From cdeb1ea507c9fd3afdeea048cec9fb79bcd7b072 Mon Sep 17 00:00:00 2001
From: Alessandro Di Federico <ale@rev.ng>
Date: Thu, 17 Mar 2022 16:32:47 +0100
Subject: [PATCH] revng driver: introduce --dry-run

---
 python/revng/cli/commands_registry.py | 5 +++++
 python/revng/cli/revng.py             | 5 ++++-
 python/revng/cli/support.py           | 4 ++++
 3 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/python/revng/cli/commands_registry.py b/python/revng/cli/commands_registry.py
index 99af52bd0..6eb8a7159 100644
--- a/python/revng/cli/commands_registry.py
+++ b/python/revng/cli/commands_registry.py
@@ -42,6 +42,9 @@ class CommandsRegistry:
     def __init__(self):
         parser = argparse.ArgumentParser(description="revng driver.")
         parser.add_argument("--version", action="store_true", help="Display version information.")
+        parser.add_argument(
+            "--dry-run", action="store_true", help="Do not execute any external command."
+        )
         parser.add_argument("--verbose", action="store_true", help="Log all executed commands.")
         parser.add_argument(
             "--perf", action="store_true", help="Run programs under perf (for use with hotspot)."
@@ -88,6 +91,8 @@ class CommandsRegistry:
         options.remaining_args = rest
         if not options.verbose:
             options.verbose = args.verbose
+        if not options.dry_run:
+            options.dry_run = args.dry_run
 
         if len(options.command_prefix) == 0:
             assert (args.gdb + args.lldb + args.valgrind + args.callgrind) <= 1
diff --git a/python/revng/cli/revng.py b/python/revng/cli/revng.py
index 6cc8b4a9e..39da20431 100755
--- a/python/revng/cli/revng.py
+++ b/python/revng/cli/revng.py
@@ -16,6 +16,9 @@ def run_revng_command(arguments, options: Options):
     if options.verbose:
         sys.stderr.write("{}\n\n".format(" \\\n  ".join([sys.argv[0]] + arguments)))
 
+    if options.dry_run:
+        return 0
+
     # Collect search prefixes
     prefixes = []
     for arg, next_arg in zip(arguments, arguments[1:] + [""]):
@@ -37,4 +40,4 @@ def run_revng_command(arguments, options: Options):
 
 
 def main():
-    return run_revng_command(sys.argv[1:], Options(None, [], [], [], False))
+    return run_revng_command(sys.argv[1:], Options(None, [], [], [], False, False))
diff --git a/python/revng/cli/support.py b/python/revng/cli/support.py
index aba0becc8..450da8cb4 100644
--- a/python/revng/cli/support.py
+++ b/python/revng/cli/support.py
@@ -25,6 +25,7 @@ class Options:
     search_prefixes: List[str]
     command_prefix: List[str]
     verbose: bool
+    dry_run: bool
 
 
 def shlex_join(split_command):
@@ -55,6 +56,9 @@ def run(command, options: Options):
         program_path = relative(command[0])
         sys.stderr.write("{}\n\n".format(" \\\n  ".join([program_path] + command[1:])))
 
+    if options.dry_run:
+        return 0
+
     signal.signal(signal.SIGINT, signal.SIG_IGN)
     environment = dict(os.environ)
     p = subprocess.Popen(