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.

1 files changed, 68 insertions, 0 deletions

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