[wasm] Implement an interpreter for WASM.

test/unittests/wasm/control-transfer-unittest.cc

+// Copyright 2016 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "test/unittests/test-utils.h"
+#include "testing/gmock/include/gmock/gmock.h"
+
+#include "src/v8.h"
+
+#include "src/wasm/wasm-interpreter.h"
+#include "src/wasm/wasm-macro-gen.h"
+
+using testing::MakeMatcher;
+using testing::Matcher;
+using testing::MatcherInterface;
+using testing::MatchResultListener;
+using testing::StringMatchResultListener;
+
+namespace v8 {
+namespace internal {
+namespace wasm {
+
+#define B1(a) kExprBlock, a, kExprEnd
+#define B2(a, b) kExprBlock, a, b, kExprEnd
+#define B3(a, b, c) kExprBlock, a, b, c, kExprEnd
+
+struct ExpectedTarget {
+  pc_t pc;
+  ControlTransfer expected;
+};
+
+// For nicer error messages.
+class ControlTransferMatcher : public MatcherInterface<const ControlTransfer&> {
+ public:
+  explicit ControlTransferMatcher(pc_t pc, const ControlTransfer& expected)
+      : pc_(pc), expected_(expected) {}
+
+  void DescribeTo(std::ostream* os) const override {
+    *os << "@" << pc_ << " {pcdiff = " << expected_.pcdiff
+        << ", spdiff = " << expected_.spdiff
+        << ", action = " << expected_.action << "}";
+  }
+
+  bool MatchAndExplain(const ControlTransfer& input,
+                       MatchResultListener* listener) const override {
+    if (input.pcdiff != expected_.pcdiff || input.spdiff != expected_.spdiff ||
+        input.action != expected_.action) {
+      *listener << "@" << pc_ << " {pcdiff = " << input.pcdiff
+                << ", spdiff = " << input.spdiff
+                << ", action = " << input.action << "}";
+      return false;
+    }
+    return true;
+  }
+
+ private:
+  pc_t pc_;
+  const ControlTransfer& expected_;
+};
+
+class ControlTransferTest : public TestWithZone {
+ public:
+  void CheckControlTransfers(const byte* start, const byte* end,
+                             ExpectedTarget* expected_targets,
+                             size_t num_targets) {
+    ControlTransferMap map =
+        WasmInterpreter::ComputeControlTransfersForTesting(zone(), start, end);
+    // Check all control targets in the map.
+    for (size_t i = 0; i < num_targets; i++) {
+      pc_t pc = expected_targets[i].pc;
+      auto it = map.find(pc);
+      if (it == map.end()) {
+        printf("expected control target @ +%zu\n", pc);
+        EXPECT_TRUE(false);
+      } else {
+        ControlTransfer& expected = expected_targets[i].expected;
+        ControlTransfer& target = it->second;
+        EXPECT_THAT(target,
+                    MakeMatcher(new ControlTransferMatcher(pc, expected)));
+      }
+    }
+
+    // Check there are no other control targets.
+    for (pc_t pc = 0; start + pc < end; pc++) {
+      bool found = false;
+      for (size_t i = 0; i < num_targets; i++) {
+        if (expected_targets[i].pc == pc) {
+          found = true;
+          break;
+        }
+      }
+      if (found) continue;
+      if (map.find(pc) != map.end()) {
+        printf("expected no control @ +%zu\n", pc);
+        EXPECT_TRUE(false);
+      }
+    }
+  }
+};
+
+// Macro for simplifying tests below.
+#define EXPECT_TARGETS(...)                                                    \
+  do {                                                                         \
+    ExpectedTarget pairs[] = {__VA_ARGS__};                                    \
+    CheckControlTransfers(code, code + sizeof(code), pairs, arraysize(pairs)); \
+  } while (false)
+
+TEST_F(ControlTransferTest, SimpleIf) {
+  byte code[] = {
+      kExprI32Const,  // @0
+      0,              //   +1
+      kExprIf,        // @2
+      kExprEnd        // @3
+  };
+  EXPECT_TARGETS({2, {2, 0, ControlTransfer::kPushVoid}},  // --
+                 {3, {1, 0, ControlTransfer::kPushVoid}});
+}
+
+TEST_F(ControlTransferTest, SimpleIf1) {
+  byte code[] = {
+      kExprI32Const,  // @0
+      0,              //   +1
+      kExprIf,        // @2
+      kExprNop,       // @3
+      kExprEnd        // @4
+  };
+  EXPECT_TARGETS({2, {3, 0, ControlTransfer::kPushVoid}},  // --
+                 {4, {1, 1, ControlTransfer::kPopAndRepush}});
+}
+
+TEST_F(ControlTransferTest, SimpleIf2) {
+  byte code[] = {
+      kExprI32Const,  // @0
+      0,              //   +1
