[wasm] Enforce that function bodies end with the \"end\" opcode.

test/unittests/wasm/function-body-decoder-unittest.cc

Index: test/unittests/wasm/function-body-decoder-unittest.cc
diff --git a/test/unittests/wasm/function-body-decoder-unittest.cc b/test/unittests/wasm/function-body-decoder-unittest.cc
index 0da781451efde4736ecbbcbdf9153190d051e670..66bbaa75807a103dc2e7d2f4932e5457ba5c01ee 100644
--- a/test/unittests/wasm/function-body-decoder-unittest.cc
+++ b/test/unittests/wasm/function-body-decoder-unittest.cc
@@ -104,11 +104,29 @@ class FunctionBodyDecoderTest : public TestWithZone {
     local_decls.AddLocals(count, type);
   }
 
+  void PrepareBytecode(const byte** startp, const byte** endp) {
+    const byte* start = *startp;
+    const byte* end = *endp;
+    size_t locals_size = local_decls.Size();
+    size_t total_size = end - start + locals_size + 1;
+    byte* buffer = static_cast<byte*>(zone()->New(total_size));
+    // Prepend the local decls to the code.
+    local_decls.Emit(buffer);
+    // Emit the code.
+    memcpy(buffer + locals_size, start, end - start);
+    // Append an extra end opcode.
+    buffer[total_size - 1] = kExprEnd;
+
+    *startp = buffer;
+    *endp = buffer + total_size;
+  }
+
   // Prepends local variable declarations and renders nice error messages for
   // verification failures.
   void Verify(ErrorCode expected, FunctionSig* sig, const byte* start,
               const byte* end) {
-    local_decls.Prepend(zone(), &start, &end);
+    PrepareBytecode(&start, &end);
+
     // Verify the code.
     DecodeResult result = VerifyWasmCode(
         zone()->allocator(), module == nullptr ? nullptr : module->module, sig,
@@ -461,11 +479,7 @@ TEST_F(FunctionBodyDecoderTest, Block0Block0) {
 }
 
 TEST_F(FunctionBodyDecoderTest, Block0_end) {
-  EXPECT_VERIFIES(v_v, WASM_EMPTY_BLOCK, kExprEnd);
-}
-
-TEST_F(FunctionBodyDecoderTest, Block0_end_end) {
-  EXPECT_FAILURE(v_v, WASM_EMPTY_BLOCK, kExprEnd, kExprEnd);
+  EXPECT_FAILURE(v_v, WASM_EMPTY_BLOCK, kExprEnd);
 }
 
 TEST_F(FunctionBodyDecoderTest, Block1) {
@@ -712,37 +726,18 @@ TEST_F(FunctionBodyDecoderTest, Block_else) {
 
 TEST_F(FunctionBodyDecoderTest, IfNop) {
   EXPECT_VERIFIES(v_i, WASM_IF(WASM_GET_LOCAL(0), WASM_NOP));
-}
-
-TEST_F(FunctionBodyDecoderTest, IfNopElseNop) {
   EXPECT_VERIFIES(v_i, WASM_IF_ELSE(WASM_GET_LOCAL(0), WASM_NOP, WASM_NOP));
 }
 
-TEST_F(FunctionBodyDecoderTest, If_end_end) {
-  static const byte code[] = {kExprGetLocal, 0, WASM_IF_OP, kExprEnd, kExprEnd};
-  EXPECT_VERIFIES_C(v_i, code);
-}
-
-TEST_F(FunctionBodyDecoderTest, If_end_end_end) {
-  static const byte code[] = {kExprGetLocal, 0,        WASM_IF_OP,
-                              kExprEnd,      kExprEnd, kExprEnd};
-  EXPECT_FAILURE_C(v_i, code);
+TEST_F(FunctionBodyDecoderTest, If_end) {
+  EXPECT_VERIFIES(v_i, kExprGetLocal, 0, WASM_IF_OP, kExprEnd);
+  EXPECT_FAILURE(v_i, kExprGetLocal, 0, WASM_IF_OP, kExprEnd, kExprEnd);
 }
 
 TEST_F(FunctionBodyDecoderTest, If_falloff1) {
-  static const byte code[] = {kExprGetLocal, 0, kExprIf};
-  EXPECT_FAILURE_C(v_i, code);
-}
-
-TEST_F(FunctionBodyDecoderTest, If_falloff2) {
-  static const byte code[] = {kExprGetLocal, 0, WASM_IF_OP};
-  EXPECT_FAILURE_C(v_i, code);
-}
-
-TEST_F(FunctionBodyDecoderTest, IfElse_falloff) {
-  static const byte code[] = {kExprGetLocal, 0, WASM_IF_OP, kExprNop,
-                              kExprElse};
-  EXPECT_FAILURE_C(v_i, code);
+  EXPECT_FAILURE(v_i, kExprGetLocal, 0, kExprIf);
+  EXPECT_FAILURE(v_i, kExprGetLocal, 0, WASM_IF_OP);
+  EXPECT_FAILURE(v_i, kExprGetLocal, 0, WASM_IF_OP, kExprNop, kExprElse);
 }
 
 TEST_F(FunctionBodyDecoderTest, IfElseNop) {