Add support for modular build structure. (#318)

* Make the library modular usable.

* Use searched-lib targets for external/OS/Windows libraries to avoid trying to refer to mangled names for them. And hence failing to find them.

* Use the OS temp dir for creating test dir to avoid putting dirs in random location based on where one runs tests from.

* Switch to library requirements instead of source. As source puts extra source in install targets.

* Updated dependencies.

* Add missing NO_LIB usage requirements.

* Add missing import-search for cconfig/predef checks.

* Add requires-b2 check to top-level build file.

* Bump B2 require to 5.2

* Change all <source> references to <library>.

* Update copyright dates.

* Move inter-lib dependencies to a project variable and into the build targets.

* Split b2 dependencies into public and private.

* Undo temp dir for test change.

* Make winapi dep target-os specific. And remove direct atomic dep as it is already handled by conditional rule.

* Remove bug targets from all build as that's not a regular project.

build.jam

@@ -0,0 +1,32 @@
+# Copyright René Ferdinand Rivera Morell 2023-2024
+# Distributed under the Boost Software License, Version 1.0.
+# (See accompanying file LICENSE_1_0.txt or copy at
+# http://www.boost.org/LICENSE_1_0.txt)
+
+require-b2 5.2 ;
+
+constant boost_dependencies :
+    /boost/assert//boost_assert
+    /boost/config//boost_config
+    /boost/container_hash//boost_container_hash
+    /boost/detail//boost_detail
+    /boost/io//boost_io
+    /boost/iterator//boost_iterator
+    /boost/smart_ptr//boost_smart_ptr
+    /boost/system//boost_system
+    /boost/type_traits//boost_type_traits ;
+
+project /boost/filesystem
+    : common-requirements
+        <include>include
+    ;
+
+explicit
+    [ alias boost_filesystem : build//boost_filesystem ]
+    [ alias all : boost_filesystem example test ]
+    ;
+
+call-if : boost-library filesystem
+    : install boost_filesystem
+    ;
+

build/Jamfile.v2

@@ -9,11 +9,12 @@
 
 import project ;
 import configure ;
+import-search /boost/config/checks ;
 import config : requires ;
 
-lib bcrypt ;
-lib advapi32 ;
-lib coredll ;
+searched-lib bcrypt ;
+searched-lib advapi32 ;
+searched-lib coredll ;
 explicit bcrypt advapi32 coredll ;
 
 # The rule checks if a config macro is defined in the command line or build properties
@@ -136,8 +137,13 @@ local cxx_requirements = [ requires
     cxx11_override
 ] ;
 
-project boost/filesystem
+project
+    : common-requirements <library>$(boost_dependencies)
     : requirements
+      <library>/boost/core//boost_core
+      <library>/boost/predef//boost_predef
+      <library>/boost/scope//boost_scope
+      <target-os>windows:<library>/boost/winapi//boost_winapi
       <host-os>hpux,<toolset>gcc:<define>_INCLUDE_STDC__SOURCE_199901
       [ check-target-builds ../config//has_attribute_init_priority "has init_priority attribute" : <define>BOOST_FILESYSTEM_HAS_INIT_PRIORITY ]
       [ check-target-builds ../config//has_stat_st_mtim "has stat::st_blksize" : <define>BOOST_FILESYSTEM_HAS_STAT_ST_BLKSIZE ]
@@ -177,6 +183,7 @@ project boost/filesystem
     : usage-requirements # pass these requirement to dependents (i.e. users)
       <link>shared:<define>BOOST_FILESYSTEM_DYN_LINK=1
       <link>static:<define>BOOST_FILESYSTEM_STATIC_LINK=1
+      <define>BOOST_FILESYSTEM_NO_LIB=1
     ;
 
 SOURCES =
@@ -216,5 +223,3 @@ lib boost_filesystem
     : usage-requirements
       $(cxx_requirements)
     ;
-
-boost-install boost_filesystem ;

config/Jamfile.v2

@@ -36,7 +36,7 @@ explicit has_posix_at_apis ;
 obj has_fallocate : has_fallocate.cpp : <include>../src ;
 explicit has_fallocate ;
 
-lib bcrypt ;
+searched-lib bcrypt ;
 explicit bcrypt ;
 
 exe has_bcrypt : has_bcrypt.cpp : <include>../src <library>bcrypt ;

test/Jamfile.v2

@@ -85,7 +85,7 @@ run operations_test.cpp : : : <link>shared <define>BOOST_FILESYSTEM_VERSION=4 <t
 run operations_test.cpp : : : <link>static <define>BOOST_FILESYSTEM_VERSION=4 : operations_test_static ;
 run operations_test.cpp : : : <link>shared <define>BOOST_FILESYSTEM_VERSION=3 : operations_test_v3 ;
 run operations_unit_test.cpp : $(HERE) : : <link>shared <define>BOOST_FILESYSTEM_VERSION=4 <test-info>always_show_run_output ;
-run copy_test.cpp : : : <define>BOOST_FILESYSTEM_VERSION=4 ;
+run copy_test.cpp : : : <define>BOOST_FILESYSTEM_VERSION=4 <library>/boost/exception//boost_exception ;
 compile-fail cf_path_nullptr_test.cpp ;
 compile path_iter_ctor_overload_test.cpp ;
 compile path_operator_ambiguity.cpp : <toolset>gcc:<warnings-as-errors>on ;
@@ -98,7 +98,7 @@ run path_unit_test.cpp : : : <link>shared $(VIS) <define>BOOST_FILESYSTEM_VERSIO
 run relative_test.cpp : : : <define>BOOST_FILESYSTEM_VERSION=4 ;
 run ../example/simple_ls.cpp : : : <define>BOOST_FILESYSTEM_VERSION=4 ;
 run ../example/file_status.cpp : : : <define>BOOST_FILESYSTEM_VERSION=4 ;
-run foreach_test.cpp : : : <define>BOOST_FILESYSTEM_VERSION=4 ;
+run foreach_test.cpp : : : <define>BOOST_FILESYSTEM_VERSION=4 <library>/boost/foreach//boost_foreach ;
 
 # `quick` target (for CI)
 run quick.cpp : : : <define>BOOST_FILESYSTEM_VERSION=4 ;