configure: Kill off FP_ARG_WITH_*

This replaces the --with-* configure flags with the usual autoconf
environment variables, as suggested by #13583.

Test Plan: Configure on various platforms

Reviewers: hvr, trofi, thomie, austin

Reviewed By: trofi

Subscribers: rwbarton, erikd

GHC Trac Issues: #13583

Differential Revision: https://phabricator.haskell.org/D3499

4 files changed, 49 insertions, 109 deletions

diff --git a/aclocal.m4 b/aclocal.m4
index 545a15a646..dfb7892497 100644
--- a/aclocal.m4
+++ b/aclocal.m4
@@ -710,75 +710,6 @@ AC_DEFUN([FPTOOLS_FLOAT_WORD_ORDER_BIGENDIAN],
 ])
 
 
-# FP_ARG_WITH_PATH_GNU_PROG_GENERAL
-# --------------------
-# Find the specified command on the path or allow a user to set it manually
-# with a --with-<command> option.
-#
-# This is ignored on the mingw32 platform.
-#
-# $1 = the variable to set
-# $2 = the with option name
-# $3 = the command to look for
-# $4 = prepend target to program name? if 'no', use the name unchanged
-# $5 = optional? if 'no', then raise an error if the command isn't found
-#
-AC_DEFUN([FP_ARG_WITH_PATH_GNU_PROG_GENERAL],
-[
-AC_ARG_WITH($2,
-[AC_HELP_STRING([--with-$2=ARG],
-        [Use ARG as the path to $2 [default=autodetect]])],
-[
-    if test "$HostOS" = "mingw32"
-    then
-        AC_MSG_WARN([Request to use $withval will be ignored])
-    else
-        $1=$withval
-    fi
-
-    # Remember that we set this manually.  Used to override CC_STAGE0
-    # and friends later, if we are not cross-compiling.
-    With_$2=$withval
-],
-[
-    if test "$HostOS" != "mingw32"
-    then
-        if test "$4" = "no" -o "$target_alias" = "" ; then
-            AC_PATH_PROG([$1], [$3])
-        else
-            AC_PATH_PROG([$1], [$target_alias-$3])
-        fi
-        if test "$5" = "no" -a -z "$$1"
-        then
-            AC_MSG_ERROR([cannot find $3 in your PATH])
-        fi
-    fi
-]
-)
-]) # FP_ARG_WITH_PATH_GNU_PROG_GENERAL
-
-
-# FP_ARG_WITH_PATH_GNU_PROG
-# --------------------
-# The usual case: prepend the target, and the program is not optional.
-AC_DEFUN([FP_ARG_WITH_PATH_GNU_PROG],
-[FP_ARG_WITH_PATH_GNU_PROG_GENERAL([$1], [$2], [$3], [yes], [no])])
-
-# FP_ARG_WITH_PATH_GNU_PROG_OPTIONAL
-# --------------------
-# Same as FP_ARG_WITH_PATH_GNU_PROG but no error will be thrown if the command
-# isn't found.
-AC_DEFUN([FP_ARG_WITH_PATH_GNU_PROG_OPTIONAL],
-[FP_ARG_WITH_PATH_GNU_PROG_GENERAL([$1], [$2], [$3], [yes], [yes])])
-
-# FP_ARG_WITH_PATH_GNU_PROG_OPTIONAL_NOTARGET
-# --------------------
-# Same as FP_ARG_WITH_PATH_GNU_PROG_OPTIONAL but don't prepend the target name
-# (used for LLVM).
-AC_DEFUN([FP_ARG_WITH_PATH_GNU_PROG_OPTIONAL_NOTARGET],
-[FP_ARG_WITH_PATH_GNU_PROG_GENERAL([$1], [$2], [$3], [no], [yes])])
-
-
 # FP_PROG_CONTEXT_DIFF
 # --------------------
 # Figure out how to do context diffs. Sets the output variable ContextDiffCmd.
@@ -2048,36 +1979,32 @@ AC_DEFUN([XCODE_VERSION],[
 # are installed with a version suffix (e.g., llc-3.1).
 #
 # $1 = the variable to set
-# $2 = the with option name
-# $3 = the command to look for
-# $4 = the version of the command to look for
+# $2 = the command to look for
+# $3 = the version of the command to look for
 #
 AC_DEFUN([FIND_LLVM_PROG],[
-    # Test for program with version name.
-    FP_ARG_WITH_PATH_GNU_PROG_OPTIONAL_NOTARGET([$1], [$2], [$3-$4])
-    if test -z "$$1"; then
-        # Test for program without version name.
-        FP_ARG_WITH_PATH_GNU_PROG_OPTIONAL_NOTARGET([$1], [$2], [$3])
-        if test -n "$$1"; then
-            AC_MSG_CHECKING([$$1 is version $4])
-            if test `$$1 --version | grep -c "version $4"` -gt 0 ; then
-                AC_MSG_RESULT(yes)
-            else
-                AC_MSG_RESULT(no)
-                $1=""
-            fi
+    # Test for program with and without version name.
+    AC_CHECK_TOOLS([$1], [$2-$3 $2])
+    if test "$$1" != ":"; then
+        AC_MSG_CHECKING([$$1 is version $3])
+        if test `$$1 --version | grep -c "version $3"` -gt 0 ; then
+            AC_MSG_RESULT(yes)
+        else
+            AC_MSG_RESULT(no)
+            $1=""
         fi
     fi
 ])
 
