Merged Boost library build system changes from the trunk. Fixes ticket #6027 - unversioned Boost library targets not getting installed or staged on Windows or Unix with versioned layout.

Covers the following trunk revisions:

--- [78934] ---
Minor stylistic changes made to the boostcpp.jam Boost library build module - wrapped comments and some code lines to 80 characters, removed duplicate imports, ordered imports alphabetically, corrected comment & end-user message typos, removed redundant quoting & trimmed trailing spaces.

--- [78935] ---
Made Boost library build script's '--with-...' & '--without-...' parameter checking more strict so e.g. '--run--with--system' is not interpreted as one of those options.

--- [78936] ---
Minor stylistic changes.

--- [78937] ---
Boost library build system code cleanup - removed a non-existing 'explicit' target being declared as explicit.

--- [78938] ---
Corrected a syntax error in Boost library's build system that was preventing unversioned library targets from being staged or installed on Windows & Unix when versioned layout is used. Closes ticket #6027 (https://svn.boost.org/trac/boost/ticket/6027).

--- [78939] ---
Boost library build system code cleanup - refactored the make-unversioned-links() rule.


[SVN r78941]

boostcpp.jam

@@ -8,27 +8,27 @@
 #    (See accompanying file LICENSE_1_0.txt or copy at
 #          http://www.boost.org/LICENSE_1_0.txt)
 
-import option ;
-import regex ;
+import "class" : new ;
 import common ;
-
+import configure ;
+import build-system ;
+import generate ;
 import modules ;
+import option ;
 import os ;
-import path ;
-import build-system ;
-import configure ;
-import set ;
 import package ;
+import path ;
 import project ;
+import regex ;
+import set ;
 import targets ;
-import generate ;
-import package ;
+
 
 ##############################################################################
-# 
+#
 # 0. General setup. Parse options, check them.
 #
-##############################################################################  
+##############################################################################
 
 BOOST_ROOT = [ modules.binding $(__name__) ] ;
 BOOST_ROOT = $(BOOST_ROOT:D) ;
@@ -36,32 +36,31 @@ BOOST_ROOT = $(BOOST_ROOT:D) ;
 rule set-version ( version )
 {
     BOOST_VERSION = $(version) ;
-    
-    local version-tag = [ MATCH "^([^.]+)[.]([^.]+)[.]([^.]+)" : $(BOOST_VERSION) ]
-      ;
+
+    local version-tag = [ MATCH ^([^.]+)[.]([^.]+)[.]([^.]+) : $(BOOST_VERSION)
+        ] ;
     if $(version-tag[3]) = 0
     {
         version-tag = $(version-tag[1-2]) ;
     }
-    
-    BOOST_VERSION_TAG = $(version-tag:J="_") ;
+    BOOST_VERSION_TAG = $(version-tag:J=_) ;
 }
 
 # Option to choose how many variants to build. The default is "minimal".
-build-type = [ option.get "build-type" ] ;
+build-type = [ option.get build-type ] ;
 build-type ?= minimal ;
-if ! ( $(build-type) in minimal complete )
+if ! ( $(build-type) in complete minimal )
 {
-    ECHO "The value of the --build-type option should be either 'complete' or 'minimal'" ;
-    EXIT ;
+    EXIT The value of the --build-type option should be either 'complete' or
+        'minimal' ;
 }
 
 # What kind of layout are we doing?
 layout = [ option.get layout : "" ] ;
-# On Windows, we used versioned layout by default in order to
-# be compatible with autolink. On other systems, we use system
-# layout which is what every other program uses. Note that windows
-# check is static, and won't 
+# On Windows, we used versioned layout by default in order to be compatible with
+# autolink. On other systems, we use system layout which is what every other
+# program uses. Note that the Windows check is static, and will not be affected
+# by specific build properties used.
 if ! $(layout)
 {
     if [ os.name ] = NT
@@ -77,42 +76,43 @@ layout-$(layout) = true ;
 
 if $(layout) = system && $(build-type) = complete
 {
-    ECHO "error: Cannot use --layout=system with --build-type complete." ;
-    ECHO "error: Please used either --layout=versioned or --layout=tagged " ;
-    ECHO "error: if you wish to build multiple variants." ;
+    ECHO error: Cannot use --layout=system with --build-type complete. ;
+    ECHO error: Please use either --layout=versioned or --layout=tagged ;
+    ECHO error: if you wish to build multiple variants. ;
     if [ os.name ] != NT
-    {        
-        ECHO "error: Note that --layout=system is default on Unix starting with Boost 1.40." ;
-    }    
+    {
+        ECHO error: Note that --layout=system is used by default on Unix
+            starting with Boost 1.40. ;
+    }
     EXIT ;
 }
 
