Changed builld-llvm.py to use .json files

LLDB has many branches in a variety of repositories.
The build-script.py file is subtly different for each set.
This is unnecessary and causes merge headaches.

This patch makes build-llvm.py consult a directory full 
of .json files, each one of which matches a particular
branch using a regular expression.

Differential revision: https://reviews.llvm.org/D30275

llvm-svn: 295897

lldb/scripts/Xcode/build-llvm.py

@@ -6,6 +6,7 @@ import fnmatch
 import os
 import platform
 import re
+import repo
 import subprocess
 import sys
 
@@ -17,42 +18,38 @@ from lldbbuild import *
 def LLVM_HASH_INCLUDES_DIFFS():
     return False
 
-# The use of "x = "..."; return x" here is important because tooling looks for
-# it with regexps.  Only change how this works if you know what you are doing.
-
-
-def LLVM_REF():
-    llvm_ref = "master"
-    return llvm_ref
-
-
-def CLANG_REF():
-    clang_ref = "master"
-    return clang_ref
-
 # For use with Xcode-style builds
 
+def process_vcs(vcs):
+    return {
+        "svn": VCS.svn,
+        "git": VCS.git
+    }[vcs]
+
+def process_root(name):
+    return {
+        "llvm": llvm_source_path(),
+        "clang": clang_source_path(),
+        "ninja": ninja_source_path()
+    }[name]
+
+def process_repo(r):
+    return {
+        'name': r["name"],
+        'vcs': process_vcs(r["vcs"]),
+        'root': process_root(r["name"]),
+        'url': r["url"],
+        'ref': r["ref"]
+    }
 
 def XCODE_REPOSITORIES():
-    return [
-        {'name': "llvm",
-         'vcs': VCS.git,
-         'root': llvm_source_path(),
-         'url': "http://llvm.org/git/llvm.git",
-         'ref': LLVM_REF()},
-
-        {'name': "clang",
-         'vcs': VCS.git,
-         'root': clang_source_path(),
-         'url': "http://llvm.org/git/clang.git",
-         'ref': CLANG_REF()},
-
-        {'name': "ninja",
-         'vcs': VCS.git,
-         'root': ninja_source_path(),
-         'url': "https://github.com/ninja-build/ninja.git",
-         'ref': "master"}
-    ]
+    identifier = repo.identifier()
+    if identifier == None:
+        sys.exit("Couldn't identify the current branch")
+    set = repo.find(identifier)
+    if set == None:
+        sys.exit("Couldn't find a repository set for the current branch")
+    return [process_repo(r) for r in set]
 
 
 def get_c_compiler():

lldb/scripts/Xcode/repo.py

@@ -0,0 +1,33 @@
+import json
+import os
+import re
+import subprocess
+
+def identifier():
+	try:
+		svn_output = subprocess.check_output(["svn", "info", "--show-item", "url"], stderr=subprocess.STDOUT).rstrip()
+		return svn_output
+	except:
+		pass
+	try:
+		git_remote_and_branch = subprocess.check_output(["git", "rev-parse", "--abbrev-ref", "--symbolic-full-name", "@{u}"]).rstrip()
+		git_remote = git_remote_and_branch.split("/")[0]
+		git_branch = "/".join(git_remote_and_branch.split("/")[1:])
+		git_url = subprocess.check_output(["git", "remote", "get-url", git_remote]).rstrip()
+		return git_url + ":" + git_branch
+	except:
+		pass
+	return None
+
+def find(identifier):
+	dir = os.path.dirname(os.path.realpath(__file__))
+	repos_dir = os.path.join(dir, "repos")
+	json_regex = re.compile(r"^.*.json$")
+	override_path = os.path.join(repos_dir, "OVERRIDE.json")
+	if os.path.isfile(override_path):
+		override_set = json.load(open(override_path))
+		return override_set["repos"]
+	for set in [json.load(open(os.path.join(repos_dir, f))) for f in filter(json_regex.match, os.listdir(repos_dir))]:
+		if re.match(set["regexp"], identifier):
+			return set["repos"]
+	return None

lldb/scripts/Xcode/repos/svn-trunk.json

@@ -0,0 +1,19 @@
+{
+    "regexp" : ".*llvm\\.org.*",
+    "repos" : [
+        {"name": "llvm",
+         "vcs": "git",
+         "url": "http://llvm.org/git/llvm.git",
+         "ref": "master"},
+
+        {"name": "clang",
+         "vcs": "git",
+         "url": "http://llvm.org/git/clang.git",
+         "ref": "master"},
+
+        {"name": "ninja",
+         "vcs": "git",
+         "url": "https://github.com/ninja-build/ninja.git",
+         "ref": "master"}
+    ]
+}