attempt to respect CXXFLAGS as set by user

Author: kevinushey

src/Makevars.in

@@ -7,7 +7,7 @@ ifeq ($(OS), Windows_NT)
 
   MAKEFLAGS = -j1
   MAKE = make -e
-  MAKE_CMD = CYGWIN=nodosfilewarning CONLY="@CC@" CPLUS="@CXX11@" PIC_KEY="@CXX11PICFLAGS@" WARNING_SUPPRESS="" $(MAKE)
+  MAKE_CMD = CYGWIN=nodosfilewarning CONLY="@CC@" CPLUS="@CXX11@" CXXFLAGS="@CXX11FLAGS@ -DTBB_NO_LEGACY=1" PIC_KEY="@CXX11PICFLAGS@" WARNING_SUPPRESS="" $(MAKE)
 
 else
 
@@ -27,15 +27,15 @@ else
   endif
 
   MAKE += -e
-  MAKE_CMD = CONLY="@CC@" CPLUS="@CXX11@" PIC_KEY="@CXX11PICFLAGS@" WARNING_SUPPRESS="" $(MAKE)
+  MAKE_CMD = CONLY="@CC@" CPLUS="@CXX11@" CXXFLAGS="@CXX11FLAGS@ -DTBB_NO_LEGACY=1" PIC_KEY="@CXX11PICFLAGS@" WARNING_SUPPRESS="" $(MAKE)
 
 endif
 
 ifdef USE_TBB
 
 PKG_CPPFLAGS += -DRCPP_PARALLEL_USE_TBB=1
 
-MAKE_ARGS := CXXFLAGS=-DTBB_NO_LEGACY=1 tbb_release tbbmalloc_release tbb_build_prefix=lib
+MAKE_ARGS := tbb_release tbbmalloc_release tbb_build_prefix=lib
 
 ifeq ($(USE_TBB),  Windows)
 

tools/config/configure.R

@@ -1,25 +1,48 @@
-if (Sys.info()[["sysname"]] == "Windows" && getRversion() < "3.1.0") {
-   define(
+
+# Figure out the appropriate CXX prefix for the current
+# version of R + configuration.
+cxx <- NULL
+candidates <- c("CXX11", "CXX1X", "CXX")
+for (candidate in candidates) {
+   config <- read_r_config(candidate, envir = NULL)
+   value <- config[[candidate]]
+   if (!is.null(value)) {
+      cxx <- candidate
+      break
+   }
+}
+
+# define the set of flags appropriate to the current
+# configuration of R
+switch(
+   cxx,
+   
+   CXX11 = define(
       CC            = "$(CC)",
-      CXX11         = "$(CXX)",
-      CXX11STD      = "-std=c++0x",
-      CXX11PICFLAGS = "-fPIC"
-   )
-} else if (getRversion() < "3.4.0") {
-   define(
+      CXX11         = "$(CXX11)",
+      CXX11FLAGS    = "$(CXX11FLAGS)",
+      CXX11STD      = "$(CXX11STD)",
+      CXX11PICFLAGS = "$(CXX11PICFLAGS)"
+   ),
+   
+   CXX1X = define(
       CC            = "$(CC)",
       CXX11         = "$(CXX1X)",
+      CXX11FLAGS    = "$(CXX1XFLAGS)",
       CXX11STD      = "$(CXX1XSTD)",
       CXX11PICFLAGS = "$(CXX1XPICFLAGS)"
-   )
-} else {
-   define(
+   ),
+   
+   CXX = define(
       CC            = "$(CC)",
-      CXX11         = "$(CXX11)",
-      CXX11STD      = "$(CXX11STD)",
-      CXX11PICFLAGS = "$(CXX11PICFLAGS)"
-   )
-}
+      CXX11         = "$(CXX)",
+      CXX11FLAGS    = "$(CXXFLAGS)",
+      CXX11STD      = "-std=c++0x",
+      CXX11PICFLAGS = "-fPIC"
+   ),
+   
+   stop("Failed to infer C / C++ compilation flags")
+)
 
 # use c++0x for compatibility with older compilers
 define(STDVER = "c++0x")