configure: Fix VAR=value before --option

Previously we were not shifting all arguments, leading to

    $ ./configure CC=gcc --enable-release
    make: unrecognized option '--enable-release'

as the loop would shift the CC=gcc argument instead of --enable-release.

Author: tavianator

configure

@@ -7,22 +7,62 @@
 
 set -eu
 
-# Save the ./configure command line for bfs --version
-export CONFIG="$0 $*"
+# Print the help message()
+help() {
+    cat <<EOF
+Usage:
 
-# Default to `make`
-MAKE="${MAKE:-make}"
-
-# Pass -j$(nproc) unless MAKEFLAGS is set
-if [ "${MAKEFLAGS+y}" ]; then
-    j=""
-else
-    j="-j$({ nproc || sysctl -n hw.ncpu || getconf _NPROCESSORS_ONLN || echo 1; } 2>/dev/null)"
-fi
-
-# Convert kebab-case to UPPER_CASE
-toupper() {
-    printf '%s' "$1" | tr 'a-z-' 'A-Z_'
+  \$ $0 [--enable-*|--disable-*] [--with-*|--without-*] [CC=...] [...]
+  \$ $MAKE $j
+
+Variables set in the environment or on the command line will be picked up:
+
+  MAKE
+      The make implementation to use
+  CC
+      The C compiler to use
+
+  CPPFLAGS="-I... -D..."
+  CFLAGS="-W... -f..."
+  LDFLAGS="-L... -Wl,..."
+      Preprocessor/compiler/linker flags
+
+  LDLIBS="-l... -l..."
+      Dynamic libraries to link
+
+  EXTRA_{CPPFLAGS,CFLAGS,LDFLAGS,LDLIBS}
+      Adds to the default flags, instead of replacing them
+
+The default flags result in a plain debug build.  Other build profiles include:
+
+  --enable-release
+      Enable optimizations, disable assertions
+  --enable-{asan,lsan,msan,tsan,ubsan}
+      Enable sanitizers
+  --enable-gcov
+      Enable code coverage instrumentation
+
+External dependencies are auto-detected by default, but you can build --with or
+--without them explicitly:
+
+  --with-libacl      --without-libacl
+  --with-libcap      --without-libcap
+  --with-libselinux  --without-libselinux
+  --with-liburing    --without-liburing
+  --with-oniguruma   --without-oniguruma
+
+Packaging:
+
+  --prefix=/path
+      Set the installation prefix (default: /usr)
+  --mandir=/path
+      Set the man page directory (default: \$PREFIX/share/man)
+
+This script is a thin wrapper around a makefile-based configuration system.
+Any other arguments will be passed directly to the $MAKE invocation, e.g.
+
+  \$ $0 $j V=1
+EOF
 }
 
 # Report an argument parsing error
@@ -32,7 +72,26 @@ invalid() {
     exit 1
 }
 
+# Get the number of cores to use
+nproc() {
+    {
+        command nproc \
+            || sysctl -n hw.ncpu \
+            || getconf _NPROCESSORS_ONLN \
+            || echo 1
+    } 2>/dev/null
+}
+
+# Save the ./configure command line for bfs --version
+export CONFIG="$0 $*"
+
+# Default to `make`
+MAKE="${MAKE-make}"
+
+# Parse the command-line arguments
 for arg; do
+    shift
+
     # --[(enable|disable|with|without)-]$name[=$value]
     value="${arg#*=}"
     name="${arg%%=*}"
@@ -80,67 +139,13 @@ for arg; do
 
     case "$arg" in
         -h|--help)
-            cat <<EOF
-Usage:
-
-  \$ $0 [--enable-*|--disable-*] [--with-*|--without-*] [CC=...] [...]
-  \$ $MAKE $j
-
-Variables set in the environment or on the command line will be picked up:
-
-  MAKE
-      The make implementation to use
-  CC
-      The C compiler to use
-
-  CPPFLAGS="-I... -D..."
-  CFLAGS="-W... -f..."
-  LDFLAGS="-L... -Wl,..."
-      Preprocessor/compiler/linker flags
-
-  LDLIBS="-l... -l..."
-      Dynamic libraries to link
-
-  EXTRA_{CPPFLAGS,CFLAGS,LDFLAGS,LDLIBS}
-      Adds to the default flags, instead of replacing them
-
-The default flags result in a plain debug build.  Other build profiles include:
-
-  --enable-release
-      Enable optimizations, disable assertions
-  --enable-{asan,lsan,msan,tsan,ubsan}
-      Enable sanitizers
-  --enable-gcov
-      Enable code coverage instrumentation
-
-External dependencies are auto-detected by default, but you can build --with or
---without them explicitly:
-
-  --with-libacl      --without-libacl
-  --with-libcap      --without-libcap
-  --with-libselinux  --without-libselinux
-  --with-liburing    --without-liburing
-  --with-oniguruma   --without-oniguruma
-
-Packaging:
-
-  --prefix=/path
-      Set the installation prefix (default: /usr)
-  --mandir=/path
-      Set the man page directory (default: \$PREFIX/share/man)
-
-This script is a thin wrapper around a makefile-based configuration system.
-Any other arguments will be passed directly to the $MAKE invocation, e.g.
-
-  \$ $0 $j V=1
-EOF
+            help
             exit 0
             ;;
 
         --enable-*|--disable-*)
             case "$name" in
                 release|asan|lsan|msan|tsan|ubsan|lint|gcov)
-                    shift
                     set -- "$@" "$NAME=$yn"
                     ;;
                 *)
@@ -152,7 +157,6 @@ EOF
         --with-*|--without-*)
             case "$name" in
                 libacl|libcap|libselinux|liburing|oniguruma)
-                    shift
                     set -- "$@" "WITH_$NAME=$yn"
                     ;;
                 *)
@@ -162,23 +166,20 @@ EOF
             ;;
 
         --prefix=*|--mandir=*)
-            shift
             set -- "$@" "$NAME=$value"
             ;;
 
         --infodir=*|--build=*|--host=*|--target=*)
-            shift
             printf 'warning: Ignoring option "%s"\n' "$arg" >&2
             ;;
 
         MAKE=*)
-            shift
             MAKE="$value"
             ;;
 
         # make flag (-j2) or variable (CC=clang)
         -*|*=*)
-            continue
+            set -- "$@" "$arg"
             ;;
 
         *)
@@ -196,6 +197,6 @@ for f in Makefile build completions docs src tests; do
 done
 
 # Set MAKEFLAGS to -j$(nproc) if it's unset
-export MAKEFLAGS="${MAKEFLAGS-$j}"
+export MAKEFLAGS="${MAKEFLAGS--j$(nproc)}"
 
 $MAKE -rf build/config.mk "$@"