Find Boost dep when there is an extra lib to link

There are several components in Boost which must be linked with extra
libraries. Boost Log is one of them and in special circumstances needs
linking with boost_log_setup.

http://www.boost.org/doc/libs/1_64_0/libs/log/doc/html/log/detailed/utilities.html#log.detailed.utilities.setup

This fix covers the case when there is no source file corresponding to
the additional library.

mesonbuild/dependencies/misc.py

@@ -142,7 +142,7 @@ class BoostDependency(ExternalDependency):
 
     def validate_requested(self):
         for m in self.requested_modules:
-            if m not in self.src_modules:
+            if m not in self.src_modules and m not in self.lib_modules and m + '-mt' not in self.lib_modules_mt:
                 msg = 'Requested Boost module {!r} not found'
                 raise DependencyException(msg.format(m))
 

test cases/frameworks/1 boost/extralib.cpp

@@ -0,0 +1,25 @@
+#include <iostream>
+#include <boost/log/trivial.hpp>
+#include <boost/log/expressions.hpp>
+#include <boost/log/utility/setup/console.hpp>
+#include <boost/log/utility/setup/common_attributes.hpp>
+
+using namespace std;
+namespace logging = boost::log;
+
+void InitLogger() {
+  logging::add_common_attributes();
+  logging::register_simple_formatter_factory<logging::trivial::severity_level, char>("Severity");
+  string log_format = "%TimeStamp% [%Severity%] - %Message%";
+
+  logging::add_console_log(
+    cout,
+    logging::keywords::format = log_format
+  );
+}
+
+int main(int argc, char **argv) {
+  InitLogger();
+  BOOST_LOG_TRIVIAL(trace) << "SOMETHING";
+  return 0;
+}

test cases/frameworks/1 boost/meson.build

@@ -1,6 +1,10 @@
 project('boosttest', 'cpp',
   default_options : ['cpp_std=c++11'])
 
+add_project_arguments(['-DBOOST_LOG_DYN_LINK'],
+  language : 'cpp'
+)
+
 # We want to have multiple separate configurations of Boost
 # within one project. The need to be independent of each other.
 # Use one without a library dependency and one with it.
@@ -10,15 +14,18 @@ linkdep = dependency('boost', modules : ['thread', 'system'])
 staticdep = dependency('boost', modules : ['thread', 'system'], static : true)
 testdep = dependency('boost', modules : 'test')
 nomoddep = dependency('boost')
+extralibdep = dependency('boost', modules : ['thread', 'system', 'log_setup', 'log'])
 
 nolinkexe = executable('nolinkedexe', 'nolinkexe.cc', dependencies : nolinkdep)
 linkexe = executable('linkedexe', 'linkexe.cc', dependencies : linkdep)
 staticexe = executable('staticlinkedexe', 'linkexe.cc', dependencies : staticdep)
 unitexe = executable('utf', 'unit_test.cpp', dependencies: testdep)
 nomodexe = executable('nomod', 'nomod.cpp', dependencies : nomoddep)
+extralibexe = executable('extralibexe', 'extralib.cpp', dependencies : extralibdep)
 
 test('Boost nolinktest', nolinkexe)
 test('Boost linktest', linkexe)
 test('Boost statictest', staticexe)
 test('Boost UTF test', unitexe)
 test('Boost nomod', nomodexe)
+test('Boost extralib test', extralibexe)