bin/uninclude: Add new utility, with simple tests

1 files changed, 107 insertions, 0 deletions

diff --git a/bin/uninclude b/bin/uninclude
new file mode 100755
index 0000000..ac2d98c
--- /dev/null
+++ b/bin/uninclude
@@ -0,0 +1,107 @@
+#!/bin/sh
+set -eu
+
+usage() {
+	cat <<-'EOF'
+		Usage:
+		  uninclude -E REGEXP -- COMMAND...
+		  uninclude -h
+	EOF
+}
+
+help() {
+	cat <<-'EOF'
+
+
+		Options:
+		  -E REGEXP     the test expression for lines to be deleted
+		  -h, --help    show this message
+
+		  COMMAND       the build/test command used to validate the uninclusion
+
+
+		Read list of files from STDIN, and for each try to delete all lines
+		that match REGEXP and see if COMMAND passes.  Do this for every match
+		untill all lines that could be removed are removed.
+
+
+		Examples:
+
+		  Remove all non-required "#include" lines from lib.c and main.c:
+
+		    $ find lib.c main.c | uninclude -E '^#include ' -- cc $CFLAGS
+		    lib.c: 3 lines unincluded
+		    main.c: nothing to uninclude
+	EOF
+}
+
+
+for flag in "$@"; do
+	case "$flag" in
+		--)
+			break
+			;;
+		--help)
+			usage
+			help
+			exit
+			;;
+		*)
+			;;
+	esac
+done
+
+while getopts 'E:h' flag; do
+	case "$flag" in
+		E)
+			REGEXP="$OPTARG"
+			;;
+		h)
+			usage
+			help
+			exit
+			;;
+		*)
+			usage >&2
+			exit 2
+			;;
+	esac
+done
+shift $((OPTIND - 1))
+
+eval "$(assert-arg -- "${REGEXP:-}" '-E REGEXP')"
+
+
+
+ORIG="$(mkstemp)"
+VALID="$(mkstemp)"
+MATCHES="$(mkstemp)"
+LINES="$(mkstemp)"
+trap 'rm -f "$ORIG" "$VALID" "$MATCHES" "$LINES"' EXIT
+while read -r file; do
+	cp "$file" "$ORIG"
+	cp "$file" "$VALID"
+
+	NTH=1
+	while true; do
+		if ! grep -nE "$REGEXP" "$file" > "$MATCHES" ||
+				[ "$NTH" -ge "$(wc -l < "$MATCHES")" ]; then
+			FROM="$(wc -l < "$ORIG")"
+			TO="$(  wc -l < "$file")"
+			if [ "$FROM" -eq "$TO" ]; then
+				printf '%s: nothing to uninclude\n' "$file" >&2
+			else
+				printf '%s: %s lines unincluded\n' "$file" $((FROM - TO)) >&2
+			fi
+			break
+		fi
+		line="$(cut -d: -f1 "$MATCHES" | lines "$NTH")"
+		sed "${line}d" "$file" | sponge "$file"
+		if ! "$@" "$file"; then
+			cp "$VALID" "$file"
+			NTH=$((NTH + 1))
+		else
+			cp "$file" "$VALID"
+		fi
+	done
+done