From c64e031717c51336da31d8e70ddd34108170e151 Mon Sep 17 00:00:00 2001
From: Matthew Fernandez <matthew.fernandez@gmail.com>
Date: Thu, 25 Nov 2021 08:16:36 -0800
Subject: [PATCH] CMake: use more standard, portable mechanism for setting
 install paths

Fixes #1973.

Suggested-by: Satadru Pramanik
---
 CHANGELOG.md                     |  3 +++
 CMakeLists.txt                   | 25 ++++++++++++++++++-------
 cmake/configure_plugins.cmake.in |  4 ++--
 3 files changed, 23 insertions(+), 9 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index f85c5c005..3b65e7da9 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -78,6 +78,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - The tclpkg Makefile no longer suppresses `-fstack-clash-protection` nor
   other compiler options containing `-x`
 - Lefty is no longer enabled in the portable source tarball.
+- on Linux, the CMake build system uses the standard `GNUInstallDirs` to locate
+  target installation paths
 
 ### Fixed
 
@@ -93,6 +95,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - expr misinterprets `<<` and `>>` #2103
 - stdout and stderr are not flushed at exit on MinGW #2178
 - Gvedit on macOS now understands the `-?` help command line argument
+- CMAKE_LIBRARY_PATH is not honored #1973
 
 ## [2.50.0] – 2021-12-04
 
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 606391c33..8186859f8 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -63,12 +63,25 @@ endif()
 find_program(GZIP gzip)
 
 # ================== Convenient values for CMake configuration =================
-set(BINARY_INSTALL_DIR      bin)
-set(LIBRARY_INSTALL_DIR     lib)
+if(${CMAKE_SYSTEM_NAME} MATCHES "Linux")
+  include(GNUInstallDirs)
+  set(BINARY_INSTALL_DIR  "${CMAKE_INSTALL_BINDIR}")
+  set(LIBRARY_INSTALL_DIR "${CMAKE_INSTALL_LIBDIR}")
+  set(HEADER_INSTALL_DIR  "${CMAKE_INSTALL_INCLUDEDIR}/graphviz")
+  set(MAN_INSTALL_DIR     "${CMAKE_INSTALL_MANDIR}")
+  set(libdir              "${CMAKE_INSTALL_FULL_LIBDIR}")
+  set(includedir          "${CMAKE_INSTALL_FULL_INCLUDEDIR}")
+else()
+  set(BINARY_INSTALL_DIR  bin)
+  set(LIBRARY_INSTALL_DIR lib)
+  set(HEADER_INSTALL_DIR  include/graphviz)
+  set(MAN_INSTALL_DIR     share/man)
+  set(libdir              "${CMAKE_INSTALL_PREFIX}/${LIBRARY_INSTALL_DIR}")
+  set(includedir          "${CMAKE_INSTALL_PREFIX}/include")
+endif()
+
 set(PLUGIN_INSTALL_DIR      ${LIBRARY_INSTALL_DIR}/graphviz)
-set(HEADER_INSTALL_DIR      include/graphviz)
-set(MAN_INSTALL_DIR         share/man)
-set(PKGCONFIG_DIR	    lib/pkgconfig)
+set(PKGCONFIG_DIR           ${LIBRARY_INSTALL_DIR}/pkgconfig)
 # TODO: Find a way to check for groff and ps2pdf for manpage pdf generation
 # set(MAN_PDF_INSTALL_DIR share/graphviz/doc/pdf)
 set(TOP_SOURCE_DIR          "${CMAKE_CURRENT_SOURCE_DIR}")
@@ -278,8 +291,6 @@ set(GVPLUGIN_VERSION "${GRAPHVIZ_PLUGIN_VERSION}")
 set(VERSION "${GRAPHVIZ_VERSION_STRING}")
 set(prefix "${CMAKE_INSTALL_PREFIX}")
 set(exec_prefix "${CMAKE_INSTALL_PREFIX}")
-set(libdir "${CMAKE_INSTALL_PREFIX}/lib")
-set(includedir "${CMAKE_INSTALL_PREFIX}/include")
 set(PACKAGE "graphviz")
 configure_file(${CMAKE_CURRENT_SOURCE_DIR}/lib/cdt/libcdt.pc.in ${CMAKE_CURRENT_SOURCE_DIR}/libcdt.pc @ONLY)
 configure_file(${CMAKE_CURRENT_SOURCE_DIR}/lib/cgraph/libcgraph.pc.in ${CMAKE_CURRENT_SOURCE_DIR}/libcgraph.pc @ONLY)
diff --git a/cmake/configure_plugins.cmake.in b/cmake/configure_plugins.cmake.in
index d4d41a17b..d0c8f0f95 100644
--- a/cmake/configure_plugins.cmake.in
+++ b/cmake/configure_plugins.cmake.in
@@ -30,9 +30,9 @@
 set(ROOT $ENV{DESTDIR}${CMAKE_INSTALL_PREFIX})
 
 if(APPLE)
-  set(ENV{DYLD_LIBRARY_PATH} "${ROOT}/lib")
+  set(ENV{DYLD_LIBRARY_PATH} "${ROOT}/@LIBRARY_INSTALL_DIR@")
 elseif(UNIX)
-  set(ENV{LD_LIBRARY_PATH} "${ROOT}/lib")
+  set(ENV{LD_LIBRARY_PATH} "${ROOT}/@LIBRARY_INSTALL_DIR@")
 endif()
 
 execute_process(
-- 
2.40.0