[Outlining] Add Try/Catch/CatchAll

src/passes/Outlining.cpp

@@ -137,6 +137,20 @@ struct ReconstructStringifyWalker
     } else if (auto curr = reason.getLoopStart()) {
       ODBG(desc = "Loop Start at ");
       ASSERT_OK(existingBuilder.visitLoopStart(curr->loop));
+    } else if (auto curr = reason.getTryStart()) {
+      // We preserve the name of the tryy because IRBuilder expects
+      // visitTryStart() to be called on an empty Try, during the normal case of
+      // parsing. TODO: Fix this.
+      auto name = curr->tryy->name;
+      ASSERT_OK(existingBuilder.visitTryStart(curr->tryy, Name()));
+      ODBG(desc = "Try Start at ");
+      curr->tryy->name = name;
+    } else if (auto curr = reason.getCatchStart()) {
+      ASSERT_OK(existingBuilder.visitCatch(curr->tag));
+      ODBG(desc = "Catch Start at ");
+    } else if (reason.getCatchAllStart()) {
+      ASSERT_OK(existingBuilder.visitCatchAll());
+      ODBG(desc = "Catch All Start at");
     } else if (reason.getEnd()) {
       ODBG(desc = "End at ");
       ASSERT_OK(existingBuilder.visitEnd());

src/passes/stringify-walker-impl.h

@@ -97,14 +97,18 @@ template<typename SubType> void StringifyWalker<SubType>::dequeueControlFlow() {
     }
     case Expression::Id::TryId: {
       auto* tryy = curr->cast<Try>();
-      addUniqueSymbol(SeparatorReason::makeTryBodyStart());
+
+      addUniqueSymbol(SeparatorReason::makeTryStart(tryy));
       Super::walk(tryy->body);
-      addUniqueSymbol(SeparatorReason::makeEnd());
-      for (auto& child : tryy->catchBodies) {
-        addUniqueSymbol(SeparatorReason::makeTryCatchStart());
-        Super::walk(child);
-        addUniqueSymbol(SeparatorReason::makeEnd());
+      for (size_t i = 0; i < tryy->catchBodies.size(); i++) {
+        if (tryy->hasCatchAll() && i == tryy->catchBodies.size() - 1) {
+          addUniqueSymbol(SeparatorReason::makeCatchAllStart());
+        } else {
+          addUniqueSymbol(SeparatorReason::makeCatchStart(tryy->catchTags[i]));
+        }
+        Super::walk(tryy->catchBodies[i]);
       }
+      addUniqueSymbol(SeparatorReason::makeEnd());
       break;
     }
     case Expression::Id::LoopId: {

src/passes/stringify-walker.h

@@ -89,9 +89,15 @@ struct StringifyWalker
       Loop* loop;
     };
 
-    struct TryBodyStart {};
+    struct TryStart {
+      Try* tryy;
+    };
+
+    struct CatchStart {
+      Name tag;
+    };
 
-    struct TryCatchStart {};
+    struct CatchAllStart {};
 
     struct End {
       Expression* curr;
@@ -101,8 +107,9 @@ struct StringifyWalker
                                    IfStart,
                                    ElseStart,
                                    LoopStart,
-                                   TryBodyStart,
-                                   TryCatchStart,
+                                   TryStart,
+                                   CatchStart,
+                                   CatchAllStart,
                                    End>;
 
     Separator reason;
@@ -124,23 +131,25 @@ struct StringifyWalker
     static SeparatorReason makeLoopStart(Loop* loop) {
       return SeparatorReason(LoopStart{loop});
     }
-    static SeparatorReason makeTryCatchStart() {
-      return SeparatorReason(TryCatchStart{});
+    static SeparatorReason makeTryStart(Try* tryy) {
+      return SeparatorReason(TryStart{tryy});
     }
-    static SeparatorReason makeTryBodyStart() {
-      return SeparatorReason(TryBodyStart{});
+    static SeparatorReason makeCatchStart(Name tag) {
+      return SeparatorReason(CatchStart{tag});
+    }
+    static SeparatorReason makeCatchAllStart() {
+      return SeparatorReason(CatchAllStart{});
     }
     static SeparatorReason makeEnd() { return SeparatorReason(End{}); }
     FuncStart* getFuncStart() { return std::get_if<FuncStart>(&reason); }
     BlockStart* getBlockStart() { return std::get_if<BlockStart>(&reason); }
     IfStart* getIfStart() { return std::get_if<IfStart>(&reason); }
     ElseStart* getElseStart() { return std::get_if<ElseStart>(&reason); }
     LoopStart* getLoopStart() { return std::get_if<LoopStart>(&reason); }
-    TryBodyStart* getTryBodyStart() {
-      return std::get_if<TryBodyStart>(&reason);
-    }
-    TryCatchStart* getTryCatchStart() {
-      return std::get_if<TryCatchStart>(&reason);
+    TryStart* getTryStart() { return std::get_if<TryStart>(&reason); }
+    CatchStart* getCatchStart() { return std::get_if<CatchStart>(&reason); }
+    CatchAllStart* getCatchAllStart() {
+      return std::get_if<CatchAllStart>(&reason);
     }
     End* getEnd() { return std::get_if<End>(&reason); }
   };
@@ -158,10 +167,12 @@ struct StringifyWalker
       return o << "Else Start";
     } else if (reason.getLoopStart()) {
       return o << "Loop Start";
-    } else if (reason.getTryBodyStart()) {
-      return o << "Try Body Start";
-    } else if (reason.getTryCatchStart()) {
-      return o << "Try Catch Start";
+    } else if (reason.getTryStart()) {
+      return o << "Try Start";
+    } else if (reason.getCatchStart()) {
+      return o << "Catch Start";
+    } else if (reason.getCatchAllStart()) {
+      return o << "Catch All Start";
     } else if (reason.getEnd()) {
       return o << "End";
     }

