[commit: ghc] wip/nfs-locking: Add rl function to the cabal build file as well. (2c635d5)

[git at git.haskell.org]

Repository : ssh://git@git.haskell.org/ghc

On branch  : wip/nfs-locking
Link       : http://ghc.haskell.org/trac/ghc/changeset/2c635d55d07ddeb2f827dd5d3007fc9b362b043a/ghc

>---------------------------------------------------------------

commit 2c635d55d07ddeb2f827dd5d3007fc9b362b043a
Author: Moritz Angermann <moritz.angermann at gmail.com>
Date:   Tue Jan 5 20:58:07 2016 +0800

    Add rl function to the cabal build file as well.


>---------------------------------------------------------------

2c635d55d07ddeb2f827dd5d3007fc9b362b043a
 build.cabal.sh | 28 +++++++++++++++++++++++++++-
 1 file changed, 27 insertions(+), 1 deletion(-)

diff --git a/build.cabal.sh b/build.cabal.sh
index cf165b8..8add516 100755
--- a/build.cabal.sh
+++ b/build.cabal.sh
@@ -2,7 +2,33 @@
 
 set -euo pipefail
 
-absoltueRoot="$(dirname "$(readlink -f "$0")")"
+# readlink on os x, doesn't support -f, to prevent the
+# need of installing coreutils (e.g. through brew, just
+# for readlink, we use the follownig substitute.
+#
+# source: http://stackoverflow.com/a/1116890
+function rl {
+    TARGET_FILE="$1"
+
+    cd "$(dirname "$TARGET_FILE")"
+    TARGET_FILE="$(basename "$TARGET_FILE")"
+
+    # Iterate down a (possible) chain of symlinks
+    while [ -L "$TARGET_FILE" ]
+    do
+        TARGET_FILE="$(readlink "$TARGET_FILE")"
+        cd "$(dirname "$TARGET_FILE")"
+        TARGET_FILE="$(basename "$TARGET_FILE")"
+    done
+
+    # Compute the canonicalized name by finding the physical path
+    # for the directory we're in and appending the target file.
+    PHYS_DIR="$(pwd -P)"
+    RESULT="$PHYS_DIR/$TARGET_FILE"
+    echo "$RESULT"
+}
+
+absoltueRoot="$(dirname "$(rl "$0")")"
 cd "$absoltueRoot"
 
 # Initialize sandbox if necessary