Add TrapsNeverHappen to SideEffects's API (#4086)

Author: MaxGraey

src/binaryen-c.cpp

@@ -4309,6 +4309,10 @@ BinaryenSideEffects BinaryenSideEffectImplicitTrap(void) {
   return static_cast<BinaryenSideEffects>(
     EffectAnalyzer::SideEffects::ImplicitTrap);
 }
+BinaryenSideEffects BinaryenSideEffectTrapsNeverHappen(void) {
+  return static_cast<BinaryenSideEffects>(
+    EffectAnalyzer::SideEffects::TrapsNeverHappen);
+}
 BinaryenSideEffects BinaryenSideEffectIsAtomic(void) {
   return static_cast<BinaryenSideEffects>(
     EffectAnalyzer::SideEffects::IsAtomic);

src/binaryen-c.h

@@ -2620,6 +2620,7 @@ BINARYEN_API BinaryenSideEffects BinaryenSideEffectWritesGlobal(void);
 BINARYEN_API BinaryenSideEffects BinaryenSideEffectReadsMemory(void);
 BINARYEN_API BinaryenSideEffects BinaryenSideEffectWritesMemory(void);
 BINARYEN_API BinaryenSideEffects BinaryenSideEffectImplicitTrap(void);
+BINARYEN_API BinaryenSideEffects BinaryenSideEffectTrapsNeverHappen(void);
 BINARYEN_API BinaryenSideEffects BinaryenSideEffectIsAtomic(void);
 BINARYEN_API BinaryenSideEffects BinaryenSideEffectThrows(void);
 BINARYEN_API BinaryenSideEffects BinaryenSideEffectDanglingPop(void);

src/ir/effects.h

@@ -256,6 +256,7 @@ class EffectAnalyzer {
     writesHeap = writesHeap || other.writesHeap;
     trap = trap || other.trap;
     implicitTrap = implicitTrap || other.implicitTrap;
+    trapsNeverHappen = trapsNeverHappen || other.trapsNeverHappen;
     isAtomic = isAtomic || other.isAtomic;
     throws = throws || other.throws;
     danglingPop = danglingPop || other.danglingPop;
@@ -687,7 +688,8 @@ class EffectAnalyzer {
     IsAtomic = 1 << 9,
     Throws = 1 << 10,
     DanglingPop = 1 << 11,
-    Any = (1 << 12) - 1
+    TrapsNeverHappen = 1 << 12,
+    Any = (1 << 13) - 1
   };
   uint32_t getSideEffects() const {
     uint32_t effects = 0;
@@ -718,6 +720,9 @@ class EffectAnalyzer {
     if (implicitTrap) {
       effects |= SideEffects::ImplicitTrap;
     }
+    if (trapsNeverHappen) {
+      effects |= SideEffects::TrapsNeverHappen;
+    }
     if (isAtomic) {
       effects |= SideEffects::IsAtomic;
     }

src/js/binaryen.js-post.js

@@ -551,6 +551,7 @@ function initializeConstants() {
     'IsAtomic',
     'Throws',
     'DanglingPop',
+    'TrapsNeverHappen',
     'Any'
   ].forEach(name => {
     Module['SideEffects'][name] = Module['_BinaryenSideEffect' + name]();

test/binaryen.js/sideffects.js

@@ -11,6 +11,7 @@ console.log("SideEffects.ImplicitTrap=" + binaryen.SideEffects.ImplicitTrap);
 console.log("SideEffects.IsAtomic=" + binaryen.SideEffects.IsAtomic);
 console.log("SideEffects.Throws=" + binaryen.SideEffects.Throws);
 console.log("SideEffects.DanglingPop=" + binaryen.SideEffects.DanglingPop);
+console.log("SideEffects.TrapsNeverHappen=" + binaryen.SideEffects.TrapsNeverHappen);
 console.log("SideEffects.Any=" + binaryen.SideEffects.Any);
 
 var module = new binaryen.Module();

test/binaryen.js/sideffects.js.txt

@@ -11,4 +11,5 @@ SideEffects.ImplicitTrap=256
 SideEffects.IsAtomic=512
 SideEffects.Throws=1024
 SideEffects.DanglingPop=2048
-SideEffects.Any=4095
+SideEffects.TrapsNeverHappen=4096
+SideEffects.Any=8191