[Cmake] Install the isl headers into the install tree.

isl headers are currently missing in a Polly installation. Because the
Polly headers depend on those, code can't be compiled against an
installed Polly.

This patch installs the isl headers. I left a TODO, as optionally it
should be possible to use a system version of isl instead of the one
shipped with Polly.

When compiling, clients of the installation need to add
-I${PREFIX}/include/polly/ to there include path right now, because
there currently is no way to export this path automatically.

Contributed-by: Philip Pfaffe <philip.pfaffe@gmail.com>

Differential Revision: https://reviews.llvm.org/D29931

llvm-svn: 295671

polly/lib/External/CMakeLists.txt

@@ -262,6 +262,20 @@ add_polly_library(PollyISL
   ${ISL_FILES}
 )
 
+
+# TODO: optionally use system isl instead
+if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
+  install(DIRECTORY
+    ${ISL_SOURCE_DIR}/include/
+    ${ISL_BINARY_DIR}/include/
+    DESTINATION include/polly
+    FILES_MATCHING
+    PATTERN "*.h"
+    PATTERN "CMakeFiles" EXCLUDE
+    PATTERN ".svn" EXCLUDE
+    )
+endif()
+
 add_executable(polly-isl-test
   isl/isl_test.c
 )