[PATCH v2 1/2] x86: pre-process opcodes table before parsing

["Jan Beulich" <JBeulich at suse dot com>]

Instead of expanding macro-like constructs in i386-gen, have the C pre-
processor do this for us. Besides being a prerequisite for the next
template folding steps, this also paves the way for removing various
hidden dependencies between #define-s in i386-opc.h and plain literal
numbers used in i386-opc.tbl.

The #undef of None is solely to leave the generated i386-tbl.h entirely
unchanged.

opcodes/
2018-07-17  Jan Beulich  <jbeulich@suse.com>

	* Makefile.am: Change dependencies and rule for
	$(srcdir)/i386-init.h.
	* Makefile.in: Re-generate.
	* i386-gen.c (process_i386_opcodes): New local variable
	"marker". Drop opening of input file. Recognize marker and line
	number directives.
	* i386-opc.tbl (OPCODE_I386_H): Define.
	(i386-opc.h): Include it.
	(None): Undefine.

---
v2: New.

--- a/opcodes/Makefile.am
+++ b/opcodes/Makefile.am
@@ -544,8 +544,10 @@ i386-gen.o: i386-gen.c i386-opc.h $(srcd
 $(srcdir)/i386-tbl.h: $(srcdir)/i386-init.h
 	@echo $@
 
-$(srcdir)/i386-init.h: @MAINT@ i386-gen$(EXEEXT_FOR_BUILD) i386-opc.tbl i386-reg.tbl
-	./i386-gen$(EXEEXT_FOR_BUILD) --srcdir $(srcdir)
+$(srcdir)/i386-init.h: @MAINT@ i386-gen$(EXEEXT_FOR_BUILD) i386-opc.tbl i386-reg.tbl i386-opc.h
+	$(CPP) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) - \
+		< $(srcdir)/i386-opc.tbl \
+		| ./i386-gen$(EXEEXT_FOR_BUILD) --srcdir $(srcdir)
 
 i386-opc.lo: $(srcdir)/i386-tbl.h
 
--- a/opcodes/i386-gen.c
+++ b/opcodes/i386-gen.c
@@ -1262,14 +1262,10 @@ process_i386_opcodes (FILE *table)
   htab_t opcode_hash_table;
   struct opcode_hash_entry **opcode_array;
   unsigned int opcode_array_size = 1024;
-  int lineno = 0;
+  int lineno = 0, marker = 0;
 
   filename = "i386-opc.tbl";
-  fp = fopen (filename, "r");
-
-  if (fp == NULL)
-    fail (_("can't find i386-opc.tbl for reading, errno = %s\n"),
-	  xstrerror (errno));
+  fp = stdin;
 
   i = 0;
   opcode_array = (struct opcode_hash_entry **)
@@ -1303,11 +1299,32 @@ process_i386_opcodes (FILE *table)
       switch (p[0])
 	{
 	case '#':
+	  if (!strcmp("### MARKER ###", buf))
+	    marker = 1;
+	  else
+	    {
+	      /* Since we ignore all included files (we only care about their
+		 #define-s here), we don't need to monitor filenames.  The final
+		 line number directive is going to refer to the main source file
+		 again.  */
+	      char *end;
+	      unsigned long ln;
+
+	      p = remove_leading_whitespaces (p + 1);
+	      if (!strncmp(p, "line", 4))
+		p += 4;
+	      ln = strtoul (p, &end, 10);
+	      if (ln > 1 && ln < INT_MAX
+		  && *remove_leading_whitespaces (end) == '"')
+		lineno = ln - 1;
+	    }
 	  /* Ignore comments.  */
 	case '\0':
 	  continue;
 	  break;
 	default:
+	  if (!marker)
+	    continue;
 	  break;
 	}
 
--- a/opcodes/i386-opc.tbl
+++ b/opcodes/i386-opc.tbl
@@ -18,6 +18,12 @@
 // Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA
 // 02110-1301, USA.
 
+#define OPCODE_I386_H
+#include "i386-opc.h"
+#undef None
+
+### MARKER ###
+
 // Move instructions.
 // We put the 64bit displacement first and we only mark constants
 // larger than 32bit as Disp64.