fixes to Libs.private in .pc file. revise -lm dependencies in autotools.

Author: sezero

CMakeLists.txt

@@ -176,7 +176,15 @@ install(FILES
   ${CMAKE_INSTALL_INCLUDEDIR}/libmodplug
 )
 
-if (NOT WIN32)
+if (NOT MSVC)
+  if(MINGW OR CYGWIN)
+    set(LIBS_PRIVATE "-luser32 -lstdc++")
+  else()
+    set(LIBS_PRIVATE "-lstdc++")
+    if(MATH_LIB)
+      set(LIBS_PRIVATE "${LIBS_PRIVATE} -lm")
+    endif()
+  endif()
   set(prefix ${CMAKE_INSTALL_PREFIX})
   set(exec_prefix ${CMAKE_INSTALL_PREFIX})
   set(libdir ${CMAKE_INSTALL_PREFIX}/${CMAKE_INSTALL_LIBDIR})
@@ -187,4 +195,4 @@ if (NOT WIN32)
   install(FILES "${PROJECT_BINARY_DIR}/libmodplug.pc"
     DESTINATION ${CMAKE_INSTALL_LIBDIR}/pkgconfig
   )
-endif (NOT WIN32)
+endif ()

configure.ac

@@ -29,7 +29,6 @@ LT_INIT([win32-dll])
 
 AC_HEADER_STDC
 AC_CHECK_HEADERS([inttypes.h stdint.h malloc.h])
-AC_CHECK_FUNCS(sinf)
 
 CXXFLAGS="$CXXFLAGS -fno-exceptions -Wall -ffast-math -fno-common -D_REENTRANT"
 
@@ -44,6 +43,30 @@ case "$host" in
 esac
 AC_SUBST(LT_LDFLAGS)
 
+LIBS_PRIVATE=-lstdc++
+LIBM=
+case "${host_os}" in
+dnl Djgpp has all c89 math funcs in libc.a
+*djgpp)
+  ;;
+dnl These systems don't have libm or don't need it (list based on libtool)
+darwin*|haiku*|beos*|cegcc*|pw32*)
+  ;;
+dnl MinGW and Cygwin don't need libm, either
+mingw*|cygwin*)
+  LIBS_PRIVATE="-luser32 ${LIBS_PRIVATE}"
+  ;;
+dnl All others:
+*) AC_CHECK_LIB(m, pow, LIBM="-lm")
+  if test x$LIBM != x; then
+    LIBS="${LIBS} ${LIBM}"
+    LIBS_PRIVATE="${LIBS_PRIVATE} ${LIBM}"
+  fi
+  ;;
+esac
+AC_SUBST(LIBS_PRIVATE)
+AC_CHECK_FUNCS(sinf)
+
 # symbol visibility
 ac_save_CXXFLAGS="$CXXFLAGS"
 CXXFLAGS="$CXXFLAGS -fvisibility=hidden -Werror"

libmodplug.pc.in

@@ -7,6 +7,6 @@ Name: libmodplug
 Description: The ModPlug mod file playing library.
 Version: @VERSION@
 Requires: 
-Libs: -L${libdir} -lmodplug 
-Libs.private: -lstdc++ -lm
+Libs: -L${libdir} -lmodplug
+Libs.private: @LIBS_PRIVATE@
 Cflags: -I${includedir}

src/Makefile.am

@@ -6,7 +6,6 @@ AM_CPPFLAGS = -I$(top_srcdir)/src/libmodplug
 
 lib_LTLIBRARIES = libmodplug.la
 libmodplug_la_LDFLAGS = -version-info $(MODPLUG_LIBRARY_VERSION) $(LT_LDFLAGS)
-libmodplug_la_LIBADD = -lm
 libmodplug_la_SOURCES = tables.h         \
                         sndmix.cpp         \
                         sndfile.cpp        \