Generate .config.rc (now .vars.rc) with redo

This avoids relying on configure generating anything, this should also
make it easier to ensure that git-bisect builds don't need any
reconfiguring or cleans.

9 files changed, 103 insertions, 59 deletions

diff --git a/.compile.do b/.compile.do
index 2a8d932..a249c44 100755
--- a/.compile.do
+++ b/.compile.do
@@ -1,6 +1,6 @@
 #!/bin/bash -e
-redo-ifchange .config.rc
-. ./.config.rc
+redo-ifchange .vars.rc
+. ./.vars.rc
 exec >"$3"
 echo "# generated by $0"
 declare -p CC CFLAGS CPPFLAGS
diff --git a/.gitignore b/.gitignore
index 0fd3620..187e67e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,11 +3,12 @@
 *.o
 *.so
 .compile
-.config.rc
 .link-executable
 .link-library
 .redo/
+.vars.rc
 all
 compile_flags.txt
+config.rc
 test
 test_gen
diff --git a/.link-executable.do b/.link-executable.do
index bb3dea6..6b2ef81 100755
--- a/.link-executable.do
+++ b/.link-executable.do
@@ -1,6 +1,6 @@
 #!/bin/bash -e
-redo-ifchange .config.rc
-. ./.config.rc
+redo-ifchange .vars.rc
+. ./.vars.rc
 exec >"$3"
 echo "# generated by $0"
 declare -p CC LDFLAGS LDLIBS
diff --git a/.link-library.do b/.link-library.do
index 7a7aad2..67ea23d 100755
--- a/.link-library.do
+++ b/.link-library.do
@@ -1,6 +1,6 @@
 #!/bin/bash -e
-redo-ifchange .config.rc
-. ./.config.rc
+redo-ifchange .vars.rc
+. ./.vars.rc
 exec >"$3"
 echo "# generated by $0"
 declare -p CC LDFLAGS LDLIBS
diff --git a/.vars.rc.do b/.vars.rc.do
new file mode 100755
index 0000000..2494f3f
--- /dev/null
+++ b/.vars.rc.do
@@ -0,0 +1,68 @@
+#!/bin/bash -e
+
+# Ensure variables from the config aren't set before the config is read to
+# avoid capturing transient state
+unset CC CFLAGS CPPFLAGS LDFLAGS LDLIBS colour debug optimise verbose warn werror
+
+CFLAGS=(-std=c11 -fPIC)
+
+wflags=(
+	-Wall -Wcast-align -Wcast-qual -Wextra -Wpedantic -Wformat=2
+	-Winit-self -Wmissing-prototypes -Wpointer-arith -Wshadow
+	-Wstrict-prototypes -Wsuggest-attribute=format
+	-Wsuggest-attribute=noreturn
+)
+
+declare -a CFLAGS CPPFLAGS LDFLAGS LDLIBS
+
+if [ -e config.rc ]; then
+	redo-ifchange config.rc
+	. ./config.rc
+else
+	redo-ifcreate config.rc
+fi
+
+check() {
+	what=$1
+	shift
+	for p do
+		if command -v "$p" >/dev/null 2>&1; then
+			echo "$p"
+			return
+		fi
+	done
+	echo "$what not set or found" >&2
+	return 1
+}
+
+CC=$(check '$CC, cc, gcc or clang' "$CC" cc gcc clang) || exit
+
+if [[ $colour ]]; then
+	if [[ $colour != 1 ]]; then no=no-; fi
+	CFLAGS+=("-f${no}diagnostics-colour")
+	LDFLAGS+=("-f${no}diagnostics-colour")
+fi
+if [[ $debug ]]; then
+	CFLAGS+=(-Og -g)
+	LDFLAGS+=(-Og -g)
+fi
+if [[ $optimise ]]; then
+	CFLAGS+=(-O2 -flto)
+	LDFLAGS+=(-O2 -flto)
+fi
+if [[ $warn ]]; then
+	CFLAGS+=("${warnings[@]}")
+fi
+if [[ $werror ]]; then
+	CFLAGS+=(-Werror)
+fi
+
+{
+	echo "# generated by $0"
+	declare -p CC CFLAGS CPPFLAGS LDFLAGS LDLIBS
+} >"$3"
+
+if [[ $verbose ]]; then
+	echo "# Configuration regenerated:" >&2
+	cat "$3" >&2
+fi
diff --git a/all.do b/all.do
index 749f446..321cf2c 100755
--- a/all.do
+++ b/all.do
@@ -1,2 +1,2 @@
 #!/bin/sh
-redo-ifchange libpack.so test
+redo-ifchange libpack.so test compile_flags.txt
diff --git a/clean b/clean
index 246aa82..2cb5f16 100755
--- a/clean
+++ b/clean
@@ -1,3 +1,3 @@
 #!/bin/sh
 find . -type f \( -name '*.d' -o -name '*.o' -o -name '*.inc' \) -exec rm -f {} +
-rm -f .compile .link-library .link-executable test_gen test libpack.so all
+rm -f .compile .link-executable .link-library .vars.rc all compile_flags.txt libpack.so test test_gen
diff --git a/compile_flags.txt.do b/compile_flags.txt.do
new file mode 100755
index 0000000..4d14f78
--- /dev/null
+++ b/compile_flags.txt.do
@@ -0,0 +1,4 @@
+#!/bin/bash
+redo-ifchange .vars.rc
+. ./.vars.rc
+printf '%s\n' "${CFLAGS[@]}" "${CPPFLAGS[@]}" >"$3"
diff --git a/configure b/configure
index 431dc4a..2085a38 100755
--- a/configure
+++ b/configure
@@ -1,17 +1,5 @@
 #!/bin/bash
 
