34287: preprocessor for signal name generation.

Some gcc header files are difficult for the signames2.awk
script to process, so if the preprocessor is gcc give the
option -P to strip out the unwanted additions.

Src/zsh.mdd

@@ -22,9 +22,18 @@ hdrdeps="zshcurses.h zshterm.h"
 :<<\Make
 @CONFIG_MK@
 
+# If we're using gcc as the preprocessor, get rid of the additional
+# lines generated by the preprocessor as they can confuse the script.
+# We don't need these in other cases either, but can't necessarily rely
+# on the option to remove them being the same.
 signames.c: signames1.awk signames2.awk ../config.h @SIGNAL_H@
 	$(AWK) -f $(sdir)/signames1.awk @SIGNAL_H@ >sigtmp.c
-	$(CPP) sigtmp.c >sigtmp.out
+	case "$(CPP)" in \
+	gcc*) \
+	$(CPP) -P sigtmp.c >sigtmp.out;; \
+	*) \
+	$(CPP) sigtmp.c >sigtmp.out;; \
+	esac
 	$(AWK) -f $(sdir)/signames2.awk sigtmp.out > $@
 	rm -f sigtmp.c sigtmp.out