Merge remote branch 'phonohawk/patch-5408'

* phonohawk/patch-5408:
  Resurrect UseLibFFIForAdjustors from bitrot.
  Detect cases where as(1) doesn't recognise .ident directive (#5408)

aclocal.m4

@@ -251,6 +251,16 @@ AC_DEFUN([FPTOOLS_SET_HASKELL_PLATFORM_VARS],
         [HaskellHaveSubsectionsViaSymbols=False
          AC_MSG_RESULT(no)])
 
+    dnl ** check for .ident assembler directive
+
+    AC_MSG_CHECKING(whether your assembler supports .ident directive)
+    AC_COMPILE_IFELSE(
+        [AC_LANG_SOURCE([__asm__ (".ident \"GHC x.y.z\"");])],
+        [AC_MSG_RESULT(yes)
+         HaskellHaveIdentDirective=True],
+        [AC_MSG_RESULT(no)
+         HaskellHaveIdentDirective=False])
+
     dnl *** check for GNU non-executable stack note support (ELF only)
     dnl     (.section .note.GNU-stack,"",@progbits)
 
@@ -283,6 +293,7 @@ AC_DEFUN([FPTOOLS_SET_HASKELL_PLATFORM_VARS],
     AC_SUBST(HaskellTargetArch)
     AC_SUBST(HaskellTargetOs)
     AC_SUBST(HaskellHaveSubsectionsViaSymbols)
+    AC_SUBST(HaskellHaveIdentDirective)
     AC_SUBST(HaskellHaveGnuNonexecStack)
 ])
 

compiler/ghc.mk

@@ -497,7 +497,7 @@ compiler/hsSyn/HsLit_HC_OPTS     += -fomit-interface-pragmas
 endif
 
 # LibFFI.hs #includes ffi.h
-compiler/stage2/build/LibFFI.hs : $(ffi_HEADER)
+compiler/stage2/build/LibFFI.hs : $(libffi_HEADERS)
 # On Windows it seems we also need to link directly to libffi
 ifeq  "$(HOSTPLATFORM)" "i386-unknown-mingw32"
 define windowsDynLinkToFfi

compiler/main/SysTools.lhs

@@ -193,6 +193,7 @@ initSysTools mbMinusB
         ; targetArch <- readSetting "target arch"
         ; targetOS <- readSetting "target os"
         ; targetHasGnuNonexecStack <- readSetting "target has GNU nonexec stack"
+        ; targetHasIdentDirective <- readSetting "target has .ident directive"
         ; targetHasSubsectionsViaSymbols <- readSetting "target has subsections via symbols"
         ; myExtraGccViaCFlags <- getSetting "GCC extra via C opts"
         -- On Windows, mingw is distributed with GHC,
@@ -257,6 +258,7 @@ initSysTools mbMinusB
                                               platformArch = targetArch,
                                               platformOS   = targetOS,
                                               platformHasGnuNonexecStack = targetHasGnuNonexecStack,
+                                              platformHasIdentDirective = targetHasIdentDirective,
                                               platformHasSubsectionsViaSymbols = targetHasSubsectionsViaSymbols
                                           },
                         sTmpDir = normalise tmpdir,

compiler/nativeGen/AsmCodeGen.lhs

@@ -525,12 +525,15 @@ makeImportsDoc dflags imports
             (if platformHasGnuNonexecStack (targetPlatform dflags)
              then Pretty.text ".section .note.GNU-stack,\"\",@progbits"
              else Pretty.empty)
+            Pretty.$$
                 -- And just because every other compiler does, lets stick in
                 -- an identifier directive: .ident "GHC x.y.z"
-            Pretty.$$ let compilerIdent = Pretty.text "GHC" Pretty.<+>
-	                                  Pretty.text cProjectVersion
-                       in Pretty.text ".ident" Pretty.<+>
-                          Pretty.doubleQuotes compilerIdent
+            (if platformHasIdentDirective (targetPlatform dflags)
+             then let compilerIdent = Pretty.text "GHC" Pretty.<+>
+	                              Pretty.text cProjectVersion
+                   in Pretty.text ".ident" Pretty.<+>
+                      Pretty.doubleQuotes compilerIdent
+             else Pretty.empty)
 
  where
 	-- Generate "symbol stubs" for all external symbols that might

compiler/utils/Platform.hs

@@ -23,6 +23,7 @@ data Platform
               platformArch                     :: Arch,
               platformOS                       :: OS,
               platformHasGnuNonexecStack       :: Bool,
+              platformHasIdentDirective        :: Bool,
               platformHasSubsectionsViaSymbols :: Bool
           }
         deriving (Read, Show, Eq)

ghc.mk

@@ -929,6 +929,7 @@ $(eval $(call bindist,.,\
     $(includes_H_FILES) \
     $(includes_DERIVEDCONSTANTS) \
     $(includes_GHCCONSTANTS) \
+    $(libffi_HEADERS) \
     $(INSTALL_LIBEXECS) \
     $(INSTALL_LIBEXEC_SCRIPTS) \
     $(INSTALL_TOPDIRS) \
@@ -1207,9 +1208,10 @@ maintainer-clean : distclean
 .PHONY: all_libraries
 
