Replace exec_program with execute_process (#402)

Signed-off-by: Addisu Z. Taddese <addisu@openrobotics.org>
Co-authored-by: Steve Peters <scpeters@openrobotics.org>

cmake/GzCheckSSE.cmake

@@ -159,7 +159,7 @@ endif()
 
 IF (ARCH MATCHES "i386" OR ARCH MATCHES "x86_64")
   IF(CMAKE_SYSTEM_NAME MATCHES "Linux")
-     EXEC_PROGRAM(cat ARGS "/proc/cpuinfo" OUTPUT_VARIABLE CPUINFO)
+     EXECUTE_PROCESS(COMMAND cat -u /proc/cpuinfo OUTPUT_VARIABLE CPUINFO)
 
      STRING(REGEX REPLACE "^.*(sse2).*$" "\\1" SSE_THERE ${CPUINFO})
      STRING(COMPARE EQUAL "sse2" "${SSE_THERE}" SSE2_TRUE)
@@ -207,7 +207,7 @@ IF (ARCH MATCHES "i386" OR ARCH MATCHES "x86_64")
      ENDIF (SSE42_TRUE)
 
   ELSEIF(CMAKE_SYSTEM_NAME MATCHES "Darwin")
-     EXEC_PROGRAM("/usr/sbin/sysctl -n machdep.cpu.features" OUTPUT_VARIABLE
+     EXECUTE_PROCESS(COMMAND /usr/sbin/sysctl -n machdep.cpu.features OUTPUT_VARIABLE
         CPUINFO)
 
      STRING(REGEX REPLACE "^.*[^S](SSE2).*$" "\\1" SSE_THERE ${CPUINFO})

cmake/cmake_uninstall.cmake.in

@@ -7,15 +7,15 @@ string(REGEX REPLACE "\n" ";" files "${files}")
 foreach(file ${files})
   message(STATUS "Uninstalling '$ENV{DESTDIR}${file}'")
   if(IS_SYMLINK "$ENV{DESTDIR}${file}" OR EXISTS "$ENV{DESTDIR}${file}")
-    exec_program(
-      "@CMAKE_COMMAND@" ARGS "-E remove \"$ENV{DESTDIR}${file}\""
+    execute_process(COMMAND
+      @CMAKE_COMMAND@ -E remove $ENV{DESTDIR}${file}
       OUTPUT_VARIABLE rm_out
-      RETURN_VALUE rm_retval
+      RESULT_VARIABLE rm_retval
       )
-    if(NOT "${rm_retval}" STREQUAL 0)
+    if(rm_retfal AND NOT rm_retval STREQUAL 0)
       message(FATAL_ERROR "Problem when removing '$ENV{DESTDIR}${file}'")
-    endif(NOT "${rm_retval}" STREQUAL 0)
+    endif()
   else(IS_SYMLINK "$ENV{DESTDIR}${file}" OR EXISTS "$ENV{DESTDIR}${file}")
     message(STATUS "File '$ENV{DESTDIR}${file}' does not exist.")
-  endif(IS_SYMLINK "$ENV{DESTDIR}${file}" OR EXISTS "$ENV{DESTDIR}${file}")
+  endif()
 endforeach(file)