Make fewer assumptions about snapshots.txt format.

- Read the file into a nested dictionary instead of variables.
- Only apply special cases where they are really needed.
- Apply a transform to the triple argument to get the platform name to
  determine whether there is a snapshot available for it.
- Apply a similar (but slightly different) transform to get the snapshot's
  file name.  It would be better if the file name matched the platform name
  in snapshots.txt, but it's too late for that now (older versions of this
  script will certainly expect the existing name format).

diff --git a/src/etc/dl-snapshot.py b/src/etc/dl-snapshot.py
index f268c18d4ab0c278ed32bc3d26b830fe72e48714..bf18bb71c8cfa1b49475481c094ece81123d06b5 100644 (file)
--- a/src/etc/dl-snapshot.py
+++ b/src/etc/dl-snapshot.py
@@ -6,22 +6,40 @@ import sys
 import tarfile
 import shutil
 import contextlib
+import re
 
+datere = re.compile('^\d{4}-\d{2}-\d{2}')
+cksumre = re.compile('^  ([^ ]+) ([^$]+)$')
+
+current = None
+snaps = {}
 with open('src/snapshots.txt') as f:
-    lines = f.readlines()
-
-date = lines[0]
-bitrig64 = lines[1]
-linux32 = lines[2]
-linux64 = lines[3]
-mac32 = lines[4]
-mac64 = lines[5]
-win32 = lines[6]
-win64 = lines[7]
+    for line in iter(f):
+        line = line.rstrip()
+        m = datere.match(line)
+        if m:
+            current = m.group()
+            snaps[current] = {}
+            continue
+
+        m = cksumre.match(line)
+        if m:
+            snaps[current][m.group(1)] = m.group(2)
+            continue
+
+        # This script currently doesn't look at older snapshots, so there is
+        # no need to look past the first section.
+        break
+
+date = snaps.keys()[0]
 triple = sys.argv[1]
 
-ts = triple.split('-')
+ts = triple.split('-', 2)
 arch = ts[0]
+
+if (arch == 'i586') or (arch == 'i386'):
+    arch = 'i686'
+
 if len(ts) == 2:
     vendor = 'unknown'
     target_os = ts[1]
@@ -29,43 +47,33 @@ else:
     vendor = ts[1]
     target_os = ts[2]
 
-intel32 = (arch == 'i686') or (arch == 'i586')
+# NB: The platform format differs from the triple format, to support
+#     bootstrapping multiple triples from the same snapshot.
+plat_arch = arch if (arch != 'i686') else 'i386'
+plat_os = target_os
+if (target_os == 'windows'):
+    plat_os = 'winnt'
+elif (target_os == 'darwin'):
+    plat_os = 'macos'
+platform = "%s-%s" % (plat_os, plat_arch)
+if platform not in snaps[date]:
+    raise Exception("no snapshot for the triple '%s'" % triple)
 
-me = None
+# Reconstitute triple with any applicable changes.  For historical reasons
+# this differs from the snapshots.txt platform name.
 if target_os == 'linux':
-    if intel32:
-        me = linux32
-        new_triple = 'i686-unknown-linux-gnu'
-    elif arch == 'x86_64':
-        me = linux64
-        new_triple = 'x86_64-unknown-linux-gnu'
+    target_os = 'linux-gnu'
 elif target_os == 'darwin':
-    if intel32:
-        me = mac32
-        new_triple = 'i686-apple-darwin'
-    elif arch == 'x86_64':
-        me = mac64
-        new_triple = 'x86_64-apple-darwin'
+    vendor = 'apple'
 elif target_os == 'windows':
-    if intel32:
-        me = win32
-        new_triple = 'i686-pc-windows-gnu'
-    elif arch == 'x86_64':
-        me = win64
-        new_triple = 'x86_64-pc-windows-gnu'
-elif target_os == 'bitrig':
-    me = bitrig64
-    new_triple = 'x86_64-unknown-bitrig'
-
-if me is None:
-    raise Exception("no snapshot for the triple: " + triple)
-
-triple = new_triple
-
-platform, hash = me.strip().split()
+    vendor = 'pc'
+    target_os = 'windows-gnu'
+triple = "%s-%s-%s" % (arch, vendor, target_os)
+hash = snaps[date][platform]
 
 tarball = 'cargo-nightly-' + triple + '.tar.gz'
-url = 'https://static-rust-lang-org.s3.amazonaws.com/cargo-dist/' + date.strip() + '/' + tarball
+url = 'https://static-rust-lang-org.s3.amazonaws.com/cargo-dist/%s/%s' % \
+  (date.strip(), tarball)
 dl_path = "target/dl/" + tarball
 dst = "target/snapshot"