 .PHONY: bootstrapping-files
-bootstrapping-files: includes/ghcautoconf.h
-bootstrapping-files: includes/DerivedConstants.h
-bootstrapping-files: includes/GHCConstants.h
+bootstrapping-files: $(includes_H_CONFIG)
+bootstrapping-files: $(includes_DERIVEDCONSTANTS)
+bootstrapping-files: $(includes_GHCCONSTANTS)
+bootstrapping-files: $(libffi_HEADERS)
 
 .DELETE_ON_ERROR:
 

libffi/ghc.mk

@@ -32,7 +32,8 @@ libffi_EnableShared    = no
 endif
 
 libffi_STATIC_LIB  = libffi/build/inst/lib/libffi.a
-ffi_HEADER         = rts/dist/build/ffi.h
+libffi_HEADERS     = rts/dist/build/ffi.h \
+                     rts/dist/build/ffitarget.h
 
 ifeq "$(OSTYPE)" "cygwin"
 LIBFFI_PATH_MANGLE = PATH=$$(cygpath "$(TOP)")/libffi:$$PATH; export PATH;
@@ -101,9 +102,8 @@ $(libffi_STAMP_INSTALL): $(libffi_STAMP_BUILD) $(TOUCH_DEP)
 $(libffi_STATIC_LIB): $(libffi_STAMP_INSTALL)
 	@test -f $@ || { echo "$< exists, but $@ does not."; echo "Suggest removing $<."; exit 1; }
 
-$(ffi_HEADER): $(libffi_STAMP_INSTALL) | $$(dir $$@)/.
-	cp libffi/build/inst/lib/libffi-*/include/ffitarget.h $(dir $@)
-	cp libffi/build/inst/lib/libffi-*/include/ffi.h $@
+$(libffi_HEADERS): $(libffi_STAMP_INSTALL) | $$(dir $$@)/.
+	cp -f libffi/build/inst/lib/libffi-*/include/$(notdir $@) $@
 
 $(eval $(call clean-target,libffi,, \
     libffi/build $(wildcard libffi/stamp.ffi.*) libffi/dist-install))

rts/ghc.mk

@@ -455,7 +455,7 @@ endif
 
 $(eval $(call dependencies,rts,dist,1))
 
-$(rts_dist_depfile_c_asm) : $(ffi_HEADER) $(DTRACEPROBES_H)
+$(rts_dist_depfile_c_asm) : $(libffi_HEADERS) $(DTRACEPROBES_H)
 
 # -----------------------------------------------------------------------------
 # compile dtrace probes if dtrace is supported
@@ -507,6 +507,13 @@ INSTALL_LIBS += $(ALL_RTS_LIBS)
 INSTALL_LIBS += $(wildcard rts/dist/build/libffi$(soext)*)
 INSTALL_LIBS += $(wildcard rts/dist/build/libffi-5.dll)
 
+install: install_libffi_headers
+
+.PHONY: install_libffi_headers
+install_libffi_headers :
+	$(call INSTALL_DIR,"$(DESTDIR)$(ghcheaderdir)")
+	$(call INSTALL_HEADER,$(INSTALL_OPTS),$(libffi_HEADERS),"$(DESTDIR)$(ghcheaderdir)/")
+
 # -----------------------------------------------------------------------------
 # cleaning
 

rts/package.conf.in

@@ -51,7 +51,7 @@ extra-libraries:
 #ifdef INSTALLING
 include-dirs:		INCLUDE_DIR PAPI_INCLUDE_DIR
 #else /* !INSTALLING */
-include-dirs:		TOP"/includes" TOP"/includes/dist-ghcconstants/header" TOP"/includes/dist-derivedconstants/header"
+include-dirs:		TOP"/rts/dist/build" TOP"/includes" TOP"/includes/dist-ghcconstants/header" TOP"/includes/dist-derivedconstants/header"
 #endif
 
 includes:		Stg.h

settings.in

@@ -11,6 +11,7 @@
  ("target os", "@HaskellTargetOs@"),
  ("target arch", "@HaskellTargetArch@"),
  ("target has GNU nonexec stack", "@HaskellHaveGnuNonexecStack@"),
+ ("target has .ident directive", "@HaskellHaveIdentDirective@"),
  ("target has subsections via symbols", "@HaskellHaveSubsectionsViaSymbols@")
  ]