Add emscripten-releases support for release tags (#243)

* Structures emscripten-releases-tags.txt to mention the latest release, and then a list of all previous releases.
* Adds a new release for 1.38.33.
* If the manifest has emscripten_releases_hash, then we write out emscripten-version.txt with the proper version. We start with the hash, and check if there is a released version for it, if so we emit that, otherwise we emit the hash.
* Windows zipfile fix.

emscripten-releases-tags.txt

@@ -1,4 +1,7 @@
 {
-  "latest": "0ea08ee8a5f0524b4c9ac94de4f161ceeacb3e74"
+  "latest": "1.38.33",
+  "releases": {
+    "1.38.33": "3b8cff670e9233a6623563add831647e8689a86b"
+  }
 }
 

emsdk

@@ -475,6 +475,9 @@ def unzip(source_filename, dest_dir, unpack_even_if_exists=False):
             if not os.path.isdir(d): os.mkdir(d)
           else:
             tmp_dst_filename = os.path.join(unzip_to_dir, member.filename)
+            parent_dir = os.path.dirname(fix_potentially_long_windows_pathname(final_dst_filename))
+            if parent_dir and not os.path.exists(parent_dir):
+              os.makedirs(parent_dir)
             os.rename(fix_potentially_long_windows_pathname(tmp_dst_filename), fix_potentially_long_windows_pathname(final_dst_filename))
 
       if common_subdir:
@@ -1501,11 +1504,17 @@ class Tool(object):
         if dst_file: success = True
         else: success = False
 
-      if success and hasattr(self, 'custom_install_script'):
-        if self.custom_install_script == 'build_optimizer': success = build_optimizer_tool(self)
-        elif self.custom_install_script == 'build_fastcomp': pass # 'build_fastcomp' is a special one that does the download on its own, others do the download manually.
-        elif self.custom_install_script == 'build_binaryen': success = build_binaryen_tool(self)
-        else: raise Exception('Unknown custom_install_script command "' + self.custom_install_script + '"!')
+      if success:
+        if hasattr(self, 'custom_install_script'):
+          if self.custom_install_script == 'build_optimizer': success = build_optimizer_tool(self)
+          elif self.custom_install_script == 'build_fastcomp': pass # 'build_fastcomp' is a special one that does the download on its own, others do the download manually.
+          elif self.custom_install_script == 'build_binaryen': success = build_binaryen_tool(self)
+          else: raise Exception('Unknown custom_install_script command "' + self.custom_install_script + '"!')
+
+        # Install an emscripten-version.txt file if told to.
+        if hasattr(self, 'emscripten_releases_hash'):
+          emscripten_version_file_path = os.path.join(to_native_path(self.expand_vars(self.activated_path)), 'emscripten-version.txt')
+          open(emscripten_version_file_path, 'w').write('"%s"' % get_emscripten_release_version(self.emscripten_releases_hash))
 
       if not success:
         print("Installation failed!")
@@ -1666,7 +1675,20 @@ def find_latest_waterfall_sdk(which):
 
 def find_latest_releases_sdk(which):
   releases_info = load_releases_info()
-  return 'sdk-releases-%s-%s-64bit' % (which, releases_info['latest'])
+  latest = releases_info['latest']
+  ident = releases_info['releases'][latest]
+  return 'sdk-releases-%s-%s-64bit' % (which, ident)
+
+
+# Given a git hash in emscripten-releases, find the emscripten
+# version for it. There may not be one if this is not the hash of
+# a release, in which case we just use the hash.
+def get_emscripten_release_version(emscripten_releases_hash):
+  releases_info = load_releases_info()
+  for key, value in dict(releases_info['releases']).items():
+    if value == emscripten_releases_hash:
+      return key
+  return emscripten_releases_hash
 
 
 # Finds the best-matching python tool for use.
@@ -1875,7 +1897,7 @@ def load_releases_info():
 # Get a list of tags for emscripten-releases.
 def load_releases_tags():
   info = load_releases_info()
-  return list(info.values())
+  return list(info['releases'].values())
 
 
 def is_string(s):

emsdk_manifest.json

@@ -217,11 +217,12 @@
     "bitness": 64,
     "linux_url": "https://storage.googleapis.com/webassembly/emscripten-releases-builds/linux/%releases-tag%/wasm-binaries.tbz2",
     "osx_url": "https://storage.googleapis.com/webassembly/emscripten-releases-builds/mac/%releases-tag%/wasm-binaries.tbz2",
-    "windows_url": "https://storage.googleapis.com/webassembly/emscripten-releases-builds/windows/%releases-tag%/wasm-binaries.tbz2",
+    "windows_url": "https://storage.googleapis.com/webassembly/emscripten-releases-builds/win/%releases-tag%/wasm-binaries.zip",
     "zipfile_prefix": "%releases-tag%-",
     "install_path": "upstream/%releases-tag%",
     "activated_path": "%installation_dir%/emscripten",
-    "activated_cfg": "LLVM_ROOT='%installation_dir%/bin';BINARYEN_ROOT='%installation_dir%'"
+    "activated_cfg": "LLVM_ROOT='%installation_dir%/bin';BINARYEN_ROOT='%installation_dir%'",
+    "emscripten_releases_hash": "%releases-tag%"
   },
   {
     "id": "releases",
@@ -229,11 +230,12 @@
     "bitness": 64,
     "linux_url": "https://storage.googleapis.com/webassembly/emscripten-releases-builds/linux/%releases-tag%/wasm-binaries.tbz2",
     "osx_url": "https://storage.googleapis.com/webassembly/emscripten-releases-builds/mac/%releases-tag%/wasm-binaries.tbz2",
-    "windows_url": "https://storage.googleapis.com/webassembly/emscripten-releases-builds/windows/%releases-tag%/wasm-binaries.zip",
+    "windows_url": "https://storage.googleapis.com/webassembly/emscripten-releases-builds/win/%releases-tag%/wasm-binaries.zip",
     "zipfile_prefix": "%releases-tag%-",
     "install_path": "fastcomp/%releases-tag%",
     "activated_path": "%installation_dir%/emscripten",
-    "activated_cfg": "LLVM_ROOT='%installation_dir%/fastcomp/bin';BINARYEN_ROOT='%installation_dir%'"
+    "activated_cfg": "LLVM_ROOT='%installation_dir%/fastcomp/bin';BINARYEN_ROOT='%installation_dir%'",
+    "emscripten_releases_hash": "%releases-tag%"
   },
 
   {