c-parser: handle sed backup files uniformly in mkrelease

mkrelease was trying to distinguish BSD and GNU sed command line
options, but was using shell substitution incorrectly. Instead, use
backup files for both versions, and then manually remove the backup file
afterwards.

Signed-off-by: Gerwin Klein <gerwin.klein@proofcraft.systems>

tools/c-parser/mkrelease

@@ -12,8 +12,8 @@
 set -e
 
 case $(uname) in
-  Darwin* ) TAR=gtar ; SEDIOPT="-i ''" ;;
-  * ) TAR=tar ; SEDIOPT=-i ;;
+  Darwin* ) TAR=gtar ;;
+  * ) TAR=tar ;;
 esac
 
 
@@ -145,18 +145,20 @@ echo "Hacking Makefile to remove ROOT generation."
 if ! grep -q '^testfiles/\$(L4V_ARCH)/ROOT' "$outputdir/src/c-parser/Makefile"; then
     die "failed to process c-parser/Makefile"
 fi
-sed $SEDIOPT \
+sed -i .bak \
     -e '/^testfiles\/\$(L4V_ARCH)\/ROOT/,/CParserTest/d' \
     -e '/^all_tests_\$(L4V_ARCH)\.thy/,/CParser/d' \
     "$outputdir/src/c-parser/Makefile"
+rm -f "$outputdir/src/c-parser/Makefile.bak"
 
 echo "Hacking Makefile to change root dir."
 if ! grep -q '^L4V_ROOT_DIR = ' "$outputdir/src/c-parser/Makefile"; then
     die "failed to process c-parser/Makefile"
 fi
-sed $SEDIOPT \
+sed -i .bak \
     -e 's/^L4V_ROOT_DIR = .*$/L4V_ROOT_DIR = ../' \
     "$outputdir/src/c-parser/Makefile"
+rm -f "$outputdir/src/c-parser/Makefile.bak"
 
 echo "Generating standalone-parser/table.ML"
 pushd "$TOPLEVEL_DIR/tools/c-parser" > /dev/null
@@ -177,7 +179,7 @@ popd > /dev/null
 echo "Making PDF of ctranslation file."
 cd "$outputdir/src/c-parser/doc"
 make ctranslation.pdf > /dev/null
-/bin/rm ctranslation.{log,aux,blg,bbl,toc}
+/bin/rm -f ctranslation.{log,aux,blg,bbl,toc}
 mv ctranslation.pdf "$outputdir/doc"
 
 popd > /dev/null