 # Possible stage only location.
-stage-locate = [ option.get "stagedir" ] ;
+stage-locate = [ option.get stagedir ] ;
 stage-locate ?= stage ;
 BOOST_STAGE_LOCATE = $(stage-locate) ;
 
 # Custom build ID.
-build-id = [ option.get "buildid" ] ;
+build-id = [ option.get buildid ] ;
 if $(build-id)
 {
-    BUILD_ID = [ regex.replace $(build-id) "[*\\/:.\"\' ]" "_" ] ;
+    BUILD_ID = [ regex.replace $(build-id) "[*\\/:.\"\' ]" _ ] ;
 }
 
-# Python build id (only for Python libraries)
+# Python build id (for Python libraries only).
 python-id = [ option.get "python-buildid" ] ;
 if $(python-id)
 {
-    PYTHON_ID = [ regex.replace $(python-id) "[*\\/:.\"\']" "_" ] ;
+    PYTHON_ID = [ regex.replace $(python-id) [*\\/:.\"\'] _ ] ;
 }
 
-##############################################################################
+
+################################################################################
 #
-# 1. The 'tag' function that adds decoration suitable to the properties if
-# versioned or tagged layout is requested. This function is called from 
-# Jamroot
+# 1. 'tag' function adding decorations suitable to the properties if versioned
+# or tagged layout is requested. Called from Jamroot.
 #
-##############################################################################  
+################################################################################
 
 rule tag ( name : type ? : property-set )
 {
@@ -125,113 +125,86 @@ rule tag ( name : type ? : property-set )
                 <base> <toolset> <threading> <runtime> -$(BOOST_VERSION_TAG)
                 -$(BUILD_ID)
                 : $(name) : $(type) : $(property-set) ] ;
-        }        
+        }
         else if $(layout) = tagged
         {
             result = [ common.format-name
                 <base> <threading> <runtime>
                 -$(BUILD_ID)
-                : $(name) : $(type) : $(property-set) ] ;            
+                : $(name) : $(type) : $(property-set) ] ;
         }
         else if $(layout) = system
         {
             result = [ common.format-name
-                <base> 
+                <base>
                 -$(BUILD_ID)
                 : $(name) : $(type) : $(property-set) ] ;
         }
         else
         {
-            ECHO "error: invalid layout '$(layout:E=)'" ;
-            EXIT ;               
+            EXIT error: invalid layout '$(layout:E=)' ;
         }
-                
-        # Optionally add version suffix. On NT, library with version suffix
-        # will not be recognized by linkers. On CYGWIN, we get strage
-        # duplicate symbol errors when library is generated with version
-        # suffix. On OSX, version suffix is not needed -- the linker expects
-        # the libFoo.1.2.3.dylib format. AIX linkers do not accept version
-        # suffixes either. Pgi compilers can not accept library with version
-        # suffix.
+
+        # Optionally add version suffix. On NT, library with version suffix will
+        # not be recognized by linkers. On CYGWIN, we get strage duplicate
+        # symbol errors when library is generated with version suffix. On OSX,
+        # version suffix is not needed -- the linker expects the
+        # libFoo.1.2.3.dylib format. AIX linkers do not accept version suffixes
+        # either. Pgi compilers can not accept a library with version suffix.
         if $(type) = SHARED_LIB &&
-          ( ! ( [ $(property-set).get <target-os> ] in windows cygwin darwin aix ) &&
-            ! ( [ $(property-set).get <toolset> ] in pgi ) )
+          ! [ $(property-set).get <target-os> ] in windows cygwin darwin aix &&
+          ! [ $(property-set).get <toolset> ] in pgi
         {
             result = $(result).$(BOOST_VERSION)  ;
         }
 
         return $(result) ;
-    }    
+    }
 }
 
-##############################################################################
+
+################################################################################
 #
 # 2. Declare targets that build and install all libraries. Specifically:
 #
 #    - 'stage-proper' that puts all libraries in stage/lib
 #    - 'install-proper' that install libraries and headers to system location
-#    - 'stage-unversioned' that creates links to libraries without boost veriosn
+#    - 'stage-unversioned' that creates links to libraries without boost version
 #       in name
 #    - 'install-unversioned' which creates unversioned linked to installed
 #       libraries.
 #
-##############################################################################  
+################################################################################
 