src/wasm-ir-builder.h

@@ -306,14 +306,17 @@ class IRBuilder : public UnifiedExpressionVisitor<IRBuilder, Result<>> {
     struct TryScope {
       Try* tryy;
       Name originalLabel;
+      Index index;
     };
     struct CatchScope {
       Try* tryy;
       Name originalLabel;
+      Index index;
     };
     struct CatchAllScope {
       Try* tryy;
       Name originalLabel;
+      Index index;
     };
     struct TryTableScope {
       TryTable* trytable;
@@ -396,15 +399,17 @@ class IRBuilder : public UnifiedExpressionVisitor<IRBuilder, Result<>> {
       return ScopeCtx(LoopScope{loop}, inputType);
     }
     static ScopeCtx makeTry(Try* tryy, Name originalLabel, Type inputType) {
-      return ScopeCtx(TryScope{tryy, originalLabel}, inputType);
+      return ScopeCtx(TryScope{tryy, originalLabel, 0}, inputType);
     }
     static ScopeCtx makeCatch(ScopeCtx&& scope, Try* tryy) {
-      scope.scope = CatchScope{tryy, scope.getOriginalLabel()};
+      scope.scope =
+        CatchScope{tryy, scope.getOriginalLabel(), scope.getIndex() + 1};
       scope.resetForDelimiter(/*keepInput=*/false);
       return scope;
     }
     static ScopeCtx makeCatchAll(ScopeCtx&& scope, Try* tryy) {
-      scope.scope = CatchAllScope{tryy, scope.getOriginalLabel()};
+      scope.scope =
+        CatchAllScope{tryy, scope.getOriginalLabel(), scope.getIndex() + 1};
       scope.resetForDelimiter(/*keepInput=*/false);
       return scope;
     }
@@ -530,6 +535,18 @@ class IRBuilder : public UnifiedExpressionVisitor<IRBuilder, Result<>> {
       }
       WASM_UNREACHABLE("unexpected scope kind");
     }
+    Index getIndex() {
+      if (auto* tryScope = std::get_if<TryScope>(&scope)) {
+        return tryScope->index;
+      }
+      if (auto* catchScope = std::get_if<CatchScope>(&scope)) {
+        return catchScope->index;
+      }
+      if (auto* catchAllScope = std::get_if<CatchAllScope>(&scope)) {
+        return catchAllScope->index;
+      }
+      WASM_UNREACHABLE("unexpected scope kind");
+    }
     Type getLabelType() {
       // Loops receive their input type rather than their output type.
       return getLoop() ? inputType : getResultType();

src/wasm/wasm-ir-builder.cpp

@@ -931,6 +931,21 @@ Result<> IRBuilder::visitElse() {
   return pushScope(ScopeCtx::makeElse(std::move(scope)));
 }
 
+void setCatchBody(Try* tryy, Expression* expr, Index index) {
+  // Indexes are managed manually to support Outlining.
+  // Its prepopulated try catchBodies and catchTags vectors
+  // cannot be appended to, as in the case of the empty try
+  // used during parsing.
+  if (tryy->catchBodies.size() < index) {
+    tryy->catchBodies.resize(tryy->catchBodies.size() + 1);
+  }
+  // The first time visitCatch is called: the body of the
+  // try is set and catchBodies is not appended to, but the tag
+  // for the following catch is appended. So, catchTags uses
+  // index as-is, but catchBodies uses index-1.
+  tryy->catchBodies[index - 1] = expr;
+}
+
 Result<> IRBuilder::visitCatch(Name tag) {
   auto scope = getScope();
   bool wasTry = true;
@@ -942,14 +957,18 @@ Result<> IRBuilder::visitCatch(Name tag) {
   if (!tryy) {
     return Err{"unexpected catch"};
   }
+  auto index = scope.getIndex();
   auto expr = finishScope();
   CHECK_ERR(expr);
   if (wasTry) {
     tryy->body = *expr;
   } else {
-    tryy->catchBodies.push_back(*expr);
+    setCatchBody(tryy, *expr, index);
+  }
+  if (tryy->catchTags.size() == index) {
+    tryy->catchTags.resize(tryy->catchTags.size() + 1);
   }
-  tryy->catchTags.push_back(tag);
+  tryy->catchTags[index] = tag;
 
