[m-rev.] diff: avoid warnings from autoconf

[Julien Fischer]

Avoid warnings from autoconf.

configure.ac:
      Use single quotes for quoting in configure script messages.
      Using `' results in warnings from autoconf.

      Delete a stray comma from the test for GNU make.

Julien.

diff --git a/configure.ac b/configure.ac
index fe74f4e..78d3f8e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -208,7 +208,7 @@ case "$PREFIX" in
      *\ *)
          AC_MSG_ERROR(
  [cannot install into a directory with a name containing
-    spaces: \`$PREFIX.'])
+    spaces: '$PREFIX.'])
          exit 1
          ;;
  esac
@@ -758,7 +758,7 @@ AC_SUBST(ENABLE_BOEHM_USE_MUNMAP)
  #-----------------------------------------------------------------------------#

  MERCURY_MSG("looking for GNU Make...")
-AC_CHECK_PROGS([GNU_MAKE], [gmake, make])
+AC_CHECK_PROGS([GNU_MAKE], [gmake make])
  if test "$GNU_MAKE" != ""; then
      case "`$GNU_MAKE -v bogus </dev/null 2>&1`" in
          "GNU Make"*)
@@ -822,7 +822,7 @@ case "$host" in
              fi
          fi
          if test "$MKFIFO" = ""; then
-            AC_MSG_WARN(cannot find a working \`mkfifo' or \`mknod')
+            AC_MSG_WARN(cannot find a working 'mkfifo' or 'mknod')
              MKFIFO=none
              AC_DEFINE_UNQUOTED(MR_MKFIFO, "")
          else
@@ -855,7 +855,7 @@ if test "$MKTEMP" != ""; then
      esac
  fi
  if test "$MKTEMP" = ""; then
-    AC_MSG_WARN(cannot find a working \`mktemp', using \`mkdir || exit')
+    AC_MSG_WARN(cannot find a working 'mktemp', using 'mkdir || exit')
      MKTEMP=""
  fi
  AC_SUBST(MKTEMP)
@@ -3275,7 +3275,7 @@ if test "$DEFAULT_GRADE" = ""; then
      DEFAULT_GRADE=$DEFAULT_BASE_GRADE.gc
  fi

-MERCURY_MSG("using grade \`$DEFAULT_GRADE' as the default grade for applications")
+MERCURY_MSG("using grade '$DEFAULT_GRADE' as the default grade for applications")
  AC_SUBST(DEFAULT_GRADE)

  #-----------------------------------------------------------------------------#
@@ -3331,16 +3331,16 @@ if test "$BOOTSTRAP_MC" = ""; then
      GRADE="$BOOTSTRAP_GRADE"
      AC_MSG_WARN(
  [Mercury compiler not yet installed -
-****    cannot use grade \`$BEST_GRADE_FOR_COMPILER'
-****    using grade \`$GRADE' to compile the compiler
+****    cannot use grade '$BEST_GRADE_FOR_COMPILER'
+****    using grade '$GRADE' to compile the compiler
  ****    after installation is complete you may reinstall
  ****    from scratch to have a faster compiler.
  ****    NOTE: before reinstalling from scratch, ensure that the
-****    source tree is clean by running \`make realclean'. Not doing
+****    source tree is clean by running 'make realclean'. Not doing
  ****    this may result in a broken Mercury installation.])
  else
      GRADE=$BEST_GRADE_FOR_COMPILER
-    MERCURY_MSG("using grade \`$GRADE' to compile the compiler")
+    MERCURY_MSG("using grade '$GRADE' to compile the compiler")
  fi
  AC_SUBST(GRADE)

@@ -4492,8 +4492,8 @@ AC_MSG_RESULT($LD_STATIC_FLAGS)
  case "$LD_STATIC_FLAGS" in
      "")
          AC_MSG_WARN(
-[\`mmc --linkage static' and \`ml --static' not implemented with
-****    this C compiler (\`$CC').])
+['mmc --linkage static' and 'ml --static' not implemented with
+****    this C compiler ('$CC').])
  esac

  #-----------------------------------------------------------------------------#