Gracefully handle assertion errors during runtime startup/teardown

src/core/exception.d

@@ -416,6 +416,21 @@ deprecated void setAssertHandler( AssertHandler h ) @trusted nothrow @nogc
     assertHandler = h;
 }
 
+private __gshared bool assertEHEnabled = false;
+extern(C) void _d_setAssertEHEnabled( bool enabled )
+{
+    assertEHEnabled = enabled;
+}
+
+private void defaultAssertHandler( string file, size_t line, string msg ) nothrow
+{
+    if ( assertEHEnabled )
+        throw msg ? new AssertError( msg, file, line ) : new AssertError( file, line );
+
+    import core.internal.abort;
+    abort( file, line, "Assertion failure during runtime startup/teardown",
+        msg ? ": " : ".", msg );
+}
 
 ///////////////////////////////////////////////////////////////////////////////
 // Overridable Callbacks
@@ -434,7 +449,7 @@ deprecated void setAssertHandler( AssertHandler h ) @trusted nothrow @nogc
 extern (C) void onAssertError( string file = __FILE__, size_t line = __LINE__ ) nothrow
 {
     if( _assertHandler is null )
-        throw new AssertError( file, line );
+        defaultAssertHandler( file, line, null );
     _assertHandler( file, line, null);
 }
 
@@ -452,7 +467,7 @@ extern (C) void onAssertError( string file = __FILE__, size_t line = __LINE__ )
 extern (C) void onAssertErrorMsg( string file, size_t line, string msg ) nothrow
 {
     if( _assertHandler is null )
-        throw new AssertError( msg, file, line );
+        defaultAssertHandler( file, line, msg );
     _assertHandler( file, line, msg );
 }
 

src/core/internal/abort.d

@@ -5,6 +5,11 @@ module core.internal.abort;
  * code, and druntime is -release compiled.
  */
 void abort(string msg, string filename = __FILE__, size_t line = __LINE__) @nogc nothrow @safe
+{
+    abort(filename, line, msg);
+}
+
+void abort(string filename, size_t line, const(char)[][] msgs...) @nogc nothrow @safe
 {
     import core.stdc.stdlib: c_abort = abort;
     // use available OS system calls to print the message to stderr
@@ -23,7 +28,7 @@ void abort(string msg, string filename = __FILE__, size_t line = __LINE__) @nogc
         auto h = (() @trusted => GetStdHandle(STD_ERROR_HANDLE))();
         if(h == INVALID_HANDLE_VALUE)
             // attempt best we can to print the message
-            assert(0, msg);
+            assert(0, msgs[0]);
         void writeStr(const(char)[][] m...) @nogc nothrow @trusted
         {
             foreach(s; m)
@@ -40,6 +45,7 @@ void abort(string msg, string filename = __FILE__, size_t line = __LINE__) @nogc
     UnsignedStringBuf strbuff;
 
     // write an appropriate message, then abort the program
-    writeStr("Aborting from ", filename, "(", line.unsignedToTempString(strbuff, 10), ") ", msg);
+    writeStr("Aborting from ", filename, "(", line.unsignedToTempString(strbuff, 10), "): ");
+    writeStr(msgs);
     c_abort();
 }

src/rt/dmain2.d

@@ -50,6 +50,7 @@ extern (C) void rt_moduleTlsDtor();
 extern (C) void thread_joinAll();
 extern (C) bool runModuleUnitTests();
 extern (C) void _d_initMonoTime();
+extern (C) void _d_setAssertEHEnabled(bool enabled);
 
 version (OSX)
 {
@@ -180,6 +181,7 @@ extern (C) int rt_init()
         initStaticDataGC();
         lifetime_init();
         rt_moduleCtor();
+        _d_setAssertEHEnabled(true);
         rt_moduleTlsCtor();
         return 1;
     }
@@ -205,6 +207,7 @@ extern (C) int rt_term()
     {
         rt_moduleTlsDtor();
         thread_joinAll();
+        _d_setAssertEHEnabled(false);
         rt_moduleDtor();
         gc_term();
         finiSections();

test/exceptions/line_trace.exp

@@ -2,8 +2,8 @@ object.Exception@src/line_trace.d(17): exception
 ----------------
 src/line_trace.d:17 void line_trace.f1() [ADDR]
 src/line_trace.d:5 _Dmain [ADDR]
-src/rt/dmain2.d:472 _D2rt6dmain211_d_run_mainUiPPaPUAAaZiZ6runAllMFZ9__lambda1MFZv [ADDR]
-src/rt/dmain2.d:447 void rt.dmain2._d_run_main(int, char**, extern (C) int function(char[][])*).tryExec(scope void delegate()) [ADDR]
-src/rt/dmain2.d:472 void rt.dmain2._d_run_main(int, char**, extern (C) int function(char[][])*).runAll() [ADDR]
-src/rt/dmain2.d:447 void rt.dmain2._d_run_main(int, char**, extern (C) int function(char[][])*).tryExec(scope void delegate()) [ADDR]
-src/rt/dmain2.d:480 _d_run_main [ADDR]
+src/rt/dmain2.d:475 _D2rt6dmain211_d_run_mainUiPPaPUAAaZiZ6runAllMFZ9__lambda1MFZv [ADDR]
+src/rt/dmain2.d:450 void rt.dmain2._d_run_main(int, char**, extern (C) int function(char[][])*).tryExec(scope void delegate()) [ADDR]
+src/rt/dmain2.d:475 void rt.dmain2._d_run_main(int, char**, extern (C) int function(char[][])*).runAll() [ADDR]
+src/rt/dmain2.d:450 void rt.dmain2._d_run_main(int, char**, extern (C) int function(char[][])*).tryExec(scope void delegate()) [ADDR]
+src/rt/dmain2.d:483 _d_run_main [ADDR]