From bdccf53eec0aa47b6316c691e9ab54308e7853db Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mateusz=20=C5=81oskot?= <mateusz@loskot.net>
Date: Mon, 2 Mar 2020 21:03:38 +0100
Subject: [PATCH] Make sure b2 exits immediately on syntax errors (#540)

Add test verifying Jam syntax error results in non-zero exit status.

Refines #538
Fixes #539
---
 src/engine/jam.cpp                    | 42 +++++++++++++++------------
 test/core_syntax_error_exit_status.py | 23 +++++++++++++++
 test/test_all.py                      |  1 +
 3 files changed, 47 insertions(+), 19 deletions(-)
 create mode 100644 test/core_syntax_error_exit_status.py

diff --git a/src/engine/jam.cpp b/src/engine/jam.cpp
index a6a01de3c..eab9bae2d 100644
--- a/src/engine/jam.cpp
+++ b/src/engine/jam.cpp
@@ -649,28 +649,32 @@ int main( int argc, char * * argv, char * * arg_environ )
                 parse_file( constant_plus, frame );
         }
 
+        /* FIXME: What shall we do if builtin_update_now,
+         * the sole place setting last_update_now_status,
+         * failed earlier?
+         */
+
         status = yyanyerrors();
-        if ( status && !last_update_now_status )
-            last_update_now_status = status;
-
-        /* Manually touch -t targets. */
-        for ( n = 0; ( s = getoptval( optv, 't', n ) ); ++n )
+        if ( !status )
         {
-            OBJECT * const target = object_new( s );
-            touch_target( target );
-            object_free( target );
-        }
+            /* Manually touch -t targets. */
+            for ( n = 0; ( s = getoptval( optv, 't', n ) ); ++n )
+            {
+                OBJECT * const target = object_new( s );
+                touch_target( target );
+                object_free( target );
+            }
 
-
-        /* Now make target. */
-        {
-            PROFILE_ENTER( MAIN_MAKE );
-            LIST * const targets = targets_to_update();
-            if ( !list_empty( targets ) )
-                status |= make( targets, anyhow );
-            else
-                status = last_update_now_status;
-            PROFILE_EXIT( MAIN_MAKE );
+            /* Now make target. */
+            {
+                PROFILE_ENTER( MAIN_MAKE );
+                LIST * const targets = targets_to_update();
+                if ( !list_empty( targets ) )
+                    status |= make( targets, anyhow );
+                else
+                    status = last_update_now_status;
+                PROFILE_EXIT( MAIN_MAKE );
+            }
         }
 
         PROFILE_EXIT( MAIN );
diff --git a/test/core_syntax_error_exit_status.py b/test/core_syntax_error_exit_status.py
new file mode 100644
index 000000000..452ea4304
--- /dev/null
+++ b/test/core_syntax_error_exit_status.py
@@ -0,0 +1,23 @@
+#!/usr/bin/python
+
+# Copyright (C) Mateusz Loskot 2020.
+# Distributed under the Boost Software License, Version 1.0. (See
+# accompanying file LICENSE_1_0.txt or copy at
+# http://www.boost.org/LICENSE_1_0.txt)
+
+# Test that Jam syntax error results in non-zero exit status
+
+import BoostBuild
+
+# Create a temporary working directory.
+t = BoostBuild.Tester()
+
+# Create the needed files.
+t.write("jamroot.jam", """
+exe hello : hello.cpp
+
+""")
+
+t.run_build_system(status=1)
+
+t.cleanup()
diff --git a/test/test_all.py b/test/test_all.py
index 98fcb487f..ebb6a8cf9 100644
--- a/test/test_all.py
+++ b/test/test_all.py
@@ -195,6 +195,7 @@ tests = ["absolute_sources",
          "core_actions_quietly",
          "core_at_file",
          "core_bindrule",
+         "core_syntax_error_exit_status",
          "core_fail_expected",
          "core_jamshell",
          "core_multifile_actions",