add system TBB autodetection on Unix

Author: Enchufa2

src/Makevars.in

@@ -14,7 +14,13 @@ ifdef TBB_ROOT
 
 endif
 
-# If TBB_LIB is defined by TBB_INC is not, make a guess.
+# If TBB_LIB is not defined, try to use autodetection
+ifndef TBB_LIB
+	TBB_LIB = @TBB_LIB_AUTO@
+	TBB_INC = @TBB_INC_AUTO@
+endif
+
+# If TBB_LIB is defined but TBB_INC is not, make a guess.
 ifdef TBB_LIB
 	ifndef TBB_INC
 		TBB_INC = $(TBB_LIB)/../include

tools/config/configure.R

@@ -126,3 +126,23 @@ if (Sys.info()[["sysname"]] == "SunOS") {
    }
 }
 
+# tbb autodetection on Unix
+define(TBB_LIB_AUTO = "", TBB_INC_AUTO = "")
+if (.Platform$OS.type == "unix") {
+   tbbLib <- Sys.glob(c(
+      "/usr/*/libtbb.so",
+      "/usr/*/*/libtbb.so",
+      "/usr/*/*/*/libtbb.so"
+   ))
+   tbbInc <- Sys.glob(c(
+      "/usr/include/tbb.h",
+      "/usr/include/*/tbb.h"
+   ))
+   if (length(tbbLib) && length(tbbInc)) {
+      define(
+         TBB_LIB_AUTO = dirname(tbbLib[1]),
+         TBB_INC_AUTO = dirname(tbbInc[1])
+      )
+   }
+}
+