[PATCH] s390: Do not generate incomplete opcode table

[Jens Remus]

The s390 opcode table s390-opc.tbl is generated from s390-opc.txt
using the 390-mkopc utility using output redirection.  If s390-mkopc
fails with a non-zero return code, e.g. due to a warning or error, an
incomplete opcode table may be generated in the build directory.  A
subsequent invocation of make then assumes that incomplete opcode
table to be up to date.  Depending on the s390-mkopc issue the build
may then proceed without any follow-on warnings or errors, causing
the preceding error or warning to go unnoticed.

Generate the s390 opcode table into an intermediate temporary file
s390-opc.tbl.tmp in the build directory and only move it to the final
target s390-opc.tbl if the generation was successful.

Tested by appending an unsupported inline comment "# TEST" to one of
the instructions defined in s390-opc.txt.

opcodes/
	* Makefile.am (s390-opc.tab): Use an intermediate temporary file
	to prevent updating of the target on error/warning.
	* Makefile.in: Regenerated.

Signed-off-by: Jens Remus <jremus@linux.ibm.com>
---

Notes (jremus):
    An generic alternative would have been to use the special built-in make
    target .DELETE_ON_ERROR [1].  But since that cannot be restricted to
    individual targets it would affect all targets.
    
    [1]: https://www.gnu.org/software/make/manual/html_node/Special-Targets.html#index-removing-targets-on-failure

 opcodes/Makefile.am | 3 ++-
 opcodes/Makefile.in | 3 ++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/opcodes/Makefile.am b/opcodes/Makefile.am
index a8642c4d07e4..c5b055dad577 100644
--- a/opcodes/Makefile.am
+++ b/opcodes/Makefile.am
@@ -583,7 +583,8 @@ s390-mkopc.o: s390-mkopc.c $(INCDIR)/opcode/s390.h
 	$(AM_V_CC)$(COMPILE_FOR_BUILD) -c $(srcdir)/s390-mkopc.c
 
 s390-opc.tab: s390-mkopc$(EXEEXT_FOR_BUILD) s390-opc.txt
-	$(AM_V_GEN)./s390-mkopc$(EXEEXT_FOR_BUILD) < $(srcdir)/s390-opc.txt > s390-opc.tab
+	$(AM_V_GEN)./s390-mkopc$(EXEEXT_FOR_BUILD) < $(srcdir)/s390-opc.txt > s390-opc.tab.tmp
+	$(AM_V_at)$(am__mv) s390-opc.tab.tmp s390-opc.tab
 
 s390-opc.lo: s390-opc.tab
 
diff --git a/opcodes/Makefile.in b/opcodes/Makefile.in
index ed61dfcf4358..0aeeb81d705a 100644
--- a/opcodes/Makefile.in
+++ b/opcodes/Makefile.in
@@ -1562,7 +1562,8 @@ s390-mkopc.o: s390-mkopc.c $(INCDIR)/opcode/s390.h
 	$(AM_V_CC)$(COMPILE_FOR_BUILD) -c $(srcdir)/s390-mkopc.c
 
 s390-opc.tab: s390-mkopc$(EXEEXT_FOR_BUILD) s390-opc.txt
-	$(AM_V_GEN)./s390-mkopc$(EXEEXT_FOR_BUILD) < $(srcdir)/s390-opc.txt > s390-opc.tab
+	$(AM_V_GEN)./s390-mkopc$(EXEEXT_FOR_BUILD) < $(srcdir)/s390-opc.txt > s390-opc.tab.tmp
+	$(AM_V_at)$(am__mv) s390-opc.tab.tmp s390-opc.tab
 
 s390-opc.lo: s390-opc.tab
 
-- 
2.48.1