From: Nehal J Wani <nehaljw.kkd1@gmail.com>
Date: Mon, 15 Feb 2021 20:19:14 +0000 (-0500)
Subject: common: CMake: specify include directory of expat
X-Git-Tag: 2.50.0~56^2
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=b53c3dda7bff02907a0daa8757f378237fff2a6e;p=graphviz

common: CMake: specify include directory of expat

A build system should not rely on the existence of 3rd party
library/header files in standard prefixes as one might want to compile
and link against a patched build or a custom install in some
non-standard location. This is also helpful for developers who rely on
package managers like Conda or Spack for their daily development.

If expat is a dep, we need to pass -I/path/containing/expat.h to the
compiler while compiling the source files of the target 'common_obj',
without which, one can face the following issue:

graphviz/lib/common/htmllex.c:28:10: fatal error: expat.h: No such file or directory
   28 | #include <expat.h>
      |          ^~~~~~~~~
compilation terminated.
---

diff --git a/lib/common/CMakeLists.txt b/lib/common/CMakeLists.txt
index b858ededa..f39a32157 100644
--- a/lib/common/CMakeLists.txt
+++ b/lib/common/CMakeLists.txt
@@ -106,6 +106,7 @@ target_include_directories(common_obj PRIVATE
     ${GRAPHVIZ_LIB_DIR}/pack
     ${GRAPHVIZ_LIB_DIR}/pathplan
     ${GRAPHVIZ_LIB_DIR}/xdot
+    ${EXPAT_INCLUDE_DIRS}
 )
 
 if (WIN32)