diff --git a/README.md b/README.md
index 9805134996211d8548311f2985c6aaf06994bd05..394e5f2048510023cf867b49242d08acc85c7fdb 100644
--- a/README.md
+++ b/README.md
@@ -99,7 +99,7 @@ handles your haskell packages and can demand that [a specific version](https://c
Installs a specified GHC version into `~/.ghcup/ghc/<ver>`, and places `ghc-<ver>` symlinks in `~/.ghcup/bin/`.
-Optionally, an unversioned `ghc` link can point to a default version of your choice.
+Optionally, unversioned `ghc` shims can be created that respect `GHCUP_GHCVER` env variable, by default read the ghc version from `~/.ghcup/.ghcup.ghcver` and can also read `.ghcup.ghcver` from the current directory.
This uses precompiled GHC binaries that have been compiled on fedora/debian by [upstream GHC](https://www.haskell.org/ghc/download_ghc_8_6_1.html#binaries).
diff --git a/ghcup b/ghcup
index e66e998bc234b09b542f0a54d09db64574d93cb9..3f675373606658594838b85ea3846556a639d6b8 100755
--- a/ghcup
+++ b/ghcup
@@ -243,6 +243,7 @@ USAGE:
FLAGS:
-h, --help Prints help information
+ -l, --local Set the GHC version for the current project/directory only
ARGS:
[VERSION|TAG] E.g. \"8.4.3\" or \"8.6.3\" or
@@ -250,9 +251,16 @@ ARGS:
(default: discovers recommended version)
DISCUSSION:
- Sets the the current GHC version by creating non-versioned
- symlinks for all ghc binaries of the specified version in
- \"~/.ghcup/bin/<binary>\".
+ Sets the current GHC version by creating a file
+ .ghcup.ghcver either in the current directory (if -l is supplied)
+ or globally in ~/.ghcup directory and then creating shims
+ for ghc/ghci and friends that read these files. The decision
+ as to which GHC version to use is as follows:
+
+ 1. if GHCUP_GHCVER env variable is set, use that as ghc version
+ 2. if .ghcup.ghcver exists in current directory, read the contents of
+ that file as ghc version
+ 3. else use ~/.ghcup/.ghcup.ghcver
")
exit 1
}
@@ -1145,7 +1153,7 @@ get_meta_download_file() {
# META_VERSION_URL.
# @STDOUT: known ghc versions
known_tool_versions() {
- [ -z "$1" ] && die "Internal error: no argument given to posix_realpath"
+ [ -z "$1" ] && die "Internal error: no argument given to known_tool_versions"
mytool=$1
meta_file="$(get_meta_version_file)"
@@ -1216,6 +1224,8 @@ array_contains() {
############################
+
+
# @FUNCTION: install_ghc
# @USAGE: <ghcversion>
# @DESCRIPTION:
@@ -1308,34 +1318,99 @@ install_ghc() {
########################
+# @FUNCTION: create_shim
+# @USAGE: <target>
+# @DESCRIPTION:
+# Creates a shim for the given target (like 'ghc'),
+# which can dynamically choose a specific requested version.
+create_shim() {
+ [ -z "$1" ] && die "Internal error: no argument given to create_shim"
+
+ shim_target=$1
+
+ debug_message "creating target shim for ${shim_target}"
+
+ cat <<-EOF > "${BIN_LOCATION}/${shim_target}" || die
+ #!/bin/sh
+
+ target="${shim_target}"
+
+ GHCUP_BASE="$INSTALL_BASE"
+
+ if [ -n "\${GHCUP_GHCVER}" ] ; then
+ exec "\${target}-\${GHCUP_GHCVER}" "\$@"
+ elif [ -f "\${PWD}/.ghcup.ghcver" ] ; then
+ ghcver="\$(cat "\${PWD}/.ghcup.ghcver")"
+
+ exec "\${target}-\${ghcver}" "\$@"
+ else
+ [ -f "\${GHCUP_BASE}/.ghcup.ghcver" ] || {
+ (>&2 echo "\${GHCUP_BASE}/.ghcup.ghcver missing! Don't know what version to run. You may need to issue: 'ghcup set <ghcver>'")
+ exit 1
+ }
+
+ ghcver="\$(cat "\${GHCUP_BASE}/.ghcup.ghcver")"
+
+ exec "\${target}-\${ghcver}" "\$@"
+ fi
+ EOF
+
+ edo chmod +x "${BIN_LOCATION}/${shim_target}"
+
+ unset shim_target
+}
+
+
+
+
# @FUNCTION: set_ghc
-# @USAGE: <ghcversion>
+# @USAGE: <ghcversion> <local-or-not>
# @DESCRIPTION:
-# Sets the current ghc version by creating symlinks.
