From 7b8b71e9847bfee9b402ee3153b2100cb86adee9 Mon Sep 17 00:00:00 2001
From: Nils Wentzell <nwentzell@flatironinstitute.org>
Date: Mon, 2 Dec 2019 17:53:17 -0500
Subject: [PATCH] [cmake] Fix various issues occuring when using a skeleton
 based app as a subproject

---
 CMakeLists.txt               | 15 ++++++++-------
 c++/app4triqs/CMakeLists.txt |  2 +-
 2 files changed, 9 insertions(+), 8 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 22796f04..b3b1bfdd 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -27,6 +27,7 @@ endif()
 # ############
 # Define Project
 project(APP4TRIQS VERSION 2.2.0 LANGUAGES C CXX)
+get_directory_property(IS_SUBPROJECT PARENT_DIRECTORY)
 
 # ############
 # Load TRIQS and CPP2PY
@@ -47,6 +48,7 @@ endif()
 if(CMAKE_INSTALL_PREFIX_INITIALIZED_TO_DEFAULT OR (NOT IS_ABSOLUTE ${CMAKE_INSTALL_PREFIX}))
   message(STATUS "No install prefix given (or invalid). Defaulting to TRIQS_ROOT")
   set(CMAKE_INSTALL_PREFIX ${TRIQS_ROOT} CACHE PATH "default install path" FORCE)
+  set(CMAKE_INSTALL_PREFIX_INITIALIZED_TO_DEFAULT FALSE)
 endif()
 message(STATUS "-------- CMAKE_INSTALL_PREFIX: ${CMAKE_INSTALL_PREFIX} --------")
 
@@ -59,9 +61,6 @@ if(NOT CMAKE_BUILD_TYPE)
 endif()
 message(STATUS "-------- BUILD-TYPE: ${CMAKE_BUILD_TYPE} --------")
 
-# Build static libraries
-set(BUILD_SHARED_LIBS OFF)
-
 # Export the list of compile-commands into compile_commands.json
 set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
 
@@ -72,7 +71,9 @@ add_compile_options(
 )
 
 # Create an Interface target for compiler warnings
-add_library(project_warnings INTERFACE)
+if(NOT TARGET project_warnings)
+  add_library(project_warnings INTERFACE)
+endif()
 install(TARGETS project_warnings EXPORT app4triqs-targets)
 target_compile_options(project_warnings
   INTERFACE
@@ -93,7 +94,7 @@ add_subdirectory(c++/app4triqs)
 
 # Tests
 option(Build_Tests "Build tests" ON)
-if(Build_Tests)
+if(Build_Tests AND NOT IS_SUBPROJECT)
   enable_testing()
   add_subdirectory(test)
 endif()
@@ -104,7 +105,7 @@ if(TRIQS_WITH_PYTHON_SUPPORT)
 
   # Build the documentation
   option(Build_Documentation "Build documentation" OFF)
-  if(Build_Documentation)
+  if(Build_Documentation AND NOT IS_SUBPROJECT)
     if(NOT TRIQS_WITH_DOCUMENTATION)
       message(WARNING "TRIQS was installed without documentation! Cannot build documentation.")
     else()
@@ -123,7 +124,7 @@ add_subdirectory(share)
 # Debian Package
 
 option(BUILD_DEBIAN_PACKAGE "Build a deb package" OFF)
-if(BUILD_DEBIAN_PACKAGE)
+if(BUILD_DEBIAN_PACKAGE AND NOT IS_SUBPROJECT)
   if(NOT CMAKE_INSTALL_PREFIX STREQUAL "/usr")
     message(FATAL_ERROR "CMAKE_INSTALL_PREFIX must be /usr for packaging")
   endif()
diff --git a/c++/app4triqs/CMakeLists.txt b/c++/app4triqs/CMakeLists.txt
index eecbd50f..1818f87a 100644
--- a/c++/app4triqs/CMakeLists.txt
+++ b/c++/app4triqs/CMakeLists.txt
@@ -1,5 +1,5 @@
 file(GLOB_RECURSE sources *.cpp)
-add_library(app4triqs_c ${sources})
+add_library(app4triqs_c STATIC ${sources})
 
 # Link against triqs and enable warnings
 target_link_libraries(app4triqs_c PUBLIC triqs PRIVATE project_warnings)