Expand macOS detection for OpenMP

Author: eddelbuettel

configure

@@ -3283,18 +3283,24 @@ rm -rf "${BUILDDIR}"
 printf %s "checking for macOS... " >&6; }
 RSysinfoName=$("${R_HOME}/bin/Rscript" --vanilla -e 'cat(Sys.info()["sysname"])')
 if test x"${RSysinfoName}" = x"Darwin"; then
-    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: found" >&5
-printf "%s\n" "found" >&6; }
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: found macOS" >&5
+printf "%s\n" "found macOS" >&6; }
     { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for macOS Apple compiler" >&5
 printf %s "checking for macOS Apple compiler... " >&6; }
     apple_compiler=$($CXX --version 2>&1 | grep -i -c -e 'apple llvm')
     if test x"${apple_compiler}" = x"1"; then
-        { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: found" >&5
-printf "%s\n" "found" >&6; }
+        { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: found macOS Apple compiler" >&5
+printf "%s\n" "found macOS Apple compiler" >&6; }
         { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: OpenMP unavailable and turned off." >&5
 printf "%s\n" "$as_me: WARNING: OpenMP unavailable and turned off." >&2;}
         can_use_openmp="no"
+    else
+        { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: not found macOS Apple compiler" >&5
+printf "%s\n" "not found macOS Apple compiler" >&6; }
     fi
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: Compiler is $CXX" >&5
+printf "%s\n" "$as_me: WARNING: Compiler is $CXX" >&2;}
+    # "${CXX}" --version
 else
     { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: not found" >&5
 printf "%s\n" "not found" >&6; }
@@ -3303,9 +3309,15 @@ fi
 if test x"${can_use_openmp}" = x"yes"; then
     { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for OpenMP" >&5
 printf %s "checking for OpenMP... " >&6; }
-    ## if R has -fopenmp we should be good
-    allldflags=$(${R_HOME}/bin/R CMD config --ldflags)
-    hasOpenMP=$(echo ${allldflags} | grep -- -fopenmp)
+    if test x"${RSysinfoName}" = x"Darwin"; then
+        ## if R has ~/.R/Makevars set we might good on macOS
+        allldflags=$(${R_HOME}/bin/R CMD config --ldflags)
+        hasOpenMP=$(echo ${allldflags} | grep -- -fopenmp)
+    else
+        ## if R has -fopenmp we should be good (non macOS)
+        allldflags=$(${R_HOME}/bin/R CMD config --ldflags)
+        hasOpenMP=$(echo ${allldflags} | grep -- -lomp)
+    fi
     if test x"${hasOpenMP}" = x""; then
         { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: missing" >&5
 printf "%s\n" "missing" >&6; }

configure.ac

@@ -80,23 +80,33 @@ rm -rf "${BUILDDIR}"
 AC_MSG_CHECKING([for macOS])
 RSysinfoName=$("${R_HOME}/bin/Rscript" --vanilla -e 'cat(Sys.info()[["sysname"]])')
 if test x"${RSysinfoName}" = x"Darwin"; then
-    AC_MSG_RESULT([found])
+    AC_MSG_RESULT([found macOS])
     AC_MSG_CHECKING([for macOS Apple compiler])
     apple_compiler=$($CXX --version 2>&1 | grep -i -c -e 'apple llvm')
     if test x"${apple_compiler}" = x"1"; then
-        AC_MSG_RESULT([found])
+        AC_MSG_RESULT([found macOS Apple compiler])
         AC_MSG_WARN([OpenMP unavailable and turned off.])
         can_use_openmp="no"
+    else
+        AC_MSG_RESULT([not found macOS Apple compiler])
     fi
+    AC_MSG_WARN([Compiler is $CXX])
+    # "${CXX}" --version
 else
     AC_MSG_RESULT([not found])
 fi
 
 if test x"${can_use_openmp}" = x"yes"; then
     AC_MSG_CHECKING([for OpenMP])
-    ## if R has -fopenmp we should be good
-    allldflags=$(${R_HOME}/bin/R CMD config --ldflags)
-    hasOpenMP=$(echo ${allldflags} | grep -- -fopenmp)
+    if test x"${RSysinfoName}" = x"Darwin"; then
+        ## if R has ~/.R/Makevars set we might good on macOS
+        allldflags=$(${R_HOME}/bin/R CMD config --ldflags)
+        hasOpenMP=$(echo ${allldflags} | grep -- -fopenmp)
+    else
+        ## if R has -fopenmp we should be good (non macOS)
+        allldflags=$(${R_HOME}/bin/R CMD config --ldflags)
+        hasOpenMP=$(echo ${allldflags} | grep -- -lomp)
+    fi
     if test x"${hasOpenMP}" = x""; then
         AC_MSG_RESULT([missing])
         arma_have_openmp="#define ARMA_DONT_USE_OPENMP 1"