Merge pull request #14687 from NixOS/repl-print-interrupt

libutil/signals: Get rid of setInterruptThrown

doc/manual/rl-next/repl-interrupt.md

@@ -0,0 +1,8 @@
+---
+synopsis: Interrupting REPL commands works more than once
+issues: [13481]
+---
+
+Previously, this only worked once per REPL session; further attempts would be ignored.
+This issue is now fixed, so REPL commands such as `:b` or `:p` can be canceled consistently.
+This is a cherry-pick of the change from the [Lix project](https://gerrit.lix.systems/c/lix/+/1097).

src/libmain/shared.cc

@@ -321,16 +321,7 @@ int handleExceptions(const std::string & programName, std::function<void()> fun)
 
     std::string error = ANSI_RED "error:" ANSI_NORMAL " ";
     try {
-        try {
-            fun();
-        } catch (...) {
-            /* Subtle: we have to make sure that any `interrupted'
-               condition is discharged before we reach printMsg()
-               below, since otherwise it will throw an (uncaught)
-               exception. */
-            setInterruptThrown();
-            throw;
-        }
+        fun();
     } catch (Exit & e) {
         return e.status;
     } catch (UsageError & e) {

src/libutil/include/nix/util/signals.hh

@@ -21,11 +21,6 @@ static inline void setInterrupted(bool isInterrupted);
  */
 static inline bool getInterrupted();
 
-/**
- * @note Does nothing on Windows
- */
-void setInterruptThrown();
-
 /**
  * @note Does nothing on Windows
  */

src/libutil/unix/signals.cc

@@ -12,24 +12,14 @@ using namespace unix;
 
 std::atomic<bool> unix::_isInterrupted = false;
 
-namespace unix {
-static thread_local bool interruptThrown = false;
-}
-
 thread_local std::function<bool()> unix::interruptCheck;
 
-void setInterruptThrown()
-{
-    unix::interruptThrown = true;
-}
-
 void unix::_interrupted()
 {
     /* Block user interrupts while an exception is being handled.
        Throwing an exception while another exception is being handled
        kills the program! */
-    if (!interruptThrown && !std::uncaught_exceptions()) {
-        interruptThrown = true;
+    if (!std::uncaught_exceptions()) {
         throw Interrupted("interrupted by the user");
     }
 }

src/libutil/windows/include/nix/util/signals-impl.hh

@@ -17,11 +17,6 @@ static inline bool getInterrupted()
     return false;
 }
 
-inline void setInterruptThrown()
-{
-    /* Do nothing for now */
-}
-
 static inline bool isInterrupted()
 {
     /* Do nothing for now */