revise comments [ci skip]

zhengqmark · zhengqmark · commit cfe7d060e4de · 2019-06-27T14:59:17.000-04:00
diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -59,8 +59,10 @@ list (APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/umbrella")
 include (umbrella-init)
 
 #
-# we don't really use mpicxx.h for now
-# (can be overridden with -DMPI_CXX_SKIP_MPICXX=Off)
+# we don't really use MPICXX for now. The difference between CXX and MPICXX
+# is that CXX refers to the MPI C API being usable from C++, whereas MPICXX
+# refers to the MPI-2 C++ API that was removed again in MPI-3.
+# To enable MPICXX, run umbrella with -DMPI_CXX_SKIP_MPICXX=Off.
 #
 set (MPI_CXX_SKIP_MPICXX ON CACHE BOOL "True if MPICXX should be skipped")
 
@@ -78,7 +80,7 @@ set (UMBRELLA_MPI 1)
 include (umbrella-main)
 
 #
-# propagate to all cmake subprojects
+# propagate the MPICXX setting to all cmake subprojects
 #
 list(APPEND UMBRELLA_CMAKECACHE -DMPI_CXX_SKIP_MPICXX:BOOL=${MPI_CXX_SKIP_MPICXX})
 

Original file line number	Diff line number	Diff line change
`@@ -59,8 +59,10 @@ list (APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/umbrella")`
`59`	`59`	`include (umbrella-init)`
`60`	`60`
`61`	`61`	`#`
`62`		`-# we don't really use mpicxx.h for now`
`63`		`-# (can be overridden with -DMPI_CXX_SKIP_MPICXX=Off)`
	`62`	`+# we don't really use MPICXX for now. The difference between CXX and MPICXX`
	`63`	`+# is that CXX refers to the MPI C API being usable from C++, whereas MPICXX`
	`64`	`+# refers to the MPI-2 C++ API that was removed again in MPI-3.`
	`65`	`+# To enable MPICXX, run umbrella with -DMPI_CXX_SKIP_MPICXX=Off.`
`64`	`66`	`#`
`65`	`67`	`set (MPI_CXX_SKIP_MPICXX ON CACHE BOOL "True if MPICXX should be skipped")`
`66`	`68`
`@@ -78,7 +80,7 @@ set (UMBRELLA_MPI 1)`
`78`	`80`	`include (umbrella-main)`
`79`	`81`
`80`	`82`	`#`
`81`		`-# propagate to all cmake subprojects`
	`83`	`+# propagate the MPICXX setting to all cmake subprojects`
`82`	`84`	`#`
`83`	`85`	`list(APPEND UMBRELLA_CMAKECACHE -DMPI_CXX_SKIP_MPICXX:BOOL=${MPI_CXX_SKIP_MPICXX})`
`84`	`86`