From 7e3092b83516e720ef367e8172421266078ee7e6 Mon Sep 17 00:00:00 2001
From: Boris Kolpackov <boris@codesynthesis.com>
Date: Wed, 7 Aug 2019 08:27:11 +0200
Subject: Improve deadlock diagnostics (suppress stack trace, reword)

---
 build2/b.cxx                          | 14 ++++++++++++--
 libbuild2/function.test.cxx           |  2 +-
 libbuild2/scheduler.cxx               |  9 ++++-----
 libbuild2/test/script/parser.test.cxx |  2 +-
 libbuild2/utility.cxx                 |  9 ++++++---
 libbuild2/utility.hxx                 |  8 +++++++-
 tests/libbuild2/driver.cxx            |  2 +-
 7 files changed, 32 insertions(+), 14 deletions(-)

diff --git a/build2/b.cxx b/build2/b.cxx
index 2bb5920..8965d64 100644
--- a/build2/b.cxx
+++ b/build2/b.cxx
@@ -16,7 +16,7 @@
 #include <cstring>   // strcmp(), strchr()
 #include <typeinfo>
 #include <iostream>  // cout
-#include <exception> // set_terminate(), terminate_handler
+#include <exception> // terminate(), set_terminate(), terminate_handler
 
 #include <libbutl/pager.mxx>
 #include <libbutl/fdstream.mxx>  // stderr_fd(), fdterm()
@@ -152,6 +152,15 @@ custom_terminate ()
     default_terminate ();
 }
 
+static void
+terminate (bool trace)
+{
+  if (!trace)
+    set_terminate (default_terminate);
+
+  std::terminate ();
+}
+
 int build2::
 main (int argc, char* argv[])
 {
@@ -412,7 +421,8 @@ main (int argc, char* argv[])
 
     // Initialize the global state.
     //
-    init (argv[0],
+    init (&::terminate,
+          argv[0],
           !ops.serial_stop (), ops.dry_run (),
           (ops.mtime_check ()    ? optional<bool> (true)  :
            ops.no_mtime_check () ? optional<bool> (false) : nullopt),
diff --git a/libbuild2/function.test.cxx b/libbuild2/function.test.cxx
index 5e442a3..a9326f4 100644
--- a/libbuild2/function.test.cxx
+++ b/libbuild2/function.test.cxx
@@ -39,7 +39,7 @@ namespace build2
     // Fake build system driver, default verbosity.
     //
     init_diag (1);
-    init (argv[0]);
+    init (nullptr, argv[0]);
     reset (strings ()); // No command line variables.
 
     function_family f ("dummy");
diff --git a/libbuild2/scheduler.cxx b/libbuild2/scheduler.cxx
index b261a82..37220c7 100644
--- a/libbuild2/scheduler.cxx
+++ b/libbuild2/scheduler.cxx
@@ -20,7 +20,6 @@
 #endif
 
 #include <cerrno>
-#include <exception> // std::terminate()
 
 #include <libbuild2/diagnostics.hxx>
 
@@ -861,12 +860,12 @@ namespace build2
           // thing about abort is if this is not a dependency cycle, then we
           // have a core to examine).
           //
-          error << "detected deadlock that could be caused by a dependency "
-                << "cycle" <<
+          error << "deadlock detected, aborting" <<
+            info << "deadlocks are normally caused by dependency cycles" <<
             info << "re-run with -s to diagnose dependency cycles" <<
-            info << "if not a dependency cycle, please report";
+            info << "if not a dependency cycle, please report as a bug";
 
-          std::terminate ();
+          terminate (false /* trace */);
         }
       }
     }
diff --git a/libbuild2/test/script/parser.test.cxx b/libbuild2/test/script/parser.test.cxx
index 8702e18..ab1f295 100644
--- a/libbuild2/test/script/parser.test.cxx
+++ b/libbuild2/test/script/parser.test.cxx
@@ -154,7 +154,7 @@ namespace build2
         // Fake build system driver, default verbosity.
         //
         init_diag (1);
-        init (argv[0]);
+        init (nullptr, argv[0]);
         sched.startup (1);  // Serial execution.
         reset (strings ()); // No command line variables.
 
diff --git a/libbuild2/utility.cxx b/libbuild2/utility.cxx
index 396ce82..506e88e 100644
--- a/libbuild2/utility.cxx
+++ b/libbuild2/utility.cxx
@@ -69,6 +69,8 @@ namespace build2
   //
   // <libbuild2/utility.hxx>
   //
+  void (*terminate) (bool);
+
   process_path argv0;
 
   const standard_version build_version (LIBBUILD2_VERSION_STR);
@@ -486,12 +488,13 @@ namespace build2
   }
 
   void
-  init (const char* a0,
+  init (void (*t) (bool),
+        const char* a0,
         bool kg, bool dr, optional<bool> mc,
         optional<path> cs, optional<path> cg)
   {
-    // Build system driver process path.
-    //
+    terminate = t;
+
     argv0 = process::path_search (a0, true);
 
     keep_going = kg;
diff --git a/libbuild2/utility.hxx b/libbuild2/utility.hxx
index 9598208..c251b64 100644
--- a/libbuild2/utility.hxx
+++ b/libbuild2/utility.hxx
@@ -119,13 +119,19 @@ namespace build2
   // Default values are for unit tests.
   //
   LIBBUILD2_SYMEXPORT void
-  init (const char* argv0,
+  init (void (*terminate) (bool),
+        const char* argv0,
         bool keep_going = false,
         bool dry_run = false,
         optional<bool> mtime_check = nullopt,
         optional<path> config_sub = nullopt,
         optional<path> config_guess = nullopt);
 
+  // Terminate function. If trace is false, then printing of the stack trace,
+  // if any, should be omitted.
+  //
+  LIBBUILD2_SYMEXPORT extern void (*terminate) (bool trace);
+
   // Build system driver process path (argv0.initial is argv[0]).
   //
   LIBBUILD2_SYMEXPORT extern process_path argv0;
diff --git a/tests/libbuild2/driver.cxx b/tests/libbuild2/driver.cxx
index 20c0ec2..706d276 100644
--- a/tests/libbuild2/driver.cxx
+++ b/tests/libbuild2/driver.cxx
@@ -20,7 +20,7 @@ main (int, char* argv[])
   // Fake build system driver, default verbosity.
   //
   init_diag (1);
-  init (argv[0]);
+  init (nullptr, argv[0]);
 
   bash::build2_bash_load ();
   in::build2_in_load ();
-- 
cgit v1.1