Auto merge of #7438 - Wafflespeanut:cargo-tidy, r=jdm

Tidy can now check for version conflicts...

fixes #7133

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components/servo/Cargo.lock

@@ -627,7 +627,7 @@ version = "0.1.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "gl_common 0.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
- "gl_generator 0.0.26 (registry+https://github.com/rust-lang/crates.io-index)",
+ "gl_generator 0.0.27 (registry+https://github.com/rust-lang/crates.io-index)",
  "khronos_api 0.0.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)",
 ]

python/tidy.py

@@ -16,7 +16,7 @@ import StringIO
 import sys
 from licenseck import licenses
 
-filetypes_to_check = [".rs", ".rc", ".cpp", ".c", ".h", ".py", ".toml", ".webidl"]
+filetypes_to_check = [".rs", ".rc", ".cpp", ".c", ".h", ".lock", ".py", ".toml", ".webidl"]
 reftest_dir = "./tests/ref"
 reftest_filetype = ".list"
 python_dependencies = [
@@ -70,7 +70,7 @@ VIM_HEADER = "/* vim:"
 
 
 def check_license(file_name, contents):
-    if file_name.endswith(".toml"):
+    if file_name.endswith(".toml") or file_name.endswith(".lock"):
         raise StopIteration
     while contents.startswith(EMACS_HEADER) or contents.startswith(VIM_HEADER):
         _, _, contents = contents.partition("\n")
@@ -148,6 +148,46 @@ def check_flake8(file_name, contents):
         yield line_num, message.strip()
 
 
+def check_lock(file_name, contents):
+    if not file_name.endswith(".lock"):
+        raise StopIteration
+    contents = contents.splitlines(True)
+    idx = 1
+    packages = {}
+    exceptions = ["glutin", "wayland-kbd"]      # package names to be neglected (as named by cargo)
+
+    while idx < len(contents):
+        content = contents[idx].strip()
+        if 'name' in content:
+            base_name = content.split('"')[1]
+            # we need the base package because some other package might demand a new version in the following lines
+            packages[base_name] = contents[idx + 1].split('"')[1], idx + 2, base_name
+        if 'dependencies' in content:
+            idx += 1
+            while contents[idx].strip() != ']':
+                package = contents[idx].strip().strip('",').split()
+                name, version = package[0], package[1]
+                if name not in packages:    # store the line number & base package name for future comparison
+                    packages[name] = (version, idx + 1, base_name)
+                elif all([packages[name][0] != version, name not in exceptions, base_name not in exceptions]):
+                    line = idx + 1
+                    version_1 = tuple(map(int, packages[name][0].split('.')))
+                    version_2 = tuple(map(int, version.split('.')))
+                    if version_1 < version_2:       # get the line & base package containing the older version
+                        packages[name], (version, line, base_name) = (version, line, base_name), packages[name]
+
+                    message = 'conflicting versions for package "%s"' % name
+                    error = '\n\t\033[93mexpected maximum version "{}"\033[0m'.format(packages[name][0]) + \
+                            '\n\t\033[91mbut, "{}" demands "{}"\033[0m' \
+                            .format(base_name, version)
+                    suggest = "\n\t\033[93mtry upgrading with\033[0m " + \
+                              "\033[96m./mach cargo-update -p {}:{}\033[0m" \
+                              .format(name, version)
+                    yield (line, message + error + suggest)
+                idx += 1
+        idx += 1
+
+
 def check_toml(file_name, contents):
     if not file_name.endswith(".toml"):
         raise StopIteration
@@ -433,7 +473,7 @@ def scan():
     files_to_check = filter(should_check, all_files)
 
     checking_functions = [check_license, check_by_line, check_flake8, check_toml,
-                          check_rust, check_webidl_spec, check_spec]
+                          check_lock, check_rust, check_webidl_spec, check_spec]
     errors = collect_errors_for_files(files_to_check, checking_functions)
 
     reftest_files = (os.path.join(r, f) for r, _, files in os.walk(reftest_dir) for f in files)