From 56b4ed39089423b8a5d1750e528d1f8a66d655b2 Mon Sep 17 00:00:00 2001
From: Raito Bezarius <raito@lix.systems>
Date: Tue, 28 Oct 2025 20:26:34 +0100
Subject: [PATCH] libmain/main: propagate status codes via return values for
 mainWrapped

This also prevent `legacy` to return nothing as it's void.

Change-Id: Ic797544a59b04b41ad9e1c46af4cad3a1cb6fdc8
Signed-off-by: Raito Bezarius <raito@lix.systems>
---
 lix/libmain/shared.cc                         |  5 ++--
 lix/libmain/shared.hh                         |  2 +-
 lix/nix/main.cc                               | 25 +++++++++++--------
 .../nix-eval-jobs/src/nix-eval-jobs.cc        |  2 ++
 4 files changed, 19 insertions(+), 15 deletions(-)

diff --git a/lix/libmain/shared.cc b/lix/libmain/shared.cc
index 0f844c4b1..a6918a5f2 100644
--- a/lix/libmain/shared.cc
+++ b/lix/libmain/shared.cc
@@ -313,8 +313,7 @@ void showManPage(const std::string & name)
     throw SysError("command 'man %1%' failed", name.c_str());
 }
 
-
-int handleExceptions(const std::string & programName, std::function<void()> fun)
+int handleExceptions(const std::string & programName, std::function<int()> fun)
 {
     ReceiveInterrupts receiveInterrupts; // FIXME: need better place for this
 
@@ -324,7 +323,7 @@ int handleExceptions(const std::string & programName, std::function<void()> fun)
     bool onlyForSubcommands = baseNameOf(programName) == "lix";
 
     try {
-        fun();
+        return fun();
     } catch (Exit & e) {
         return e.status;
     } catch (UsageError & e) {
diff --git a/lix/libmain/shared.hh b/lix/libmain/shared.hh
index 042a38797..bb6a485ea 100644
--- a/lix/libmain/shared.hh
+++ b/lix/libmain/shared.hh
@@ -14,7 +14,7 @@
 
 namespace nix {
 
-int handleExceptions(const std::string & programName, std::function<void()> fun);
+int handleExceptions(const std::string & programName, std::function<int()> fun);
 
 /**
  * Don't forget to call initPlugins() after settings are initialized!
diff --git a/lix/nix/main.cc b/lix/nix/main.cc
index 3ab140b58..8f67698fa 100644
--- a/lix/nix/main.cc
+++ b/lix/nix/main.cc
@@ -453,7 +453,7 @@ void registerNixHelp()
     registerCommand<CmdHelpStores>("help-stores");
 }
 
-void mainWrapped(AsyncIoRoot & aio, int argc, char * * argv)
+int mainWrapped(AsyncIoRoot & aio, int argc, char ** argv)
 {
     savedArgv = argv;
 
@@ -461,7 +461,7 @@ void mainWrapped(AsyncIoRoot & aio, int argc, char * * argv)
        started. */
     if (argc > 0 && argv[0] == chrootHelperName) {
         chrootHelper(argc, argv);
-        return;
+        return 0;
     }
 
     initNix();
@@ -493,7 +493,8 @@ void mainWrapped(AsyncIoRoot & aio, int argc, char * * argv)
         registerLegacyCommands();
         auto legacy = (*LegacyCommandRegistry::commands)[programName];
         if (legacy) {
-            return legacy(aio, std::string(baseNameOf(argv[0])), Strings(argv + 1, argv + argc));
+            legacy(aio, std::string(baseNameOf(argv[0])), Strings(argv + 1, argv + argc));
+            return 0;
         }
     }
 
@@ -516,7 +517,7 @@ void mainWrapped(AsyncIoRoot & aio, int argc, char * * argv)
 
     if (argc == 2 && std::string(argv[1]) == "__dump-cli") {
         logger->cout(args.dumpCli());
-        return;
+        return 0;
     }
 
     if (argc == 2 && std::string(argv[1]) == "__dump-language") {
@@ -559,17 +560,17 @@ void mainWrapped(AsyncIoRoot & aio, int argc, char * * argv)
             std::move(constantsJson);
         });
         logger->cout("%s", res);
-        return;
+        return 0;
     }
 
     if (argc == 2 && std::string(argv[1]) == "__dump-xp-features") {
         logger->cout(documentExperimentalFeatures().dump());
-        return;
+        return 0;
     }
 
     if (argc == 2 && std::string(argv[1]) == "__dump-dp-features") {
         logger->cout(documentDeprecatedFeatures().dump());
-        return;
+        return 0;
     }
 
     try {
@@ -589,7 +590,7 @@ void mainWrapped(AsyncIoRoot & aio, int argc, char * * argv)
         }
         for (auto & s : args.completions->completions)
             logger->cout(s.completion + "\t" + trim(s.description));
-        return;
+        return 0;
     }
 
     if (args.helpRequested) {
@@ -603,12 +604,12 @@ void mainWrapped(AsyncIoRoot & aio, int argc, char * * argv)
                 break;
         }
         showHelp(aio, subcommand, args);
-        return;
+        return 0;
     }
 
     if (args.showVersion) {
         printVersion(programName);
-        return;
+        return 0;
     }
 
     if (!args.command)
@@ -643,6 +644,8 @@ void mainWrapped(AsyncIoRoot & aio, int argc, char * * argv)
         evalSettings.pureEval.setDefault(false);
     }
     args.run();
+
+    return 0;
 }
 
 }
@@ -660,6 +663,6 @@ int main(int argc, char * * argv)
 
     return nix::handleExceptions(argv[0], [&]() {
         nix::AsyncIoRoot aio;
-        nix::mainWrapped(aio, argc, argv);
+        return nix::mainWrapped(aio, argc, argv);
     });
 }
diff --git a/subprojects/nix-eval-jobs/src/nix-eval-jobs.cc b/subprojects/nix-eval-jobs/src/nix-eval-jobs.cc
index 100e6ec7f..1653ae214 100644
--- a/subprojects/nix-eval-jobs/src/nix-eval-jobs.cc
+++ b/subprojects/nix-eval-jobs/src/nix-eval-jobs.cc
@@ -423,5 +423,7 @@ int main(int argc, char **argv) {
                 },
                 resolveNamedConstituents(state->jobs));
         }
+
+        return 0;
     });
 }