tests/common/146: Also test against external C++ libs

test cases/common/146 C and CPP link/meson.build

@@ -14,11 +14,45 @@
 
 project('C and C++ static link test', ['c', 'cpp'])
 
-libcppfoo = static_library('cppfoo', ['foo.cpp', 'foo.hpp'])
-libcfoo = static_library('cfoo', ['foo.c', 'foo.h'])
+libc = static_library('cfoo', ['foo.c', 'foo.h'])
+
+# Test that linking C libs to external static C++ libs uses the C++ linker
+# Since we can't depend on the test system to provide this, we create one
+# ourselves at configure time and then 'find' it with cxx.find_library().
+cxx = meson.get_compiler('cpp')
+
+if cxx.get_id() == 'msvc'
+  compile_cmd = ['/c', '@INPUT@', '/Fo@OUTPUT@']
+  stlib_cmd = ['lib', '/OUT:@OUTPUT@', '@INPUT@']
+else
+  compile_cmd = ['-c', '-fPIC', '@INPUT@', '-o', '@OUTPUT@']
+  stlib_cmd = ['ar', 'csr', '@OUTPUT@', '@INPUT@']
+endif
+
+foo_cpp_o = configure_file(
+  input : 'foo.cpp',
+  output : 'foo.cpp.o',
+  command : cxx.cmd_array() + compile_cmd)
+
+configure_file(
+  input : foo_cpp_o,
+  output : 'libstcppext.a',
+  command : stlib_cmd)
+
+libstcppext = cxx.find_library('stcppext', dirs : meson.current_build_dir())
+
+libfooext = shared_library(
+  'fooext',
+  ['foobar.c', 'foobar.h'],
+  link_with : libc,
+  dependencies : libstcppext,
+)
+
+# Test that linking C libs to internal static C++ libs uses the C++ linker
+libcpp = static_library('cppfoo', ['foo.cpp', 'foo.hpp'])
 
 libfoo = shared_library(
   'foo',
   ['foobar.c', 'foobar.h'],
-  link_with : [libcfoo, libcppfoo],
+  link_with : [libc, libcpp],
 )