-# Worker function suitable to the 'generate' metatarget. Creates a link
-# to 'source', striping any version number from the name.
+# Worker function suitable to the 'generate' metatarget. Creates a link to
+# 'source', striping any version number information from the name.
 rule make-unversioned-links ( project name ? : property-set : sources * )
 {
-    local result ;
-    local filtered ;
-    local pattern ;
-    local nt = [ modules.peek : NT ] ;
-
-    # Collect the libraries that have the version number in 'filtered'.
-    for local s in $(sources)
+    local filter ;
+    if [ modules.peek : NT ]
     {
-        local m ;
-        if $(nt)
-        {
-            m = [ MATCH "(.*[.]lib)" : [ $(s).name ] ] ;
-        }
-        else
-        {
-            m = [ MATCH "(.*[.]so[.0-9]+)" "(.*[.]dylib)" "(.*[.]a)" :
-              [ $(s).name ] ] ;
-        }
-        if $(m)
-        {
-            filtered += $(s) ;
-        }
+        filter = (.*[.]lib) ;
     }
-
-    # Create links without version.
-    for local s in $(filtered)
+    else
     {
-        local name = [ $(s).name ] ;
-        local ea = [ $(s).action ] ;
-        local ep = [ $(ea).properties ] ;
-        local a  = [ new non-scanning-action $(s) : symlink.ln : $(ep) ] ;
+        filter =
+            (.*[.]so)[.0-9]*
+            (.*[.]dylib)
+            (.*[.]a) ;
+    }
 
-        local noversion-file ;
-        if $(nt)
-        {
-            noversion-file = [ MATCH "(.*)-[0-9_]+(.*[.]lib)" : $(name) ] ;
-        }
-        else
+    local result ;
+    for local s in $(sources)
+    {
+        local m = [ MATCH ^(.*)-[0-9_]+$(filter)$ : [ $(s).name ] ] ;
+        if $(m)
         {
-            noversion-file =
-              [ MATCH "(.*)-[0-9_]+(.*[.]so)[.0-9]*" : $(name) ]
-                [ MATCH "(.*)-[0-9_]+(.*[.]dylib)" : $(name) ]
-                  [ MATCH "(.*)-[0-9_]+(.*[.]a)" : $(name) ]
-                    [ MATCH "(.*)-[0-9_]+(.*[.]dll[.]a)" : $(name) ] ;
+            local ea = [ $(s).action ] ;
+            local ep = [ $(ea).properties ] ;
+            local a = [ new non-scanning-action $(s) : symlink.ln : $(ep) ] ;
+            result += [ new file-target $(m:J=) exact : [ $(s).type ] :
+                $(project) : $(a) ] ;
         }
-
-        local new-name =
-          $(noversion-file[1])$(noversion-file[2]) ;
-        result += [ new file-target $(new-name) exact : [ $(s).type ] : $(project)
-          : $(a) ] ;
-
     }
     return $(result) ;
 }
@@ -242,13 +215,14 @@ rule declare_install_and_stage_proper_targets ( libraries * : headers * )
 
     if $(layout-versioned)
     {
-        install-requirements += <install-header-subdir>boost-$(BOOST_VERSION_TAG)/boost ;
+        install-requirements +=
+            <install-header-subdir>boost-$(BOOST_VERSION_TAG)/boost ;
     }
     else
     {
         install-requirements += <install-header-subdir>boost ;
     }
-    
+
     if [ os.name ] = NT
     {
         install-requirements += <install-default-prefix>C:/Boost ;
@@ -257,37 +231,36 @@ rule declare_install_and_stage_proper_targets ( libraries * : headers * )
     {
         install-requirements += <install-default-prefix>/usr/local ;
     }
-    
+
     p = [ project.current ] ;
-    
+
     # Complete install.
     package.install install-proper
-      : $(install-requirements) <install-no-version-symlinks>on
-      :
-      : libs/$(libraries)/build
-      : $(headers)
-      ;
-    
+        : $(install-requirements) <install-no-version-symlinks>on
+        :
+        : libs/$(libraries)/build
+        : $(headers)
+        ;
     $(p).mark-target-as-explicit install-proper ;
 