-CFLAGS=(-std=c11 -fPIC)
-CPPFLAGS=()
-LDLIBS=()
-LDFLAGS=()
-
-warnings=(
-	-Wall -Wcast-align -Wcast-qual -Wextra -Wpedantic -Wformat=2
-	-Winit-self -Wmissing-prototypes -Wpointer-arith -Wshadow
-	-Wstrict-prototypes -Wsuggest-attribute=format
-	-Wsuggest-attribute=noreturn
-)
-
 usage () { echo "Usage: $0 [-h|options...]"; }
 
 help () {
@@ -24,7 +12,6 @@ Options:
   -c when     Enable compiler colours (always|auto|off) [default: auto]
   -d          Enable debugging flags
   -e          Enable -Werror
-  -f          Generate a compile_flags.txt
   -h          Show this help
   -o          Enable optimisation flags
   -v          Print results of configuration
@@ -34,49 +21,33 @@ Environment:
 EOF
 }
 
-check() {
-	what=$1
-	shift
-	for p do
-		if command -v "$p" >/dev/null 2>&1; then
-			echo "$p"
-			return
-		fi
-	done
-	echo "$what not set or found" >&2
-	return 1
-}
-
-CC=$(check '$CC, cc, gcc or clang' "$CC" cc gcc clang) || exit
+exec 3>config.rc
+conf() { echo "$1" >&3; }
 
 colour=auto
-while getopts B:C:L:P:c:defhovw opt; do
+while getopts B:C:L:P:c:dehovw opt; do
+	qopt=${OPTARG@Q}
 	case $opt in
-	B) LDLIBS+=("$OPTARG");;
-	C) CFLAGS+=("$OPTARG");;
-	L) LDFLAGS+=("$OPTARG");;
-	P) CPPFLAGS+=("$OPTARG");;
+	B) conf "LDLIBS+=($qopt)";;
+	C) conf "CFLAGS+=($qopt)";;
+	L) conf "LDFLAGS+=($qopt)";;
+	P) conf "CPPFLAGS+=($qopt)";;
 	c) colour="$OPTARG";;
-	d) CFLAGS+=(-Og -g); LDFLAGS+=(-Og -g);;
-	e) CFLAGS+=(-Werror);;
-	f) gen_flags=1;;
+	d) conf "debug=1" >&3;;
+	e) conf "werror=1" >&3;;
 	h) usage; help; exit;;
-	o) CFLAGS+=(-O2 -flto); LDFLAGS+=(-O2 -flto);;
-	v) verbose=1;;
-	w) CFLAGS+=("${warnings[@]}");;
+	o) conf "optimise=1" >&3;;
+	v) conf "verbose=1" >&3;;
+	w) conf "warn=1" >&3;;
 	?) usage >&2; exit 1;;
 	esac
 done
-if [[ $colour == auto && -t 1 ]]; then
-	colour=always
-fi
-if [[ $colour == always ]]; then
-	CFLAGS+=(-fdiagnostics-color)
-fi
 
-{
-	echo "# generated using $0 $@"
-	declare -p CC CFLAGS CPPFLAGS LDFLAGS LDLIBS
-} >.config.rc
-[[ $verbose ]] && cat .config.rc
-[[ $gen_flags ]] && printf '%s\n' "${CFLAGS[@]}" "${CPPFLAGS[@]}" >compile_flags.txt
+case "$colour" in
+	auto) [[ -t 1 ]] && conf "colour=1" || conf "colour=0";;
+	always) conf "colour=1";;
+	off) conf "colour=0";;
+	*) usage >&2; exit 1;;
+esac
+
+[[ $CC ]] && conf "CC=${CC@Q}"