bugc: use proper typed invoke/return context construction

Replace `as unknown as Format.Program.Context` casts with
properly typed construction using Context.Invoke and
Context.Return interfaces. Add required `target` pointer
to invoke contexts and always provide `data` pointer in
return contexts. Update tests accordingly.

Author: gnidan

packages/bugc/src/evmgen/call-contexts.test.ts

@@ -73,6 +73,10 @@ code {
     expect(invoke.jump).toBe(true);
     expect(invoke.identifier).toBe("add");
 
+    // Should have target pointer
+    const target = invoke.target as Record<string, unknown>;
+    expect(target.pointer).toBeDefined();
+
     // Should have argument pointers
     const args = invoke.arguments as Record<string, unknown>;
     const pointer = args.pointer as Record<string, unknown>;
@@ -107,7 +111,6 @@ code {
     const ctx = (returnJumpdests[0].context as Record<string, unknown>)!;
     const ret = ctx.return as Record<string, unknown>;
 
-    expect(ret.jump).toBe(true);
     expect(ret.identifier).toBe("add");
 
     // Should have data pointer to return value at

packages/bugc/src/evmgen/generation/block.ts

@@ -70,29 +70,23 @@ export function generate<S extends Stack>(
 
         // Add JUMPDEST with continuation annotation if applicable
         if (isContinuation) {
-          // Check if the call has a return value
-          const predBlock = func!.blocks.get(predecessor!);
-          const hasReturnValue =
-            predBlock?.terminator.kind === "call" &&
-            !!predBlock.terminator.dest;
-
           // Return context describes state after JUMPDEST
           // executes: TOS is the return value (if any).
-          const continuationDebug = {
-            context: {
-              return: {
-                jump: true as const,
-                identifier: calledFunction,
-                ...(hasReturnValue && {
-                  data: {
-                    pointer: {
-                      location: "stack" as const,
-                      slot: 0,
-                    },
-                  },
-                }),
+          // data pointer is required by the schema; for
+          // void returns, slot 0 is still valid (empty).
+          const returnCtx: Format.Program.Context.Return = {
+            return: {
+              identifier: calledFunction,
+              data: {
+                pointer: {
+                  location: "stack" as const,
+                  slot: 0,
+                },
               },
-            } as unknown as Format.Program.Context,
+            },
+          };
+          const continuationDebug = {
+            context: returnCtx as Format.Program.Context,
           };
           result = result.then(JUMPDEST({ debug: continuationDebug }));
         } else {

packages/bugc/src/evmgen/generation/control-flow/terminator.ts

@@ -245,23 +245,25 @@ export function generateCallTerminator<S extends Stack>(
 
     // Invoke context describes state after JUMP executes:
     // the callee has been entered with args on the stack.
-    // Cast needed because invoke context TS types don't
-    // exist yet (only YAML schemas on call-return branch).
-    const invokeContext = {
-      context: {
-        invoke: {
-          jump: true as const,
-          identifier: funcName,
-          ...(argPointers.length > 0 && {
-            arguments: {
-              pointer: {
-                group: argPointers,
-              },
-            },
-          }),
+    // target points to the function address at stack slot 0
+    // (consumed by JUMP, but describes the call target).
+    const invoke: Format.Program.Context.Invoke = {
+      invoke: {
+        jump: true as const,
+        identifier: funcName,
+        target: {
+          pointer: { location: "stack" as const, slot: 0 },
         },
-      } as unknown as Format.Program.Context,
+        ...(argPointers.length > 0 && {
+          arguments: {
+            pointer: {
+              group: argPointers,
+            },
+          },
+        }),
+      },
     };
+    const invokeContext = { context: invoke as Format.Program.Context };
 
     currentState = {
       ...currentState,

packages/bugc/src/evmgen/generation/function.ts

@@ -36,20 +36,27 @@ function generatePrologue<S extends Stack>(
       slot: params.length - 1 - i,
     }));
 
-    const entryDebug = {
-      context: {
-        invoke: {
-          jump: true as const,
-          identifier: func.name || "anonymous",
-          ...(argPointers.length > 0 && {
-            arguments: {
-              pointer: {
-                group: argPointers,
-              },
-            },
-          }),
+    const entryInvoke: Format.Program.Context.Invoke = {
+      invoke: {
+        jump: true as const,
+        identifier: func.name || "anonymous",
+        target: {
+          pointer: {
+            location: "stack" as const,
+            slot: 0,
+          },
         },
-      } as unknown as Format.Program.Context,
+        ...(argPointers.length > 0 && {
+          arguments: {
+            pointer: {
+              group: argPointers,
+            },
+          },
+        }),
+      },
+    };
+    const entryDebug = {
+      context: entryInvoke as Format.Program.Context,
     };
     currentState = {
       ...currentState,