     # Install just library.
     install stage-proper
-      : libs/$(libraries)/build
-      : <location>$(stage-locate)/lib
-        <install-dependencies>on <install-type>LIB
-        <install-no-version-symlinks>on
-      ;
+        : libs/$(libraries)/build
+        : <location>$(stage-locate)/lib
+          <install-dependencies>on <install-type>LIB
+          <install-no-version-symlinks>on
+        ;
     $(p).mark-target-as-explicit stage-proper ;
 
     if $(layout-versioned) && ( [ modules.peek : NT ] || [ modules.peek : UNIX ] )
     {
         generate stage-unversioned : stage-proper :
-          <generating-rule>boostcpp.make-unversioned-links ;
+          <generating-rule>@boostcpp.make-unversioned-links ;
         $(p).mark-target-as-explicit stage-unversioned ;
 
         generate install-unversioned : install-proper :
-          <generating-rule>boostcpp.make-unversioned-links ;
-        $(p).mark-target-as-explicit  explicit install-unversioned ;
+          <generating-rule>@boostcpp.make-unversioned-links ;
+        $(p).mark-target-as-explicit install-unversioned ;
     }
     else
     {
@@ -299,41 +272,41 @@ rule declare_install_and_stage_proper_targets ( libraries * : headers * )
     }
 }
 
-##############################################################################  
+
+################################################################################
 #
-#  3. Declare top-level targets 'stage' and 'install'. These examine
-#  the --build-type option and, in case it's 'complete', build the
-#  'install-proper' and 'stage-proper' targets with a number of
-#  property sets.
+#  3. Declare top-level targets 'stage' and 'install'. These examine the
+#  --build-type option and, in case it is 'complete', build the 'install-proper'
+#  and 'stage-proper' targets with a number of property sets.
 #
-##############################################################################  
+################################################################################
 
 class top-level-target : alias-target-class
 {
     import modules ;
-    import errors ; 
-    
+
     rule __init__ ( name : project : sources * : requirements *
         : default-build * : usage-requirements * )
     {
         alias-target-class.__init__ $(name) : $(project) : $(sources) :
             $(requirements) : $(default-build) : $(usage-requirements) ;
-        
+
         self.build-type = [ modules.peek boostcpp : build-type ] ;
-        # On Linux, we build release variant by default, since few users will
-        # ever want to debug C++ Boost libraries, and there's no ABI
-        # incompatibility between debug and release variants. We build
-        # shared and static libraries since that's what most packages
-        # seem to provide (.so in libfoo and .a in libfoo-dev).
-        self.minimal-properties = [ property-set.create 
-            <variant>release <threading>multi <link>shared <link>static <runtime-link>shared ] ;
+        # On Linux, we build the release variant by default, since few users
+        # will ever want to debug C++ Boost libraries, and there is no ABI
+        # incompatibility between debug and release variants. We build shared
+        # and static libraries since that is what most packages seem to provide
+        # (.so in libfoo and .a in libfoo-dev).
+        self.minimal-properties = [ property-set.create <variant>release
+            <threading>multi <link>shared <link>static <runtime-link>shared ] ;
         # On Windows, new IDE projects use:
         #
         #   runtime-link=dynamic, threading=multi, variant=(debug|release)
         #
         # and in addition, C++ Boost's autolink defaults to static linking.
-        self.minimal-properties-win = [ property-set.create 
-            <variant>debug <variant>release <threading>multi <link>static <runtime-link>shared ] ;
+        self.minimal-properties-win = [ property-set.create <variant>debug
+            <variant>release <threading>multi <link>static <runtime-link>shared
+            ] ;
 
