chantal: add line conditions step skips

chantal/__main__.py

@@ -23,6 +23,7 @@ def main():
         cmd.add_argument("clone_url")
         cmd.add_argument("commit_sha")
         cmd.add_argument("desc_file")
+        cmd.add_argument("job")
         cmd.add_argument("--shallow", type=int, default=0)
         cmd.add_argument("--folder", default="repo")
 

chantal/build.py

@@ -41,7 +41,7 @@ def build_job(args):
 
     try:
         with open(args.desc_file) as controlfile:
-            steps = parse_control_file(controlfile.read())
+            steps = parse_control_file(controlfile.read(), args)
     except FileNotFoundError:
         raise FatalBuildError(
             "no kevin config file named '%s' was found" % (args.desc_file))
@@ -50,16 +50,24 @@ def build_job(args):
                                              exc.args[1]))
 
     for step in steps:
-        step_state(step, "waiting", "waiting")
+        if not step.skip:
+            step_state(step, "waiting", "waiting")
 
     errors = []
     success = set()
     for step in steps:
+        depend_issues = set(step.depends) - success
+
+        if step.skip:
+            # the step has been marked to be skipped in the control file.
+            # do not run it or produce any output.
+            if not depend_issues:
+                success.add(step.name)
+            continue
+
         if not errors:
             job_state("running", "running (" + step.name + ")")
 
-        depend_issues = set(step.depends) - success
-
         if depend_issues:
             text = "depends failed: " + ", ".join(depend_issues)
             step_state(step, "error", text)

chantal/controlfile.py

@@ -18,7 +18,7 @@ def get_indent(line):
     return line[:-len(line.lstrip())]
 
 
-def preprocess_lines(data):
+def preprocess_lines(data, args):
     """
     Preprocesses the raw text in data,
 
@@ -28,6 +28,8 @@ def preprocess_lines(data):
 
     Yields tuples of lineno, line, isindented
     """
+    condition_env = args.__dict__.copy()
+
     file_indent = None
     for lineno, line in enumerate(data.split('\n')):
         indent = get_indent(line)
@@ -42,6 +44,29 @@ def preprocess_lines(data):
                     "Illegal indent; expected %r" % file_indent
                 )
 
+        # check the condition at the end of the line
+        if line.endswith(" ?)"):
+            try:
+                line, condition = line[:-3].rsplit("(? if ", maxsplit=1)
+            except ValueError:
+                raise ParseError(
+                    lineno,
+                    "Expected '(? if ' to match ' ?)' at end of line"
+                ) from None
+
+            try:
+                condition_env["lineno"] = lineno
+                condition_result = eval(condition, condition_env)
+            except Exception as exc:
+                raise ParseError(
+                    lineno,
+                    "Could not eval() condition: %r" % exc
+                ) from None
+
+            if not condition_result:
+                # the line is disabled.
+                continue
+
         # remove comments at the end of the line
         line = line.partition('#')[0].strip()
         # skip empty lines
@@ -51,7 +76,7 @@ def preprocess_lines(data):
         yield lineno, line, bool(indent)
 
 
-def parse_control_file(data):
+def parse_control_file(data, args):
     """
     Parses control file contents, yields a list of steps.
     """
@@ -60,7 +85,7 @@ def parse_control_file(data):
 
     result = []
 
-    for lineno, line, isindented in preprocess_lines(data):
+    for lineno, line, isindented in preprocess_lines(data, args):
         if isindented:
             # step content
             try:
@@ -112,6 +137,7 @@ def __init__(self, line, lineno, existing):
 
         # the various attributes that may be set in header lines.
         self.hidden = False
+        self.skip = False
         self.outputs = []
         self.env = {}
 
@@ -147,7 +173,7 @@ def process_header(self, key, val, lineno, all_outputs):
         key: what does this header do?
         val: definition of the specific header action
         """
-        if key in {"hidden"}:
+        if key in {"hidden", "skip"}:
             # boolean flags
             if val is not None:
                 raise ParseError(lineno, key + " is just a flag, nothing more.")

kevin/chantal.py

@@ -192,7 +192,8 @@ def run(self, job):
             ("python3", "-u", "-m", "chantal",
              job.build.clone_url,
              job.build.commit_hash,
-             job.build.project.cfg.job_desc_file),
+             job.build.project.cfg.job_desc_file,
+             job.name),
             timeout=job.build.project.cfg.job_timeout,
             silence_timeout=job.build.project.cfg.job_silence_timeout,
         )