From 2d2df9761ea1669cad5565f24e0d06ec02cc8fe1 Mon Sep 17 00:00:00 2001
From: Jan de Mooij <jdemooij@mozilla.com>
Date: Thu, 5 Dec 2019 12:54:34 +0000
Subject: [PATCH] Bug 1598548 part 7 - Add a RetAddrEntry::Kind for interrupt
 check callVM. r=tcampbell

This is necessary for the next patch: it will merge JSOP_LOOPHEAD
and JSOP_LOOPENTRY but that means there can be multiple callVMs for
that op and this confuses DebugModeOSR (interrupts can trigger debugger
recompilation).

Differential Revision: https://phabricator.services.mozilla.com/D55631

--HG--
extra : moz-landing-system : lando
---
 js/src/jit/BaselineCodeGen.cpp      | 6 +++++-
 js/src/jit/BaselineDebugModeOSR.cpp | 4 ++++
 js/src/jit/BaselineJIT.h            | 3 +++
 3 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/js/src/jit/BaselineCodeGen.cpp b/js/src/jit/BaselineCodeGen.cpp
index 194df45cc569..6604d99b48a0 100644
--- a/js/src/jit/BaselineCodeGen.cpp
+++ b/js/src/jit/BaselineCodeGen.cpp
@@ -1259,8 +1259,12 @@ bool BaselineCodeGen<Handler>::emitInterruptCheck() {
 
   prepareVMCall();
 
+  // Use a custom RetAddrEntry::Kind so DebugModeOSR can distinguish this call
+  // from other callVMs that might happen at this pc.
+  const RetAddrEntry::Kind kind = RetAddrEntry::Kind::InterruptCheck;
+
   using Fn = bool (*)(JSContext*);
-  if (!callVM<Fn, InterruptCheck>()) {
+  if (!callVM<Fn, InterruptCheck>(kind)) {
     return false;
   }
 
diff --git a/js/src/jit/BaselineDebugModeOSR.cpp b/js/src/jit/BaselineDebugModeOSR.cpp
index 9676fdb40b33..f251d25a8f6f 100644
--- a/js/src/jit/BaselineDebugModeOSR.cpp
+++ b/js/src/jit/BaselineDebugModeOSR.cpp
@@ -182,6 +182,8 @@ static const char* RetAddrEntryKindToString(RetAddrEntry::Kind kind) {
       return "warmup counter";
     case RetAddrEntry::Kind::StackCheck:
       return "stack check";
+    case RetAddrEntry::Kind::InterruptCheck:
+      return "interrupt check";
     case RetAddrEntry::Kind::DebugTrap:
       return "debug trap";
     case RetAddrEntry::Kind::DebugPrologue:
@@ -284,6 +286,7 @@ static void PatchBaselineFramesForDebugMode(
         switch (kind) {
           case RetAddrEntry::Kind::IC:
           case RetAddrEntry::Kind::CallVM:
+          case RetAddrEntry::Kind::InterruptCheck:
           case RetAddrEntry::Kind::WarmupCounter:
           case RetAddrEntry::Kind::StackCheck: {
             // Cases A, B, C, D above.
@@ -298,6 +301,7 @@ static void PatchBaselineFramesForDebugMode(
             switch (kind) {
               case RetAddrEntry::Kind::IC:
               case RetAddrEntry::Kind::CallVM:
+              case RetAddrEntry::Kind::InterruptCheck:
                 retAddrEntry = &bl->retAddrEntryFromPCOffset(pcOffset, kind);
                 break;
               case RetAddrEntry::Kind::WarmupCounter:
diff --git a/js/src/jit/BaselineJIT.h b/js/src/jit/BaselineJIT.h
index 4db6d89d1b1b..9a876d1b3a5d 100644
--- a/js/src/jit/BaselineJIT.h
+++ b/js/src/jit/BaselineJIT.h
@@ -110,6 +110,9 @@ class RetAddrEntry {
     // A callVM for the over-recursion check on function entry.
     StackCheck,
 
+    // A callVM for an interrupt check.
+    InterruptCheck,
+
     // DebugTrapHandler (for debugger breakpoints/stepping).
     DebugTrap,