         self.complete-properties = [ property-set.create
             <variant>debug <variant>release
@@ -341,65 +314,66 @@ class top-level-target : alias-target-class
             <link>shared <link>static
             <runtime-link>shared <runtime-link>static ] ;
     }
-    
+
     rule generate ( property-set )
     {
-        local x = [ modules.peek : top-level-targets ] ;
-        x += $(self.name) ;
-        modules.poke : top-level-targets : $(x) ;
+        modules.poke : top-level-targets : [ modules.peek : top-level-targets ]
+            $(self.name) ;
         if $(self.build-type) = minimal
         {
             local expanded ;
-            
+
             local os = [ $(property-set).get <target-os> ] ;
-            # Because we completely override parent's 'generate'
-            # we need to check for default value of feature ourself.
+            # Because we completely override the parent's 'generate' we need to
+            # check for default feature values ourselves.
             if ! $(os)
             {
                 os = [ feature.defaults <target-os> ] ;
                 os = $(os:G=) ;
             }
-            
+
             if $(os) = windows
-            {                
+            {
                 expanded = [ targets.apply-default-build $(property-set)
-                  : $(self.minimal-properties-win) ] ;
+                    : $(self.minimal-properties-win) ] ;
             }
             else
             {
                 expanded = [ targets.apply-default-build $(property-set)
-                  : $(self.minimal-properties) ] ;
-            }            
+                    : $(self.minimal-properties) ] ;
+            }
             return [ build-multiple $(expanded) ] ;
         }
         else if $(self.build-type) = complete
-        {                                    
+        {
             local expanded = [ targets.apply-default-build $(property-set)
-              : $(self.complete-properties) ] ;
-            
-            # Filter inappopriate combinations
+                : $(self.complete-properties) ] ;
+
+            # Filter inappopriate combinations.
             local filtered ;
             for local p in $(expanded)
             {
                 # See comment in handle-static-runtime regarding this logic.
-                if [ $(p).get <link> ] = shared && [ $(p).get <runtime-link> ] = static
-                   && [ $(p).get <toolset> ] != cw
+                if [ $(p).get <link> ] = shared
+                    && [ $(p).get <runtime-link> ] = static
+                    && [ $(p).get <toolset> ] != cw
                 {
-                    # Skip this
+                    # Skip this.
                 }
                 else
                 {
                     filtered += $(p) ;
                 }
-            }            
-            return [ build-multiple $(filtered) ] ;            
+            }
+            return [ build-multiple $(filtered) ] ;
         }
         else
         {
-            errors.error "Unknown build type" ; 
-        }               
+            import errors ;
+            errors.error "Unknown build type" ;
+        }
     }
-    
+
     rule build-multiple ( property-sets * )
     {
         local usage-requirements = [ property-set.empty ] ;
@@ -414,27 +388,27 @@ class top-level-target : alias-target-class
             }
         }
         return $(usage-requirements) [ sequence.unique $(result) ] ;
-    }    
+    }
 }
 
 rule declare_top_level_targets ( libraries * : headers * )
 {
     declare_install_and_stage_proper_targets $(libraries) : $(headers) ;
-    
+
     targets.create-metatarget top-level-target : [ project.current ]
         : install
-        : install-proper install-unversioned 
+        : install-proper install-unversioned
         ;
     targets.create-metatarget top-level-target : [ project.current ]
         : stage
-        : stage-proper stage-unversioned 
+        : stage-proper stage-unversioned
         ;
 
     p = [ project.current ] ;
     $(p).mark-target-as-explicit install stage ;
-    
-    # This target is built by default, and will forward to 'stage'
-    # after producing some explanations.
+
+    # This target is built by default, and will forward to 'stage' after
+    # producing some explanations.
     targets.create-metatarget top-level-target : [ project.current ]
         : forward
         : explain stage
@@ -444,16 +418,16 @@ rule declare_top_level_targets ( libraries * : headers * )
 
 stage-abs = [ path.native [ path.root $(stage-locate)/lib [ path.pwd ] ] ] ;
 
-##############################################################################
+
+################################################################################
 #
-# 4. Add hook to report configuration before the build, and confirmation
-# with setup instructions after the build
+# 4. Add hook to report configuration before the build, and confirmation with
+# setup instructions after the build.
 #
-##############################################################################  
+################################################################################
 
-message explain :
-"\nBuilding the Boost C++ Libraries.\n\n" ;
-p = [ project.current ] ;
+message explain : "\nBuilding the Boost C++ Libraries.\n\n" ;
+local p = [ project.current ] ;
 $(p).mark-target-as-explicit explain ;
 
 rule pre-build ( )
@@ -461,109 +435,107 @@ rule pre-build ( )
     local tl = [ modules.peek : top-level-targets ] ;
     if stage in $(tl) || install in $(tl)
     {
-        # FIXME: remove if when Boost regression tests use trunk
-        # bjam.
+        # FIXME: Remove 'if' when Boost regression tests start using trunk bjam.
         if PAD in [ RULENAMES ]
-        {            
+        {
             configure.print-component-configuration ;
-        }        
+        }
     }
 }
 IMPORT $(__name__) : pre-build : : $(__name__).pre-build ;
 build-system.set-pre-build-hook $(__name__).pre-build ;
 
-# FIXME: revive stage_abs
-rule post-build ( ok ? ) 
+# FIXME: Revise stage_abs.
+rule post-build ( ok ? )
 {
-    if forward in [ modules.peek : top-level-targets ] 
-    {        
+    if forward in [ modules.peek : top-level-targets ]
+    {
         if $(ok)
         {
-        ECHO 
-"\n\nThe Boost C++ Libraries were successfully built!
-          
+            ECHO "
+
+The Boost C++ Libraries were successfully built!
+
 The following directory should be added to compiler include paths:
-          
+
     $(BOOST_ROOT)
-      
+
 The following directory should be added to linker library paths:
-      
+
     $(stage-abs)
 " ;
-        }    
-    }    
+        }
+    }
 }
 IMPORT $(__name__) : post-build : : $(__name__).post-build ;
 build-system.set-post-build-hook $(__name__).post-build ;
 