+# Sets the current ghc version by creating shims and ghc version config file.
set_ghc() {
- [ -z "$1" ] && die "Internal error: no argument given to set_ghc"
+ { [ -z "$1" ] || [ -z "$2" ] ;} && die "Internal error: not enough arguments given to set_ghc"
myghcver=$1
+ is_local=$2
inst_location=$(get_ghc_location "$1")
[ -z "${inst_location}" ] && die "failed to get install location"
[ -e "${inst_location}" ] || die "GHC ${myghcver} not installed yet, use: ${SCRIPT} install ${myghcver}"
- status_message "Setting GHC to ${myghcver}"
+ if ${is_local} ; then
+ status_message "Setting local GHC to ${myghcver}"
+ else
+ status_message "Setting global GHC to ${myghcver}"
+ fi
+ # create shims
for f in "${inst_location}"/bin/*-"${myghcver}" ; do
[ -e "${f}" ] || die "Something went wrong, ${f} does not exist!"
source_fn=$(basename "${f}")
target_fn=$(echo "${source_fn}" | sed "s#-${myghcver}##")
- # shellcheck disable=SC2046
- edo ln $(optionv "-v") -sf ../ghc/"${myghcver}/bin/${source_fn}" "${BIN_LOCATION}/${target_fn}"
+
+ # for backwards compat with old-style ghcup symlink we need to clean these up
+ if [ -L "${BIN_LOCATION}/${target_fn}" ] ; then
+ edo rm "${BIN_LOCATION}/${target_fn}"
+ fi
+
+ create_shim "${target_fn}"
unset source_fn target_fn
done
+
+ # create alias symlinks
# shellcheck disable=SC2046
edo ln $(optionv "-v") -sf runghc "${BIN_LOCATION}"/runhaskell
# shellcheck disable=SC2046
edo ln $(optionv "-v") -sf haddock-ghc "${BIN_LOCATION}"/haddock
+ # set ghc version
+ if ${is_local} ; then
+ printf "%s" "${myghcver}" > "${PWD}/.ghcup.ghcver" || die "failed to set GHC version locally! Not enough permissions?"
+ else
+ printf "%s" "${myghcver}" > "${INSTALL_BASE}/.ghcup.ghcver" || die "failed to set GHC version globally! Not enough permissions?"
+ fi
+
status_message "Done, make sure \"${BIN_LOCATION}\" is in your PATH!"
unset myghcver inst_location f
@@ -1857,10 +1932,13 @@ while [ $# -gt 0 ] ; do
fi
break;;
set)
+ IS_LOCAL=false
shift 1
while [ $# -gt 0 ] ; do
case $1 in
-h|--help) set_usage;;
+ -l|--local) IS_LOCAL=true
+ shift 1 ;;
*) GHC_VER=$1
break;;
esac
@@ -1871,13 +1949,13 @@ while [ $# -gt 0 ] ; do
if [ -z "${_tool_ver}" ] ; then
die "Could not find a recommended GHC version, please report a bug at ${BUG_URL}!"
fi
- set_ghc "${_tool_ver}"
+ set_ghc "${_tool_ver}" ${IS_LOCAL}
else
# could be a version or a tag, let's check
if array_contains "${GHC_VER}" "$(known_tool_versions "ghc")" ; then
- set_ghc "${GHC_VER}"
+ set_ghc "${GHC_VER}" ${IS_LOCAL}
elif array_contains "${GHC_VER}" "$(known_tool_tags "ghc")" ; then
- set_ghc "$(get_tool_ver_from_tag "ghc" "${GHC_VER}")"
+ set_ghc "$(get_tool_ver_from_tag "ghc" "${GHC_VER}")" ${IS_LOCAL}
else
die "\"${GHC_VER}\" is not a known version or tag!"
fi