From d5edbb905cd1cdb656706e54e6dc32ca9e6770a0 Mon Sep 17 00:00:00 2001
From: Bartosz Kostrzewa <bartosz_kostrzewa@fastmail.com>
Date: Wed, 27 Jun 2018 10:48:19 +0200
Subject: [PATCH 1/4] Added automatic detection of quadmath library to
 configure.ac, while preserving the custom setting of paths via install.src,
 if desired. When gsl and quadmath are installed in default paths, sourcing of
 install.src is not required to insteall rzeta

---
 configure.ac | 26 ++++++++++++++++++++++++++
 src/Makevars |  5 -----
 2 files changed, 26 insertions(+), 5 deletions(-)
 delete mode 100644 src/Makevars

diff --git a/configure.ac b/configure.ac
index e50e71f..3f35e1e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1,6 +1,7 @@
 
 AC_INIT([src/qzeta_function.c])
 AC_PROG_CXX
+
 AC_CHECK_LIB(gsl, gsl_sf_airy_Ai_e,
              [LIBS="${LIBS} -lgsl -lgslcblas"], 
              [AC_MSG_ERROR([Cannot find Gnu Scientific Library.])],
@@ -33,6 +34,31 @@ else
   AC_MSG_RESULT([yes])
 fi
 
+AC_SEARCH_LIBS([expq],
+               [quadmath],
+               [],
+               [AC_MSG_ERROR([unable to find the quadmath libary!])]
+               )
+
+gsl_custom_lib=""
+gsl_custom_include=""
+if test -n "${GSL_DIR}"; then
+  gsl_custom_lib="-L${GSL_DIR}/lib -lgsl -lgslcblas"
+  gsl_custom_include="-I${GSL_DIR}/include"
+fi
+
+quadmath_custom_lib=""
+quadmath_custom_include=""
+if test -n "${QUADMATH_LIB_DIR}"; then
+  quadmath_custom_lib="-L${QUADMATH_LIB_DIR}/ -lquadmath"
+fi
+if test -n "${QUADMATH_INCLUDE_DIR}"; then
+  quadmath_custom_include="-I${QUADMATH_INCLUDE_DIR}/"
+fi
+
+echo "PKG_LIBS=-lm ${LIBS} ${quadmath_custom_lib} ${gsl_custom_lib}" > src/Makevars
+echo "PKG_CFLAGS=-march=native -mtune=native -O3 -Wall ${quadmath_custom_include} ${gsl_custom_include}" >> src/Makevars
+echo "PKG_LDFLAGS=-lm ${LIBS} ${gsl_custom_lib} ${quadmath_custom_lib}" >> src/Makevars
 
 AC_OUTPUT()
 
diff --git a/src/Makevars b/src/Makevars
deleted file mode 100644
index 8887bf3..0000000
--- a/src/Makevars
+++ /dev/null
@@ -1,5 +0,0 @@
-# So 19. Nov 15:42:30 CET 2017
-
-PKG_LIBS=-L${GSL_DIR}/lib -lgsl -lgslcblas -L${QUADMATH_LIB_DIR}/ -lquadmath -lm
-PKG_CFLAGS=-I${GSL_DIR}/include -I${QUADMATH_INCLUDE_DIR}/  -O3 -Wall
-PKG_LDFLAGS=-L${GSL_DIR}/lib/ -lgsl -lgslcblas  -L${QUADMATH_LIB_DIR}/ -lquadmath -lm

From 5f13b51a6d9615640be2cd0ee9d8aca058496f00 Mon Sep 17 00:00:00 2001
From: Bartosz Kostrzewa <bartosz_kostrzewa@fastmail.com>
Date: Wed, 27 Jun 2018 12:15:06 +0200
Subject: [PATCH 2/4] enable quadmath library detection in configure only if no
 custom path has been specified

---
 configure.ac | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/configure.ac b/configure.ac
index 3f35e1e..ef7a0cc 100644
--- a/configure.ac
+++ b/configure.ac
@@ -34,11 +34,13 @@ else
   AC_MSG_RESULT([yes])
 fi
 
-AC_SEARCH_LIBS([expq],
-               [quadmath],
-               [],
-               [AC_MSG_ERROR([unable to find the quadmath libary!])]
-               )
+if test -z "${QUADMATH_LIB_DIR}"; then
+  AC_SEARCH_LIBS([expq],
+                 [quadmath],
+                 [],
+                 [AC_MSG_ERROR([unable to find the quadmath libary!])]
+                 )
+fi
 
 gsl_custom_lib=""
 gsl_custom_include=""

From b16920d8a06f0d8f2d990ec88d9cf6bcab5d50f0 Mon Sep 17 00:00:00 2001
From: Bartosz Kostrzewa <bartosz_kostrzewa@fastmail.com>
Date: Thu, 28 Jun 2018 16:44:13 +0200
Subject: [PATCH 3/4] add some comments to configure.ac

---
 configure.ac | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/configure.ac b/configure.ac
index ef7a0cc..00790e6 100644
--- a/configure.ac
+++ b/configure.ac
@@ -34,6 +34,11 @@ else
   AC_MSG_RESULT([yes])
 fi
 
+# if the user has not specified a library path for the quadmath library
+# we try to auto-detect it
+# currenty, if we fail to find it, we abort compilation
+# in the future one could disable the quad precision
+# implementation in this case
 if test -z "${QUADMATH_LIB_DIR}"; then
   AC_SEARCH_LIBS([expq],
                  [quadmath],
@@ -58,6 +63,7 @@ if test -n "${QUADMATH_INCLUDE_DIR}"; then
   quadmath_custom_include="-I${QUADMATH_INCLUDE_DIR}/"
 fi
 
+# construct src/Makevars with the manually or automatically detected library paths and flags
 echo "PKG_LIBS=-lm ${LIBS} ${quadmath_custom_lib} ${gsl_custom_lib}" > src/Makevars
 echo "PKG_CFLAGS=-march=native -mtune=native -O3 -Wall ${quadmath_custom_include} ${gsl_custom_include}" >> src/Makevars
 echo "PKG_LDFLAGS=-lm ${LIBS} ${gsl_custom_lib} ${quadmath_custom_lib}" >> src/Makevars

From 64798f2cccdc70a495144a0fcb06eee7c84668c2 Mon Sep 17 00:00:00 2001
From: Bartosz Kostrzewa <bartosz_kostrzewa@fastmail.com>
Date: Thu, 28 Jun 2018 16:45:10 +0200
Subject: [PATCH 4/4] add script to clean the build directory, such that
 rebuilding works properly

---
 clean.sh | 2 ++
 1 file changed, 2 insertions(+)
 create mode 100755 clean.sh

diff --git a/clean.sh b/clean.sh
new file mode 100755
index 0000000..41e1170
--- /dev/null
+++ b/clean.sh
@@ -0,0 +1,2 @@
+rm -f */*.o
+rm -f */*.so