 
-##############################################################################
-# 
-# 5. Top-level setup 
+################################################################################
 #
-##############################################################################  
-
+# 5. Top-level setup.
+#
+################################################################################
 
 # Decides which libraries are to be installed by looking at --with-<library>
 # --without-<library> arguments. Returns the list of directories under "libs"
 # which must be built and installed.
 #
-rule libraries-to-install ( existing-libraries * )
+rule libraries-to-install ( existing-libs * )
 {
-   local argv = [ modules.peek : ARGV ] ;
-   local with-parameter = [ MATCH --with-(.*) : $(argv) ] ;
-   local without-parameter = [ MATCH --without-(.*) : $(argv) ] ;
-   
-   if ! $(with-parameter) && ! $(without-parameter)
-   {
-       # Nothing is specified on command line. See if maybe
-       # project-config.jam has some choices. 
-       local project-config-libs = [ modules.peek project-config : libraries ] ;
-       with-parameter = [ MATCH --with-(.*) : $(project-config-libs) ] ;
-       without-parameter = [ MATCH --without-(.*) : $(project-config-libs) ] ;
-   }
-
-   # Do some checks.
-   if $(with-parameter) && $(without-parameter)
-   {
-       ECHO "error: both --with-<library> and --without-<library> specified" ;
-       EXIT ;
-   }
-
-   local wrong = [ set.difference $(with-parameter) : $(existing-libraries) ] ;
-   if $(wrong)
-   {
-       ECHO "error: wrong library name '$(wrong[1])' in the --with-<library> option." ;
-       EXIT ;
-   }
-   local wrong = [ set.difference $(without-parameter) : $(existing-libraries) ] ;
-   if $(wrong)
-   {
-       ECHO "error: wrong library name '$(wrong[1])' in the --without-<library> option." ;
-       EXIT ;
-   }
-
-   if $(with-parameter)
-   {
-       return [ set.intersection $(existing-libraries) : $(with-parameter) ] ;
-   }
-   else
-   {
-       return [ set.difference $(existing-libraries) : $(without-parameter) ] ;
-   }
+    local argv = [ modules.peek : ARGV ] ;
+    local with-parameter = [ MATCH ^--with-(.*) : $(argv) ] ;
+    local without-parameter = [ MATCH ^--without-(.*) : $(argv) ] ;
+
+    if ! $(with-parameter) && ! $(without-parameter)
+    {
+        # Nothing is specified on command line. See if maybe project-config.jam
+        # has some choices.
+        local libs = [ modules.peek project-config : libraries ] ;
+        with-parameter = [ MATCH ^--with-(.*) : $(libs) ] ;
+        without-parameter = [ MATCH ^--without-(.*) : $(libs) ] ;
+    }
+
+    # Do some checks.
+    if $(with-parameter) && $(without-parameter)
+    {
+        EXIT error: both --with-<library> and --without-<library> specified ;
+    }
+
+    local wrong = [ set.difference $(with-parameter) : $(existing-libs) ] ;
+    if $(wrong)
+    {
+        EXIT error: wrong library name '$(wrong[1])' in the --with-<library>
+            option. ;
+    }
+    local wrong = [ set.difference $(without-parameter) : $(existing-libs) ] ;
+    if $(wrong)
+    {
+        EXIT error: wrong library name '$(wrong[1])' in the --without-<library>
+            option. ;
+    }
+
+    if $(with-parameter)
+    {
+        return [ set.intersection $(existing-libs) : $(with-parameter) ] ;
+    }
+    else
+    {
+        return [ set.difference $(existing-libs) : $(without-parameter) ] ;
+    }
 }
 
 rule declare-targets ( all-libraries * : headers * )
 {
     configure.register-components $(all-libraries) ;
-    
+
     # Select the libraries to install.
     libraries = [ libraries-to-install $(all-libraries) ] ;
     configure.components-building $(libraries) ;
 
     if [ option.get "show-libraries" : : true ]
     {
-        ECHO "The following libraries require building:" ;
+        ECHO The following libraries require building: ;
         for local l in $(libraries)
         {
             ECHO "    - $(l)" ;