Use configure script to detect endianness (fixes #65)

Author: paleolimbot

configure

@@ -52,7 +52,7 @@ CFLAGS=`${R_HOME}/bin/R CMD config CFLAGS`
 CPPFLAGS=`${R_HOME}/bin/R CMD config CPPFLAGS`
 
 # For debugging
-echo "Using PKG_CFLAGS=$PKG_CFLAGS"
+echo "Testing compiler using PKG_CFLAGS=$PKG_CFLAGS"
 
 # Test configuration
 ${CC} ${CPPFLAGS} ${PKG_CFLAGS} ${CFLAGS} -E ${PKG_TEST_FILE} >/dev/null 2>configure.log
@@ -100,7 +100,22 @@ fi
 fi #SONAME
 fi #AUTOBREW
 
+# Define system endianness (compile-time endianness using system/compiler
+# defines isn't detected on Solaris)
+# based on endian detection from the feather package by @hadley
+R_ENDIAN=`${R_HOME}/bin/Rscript -e 'cat(.Platform$endian)'`
+# Trim off any warning messages that Rscript appends in front of the platform endianness
+R_ENDIAN=`expr "$R_ENDIAN" : '.*\(little\)$'`
+SYS_ENDIAN=""
+if [ "$R_ENDIAN" = "little" ]; then
+    PKG_CFLAGS="$PKG_CFLAGS -DIS_LITTLE_ENDIAN"
+else
+    PKG_CFLAGS="$PKG_CFLAGS -DIS_BIG_ENDIAN"
+fi
+
 echo "Using PKG_LIBS=$PKG_LIBS"
+echo "Using PKG_CFLAGS=$PKG_CFLAGS"
+
 
 # Write to Makevars
 sed -e "s|@cflags@|$PKG_CFLAGS|" -e "s|@libs@|$PKG_LIBS|" src/Makevars.in > src/Makevars

data-raw/update-s2.R

@@ -85,6 +85,10 @@ print_next <- function() {
   )
   cli::cat_bullet("Remove extra semi-colon at s2boolean_operation.h#376")
   cli::cat_bullet("Remove extra semi-colons because of FROMHOST_TYPE_MAP macro (utils/endian/endian.h#565)")
+  cli::cat_bullet(
+    "Check for definition of IS_LITTLE_ENDIAN and IS_BIG_ENDIAN to allow configure script ",
+    "override (s2/base/port.h:273) without macro redefinition warnings"
+  )
   cli::cat_bullet("Replace `abort()` with `cpp_compat_abort()`")
   cli::cat_bullet("Replace `cerr`/`cout` with `cpp_compat_cerr`/`cpp_compat_cout`")
   cli::cat_bullet("Replace `srandom()` with `cpp_compat_srandom()`")

inst/include/s2/base/port.h

@@ -274,6 +274,15 @@ inline void sized_delete_array(void *ptr, size_t size) {
 // -----------------------------------------------------------------------------
 
 // IS_LITTLE_ENDIAN, IS_BIG_ENDIAN
+
+// Allow compiler -D defines to override detection here
+// which occasionally fails (e.g., on CRAN Solaris)
+#if defined(IS_LITTLE_ENDIAN)
+#undef IS_BIG_ENDIAN
+#elif defined(IS_BIG_ENDIAN)
+#undef IS_LITTLE_ENDIAN
+#else
+
 #if defined __linux__ || defined OS_ANDROID || defined(__ANDROID__)
 // TODO(user): http://b/21460321; use one of OS_ANDROID or __ANDROID__.
 // _BIG_ENDIAN
@@ -318,6 +327,7 @@ inline void sized_delete_array(void *ptr, size_t size) {
 
 #endif  // __BYTE_ORDER
 #endif  // _MSC_VER
+#endif // #if defined(IS_LITTLE_ENDIAN) ... #else
 
 // byte swap functions (bswap_16, bswap_32, bswap_64).