2 files changed, 163 insertions, 0 deletions
diff --git a/tools/lint/shell/__init__.py b/tools/lint/shell/__init__.py
new file mode 100644
index 0000000000..b75dc2d159
--- /dev/null
+++ b/tools/lint/shell/__init__.py
@@ -0,0 +1,148 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+import json
+import os
+from json.decoder import JSONDecodeError
+
+import mozpack.path as mozpath
+from mozfile import which
+from mozlint import result
+from mozlint.util.implementation import LintProcess
+from mozpack.files import FileFinder
+
+SHELLCHECK_NOT_FOUND = """
+Unable to locate shellcheck, please ensure it is installed and in
+your PATH or set the SHELLCHECK environment variable.
+
+https://shellcheck.net or your system's package manager.
+""".strip()
+
+results = []
+
+
+class ShellcheckProcess(LintProcess):
+    def process_line(self, line):
+        try:
+            data = json.loads(line)
+        except JSONDecodeError as e:
+            print("Unable to load shellcheck output ({}): {}".format(e, line))
+            return
+
+        for entry in data:
+            res = {
+                "path": entry["file"],
+                "message": entry["message"],
+                "level": "error",
+                "lineno": entry["line"],
+                "column": entry["column"],
+                "rule": entry["code"],
+            }
+            results.append(result.from_config(self.config, **res))
+
+
+def determine_shell_from_script(path):
+    """Returns a string identifying the shell used.
+
+    Returns None if not identifiable.
+
+    Copes with the following styles:
+    #!bash
+    #!/bin/bash
+    #!/usr/bin/env bash
+    """
+    with open(path, "r") as f:
+        head = f.readline()
+
+        if not head.startswith("#!"):
+            return
+
+        # allow for parameters to the shell
+        shebang = head.split()[0]
+
+        # if the first entry is a variant of /usr/bin/env
+        if "env" in shebang:
+            shebang = head.split()[1]
+
+        if shebang.endswith("sh"):
+            # Strip first to avoid issues with #!bash
+            return shebang.strip("#!").split("/")[-1]
+    # make it clear we return None, rather than fall through.
+    return
+
+
+def find_shell_scripts(config, paths):
+    found = dict()
+
+    root = config["root"]
+    exclude = [mozpath.join(root, e) for e in config.get("exclude", [])]
+
+    if config.get("extensions"):
+        pattern = "**/*.{}".format(config.get("extensions")[0])
+    else:
+        pattern = "**/*.sh"
+
+    files = []
+    for path in paths:
+        path = mozpath.normsep(path)
+        ignore = [
+            e[len(path) :].lstrip("/")
+            for e in exclude
+            if mozpath.commonprefix((path, e)) == path
+        ]
+        finder = FileFinder(path, ignore=ignore)
+        files.extend([os.path.join(path, p) for p, f in finder.find(pattern)])
+
+    for filename in files:
+        shell = determine_shell_from_script(filename)
+        if shell:
+            found[filename] = shell
+    return found
+
+
+def run_process(config, cmd):
+    proc = ShellcheckProcess(config, cmd)
+    proc.run()
+    try:
+        proc.wait()
+    except KeyboardInterrupt:
+        proc.kill()
+
+
+def get_shellcheck_binary():
+    """
+    Returns the path of the first shellcheck binary available
+    if not found returns None
+    """
+    binary = os.environ.get("SHELLCHECK")
+    if binary:
+        return binary
+
+    return which("shellcheck")
+
+
+def lint(paths, config, **lintargs):
+    log = lintargs["log"]
+    binary = get_shellcheck_binary()
+
+    if not binary:
+        print(SHELLCHECK_NOT_FOUND)
+        if "MOZ_AUTOMATION" in os.environ:
+            return 1
+        return []
+
+    config["root"] = lintargs["root"]
+
+    files = find_shell_scripts(config, paths)
+
+    base_command = [binary, "-f", "json"]
+    if config.get("excludecodes"):
+        base_command.extend(["-e", ",".join(config.get("excludecodes"))])
+
+    for f in files:
+        cmd = list(base_command)
+        cmd.extend(["-s", files[f], f])
+        log.debug("Command: {}".format(cmd))
+        run_process(config, cmd)
+    return results
diff --git a/tools/lint/shellcheck.yml b/tools/lint/shellcheck.yml
new file mode 100644
index 0000000000..0100e3d5cc
--- /dev/null
+++ b/tools/lint/shellcheck.yml
@@ -0,0 +1,15 @@
+---
+shellcheck:
+    description: Shell script linter
+    include:
+        - extensions/spellcheck/locales/en-US/hunspell/dictionary-sources/
+        - taskcluster/docker/
+    exclude: []
+    # 1090: https://github.com/koalaman/shellcheck/wiki/SC1090
+    # 'Can't follow a non-constant source'
+    extensions: ['sh']
+    support-files:
+        - 'tools/lint/shell/**'
+    excludecodes: ['1090', '1091']
+    type: external
+    payload: shell:lint