Add Ctrl-C handling to the REPL

luau-lang · Jun 14, 2022 · 58c5c60 · 58c5c60
1 parent b066e4c
commit 58c5c60
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Showing 4 changed files with 24 additions and 2 deletions.
diff --git a/CLI/Repl.cpp b/CLI/Repl.cpp
@@ -225,6 +225,10 @@ std::string runCode(lua_State* L, const std::string& source)
             lua_pcall(T, n, 0, 0);
         }
     }
+    else if (status == LUA_SIGINT)
+    {
+        fputs("\nExecution interrupted\n", stdout);
+    }
     else
     {
         std::string error;

diff --git a/VM/include/lua.h b/VM/include/lua.h
@@ -33,6 +33,7 @@ enum lua_Status
     LUA_ERRMEM,
     LUA_ERRERR,
     LUA_BREAK, /* yielded for a debug breakpoint */
+    LUA_SIGINT, /* thread stopped after receiving a SIGINT */
 };
 
 typedef struct lua_State lua_State;

diff --git a/VM/src/ldo.cpp b/VM/src/ldo.cpp
@@ -290,6 +290,9 @@ static void resume_continue(lua_State* L)
 
         Closure* cl = curr_func(L);
 
+        if (L->status == LUA_SIGINT)
+            break;
+
         if (cl->isC)
         {
             LUAU_ASSERT(cl->c.cont);

diff --git a/VM/src/lvmexecute.cpp b/VM/src/lvmexecute.cpp
@@ -13,6 +13,7 @@
 #include "lbuiltins.h"
 #include "lnumutils.h"
 #include "lbytecode.h"
+#include <csignal>
 
 #include <string.h>
 
@@ -124,13 +125,24 @@
  * VM_CONTINUE() Use an opcode override to dispatch with computed goto or
  * switch statement to skip a LOP_BREAK instruction.
  */
+volatile sig_atomic_t sigint_received = 0;
+static void handle_sig(int signum) {
+    sigint_received = 1;
+}
 #if VM_USE_CGOTO
 #define VM_CASE(op) CASE_##op:
-#define VM_NEXT() goto*(SingleStep ? &&dispatch : kDispatchTable[LUAU_INSN_OP(*pc)])
+
+#define VM_NEXT() \
+    if (sigint_received)\
+     { sigint_received = 0; L->status = LUA_SIGINT; goto exit; } \
+    else goto*(SingleStep ? &&dispatch : kDispatchTable[LUAU_INSN_OP(*pc)])
 #define VM_CONTINUE(op) goto* kDispatchTable[uint8_t(op)]
 #else
 #define VM_CASE(op) case op:
-#define VM_NEXT() goto dispatch
+#define VM_NEXT() \
+    if (sigint_received)\
+     { sigint_received = 0; } \
+    else goto dispatch
 #define VM_CONTINUE(op) \
     dispatchOp = uint8_t(op); \
     goto dispatchContinue
@@ -320,6 +332,8 @@ static void luau_execute(lua_State* L)
     base = L->base;
     k = cl->l.p->k;
 
+    signal(SIGINT, handle_sig);
+
     VM_NEXT(); // starts the interpreter "loop"
 
     {