   if (binaryPos && func) {
     auto& delimiterLocs = func->delimiterLocations[tryy];
@@ -980,12 +999,13 @@ Result<> IRBuilder::visitCatchAll() {
   if (!tryy) {
     return Err{"unexpected catch"};
   }
+  auto index = scope.getIndex();
   auto expr = finishScope();
   CHECK_ERR(expr);
   if (wasTry) {
     tryy->body = *expr;
   } else {
-    tryy->catchBodies.push_back(*expr);
+    setCatchBody(tryy, *expr, index);
   }
 
   if (binaryPos && func) {
@@ -1123,7 +1143,8 @@ Result<> IRBuilder::visitEnd() {
     push(maybeWrapForLabel(tryy));
   } else if (Try * tryy;
              (tryy = scope.getCatch()) || (tryy = scope.getCatchAll())) {
-    tryy->catchBodies.push_back(*expr);
+    auto index = scope.getIndex();
+    setCatchBody(tryy, *expr, index);
     tryy->name = scope.label;
     tryy->finalize(tryy->type);
     push(maybeWrapForLabel(tryy));

test/gtest/stringify.cpp

@@ -98,19 +98,16 @@ adding unique symbol for End
 adding unique symbol for If Start
 in visitExpression for i32.const 30
 adding unique symbol for End
-adding unique symbol for Try Body Start
+adding unique symbol for Try Start
 in visitExpression for nop
-adding unique symbol for End
-adding unique symbol for Try Catch Start
+adding unique symbol for Catch Start
 in visitExpression for block
-adding unique symbol for End
-adding unique symbol for Try Catch Start
+adding unique symbol for Catch Start
 in visitExpression for block
 adding unique symbol for End
-adding unique symbol for Try Body Start
+adding unique symbol for Try Start
 in visitExpression for nop
-adding unique symbol for End
-adding unique symbol for Try Catch Start
+adding unique symbol for Catch Start
 in visitExpression for block
 adding unique symbol for End
 adding unique symbol for Block Start

test/lit/passes/outlining.wast

@@ -1164,3 +1164,83 @@
     )
   )
 )
+
+;; Tests that the contents of Catch are outlined
+(module
+  ;; CHECK:      (type $1 (func (result i32)))
+
+  ;; CHECK:      (type $0 (func))
+  (type $0 (func))
+  (type $1 (func (result i32)))
+  ;; CHECK:      (tag $eimport$1 (type $0))
+  (tag $eimport$1 (type $0))
+  ;; CHECK:      (func $outline$ (type $1) (result i32)
+  ;; CHECK-NEXT:  (drop
+  ;; CHECK-NEXT:   (i32.const -12)
+  ;; CHECK-NEXT:  )
+  ;; CHECK-NEXT:  (i32.const -2147483647)
+  ;; CHECK-NEXT: )
+
+  ;; CHECK:      (func $a (type $1) (result i32)
+  ;; CHECK-NEXT:  (local $0 externref)
+  ;; CHECK-NEXT:  (try (result i32)
+  ;; CHECK-NEXT:   (do
+  ;; CHECK-NEXT:    (i32.const -20)
+  ;; CHECK-NEXT:   )
+  ;; CHECK-NEXT:   (catch $eimport$1
+  ;; CHECK-NEXT:    (call $outline$)
+  ;; CHECK-NEXT:   )
+  ;; CHECK-NEXT:   (catch_all
+  ;; CHECK-NEXT:    (i32.const -15)
+  ;; CHECK-NEXT:   )
+  ;; CHECK-NEXT:  )
+  ;; CHECK-NEXT: )
+  (func $a (result i32)
+    (local $0 externref)
+    (try (result i32)
+      (do
+        (i32.const -20)
+      )
+      (catch $eimport$1
+        (drop
+          (i32.const -12)
+        )
+        (i32.const -2147483647)
+      )
+      (catch_all
+        (i32.const -15)
+      )
+    )
+  )
+  ;; CHECK:      (func $b (type $1) (result i32)
+  ;; CHECK-NEXT:  (local $0 externref)
+  ;; CHECK-NEXT:  (try (result i32)
+  ;; CHECK-NEXT:   (do
+  ;; CHECK-NEXT:    (i32.const -20)
+  ;; CHECK-NEXT:   )
+  ;; CHECK-NEXT:   (catch $eimport$1
+  ;; CHECK-NEXT:    (call $outline$)
+  ;; CHECK-NEXT:   )
+  ;; CHECK-NEXT:   (catch_all
+  ;; CHECK-NEXT:    (i32.const -15)
+  ;; CHECK-NEXT:   )
+  ;; CHECK-NEXT:  )
+  ;; CHECK-NEXT: )
+  (func $b (result i32)
+    (local $0 externref)
+    (try (result i32)
+      (do
+        (i32.const -20)
+      )
+      (catch $eimport$1
+        (drop
+          (i32.const -12)
+        )
+        (i32.const -2147483647)
+      )
+      (catch_all
+        (i32.const -15)
+      )
+    )
+  )
+)