Add ability to USE_SYSTEM_PCRE

Make.inc

@@ -50,11 +50,13 @@ TARGET_OPENBLAS_ARCH=
 USE_SYSTEM_LIBUNWIND=0
 USE_SYSTEM_LLVM=0
 USE_SYSTEM_READLINE=0
+USE_SYSTEM_PCRE=0
 
 ifeq ($(USE_DEBIAN), 1)
 USE_SYSTEM_LIBUNWIND=1
 USE_SYSTEM_LLVM=1
 USE_SYSTEM_READLINE=1
+USE_SYSTEM_PCRE=1
 endif
 
 ifeq ($(USE_SYSTEM_LIBUNWIND), 1)
@@ -75,6 +77,12 @@ else
 READLINE = $(EXTROOT)/lib/libreadline.a -lncurses -lcurses
 endif
 
+ifeq ($(USE_SYSTEM_PCRE), 1)
+PCRE_CONFIG = pcre-config
+else
+PCRE_CONFIG = $(EXTROOT)/bin/pcre-config
+endif
+
 ifeq ($(OS), Linux)
 SHLIB_EXT = so
 OSLIBS += -Wl,--export-dynamic -Wl,--version-script=$(JULIAHOME)/src/julia.expmap $(LIBUNWIND)

j/Makefile

@@ -6,7 +6,7 @@ PCRE_CONST = 0x[0-9a-fA-F]+|[-+]?\s*[0-9]+
 all: pcre_h.j errno_h.j
 
 pcre_h.j:
-	$(QUIET_PERL) cpp -dM $(EXTROOT)/include/pcre.h | perl -nle '/^\s*#define\s+(PCRE\w*)\s*\(?($(PCRE_CONST))\)?\s*$$/ and print "const $$1 = int32($$2)"' | sort > $@
+	$(QUIET_PERL) cpp -dM $(shell $(PCRE_CONFIG) --prefix)/include/pcre.h | perl -nle '/^\s*#define\s+(PCRE\w*)\s*\(?($(PCRE_CONST))\)?\s*$$/ and print "const $$1 = int32($$2)"' | sort > $@
 
 errno_h.j:
 	$(QUIET_PERL) echo '#include "errno.h"' | cpp -dM - | perl -nle 'print "const $$1 = int32($$2)" if /^#define\s+(E\w+)\s+(\d+)\s*$$/' | sort > $@