1 files changed, 76 insertions, 4 deletions

diff --git a/src/wasm-ir-builder.h b/src/wasm-ir-builder.h
index e7613b373..ee6721738 100644
--- a/src/wasm-ir-builder.h
+++ b/src/wasm-ir-builder.h
@@ -64,13 +64,21 @@ public:
   [[nodiscard]] Result<> visitIfStart(If* iff, Name label = {});
   [[nodiscard]] Result<> visitElse();
   [[nodiscard]] Result<> visitLoopStart(Loop* iff);
+  [[nodiscard]] Result<> visitTryStart(Try* tryy, Name label = {});
+  [[nodiscard]] Result<> visitCatch(Name tag);
+  [[nodiscard]] Result<> visitCatchAll();
+  [[nodiscard]] Result<> visitDelegate(Index label);
   [[nodiscard]] Result<> visitEnd();
 
   // Binaryen IR uses names to refer to branch targets, but in general there may
   // be branches to constructs that do not yet have names, so in IRBuilder we
   // use indices to refer to branch targets instead, just as the binary format
   // does. This function converts a branch target name to the correct index.
-  [[nodiscard]] Result<Index> getLabelIndex(Name label);
+  //
+  // Labels in delegates need special handling because the indexing needs to be
+  // relative to the try's enclosing scope rather than the try itself.
+  [[nodiscard]] Result<Index> getLabelIndex(Name label,
+                                            bool inDelegate = false);
 
   // Instead of calling visit, call makeXYZ to have the IRBuilder allocate the
   // nodes. This is generally safer than calling `visit` because the function
@@ -145,7 +153,7 @@ public:
   // [[nodiscard]] Result<> makeTableGrow();
   // [[nodiscard]] Result<> makeTableFill();
   // [[nodiscard]] Result<> makeTableCopy();
-  // [[nodiscard]] Result<> makeTry();
+  [[nodiscard]] Result<> makeTry(Name label, Type type);
   [[nodiscard]] Result<> makeThrow(Name tag);
   // [[nodiscard]] Result<> makeRethrow();
   // [[nodiscard]] Result<> makeTupleMake();
@@ -232,8 +240,27 @@ private:
     struct LoopScope {
       Loop* loop;
     };
-    using Scope = std::
-      variant<NoScope, FuncScope, BlockScope, IfScope, ElseScope, LoopScope>;
+    struct TryScope {
+      Try* tryy;
+      Name originalLabel;
+    };
+    struct CatchScope {
+      Try* tryy;
+      Name originalLabel;
+    };
+    struct CatchAllScope {
+      Try* tryy;
+      Name originalLabel;
+    };
+    using Scope = std::variant<NoScope,
+                               FuncScope,
+                               BlockScope,
+                               IfScope,
+                               ElseScope,
+                               LoopScope,
+                               TryScope,
+                               CatchScope,
+                               CatchAllScope>;
 
     // The control flow structure we are building expressions for.
     Scope scope;
@@ -264,6 +291,15 @@ private:
       return ScopeCtx(ElseScope{iff, originalLabel}, label);
     }
     static ScopeCtx makeLoop(Loop* loop) { return ScopeCtx(LoopScope{loop}); }
+    static ScopeCtx makeTry(Try* tryy, Name originalLabel = {}) {
+      return ScopeCtx(TryScope{tryy, originalLabel});
+    }
+    static ScopeCtx makeCatch(Try* tryy, Name originalLabel, Name label) {
+      return ScopeCtx(CatchScope{tryy, originalLabel}, label);
+    }
+    static ScopeCtx makeCatchAll(Try* tryy, Name originalLabel, Name label) {
+      return ScopeCtx(CatchAllScope{tryy, originalLabel}, label);
+    }
 
     bool isNone() { return std::get_if<NoScope>(&scope); }
     Function* getFunction() {
@@ -296,6 +332,24 @@ private:
       }
       return nullptr;
     }
+    Try* getTry() {
+      if (auto* tryScope = std::get_if<TryScope>(&scope)) {
+        return tryScope->tryy;
+      }
+      return nullptr;
+    }
+    Try* getCatch() {
+      if (auto* catchScope = std::get_if<CatchScope>(&scope)) {
+        return catchScope->tryy;
+      }
+      return nullptr;
+    }
+    Try* getCatchAll() {
+      if (auto* catchAllScope = std::get_if<CatchAllScope>(&scope)) {
+        return catchAllScope->tryy;
+      }
+      return nullptr;
+    }
     Type getResultType() {
       if (auto* func = getFunction()) {
         return func->type.getSignature().results;
@@ -312,6 +366,15 @@ private:
       if (auto* loop = getLoop()) {
         return loop->type;
       }
+      if (auto* tryy = getTry()) {
+        return tryy->type;
+      }
+      if (auto* tryy = getCatch()) {
+        return tryy->type;
+      }
+      if (auto* tryy = getCatchAll()) {
+        return tryy->type;
+      }
       WASM_UNREACHABLE("unexpected scope kind");
     }
     Name getOriginalLabel() {
@@ -330,6 +393,15 @@ private:
       if (auto* loop = getLoop()) {
         return loop->name;
       }
+      if (auto* tryScope = std::get_if<TryScope>(&scope)) {
+        return tryScope->originalLabel;
+      }
+      if (auto* catchScope = std::get_if<CatchScope>(&scope)) {
+        return catchScope->originalLabel;
+      }
+      if (auto* catchAllScope = std::get_if<CatchAllScope>(&scope)) {
+        return catchAllScope->originalLabel;
+      }
       WASM_UNREACHABLE("unexpected scope kind");
     }
   };