enforce passage of -std flag (#227)

Author: kevinushey

src/Makevars.in

@@ -38,15 +38,15 @@ ifeq ($(OS), Windows_NT)
 
 	MAKE = make
 	MAKEFLAGS = -e -j1
-	MAKE_CMD =                                    \
-		MSYS2_ARG_CONV_EXCL="*"                   \
-		CYGWIN=nodosfilewarning                   \
-		CONLY="@WINDOWS_CC@"                      \
-		CPLUS="@WINDOWS_CXX11@"                   \
-		CXXFLAGS="$(TBB_CXXFLAGS)" 				  \
-		PIC_KEY="@CXX11PICFLAGS@"                 \
-		WARNING_SUPPRESS=""                       \
-		WINARM64_CLANG="$(WINARM64_CLANG)"        \
+	MAKE_CMD =                            \
+		MSYS2_ARG_CONV_EXCL="*"            \
+		CYGWIN=nodosfilewarning            \
+		CONLY="@WINDOWS_CC@"               \
+		CPLUS="@WINDOWS_CXX11@"            \
+		CXXFLAGS="$(TBB_CXXFLAGS)"         \
+		PIC_KEY="@CXX11PICFLAGS@"          \
+		WARNING_SUPPRESS=""                \
+		WINARM64_CLANG="$(WINARM64_CLANG)" \
 		$(MAKE)
 
 else
@@ -71,7 +71,7 @@ else
 	endif
 
 	MAKEFLAGS += -e
-	MAKE_CMD =                                     \
+	MAKE_CMD =                                    \
 		CONLY="@CC@ $(PKG_CPPFLAGS) @CPPFLAGS@"    \
 		CPLUS="@CXX11@ $(PKG_CPPFLAGS) @CPPFLAGS@" \
 		CXXFLAGS="@CXX11FLAGS@ -DTBB_NO_LEGACY=1"  \
@@ -93,6 +93,7 @@ ifeq ($(USE_TBB), Windows)
 	# rtools: turn on hacks to compensate for make and shell differences rtools<=>MinGW
 	# compiler: overwrite default (which is cl = MS compiler)
 	MAKE_ARGS += rtools=true compiler=gcc
+	
 	# TBB configure will detect mingw runtime with unknown arch on WINARM64_CLANG but not an 
 	#   issue as we are using compiler built-ins instead of arch-specific code
 	ifneq ($(WINARM64_CLANG), true)
@@ -160,7 +161,7 @@ else
 	@mkdir -p ../inst/include
 	@cp -R tbb/include/* ../inst/include/
 	@(cd tbb/src && $(MAKE_CMD) $(MAKE_ARGS) info)
-	@(cd tbb/src && $(MAKE_CMD) @STDVER@ $(MAKE_ARGS) $(MAKE_TARGETS) $(MAKE_LOG))
+	@(cd tbb/src && $(MAKE_CMD) $(MAKE_ARGS) $(MAKE_TARGETS) $(MAKE_LOG))
 endif
 
 # NOTE: we do not want to clean ../inst/lib or ../inst/libs here,

tools/config/configure.R

@@ -50,6 +50,16 @@ broken <-
 if (broken)
    cxxflags <- gsub("-Werror=format-security", "-Wformat -Werror=format-security", cxxflags)
 
+# add C++ standard if not set
+if (!grepl("-std=", cxxflags, fixed = TRUE)) {
+   stdflag <- if (getRversion() < "4.0") {
+      "-std=c++0x"
+   } else {
+      "$(CXX11STD)"
+   }
+   cxxflags <- paste(stdflag, cxxflags)
+}
+
 # avoid including /usr/local/include, as this can cause
 # RcppParallel to find and use a version of libtbb installed
 # there as opposed to the bundled version
@@ -115,13 +125,6 @@ if (info[["sysname"]] == "Windows") {
 
 }
 
-# use c++0x for compatibility with older compilers
-if (getRversion() < "4.0") {
-   define(STDVER = "stdver=c++0x")
-} else {
-   define(STDVER = "")
-}
-
 # on Solaris, check if we're using gcc or g++
 if (Sys.info()[["sysname"]] == "SunOS") {
    cxx <- r_cmd_config("CXX")