Add in proper configure check for mpfr.

svn path=/trunk/playground/utils/abakus/; revision=745805

CMakeLists.txt

@@ -4,6 +4,24 @@ set (CMAKE_MODULE_PATH ${CMAKE_SOURCE_DIR}/cmake/modules)
 FIND_PACKAGE(KDE4 REQUIRED)
 
 include(KDE4Defaults)
+include(CheckCXXSourceCompiles)
+
+# Check for libmpfr and libgmp, and verify existence of _mpfr_struct
+set(CMAKE_REQUIRED_LIBRARIES gmp mpfr)
+check_cxx_source_compiles(
+    "#include <mpfr.h>
+
+    int main() {
+    mpfr_t a;
+    mpfr_ptr ptr;
+    __mpfr_struct debug;
+
+    mpfr_init(a);
+    return 0;
+    }
+    "
+    HAVE_MPFR
+    )
 
 INCLUDE_DIRECTORIES(${KDE4_INCLUDES} ${QT4_INCLUDES})
 ADD_DEFINITIONS(${QT_DEFINITIONS} ${KDE4_DEFINITIONS})

src/CMakeLists.txt

@@ -123,8 +123,8 @@ set(abakus_SRCS
     )
 
 set(MPFR_LIBS)
-set(HAVE_MPFR 0)
 IF(HAVE_MPFR)
+    MESSAGE("Using the MPFR high-precision mathematics library")
     SET(MPFR_LIBS mpfr gmp)
 ELSE(HAVE_MPFR)
     SET(abakus_SRCS ${abakus_SRCS} hmath.cpp number.c)

src/numerictypes.h

@@ -260,7 +260,7 @@ public:
     explicit number(const QByteArray &str)
     {
         m_t = (mpfr_ptr) new __mpfr_struct;
-        mpfr_init_set_str (m_tr, str.constData(), 10, RoundDirection);
+        mpfr_init_set_str (m_t, str.constData(), 10, RoundDirection);
     }
 
     explicit number(int i)