 # FIND_LD
+# ---------
 # Find the version of `ld` to use. This is used in both in the top level
 # configure.ac and in distrib/configure.ac.in.
 #
 # $1 = the variable to set
 #
 AC_DEFUN([FIND_LD],[
-    FP_ARG_WITH_PATH_GNU_PROG([LD], [ld], [ld])
+    AC_CHECK_TARGET_TOOL([LD], [ld])
     case $target in
         arm*linux*       | \
         aarch64*linux*   )
@@ -2085,7 +2012,7 @@ AC_DEFUN([FIND_LD],[
             # This case should catch at least arm-unknown-linux-gnueabihf,
             # arm-linux-androideabi, arm64-unknown-linux and
             # aarch64-linux-android
-            FP_ARG_WITH_PATH_GNU_PROG([LD_GOLD], [ld.gold], [ld.gold])
+            AC_CHECK_TARGET_TOOL([LD_GOLD], [ld.gold])
             $1="$LD_GOLD"
             ;;
         *)
diff --git a/configure.ac b/configure.ac
index 194d37bd57..46e37ab3e6 100644
--- a/configure.ac
+++ b/configure.ac
@@ -502,7 +502,14 @@ AC_SUBST([LdCmd])
 
 dnl ** Which nm to use?
 dnl --------------------------------------------------------------
-FP_ARG_WITH_PATH_GNU_PROG([NM], [nm], [nm])
+if test "$HostOS" != "mingw32"; then
+    AC_CHECK_TARGET_TOOL([NM], [nm])
+    if test "$NM" = ":"; then
+        AC_MSG_ERROR([cannot find nm in your PATH])
+    fi
+fi
+NmCmd="$NM"
+AC_SUBST([NmCmd])
 
 if test "$TargetOS_CPP" = "darwin"
 then
@@ -529,40 +536,40 @@ then
         esac
 fi
 
-NmCmd="$NM"
-AC_SUBST([NmCmd])
-
 dnl ** Which objdump to use?
 dnl --------------------------------------------------------------
-FP_ARG_WITH_PATH_GNU_PROG_OPTIONAL([OBJDUMP], [objdump], [objdump])
+dnl Note: we may not have objdump on OS X, and we only need it on Windows (for DLL checks)
+case $HostOS_CPP in
+  cygwin32|mingw32)
+    AC_CHECK_TARGET_TOOL([OBJDUMP], [objdump])
+    ;;
+esac
+
 ObjdumpCmd="$OBJDUMP"
 AC_SUBST([ObjdumpCmd])
 
 dnl ** Which ar to use?
 dnl --------------------------------------------------------------
-FP_ARG_WITH_PATH_GNU_PROG([AR], [ar], [ar])
+if test "$HostOS" != "mingw32"; then
+    AC_CHECK_TARGET_TOOL([AR], [ar])
+    if test "$AR" = ":"; then
+        AC_MSG_ERROR([cannot find ar in your PATH])
+    fi
+fi
 ArCmd="$AR"
 fp_prog_ar="$AR"
 AC_SUBST([ArCmd])
 
