From 175d1420fd0160346d3b40c73622e685f7b6eca6 Mon Sep 17 00:00:00 2001
From: Roberto Di Remigio <roberto.diremigio@gmail.com>
Date: Fri, 3 Aug 2018 16:50:36 -0400
Subject: [PATCH] Fix build with MSYS

---
 chapter-08/recipe-03/c-example/CMakeLists.txt          |  4 ++++
 .../c-example/external/upstream/fftw3/CMakeLists.txt   | 10 ++++++++--
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/chapter-08/recipe-03/c-example/CMakeLists.txt b/chapter-08/recipe-03/c-example/CMakeLists.txt
index 1c81152c3..8914542f6 100644
--- a/chapter-08/recipe-03/c-example/CMakeLists.txt
+++ b/chapter-08/recipe-03/c-example/CMakeLists.txt
@@ -6,6 +6,10 @@ set(CMAKE_C_STANDARD 99)
 set(CMAKE_C_EXTENSIONS OFF)
 set(CMAKE_C_STANDARD_REQUIRED ON)
 
+set_property(DIRECTORY PROPERTY EP_BASE ${CMAKE_BINARY_DIR}/subprojects)
+
+option(FFTW3_FORCE_SUPERBUILD "Always build FFTW3 on our own" OFF)
+
 add_subdirectory(external/upstream)
 
 include(ExternalProject)
diff --git a/chapter-08/recipe-03/c-example/external/upstream/fftw3/CMakeLists.txt b/chapter-08/recipe-03/c-example/external/upstream/fftw3/CMakeLists.txt
index 321208713..037016ae9 100644
--- a/chapter-08/recipe-03/c-example/external/upstream/fftw3/CMakeLists.txt
+++ b/chapter-08/recipe-03/c-example/external/upstream/fftw3/CMakeLists.txt
@@ -1,10 +1,14 @@
 find_package(FFTW3 CONFIG QUIET)
-if(FFTW3_FOUND)
+if(FFTW3_FOUND AND (NOT FFTW3_FORCE_SUPERBUILD))
   get_property(_loc TARGET FFTW3::fftw3 PROPERTY LOCATION)
   message(STATUS "Found FFTW3: ${_loc} (found version ${FFTW3_VERSION})")
   add_library(fftw3_external INTERFACE)  # dummy
 else()
-  message(STATUS "Suitable FFTW3 could not be located. Downloading and building!")
+  if(FFTW3_FORCE_SUPERBUILD)
+    message(STATUS "Forcing superbuild of FFTW3.")
+  else()
+    message(STATUS "Suitable FFTW3 could not be located. Downloading and building!")
+  endif()
   include(ExternalProject)
   ExternalProject_Add(fftw3_external
     URL
@@ -17,6 +21,8 @@ else()
       ""
     CMAKE_ARGS
       -DCMAKE_INSTALL_PREFIX=${DEPS_INSTALL_PREFIX}
+    CMAKE_CACHE_ARGS
+      -DCMAKE_C_FLAGS:STRING=-DWITH_OUR_MALLOC
     )
   include(GNUInstallDirs)
   set(FFTW3_DIR ${DEPS_INSTALL_PREFIX}/${CMAKE_INSTALL_LIBDIR}/cmake/fftw3