Index: flang/include/flang/Optimizer/Builder/Todo.h
===================================================================
--- flang/include/flang/Optimizer/Builder/Todo.h
+++ flang/include/flang/Optimizer/Builder/Todo.h
@@ -29,48 +29,40 @@
 #undef TODOQUOTE
 #define TODOQUOTE(X) #X
 
+// Give backtrace only in debug builds.
+#undef GEN_TRACE
 #ifdef NDEBUG
-
-// In a release build, just give a message and exit.
-#define TODO_NOLOC(ToDoMsg)                                                    \
-  do {                                                                         \
-    llvm::errs() << __FILE__ << ':' << __LINE__                                \
-                 << ": not yet implemented: " << ToDoMsg << '\n';              \
-    std::exit(1);                                                              \
-  } while (false)
-
-#undef TODO_DEFN
-#define TODO_DEFN(MlirLoc, ToDoMsg, ToDoFile, ToDoLine)                        \
-  do {                                                                         \
-    mlir::emitError(MlirLoc, ToDoFile ":" TODOQUOTE(                           \
-                                 ToDoLine) ": not yet implemented: " ToDoMsg); \
-    std::exit(1);                                                              \
-  } while (false)
-
-#define TODO(MlirLoc, ToDoMsg) TODO_DEFN(MlirLoc, ToDoMsg, __FILE__, __LINE__)
-
+#define GEN_TRACE false
 #else
+#define GEN_TRACE true
+#endif
 
-// In a developer build, print a message and give a backtrace.
 #undef TODO_NOLOCDEFN
-#define TODO_NOLOCDEFN(ToDoMsg, ToDoFile, ToDoLine)                            \
+#define TODO_NOLOCDEFN(ToDoMsg, ToDoFile, ToDoLine, GenTrace)                  \
   do {                                                                         \
-    llvm::report_fatal_error(                                                  \
-        ToDoFile ":" TODOQUOTE(ToDoLine) ": not yet implemented: " ToDoMsg);   \
+    llvm::report_fatal_error(llvm::Twine(ToDoFile ":" TODOQUOTE(               \
+                                 ToDoLine) ": not yet implemented: ") +        \
+                                 llvm::Twine(ToDoMsg),                         \
+                             GenTrace);                                        \
   } while (false)
 
-#define TODO_NOLOC(ToDoMsg) TODO_NOLOCDEFN(ToDoMsg, __FILE__, __LINE__)
+#define TODO_NOLOC(ToDoMsg) TODO_NOLOCDEFN(ToDoMsg, __FILE__, __LINE__, false)
+#define TODO_NOLOC_TRACE(ToDoMsg)                                              \
+  TODO_NOLOCDEFN(ToDoMsg, __FILE__, __LINE__, GENTRACE)
 
 #undef TODO_DEFN
-#define TODO_DEFN(MlirLoc, ToDoMsg, ToDoFile, ToDoLine)                        \
+#define TODO_DEFN(MlirLoc, ToDoMsg, ToDoFile, ToDoLine, GenTrace)              \
   do {                                                                         \
-    fir::emitFatalError(                                                       \
-        MlirLoc,                                                               \
-        ToDoFile ":" TODOQUOTE(ToDoLine) ": not yet implemented: " ToDoMsg);   \
+    fir::emitFatalError(MlirLoc,                                               \
+                        llvm::Twine(ToDoFile ":" TODOQUOTE(                    \
+                            ToDoLine) ": not yet implemented: ") +             \
+                            llvm::Twine(ToDoMsg),                              \
+                        GenTrace);                                             \
   } while (false)
 
-#define TODO(MlirLoc, ToDoMsg) TODO_DEFN(MlirLoc, ToDoMsg, __FILE__, __LINE__)
-
-#endif
+#define TODO(MlirLoc, ToDoMsg)                                                 \
+  TODO_DEFN(MlirLoc, ToDoMsg, __FILE__, __LINE__, false)
+#define TODO_TRACE(MlirLoc, ToDoMsg)                                           \
+  TODO_DEFN(MlirLoc, ToDoMsg, __FILE__, __LINE__, GEN_TRACE)
 
 #endif // FORTRAN_LOWER_TODO_H
Index: flang/include/flang/Optimizer/Support/FatalError.h
===================================================================
--- flang/include/flang/Optimizer/Support/FatalError.h
+++ flang/include/flang/Optimizer/Support/FatalError.h
@@ -19,11 +19,14 @@
 namespace fir {
 
 /// Fatal error reporting helper. Report a fatal error with a source location
-/// and immediately abort flang.
+/// and immediately interrupt flang. If `genCrashDiag` is true, then
+/// the execution is aborted and the backtrace is printed, otherwise,
+/// flang exits with non-zero exit code and without backtrace printout.
 [[noreturn]] inline void emitFatalError(mlir::Location loc,
-                                        const llvm::Twine &message) {
+                                        const llvm::Twine &message,
+                                        bool genCrashDiag = true) {
   mlir::emitError(loc, message);
-  llvm::report_fatal_error("aborting");
+  llvm::report_fatal_error("aborting", genCrashDiag);
 }
 
 } // namespace fir
Index: flang/test/lit.cfg.py
===================================================================
--- flang/test/lit.cfg.py
+++ flang/test/lit.cfg.py
@@ -94,14 +94,17 @@
     ToolSubst('%flang_fc1', command=FindTool('flang-new'), extra_args=['-fc1'],
         unresolved='fatal')]
 
-# Flang has several unimplemented features. TODO messages are used to mark and fail if these
-# features are exercised. TODOs exit with an error in non-assert builds but in assert builds
-# it aborts. To catch aborts, the `--crash` option for the `not` command has to be used.
+# Flang has several unimplemented features. TODO messages are used to mark
+# and fail if these features are exercised. Some TODOs exit with a non-zero
+# exit code, but others abort the execution in assert builds.
+# To catch aborts, the `--crash` option for the `not` command has to be used.
+tools.append(ToolSubst('%not_todo_cmd', command=FindTool('not'), unresolved='fatal'))
 if 'asserts' in config.available_features:
-    tools.append(ToolSubst('%not_todo_cmd', command=FindTool('not'), extra_args=['--crash'],
-        unresolved='fatal'))
+    tools.append(ToolSubst('%not_todo_abort_cmd', command=FindTool('not'),
+        extra_args=['--crash'], unresolved='fatal'))
 else:
-    tools.append(ToolSubst('%not_todo_cmd', command=FindTool('not'), unresolved='fatal'))
+    tools.append(ToolSubst('%not_todo_abort_cmd', command=FindTool('not'),
+        unresolved='fatal'))
 
 # Define some variables to help us test that the flang runtime doesn't depend on
 # the C++ runtime libraries. For this we need a C compiler. If for some reason