CMake: Generate and install squirrel.pc

Closes: https://github.com/albertodemichelis/squirrel/issues/259

CMakeLists.txt

@@ -1,5 +1,10 @@
-cmake_minimum_required(VERSION 3.4)
-project(squirrel VERSION 3.2 LANGUAGES C CXX)
+cmake_minimum_required(VERSION 3.12)
+project(squirrel
+  VERSION 3.2
+  DESCRIPTION "The Squirrel programming language"
+  HOMEPAGE_URL "http://squirrel-lang.org/"
+  LANGUAGES C CXX
+  )
 
 option(DISABLE_STATIC "Avoid building/installing static libraries.")
 option(LONG_OUTPUT_NAMES "Use longer names for binaries and libraries: squirrel3 (not sq).")
@@ -33,6 +38,15 @@ elseif(MSVC)
   add_definitions(-D_CRT_SECURE_NO_WARNINGS)
 endif()
 
+# Need to be defined here to be visible to squirrel.pc.in
+if(LONG_OUTPUT_NAMES)
+  set(LIBSQUIRREL_NAME squirrel3)
+  set(SQSTDLIB_NAME sqstdlib3)
+else()
+  set(LIBSQUIRREL_NAME squirrel)
+  set(SQSTDLIB_NAME sqstdlib)
+endif()
+
 add_subdirectory(squirrel)
 add_subdirectory(sqstdlib)
 if(NOT SQ_DISABLE_INTERPRETER)
@@ -95,6 +109,12 @@ configure_package_config_file(
   INSTALL_DESTINATION "${CMAKE_INSTALL_LIBDIR}/cmake/squirrel"
   )
 
+configure_file(
+  "${CMAKE_CURRENT_SOURCE_DIR}/squirrel.pc.in"
+  ${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}.pc
+  @ONLY
+)
+
 if(NOT SQ_DISABLE_INSTALLER AND NOT SQ_DISABLE_CMAKE_INSTALLER)
   export(EXPORT squirrel
     NAMESPACE squirrel::
@@ -108,6 +128,17 @@ if(NOT SQ_DISABLE_INSTALLER AND NOT SQ_DISABLE_CMAKE_INSTALLER)
     COMPONENT Development
     )
 
+  # pc(5) only allows static variant to have extra flags, not an entirely new
+  # set of flags. While it's uncommon, a way to do it would be to generate a
+  # ${PROJECT_NAME}_static.pc file.
+  if(NOT DISABLE_DYNAMIC)
+    install(
+      FILES ${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}.pc
+      DESTINATION ${CMAKE_INSTALL_LIBDIR}/pkgconfig
+      COMPONENT Development
+    )
+  endif()
+
   install(EXPORT squirrel
     NAMESPACE squirrel::
     DESTINATION "${CMAKE_INSTALL_LIBDIR}/cmake/squirrel"

sqstdlib/CMakeLists.txt

@@ -11,6 +11,7 @@ if(NOT DISABLE_DYNAMIC)
   add_library(sqstdlib SHARED ${SQSTDLIB_SRC})
   add_library(squirrel::sqstdlib ALIAS sqstdlib)
   set_property(TARGET sqstdlib PROPERTY EXPORT_NAME sqstdlib)
+  set_property(TARGET sqstdlib PROPERTY OUTPUT_NAME ${SQSTDLIB_NAME})
   target_link_libraries(sqstdlib squirrel)
   if(NOT SQ_DISABLE_INSTALLER)
     install(TARGETS sqstdlib EXPORT squirrel
@@ -42,10 +43,6 @@ if(NOT DISABLE_STATIC)
 endif()
 
 if(LONG_OUTPUT_NAMES)
-  if(NOT DISABLE_DYNAMIC)
-    set_target_properties(sqstdlib PROPERTIES OUTPUT_NAME sqstdlib3)
-  endif()
-
   if(NOT DISABLE_STATIC)
     set_target_properties(sqstdlib_static PROPERTIES OUTPUT_NAME sqstdlib3_static)
   endif()

squirrel.pc.in

@@ -0,0 +1,12 @@
+prefix=@CMAKE_INSTALL_PREFIX@
+libdir=@CMAKE_INSTALL_FULL_LIBDIR@
+includedir=@CMAKE_INSTALL_FULL_INCLUDEDIR@
+
+Name: @PROJECT_NAME@
+Version: @PROJECT_VERSION@
+Description: @PROJECT_DESCRIPTION@
+URL: @PROJECT_HOMEPAGE_URL@
+Requires:
+Provides: squirrel3 = @PROJECT_VERSION@
+Libs: -L${libdir} -l@LIBSQUIRREL_NAME@ -l@SQSTDLIB_NAME@
+Cflags: -I${includedir}

squirrel/CMakeLists.txt

@@ -15,6 +15,7 @@ if(NOT DISABLE_DYNAMIC)
   add_library(squirrel SHARED ${SQUIRREL_SRC})
   add_library(squirrel::squirrel ALIAS squirrel)
   set_property(TARGET squirrel PROPERTY EXPORT_NAME squirrel)
+  set_property(TARGET squirrel PROPERTY OUTPUT_NAME ${LIBSQUIRREL_NAME})
   if(NOT SQ_DISABLE_INSTALLER)
     install(TARGETS squirrel EXPORT squirrel
       RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR} COMPONENT Libraries
@@ -45,10 +46,6 @@ if(NOT DISABLE_STATIC)
 endif()
 
 if(LONG_OUTPUT_NAMES)
-  if(NOT DISABLE_DYNAMIC)
-    set_target_properties(squirrel PROPERTIES OUTPUT_NAME squirrel3)
-  endif()
-
   if(NOT DISABLE_STATIC)
     set_target_properties(squirrel_static PROPERTIES OUTPUT_NAME squirrel3_static)
   endif()