r: fix for clang 17

Author: fxcoudert

Formula/r/r.rb

@@ -65,6 +65,10 @@ class R < Formula
   # needed to preserve executable permissions on files without shebangs
   skip_clean "lib/R/bin", "lib/R/doc"
 
+  # Fix build with clang 17
+  # https://github.com/wch/r-source/commit/489a6b8d330bb30da82329f1949f44a0f633f1e8
+  patch :DATA
+
   def install
     # `configure` doesn't like curl 8+, but convince it that everything is ok.
     # TODO: report this upstream.
@@ -165,3 +169,28 @@ def post_install
                  shell_output("#{bin}/Rscript -e 'library(tcltk)' -e 'tclvalue(.Tcl(\"tk windowingsystem\"))'").chomp
   end
 end
+__END__
+diff -pur R-4.5.0/src/nmath/mlutils.c R-4.5.0-patched/src/nmath/mlutils.c
+--- R-4.5.0/src/nmath/mlutils.c	2025-03-14 00:02:15
++++ R-4.5.0-patched/src/nmath/mlutils.c	2025-05-24 12:16:15
+@@ -105,7 +105,20 @@ double R_pow_di(double x, int n)
+     return pow;
+ }
+ 
++/* It is not clear why these are being defined in standalone nmath:
++ * but that they are is stated in the R-admin manual.
++ *
++ * In R NA_AREAL is a specific NaN computed during initialization.
++ */
++#if defined(__clang__) && defined(NAN)
++// C99 (optionally) has NAN, which is a float but will coerce to double.
++double NA_REAL = NAN;
++#else
++// ML_NAN is defined as (0.0/0.0) in nmath.h
++// Fails to compile in Intel ics 2025.0, Apple clang 17, LLVM clang 20
+ double NA_REAL = ML_NAN;
++#endif
++
+ double R_PosInf = ML_POSINF, R_NegInf = ML_NEGINF;
+ 
+ #include <stdio.h>