBSD GNU/kFreeBSD GNU))
     # Add soname to the library.
     LLVMLibsOptions += -Wl,--soname,lib$(LIBRARYNAME)$(SHLIBEXT)
 endif
 
-ifeq ($(HOST_OS), $(filter $(HOST_OS), Linux GNU))
+ifeq ($(HOST_OS), $(filter $(HOST_OS), Linux GNU GNU/kFreeBSD))
     # Don't allow unresolved symbols.
     LLVMLibsOptions += -Wl,--no-undefined
 endif