 dnl ** Which ranlib to use?
 dnl --------------------------------------------------------------
-FP_ARG_WITH_PATH_GNU_PROG([RANLIB], [ranlib], [ranlib])
+AC_PROG_RANLIB
+if test "$RANLIB" = ":"; then
+    AC_MSG_ERROR([cannot find ranlib in your PATH])
+fi
 RanlibCmd="$RANLIB"
 RANLIB="$RanlibCmd"
 
 
-# Note: we may not have objdump on OS X, and we only need it on Windows (for DLL checks)
-case $HostOS_CPP in
-cygwin32|mingw32)
-    dnl ** Which objdump to use?
-    dnl --------------------------------------------------------------
-    FP_ARG_WITH_PATH_GNU_PROG([OBJDUMP], [objdump], [objdump])
-    ObjdumpCmd="$OBJDUMP"
-    AC_SUBST([ObjdumpCmd])
-    ;;
-esac
-
 # Here is where we re-target which specific version of the LLVM
 # tools we are looking for. In the past, GHC supported a number of
 # versions of LLVM simultaneously, but that stopped working around
@@ -574,13 +581,13 @@ AC_DEFINE_UNQUOTED([sUPPORTED_LLVM_VERSION], ${sUPPORTED_LLVM_VERSION}, [The sup
 
 dnl ** Which LLVM llc to use?
 dnl --------------------------------------------------------------
-FIND_LLVM_PROG([LLC], [llc], [llc], [$LlvmVersion])
+FIND_LLVM_PROG([LLC], [llc], [$LlvmVersion])
 LlcCmd="$LLC"
 AC_SUBST([LlcCmd])
 
 dnl ** Which LLVM opt to use?
 dnl --------------------------------------------------------------
-FIND_LLVM_PROG([OPT], [opt], [opt], [$LlvmVersion])
+FIND_LLVM_PROG([OPT], [opt], [$LlvmVersion])
 OptCmd="$OPT"
 AC_SUBST([OptCmd])
 
diff --git a/distrib/configure.ac.in b/distrib/configure.ac.in
index e733f64bbe..ffa057449d 100644
--- a/distrib/configure.ac.in
+++ b/distrib/configure.ac.in
@@ -74,13 +74,13 @@ LlvmVersion=@LlvmVersion@
 
 dnl ** Which LLVM llc to use?
 dnl --------------------------------------------------------------
-FIND_LLVM_PROG([LLC], [llc], [llc], [$LlvmVersion])
+FIND_LLVM_PROG([LLC], [llc], [$LlvmVersion])
 LlcCmd="$LLC"
 AC_SUBST([LlcCmd])
 
 dnl ** Which LLVM opt to use?
 dnl --------------------------------------------------------------
-FIND_LLVM_PROG([OPT], [opt], [opt], [$LlvmVersion])
+FIND_LLVM_PROG([OPT], [opt], [$LlvmVersion])
 OptCmd="$OPT"
 AC_SUBST([OptCmd])
 
diff --git a/docs/users_guide/8.4.1-notes.rst b/docs/users_guide/8.4.1-notes.rst
index e72213fd5e..71eaa40331 100644
--- a/docs/users_guide/8.4.1-notes.rst
+++ b/docs/users_guide/8.4.1-notes.rst
@@ -24,6 +24,12 @@ Language
 Compiler
 ~~~~~~~~
 
+- The ``configure`` script now no longer accepts ``--with-TOOL`` flags (e.g.
+  ``--with-nm``, ``--with-ld``, etc.). Instead, these are taken from environment
+  variables, as is typical in ``autoconf`` scripts. For instance,
+  ``./configure --with-nm=/usr/local/bin/nm`` turns into
+  ``./configure NM=/usr/local/bin/nm``.
+
 - Derived ``Functor``, ``Foldable``, and ``Traversable`` instances are now
   optimized when their last type parameters have phantom roles.
   Specifically, ::