[PATCH] x86: correct build dependencies in opcodes/

[PATCH] x86: correct build dependencies in opcodes/

[Jan Beulich]

With the command in the rule merely being "echo", i386-tbl.h won't be
rebuilt if missing, when at the same time i386-init.h is present and
up-to-date. Use a pattern rule instead to express the multiple targets
correctly (the &: rule separator is supported only by GNU make 4.3 and
newer). Note that now, for the opposite case to work (i386-tbl.h is
up-to-date but i386-init.h is missing), i386-init.h also needs
mentioning as a dependency somewhere: Add a fake dependency for
i386-opc.lo ("fake" because i386-opc.c doesn't include that header).

At the same time use $(AM_V_GEN) in the actual rule, replacing the
earlier (open-coded) "echo". And while there also drop a duplicate
dependency of i386-gen.o on i386-opc.h.

--- a/opcodes/Makefile.am
+++ b/opcodes/Makefile.am
@@ -552,18 +552,20 @@ i386-gen$(EXEEXT_FOR_BUILD): i386-gen.o
 i386-gen.o: i386-gen.c i386-opc.h $(srcdir)/../include/opcode/i386.h \
 	$(INCDIR)/ansidecl.h $(INCDIR)/getopt.h $(INCDIR)/hashtab.h \
 	$(INCDIR)/libiberty.h $(INCDIR)/opcode/i386.h $(INCDIR)/safe-ctype.h \
-	config.h i386-opc.h sysdep.h
+	config.h sysdep.h
 	$(COMPILE_FOR_BUILD) -c $(srcdir)/i386-gen.c
 
-$(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-opc.h
-	$(CPP) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) - \
+# i386-gen will generate both headers in one go.  Use a pattern rule to properly
+# express this, with the inner dash ('-') arbitrarily chosen to be the stem.
+$(srcdir)/i386%tbl.h $(srcdir)/i386%init.h: @MAINT@ i386-gen$(EXEEXT_FOR_BUILD) i386-opc.tbl i386-reg.tbl i386-opc.h
+	$(AM_V_GEN)$(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
+# While not really a dependency, specify i386-init.h here as well to make sure
+# it is generated even if i386-tbl.h is present and up-to-date.
+i386-opc.lo: $(srcdir)/i386-init.h
 
 ia64-gen$(EXEEXT_FOR_BUILD): ia64-gen.o $(BUILD_LIB_DEPS)
 	$(AM_V_CCLD)$(LINK_FOR_BUILD) ia64-gen.o $(BUILD_LIBS)
--- a/opcodes/Makefile.in
+++ b/opcodes/Makefile.in
@@ -1527,18 +1527,20 @@ i386-gen$(EXEEXT_FOR_BUILD): i386-gen.o
 i386-gen.o: i386-gen.c i386-opc.h $(srcdir)/../include/opcode/i386.h \
 	$(INCDIR)/ansidecl.h $(INCDIR)/getopt.h $(INCDIR)/hashtab.h \
 	$(INCDIR)/libiberty.h $(INCDIR)/opcode/i386.h $(INCDIR)/safe-ctype.h \
-	config.h i386-opc.h sysdep.h
+	config.h sysdep.h
 	$(COMPILE_FOR_BUILD) -c $(srcdir)/i386-gen.c
 
-$(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-opc.h
-	$(CPP) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) - \
+# i386-gen will generate both headers in one go.  Use a pattern rule to properly
+# express this, with the inner dash ('-') arbitrarily chosen to be the stem.
+$(srcdir)/i386%tbl.h $(srcdir)/i386%init.h: @MAINT@ i386-gen$(EXEEXT_FOR_BUILD) i386-opc.tbl i386-reg.tbl i386-opc.h
+	$(AM_V_GEN)$(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
+# While not really a dependency, specify i386-init.h here as well to make sure
+# it is generated even if i386-tbl.h is present and up-to-date.
+i386-opc.lo: $(srcdir)/i386-init.h
 
 ia64-gen$(EXEEXT_FOR_BUILD): ia64-gen.o $(BUILD_LIB_DEPS)
 	$(AM_V_CCLD)$(LINK_FOR_BUILD) ia64-gen.o $(BUILD_LIBS)