Remove the need for LLVM_SRC in llvm.py

Add an extra parameter to llvm.py representing the environment that we
want the command to refer to. We then compute the path to the LLVM
source tree based on that and LLVM_ROOT (which is still an environment
variable for the time being).

The bash helper keeps its old interface and uses LLVM_SRC to compute the
environment that it will pass down to llvm.py. We also perform a small
number of drive-by fixes to this helper (e.g. replacing python with
python3).

Change-Id: Ie7a33103969622294e158f83be8b9f57832ef1dc

1 files changed, 20 insertions, 8 deletions

diff --git a/scripts/llvm.py b/scripts/llvm.py
index 706af11..13e5de6 100644
--- a/scripts/llvm.py
+++ b/scripts/llvm.py
@@ -19,17 +19,25 @@ def die(message, config_to_dump=None):
 
     exit(1)
 
+
+def get_llvm_root():
+    """Get the path to the LLVM root, which contains the repos as well as all
+    the work environments."""
+    return os.environ["LLVM_ROOT"]
+
+
+def get_worktree_root(env):
+    """
+    Get the path to the LLVM worktree corresponding to env. The value will be
+    based on the LLVM root.
+    """
+    return os.path.join(get_llvm_root(), env, "llvm")
+
 # Figure out the path to the LLVM repos
 if "LLVM_ROOT" not in os.environ:
     die("Please, define $LLVM_ROOT to point to the root\n"
         "path where the worktree setup should be performed")
-llvm_repos_root = os.path.join(os.environ["LLVM_ROOT"], "repos")
-
-# Figure out the path to the current LLVM tree
-if "LLVM_SRC" not in os.environ:
-    die("Please, define $LLVM_SRC to point to the current LLVM\n"
-        "worktree directory, or run llvm-env to set it for you")
-llvm_worktree_root = os.environ["LLVM_SRC"]
+llvm_repos_root = os.path.join(get_llvm_root(), "repos")
 
 
 def dump_config(config):
@@ -48,6 +56,8 @@ def projects(args):
     """Add/remove subprojects based on the values in args."""
 
     proj = Proj()
+
+    llvm_worktree_root = get_worktree_root(args.env)
     config = LLVMSourceConfig(proj, llvm_worktree_root)
 
     if not args.add and not args.remove:
@@ -77,10 +87,12 @@ def projects(args):
 valid_subprojects = list(LLVMSubproject.get_all_subprojects().keys())
 
 options = ArgumentParser(formatter_class=RawTextHelpFormatter)
+options.add_argument('env', help="The environment to update.")
+
 subcommands = options.add_subparsers()
 
 # Subcommand for adding / removing subprojects
-projs = subcommands.add_parser("projects", help="Add/remove LLVM subprojects")
+projs = subcommands.add_parser("projects", help="Add/remove LLVM subprojects.")
 projs.set_defaults(run_command=projects)
 
 # TODO: Overwriting previous values is not necessarily what users expect (so for