Add more package metadata to the pkg-config files

The pkg-config files have been filled in more thoroughly to allow users
to use mesa more effectively. By adding metadata to Requires.private,
Libs.private and Cflags, we can ensure that all the libraries and
headers will be found in all situations. However, the full substitutions
are only done when using the configure script.

This also fixes the glu pkg-config file to account for using GL or
OSMesa.

Fixes bug 18161.
diff --git a/configure.ac b/configure.ac
index 66e080e..8026d9d 100644
--- a/configure.ac
+++ b/configure.ac
@@ -507,14 +507,18 @@
 xlib)
     if test "$x11_pkgconfig" = yes; then
         PKG_CHECK_MODULES([XLIBGL], [x11 xext])
+        GL_PC_REQ_PRIV="x11 xext"
         X11_INCLUDES="$X11_INCLUDES $XLIBGL_CFLAGS"
         GL_LIB_DEPS="$XLIBGL_LIBS"
     else
         # should check these...
         X11_INCLUDES="$X11_INCLUDES $X_CFLAGS"
         GL_LIB_DEPS="$X_LIBS -lX11 -lXext"
+        GL_PC_LIB_PRIV="$GL_LIB_DEPS"
+        GL_PC_CFLAGS="$X11_INCLUDES"
     fi
     GL_LIB_DEPS="$GL_LIB_DEPS $SELINUX_LIBS -lm -lpthread $OS_LIBS"
+    GL_PC_LIB_PRIV="$GL_PC_LIB_PRIV $SELINUX_LIBS -lm -lpthread $OS_LIBS"
 
     # if static, move the external libraries to the programs
     # and empty the libraries for libGL
@@ -532,6 +536,8 @@
     # Check for libdrm
     PKG_CHECK_MODULES([LIBDRM], [libdrm >= $LIBDRM_REQUIRED])
     PKG_CHECK_MODULES([DRI2PROTO], [dri2proto >= $DRI2PROTO_REQUIRED])
+    GL_PC_REQ_PRIV="libdrm >= $LIBDRM_REQUIRED dri2proto >= $DRI2PROTO_REQUIRED"
+    DRI_PC_REQ_PRIV="libdrm >= $LIBDRM_REQUIRED"
 
     # find the DRI deps for libGL
     if test "$x11_pkgconfig" = yes; then
@@ -542,16 +548,20 @@
         fi
 
         PKG_CHECK_MODULES([DRIGL], [$dri_modules])
+        GL_PC_REQ_PRIV="$GL_PC_REQ_PRIV $dri_modules"
         X11_INCLUDES="$X11_INCLUDES $DRIGL_CFLAGS"
         GL_LIB_DEPS="$DRIGL_LIBS"
     else
         # should check these...
         X11_INCLUDES="$X11_INCLUDES $X_CFLAGS"
         GL_LIB_DEPS="$X_LIBS -lX11 -lXext -lXxf86vm -lXdamage -lXfixes"
+        GL_PC_LIB_PRIV="$GL_LIB_DEPS"
+        GL_PC_CFLAGS="$X11_INCLUDES"
 
         # XCB can only be used from pkg-config
         if test "$enable_xcb" = yes; then
             PKG_CHECK_MODULES([XCB],[x11-xcb xcb-glx])
+            GL_PC_REQ_PRIV="$GL_PC_REQ_PRIV x11-xcb xcb-glx"
             X11_INCLUDES="$X11_INCLUDES $XCB_CFLAGS"
             GL_LIB_DEPS="$GL_LIB_DEPS $XCB_LIBS"
         fi
@@ -559,6 +569,7 @@
 
     # need DRM libs, -lpthread, etc.
     GL_LIB_DEPS="$GL_LIB_DEPS $LIBDRM_LIBS -lm -lpthread $DLOPEN_LIBS $OS_LIBS"
+    GL_PC_LIB_PRIV="-lm -lpthread $DLOPEN_LIBS $OS_LIBS"
     ;;
 osmesa)
     # No libGL for osmesa
@@ -566,6 +577,10 @@
     ;;
 esac
 AC_SUBST([GL_LIB_DEPS])
+AC_SUBST([GL_PC_REQ_PRIV])
+AC_SUBST([GL_PC_LIB_PRIV])
+AC_SUBST([GL_PC_CFLAGS])
+AC_SUBST([DRI_PC_REQ_PRIV])
 
