First cut at the Wrap dependency downloader.

interpreter.py

@@ -19,6 +19,7 @@ import dependencies
 import mlog
 import build
 import optinterpreter
+import wrap
 import os, sys, platform, subprocess, shutil, uuid
 
 class InterpreterException(coredata.MesonException):
@@ -915,7 +916,12 @@ class Interpreter():
         subdir = os.path.join('subprojects', dirname)
         abs_subdir = os.path.join(self.build.environment.get_source_dir(), subdir)
         if not os.path.isdir(abs_subdir):
-            raise InterpreterException('Subproject directory does not exist.')
+            r = wrap.Resolver(os.path.join(self.build.environment.get_source_dir(), 'subprojects'))
+            resolved = r.resolve(dirname)
+            if resolved is None:
+                raise InterpreterException('Subproject directory does not exist and can not be downloaded.')
+            subdir = os.path.join('subprojects', resolved)
+            abs_subdir = os.path.join(self.build.environment.get_source_dir(), 'subprojects', subdir)
         self.global_args_frozen = True
         mlog.log('\nExecuting subproject ', mlog.bold(dirname), '.\n', sep='')
         subi = Interpreter(self.build, dirname, subdir)

manual tests/1 basic/main.c

@@ -0,0 +1,12 @@
+#include<sqlite3.h>
+#include<stdio.h>
+
+int main(int argc, char **argv) {
+    sqlite3 *db;
+    if(sqlite3_open(":memory:", &db) != SQLITE_OK) {
+        printf("Sqlite failed.\n");
+        return 1;
+    }
+    sqlite3_close(db);
+    return 0;
+}

manual tests/1 basic/meson.build

@@ -0,0 +1,11 @@
+project('downloader', 'c')
+
+s = subproject('sqlite')
+
+e = executable('dtest', 'main.c',
+include_directories : s.get_variable('sqinc'),
+link_args : ['-pthread', '-ldl'],
+c_args : '-pthread',
+link_with : s.get_variable('sqlib'))
+
+test('dltest', e)

manual tests/1 basic/subprojects/sqlite.wrap

@@ -0,0 +1,10 @@
+[mesonwrap]
+directory = sqlite-amalgamation-3080802
+
+source_url = http://sqlite.com/2015/sqlite-amalgamation-3080802.zip
+source_filename = sqlite-amalgamation-3080802.zip
+source_hash = 5ebeea0dfb75d090ea0e7ff84799b2a7a1550db3fe61eb5f6f61c2e971e57663
+
+patch_url = https://dl.dropboxusercontent.com/u/37517477/sqlite-meson.tar.gz
+patch_filename = sqlite-meson.tar.gz
+patch_hash = 8c9d00702d5fe4a6bf25a36b821a332f6b2dfd117c66fe818b88b23d604635e9

wrap.py

@@ -0,0 +1,92 @@
+# Copyright 2015 The Meson development team
+
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+
+#     http://www.apache.org/licenses/LICENSE-2.0
+
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import mlog
+import glob, urllib.request, os, hashlib, shutil
+
+class PackageDefinition:
+    def __init__(self, fname):
+        self.values = {}
+        ifile = open(fname)
+        first = ifile.readline().strip()
+        if first != '[mesonwrap]':
+            raise RuntimeError('Invalid format of package file')
+        for line in ifile:
+            line = line.strip()
+            if line == '':
+                continue
+            (k, v) = line.split('=', 1)
+            k = k.strip()
+            v = v.strip()
+            self.values[k] = v
+
+    def get(self, key):
+        return self.values[key]
+
+    def has_patch(self):
+        return 'patch_url' in self.values
+
+class Resolver:
+    def __init__(self, subdir_root):
+        self.subdir_root = subdir_root
+        self.cachedir = os.path.join(self.subdir_root, 'packagecache')
+
+    def resolve(self, packagename):
+        fname = os.path.join(self.subdir_root, packagename + '.wrap')
+        if not os.path.isfile(fname):
+            return None
+        p = PackageDefinition(fname)
+        self.download(p, packagename)
+        self.extract_package(p)
+        return p.get('directory')
+
+    def get_data(self, url):
+        u = urllib.request.urlopen(url)
+        data = u.read()
+        u.close()
+        h = hashlib.sha256()
+        h.update(data)
+        hashvalue = h.hexdigest()
+        return (data, hashvalue)
+
+    def download(self, p, packagename):
+        ofname = os.path.join(self.cachedir, p.get('source_filename'))
+        if os.path.exists(ofname):
+            print('Using', packagename, 'from cache.')
+            return
+        srcurl = p.get('source_url')
+        print('Dowloading', packagename, 'from', srcurl)
+        (srcdata, dhash) = self.get_data(srcurl)
+        expected = p.get('source_hash')
+        if dhash != expected:
+            raise RuntimeError('Incorrect hash for source %s:\n %s expected\n %s actual.' % (packagename, expected, dhash))
+        if p.has_patch():
+            purl = p.get('patch_url')
+            print('Downloading patch from', purl)
+            (pdata, phash) = self.get_data(purl)
+            expected = p.get('patch_hash')
+            if phash != expected:
+                raise RuntimeError('Incorrect hash for patch %s:\n %s expected\n %s actual.' % (packagename, expected, phash))
+            open(os.path.join(self.cachedir, p.get('patch_filename')), 'wb').write(pdata)
+        else:
+            print('Package does not require patch.')
+        open(ofname, 'wb').write(srcdata)
+
+    def extract_package(self, package):
+        if os.path.isdir(os.path.join(self.subdir_root, package.get('directory'))):
+            return
+        print(os.path.join(self.cachedir, package.get('source_filename')))
+        shutil.unpack_archive(os.path.join(self.cachedir, package.get('source_filename')), self.subdir_root)
+        if package.has_patch():
+            shutil.unpack_archive(os.path.join(self.cachedir, package.get('patch_filename')), self.subdir_root)