[m-rev.] for review: enable library grade detection

[Julien Fischer]

Enable library grade detection by default.

Use -R instead of -r with cp by default.

Fix some documentation errors.

compiler/options.m:
 	Enable library grade detection by default.

 	Document the --no-detect-libgrades option.

 	Make the default install command dir option, -R,
 	rather than -r.  The former is more portable.

scripts/Mercury.config.in:
 	Do not hardcode the set of library grades at configuration time.

compiler/mercury_compile.m:
 	Do not clear the library grade set before adding any detected
 	grades since doing so also prevents additional grades being
 	specified via the LIBGRADES variable.

doc/user_guide.texi:
 	Document --no-detect-libgrades.

 	Replace some uses of `:' as a module qualifier.

 	Fix a typo: s/outut/output/.

Julien.

diff --git a/compiler/mercury_compile.m b/compiler/mercury_compile.m
index aded039..b694ecc 100644
--- a/compiler/mercury_compile.m
+++ b/compiler/mercury_compile.m
@@ -2092,15 +2092,7 @@ do_detect_libgrades(VeryVerbose, StdLibDir, GradeOpts, !IO) :-
      dir.foldl2(do_detect_libgrade(VeryVerbose), ModulesDir,
          [], MaybeGradeOpts, !IO),
      (
-        MaybeGradeOpts = ok(GradeOpts0),
-        (
-            GradeOpts0 = [],
-            GradeOpts = GradeOpts0
-        ;
-            GradeOpts0 = [_ | _],
-            % Override any --libgrades settings from Mercury.config.
-            GradeOpts = ["--no-libgrade" | GradeOpts0]
-        )
+        MaybeGradeOpts = ok(GradeOpts)
      ;
          MaybeGradeOpts = error(_, _),
          GradeOpts = []
diff --git a/compiler/options.m b/compiler/options.m
index 45048bb..4a07250 100644
--- a/compiler/options.m
+++ b/compiler/options.m
@@ -1893,8 +1893,8 @@ option_defaults_2(build_system_option, [
      mercury_configuration_directory_special - string_special,
      mercury_configuration_directory     -   maybe_string(no),
      install_command                     -   string("cp"),
-    install_command_dir_option          -   string("-r"),
-    detect_libgrades                    -   bool(no),
+    install_command_dir_option          -   string("-R"),
+    detect_libgrades                    -   bool(yes),
      libgrades                           -   accumulating([]),
      libgrades_include_components        -   accumulating([]),
      libgrades_exclude_components        -   accumulating([]),
@@ -5788,12 +5788,10 @@ options_help_build_system -->
          "\tSpecify the flag to pass to the install command to install",
          "\ta directory. The given command will be invoked as",
          "\t`<command> <option> <source> <target>'",
-        "\tto install each directory. The default option is `-r'.",
-
-        % `--detect-libgrades' is a developer-only that controls
-        % whether the compiler should scan the installation directory
-        % to determine which standard library grades are available.
- 
+        "\tto install each directory. The default option is `-R'.",
+        "--no-detect-libgrades",
+        "\tDo not scan the installation directory to determine which",
+        "\tstandard library grades are available.",
          "--libgrade <grade>",
          "\tAdd <grade> to the list of compilation grades in",
          "\twhich a library to be installed should be built.",
diff --git a/doc/user_guide.texi b/doc/user_guide.texi
index eccc6d9..29992bd 100644
--- a/doc/user_guide.texi
+++ b/doc/user_guide.texi
@@ -968,8 +968,8 @@ It may be as simple as this @file{mypackage.m} file:

  @noindent
  This defines a module @samp{mypackage} containing
-sub-modules @samp{mypackage:foo}, @samp{mypackage:bar},
-and @samp{mypackage:baz}.
+sub-modules @samp{mypackage.foo}, @samp{mypackage.bar},
+and @samp{mypackage.baz}.

  It is also possible to build libraries of unrelated
  modules, so long as the top-level module imports all
@@ -7081,7 +7081,7 @@ library as well as any other libraries specified via the
  @findex --output-grade-defines
  Print the flags that are passed to the C compiler to define the macros used to
  specify the compilation grade.
-The flags are printed to the standard outut.
+The flags are printed to the standard output.

  @sp 1
  @item --output-c-include-dir-flags
@@ -9371,7 +9371,13 @@ The default command is @samp{cp}.
  Specify the flag to pass to the install command to install
  a directory. The given command will be invoked as
  @code{@var{command} @var{option} @var{source} @var{target}}
-to install each directory. The default option is @samp{-r}.
+to install each directory. The default option is @samp{-R}.
+
+ at sp 1
+ at item --no-detect-libgrades
+ at findex --no-detect-libgrades
+Do not scan the installation direcotry to determine which
+standard library grades are available.

  @sp 1
  @item --libgrade @var{grade}
@@ -10849,7 +10855,7 @@ against, e.g. the @samp{--ml} and @samp{--mld} options.
  (@pxref{Libraries}).
  The Mercury standard library is always included in this set.

-In C grades the @samp{--generate-standalone-interface} option causes
+In C grades, the @samp{--generate-standalone-interface} option causes
  the compiler to generate an object file that should be linked into
  the executable.
  This object file contains two functions:
diff --git a/scripts/Mercury.config.in b/scripts/Mercury.config.in
index 3d06b09..d487803 100644
--- a/scripts/Mercury.config.in
+++ b/scripts/Mercury.config.in
@@ -130,6 +130,4 @@ DEFAULT_MCFLAGS=\
  		@HAVE_BOXED_FLOATS@ \
  		@MCFLAGS_FOR_CC@ \
  		$(MERCURY_DEFAULT_OPT_LEVEL) \
-		@MMC_USE_SYMLINKS_OPT@ \
-		@LIBGRADE_OPTS@ 
-
+		@MMC_USE_SYMLINKS_OPT@