 dnl
 dnl More X11 setup
@@ -825,6 +840,8 @@
 
         # Link libGLU to libOSMesa instead of libGL
         GLU_LIB_DEPS=""
+        GLU_PC_LIB='-L$(INSTALL_LIB_DIR) -l$(OSMESA_LIB)'
+        GLU_PC_CFLAGS='-I$(INSTALL_INC_DIR)'
         if test "$enable_static" = no; then
             GLU_MESA_DEPS='-l$(OSMESA_LIB)'
         else
@@ -833,6 +850,8 @@
         ;;
     *)
         # If static, empty GLU_LIB_DEPS and add libs for programs to link
+        GLU_PC_REQ="gl"
+        GLU_PC_LIB_PRIV="-lm"
         if test "$enable_static" = no; then
             GLU_LIB_DEPS="-lm"
             GLU_MESA_DEPS='-l$(GL_LIB)'
@@ -847,8 +866,14 @@
 if test "$enable_static" = no; then
     GLU_LIB_DEPS="$GLU_LIB_DEPS $OS_CPLUSPLUS_LIBS"
 fi
+GLU_PC_LIB_PRIV="$GLU_PC_LIB_PRIV $OS_CPLUSPLUS_LIBS"
 AC_SUBST([GLU_LIB_DEPS])
 AC_SUBST([GLU_MESA_DEPS])
+AC_SUBST([GLU_PC_REQ])
+AC_SUBST([GLU_PC_REQ_PRIV])
+AC_SUBST([GLU_PC_LIB])
+AC_SUBST([GLU_PC_LIB_PRIV])
+AC_SUBST([GLU_PC_CFLAGS])
 
 dnl
 dnl GLw configuration
@@ -873,10 +898,13 @@
     SRC_DIRS="$SRC_DIRS glw"
     if test "$x11_pkgconfig" = yes; then
         PKG_CHECK_MODULES([GLW],[x11 xt])
+        GLW_PC_REQ_PRIV="x11 xt"
         GLW_LIB_DEPS="$GLW_LIBS"
     else
         # should check these...
         GLW_LIB_DEPS="$X_LIBS -lXt -lX11"
+        GLW_PC_LIB_PRIV="$GLW_LIB_DEPS"
+        GLW_PC_CFLAGS="$X11_INCLUDES"
     fi
 
     GLW_SOURCES="GLwDrawA.c"
@@ -895,9 +923,12 @@
         fi
         # MOTIF_LIBS is prepended to GLW_LIB_DEPS since Xm needs Xt/X11
         GLW_LIB_DEPS="$MOTIF_LIBS $GLW_LIB_DEPS"
+        GLW_PC_LIB_PRIV="$MOTIF_LIBS $GLW_PC_LIB_PRIV"
+        GLW_PC_CFLAGS="$MOTIF_CFLAGS $GLW_PC_CFLAGS"
     fi
 
     # If static, empty GLW_LIB_DEPS and add libs for programs to link
+    GLW_PC_LIB_PRIV="$GLW_PC_LIB_PRIV $OS_LIBS"
     if test "$enable_static" = no; then
         GLW_MESA_DEPS='-l$(GL_LIB)'
         GLW_LIB_DEPS="$GLW_LIB_DEPS $OS_LIBS"
@@ -911,6 +942,9 @@
 AC_SUBST([GLW_MESA_DEPS])
 AC_SUBST([GLW_SOURCES])
 AC_SUBST([MOTIF_CFLAGS])
+AC_SUBST([GLW_PC_REQ_PRIV])
+AC_SUBST([GLW_PC_LIB_PRIV])
+AC_SUBST([GLW_PC_CFLAGS])
 
 dnl
 dnl GLUT configuration
@@ -945,12 +979,16 @@
     fi
     if test "$x11_pkgconfig" = yes; then
         PKG_CHECK_MODULES([GLUT],[x11 xmu xi])
+        GLUT_PC_REQ_PRIV="x11 xmu xi"
         GLUT_LIB_DEPS="$GLUT_LIBS"
     else
         # should check these...
         GLUT_LIB_DEPS="$X_LIBS -lX11 -lXmu -lXi"
+        GLUT_PC_LIB_PRIV="$GLUT_LIB_DEPS"
+        GLUT_PC_CFLAGS="$X11_INCLUDES"
     fi
     GLUT_LIB_DEPS="$GLUT_LIB_DEPS -lm $OS_LIBS"
+    GLUT_PC_LIB_PRIV="$GLUT_PC_LIB_PRIV -lm $OS_LIBS"
 
     # If glut is available, we can build most programs
     if test "$with_demos" = yes; then
@@ -969,6 +1007,9 @@
 AC_SUBST([GLUT_LIB_DEPS])
 AC_SUBST([GLUT_MESA_DEPS])
 AC_SUBST([GLUT_CFLAGS])
+AC_SUBST([GLUT_PC_REQ_PRIV])
+AC_SUBST([GLUT_PC_LIB_PRIV])
+AC_SUBST([GLUT_PC_CFLAGS])
 
 dnl
 dnl Program library dependencies