+      kExprIf,        // @2
+      kExprNop,       // @3
+      kExprNop,       // @4
+      kExprEnd        // @5
+  };
+  EXPECT_TARGETS({2, {4, 0, ControlTransfer::kPushVoid}},  // --
+                 {5, {1, 2, ControlTransfer::kPopAndRepush}});
+}
+
+TEST_F(ControlTransferTest, SimpleIfElse) {
+  byte code[] = {
+      kExprI32Const,  // @0
+      0,              //   +1
+      kExprIf,        // @2
+      kExprElse,      // @3
+      kExprEnd        // @4
+  };
+  EXPECT_TARGETS({2, {2, 0, ControlTransfer::kNoAction}},  // --
+                 {3, {2, 0, ControlTransfer::kPushVoid}},  // --
+                 {4, {1, 0, ControlTransfer::kPushVoid}});
+}
+
+TEST_F(ControlTransferTest, SimpleIfElse1) {
+  byte code[] = {
+      kExprI32Const,  // @0
+      0,              //   +1
+      kExprIf,        // @2
+      kExprNop,       // @3
+      kExprElse,      // @4
+      kExprNop,       // @5
+      kExprEnd        // @6
+  };
+  EXPECT_TARGETS({2, {3, 0, ControlTransfer::kNoAction}},      // --
+                 {4, {3, 1, ControlTransfer::kPopAndRepush}},  // --
+                 {6, {1, 1, ControlTransfer::kPopAndRepush}});
+}
+
+TEST_F(ControlTransferTest, IfBr) {
+  byte code[] = {
+      kExprI32Const,  // @0
+      0,              //   +1
+      kExprIf,        // @2
+      kExprBr,        // @3
+      ARITY_0,        //   +1
+      0,              //   +1
+      kExprEnd        // @6
+  };
+  EXPECT_TARGETS({2, {5, 0, ControlTransfer::kPushVoid}},  // --
+                 {3, {4, 0, ControlTransfer::kPushVoid}},  // --
+                 {6, {1, 1, ControlTransfer::kPopAndRepush}});
+}
+
+TEST_F(ControlTransferTest, IfBrElse) {
+  byte code[] = {
+      kExprI32Const,  // @0
+      0,              //   +1
+      kExprIf,        // @2
+      kExprBr,        // @3
+      ARITY_0,        //   +1
+      0,              //   +1
+      kExprElse,      // @6
+      kExprEnd        // @7
+  };
+  EXPECT_TARGETS({2, {5, 0, ControlTransfer::kNoAction}},      // --
+                 {3, {5, 0, ControlTransfer::kPushVoid}},      // --
+                 {6, {2, 1, ControlTransfer::kPopAndRepush}},  // --
+                 {7, {1, 0, ControlTransfer::kPushVoid}});
+}
+
+TEST_F(ControlTransferTest, IfElseBr) {
+  byte code[] = {
+      kExprI32Const,  // @0
+      0,              //   +1
+      kExprIf,        // @2
+      kExprNop,       // @3
+      kExprElse,      // @4
+      kExprBr,        // @5
+      ARITY_0,        //   +1
+      0,              //   +1
+      kExprEnd        // @8
+  };
+  EXPECT_TARGETS({2, {3, 0, ControlTransfer::kNoAction}},      // --
+                 {4, {5, 1, ControlTransfer::kPopAndRepush}},  // --
+                 {5, {4, 0, ControlTransfer::kPushVoid}},      // --
+                 {8, {1, 1, ControlTransfer::kPopAndRepush}});
+}
+
+TEST_F(ControlTransferTest, BlockEmpty) {
+  byte code[] = {
+      kExprBlock,  // @0
+      kExprEnd     // @1
+  };
+  EXPECT_TARGETS({1, {1, 0, ControlTransfer::kPushVoid}});
+}
+
+TEST_F(ControlTransferTest, Br0) {
+  byte code[] = {
+      kExprBlock,  // @0
+      kExprBr,     // @1
+      ARITY_0,     //   +1
+      0,           //   +1
+      kExprEnd     // @4
+  };
+  EXPECT_TARGETS({1, {4, 0, ControlTransfer::kPushVoid}},
+                 {4, {1, 1, ControlTransfer::kPopAndRepush}});
+}
+
+TEST_F(ControlTransferTest, Br1) {
+  byte code[] = {
+      kExprBlock,  // @0
+      kExprNop,    // @1
+      kExprBr,     // @2
+      ARITY_0,     //   +1
+      0,           //   +1
+      kExprEnd     // @5
+  };
+  EXPECT_TARGETS({2, {4, 1, ControlTransfer::kPopAndRepush}},  // --
+                 {5, {1, 2, ControlTransfer::kPopAndRepush}});
+}
+
+TEST_F(ControlTransferTest, Br2) {
+  byte code[] = {
+      kExprBlock,  // @0
+      kExprNop,    // @1
+      kExprNop,    // @2
+      kExprBr,     // @3
+      ARITY_0,     //   +1
+      0,           //   +1
+      kExprEnd     // @6
+  };
+  EXPECT_TARGETS({3, {4, 2, ControlTransfer::kPopAndRepush}},  // --
+                 {6, {1, 3, ControlTransfer::kPopAndRepush}});
+}
+
+TEST_F(ControlTransferTest, Br0b) {
+  byte code[] = {
+      kExprBlock,  // @0
+      kExprBr,     // @1
+      ARITY_0,     //   +1
+      0,           //   +1
+      kExprNop,    // @4
+      kExprEnd     // @5
+  };
+  EXPECT_TARGETS({1, {5, 0, ControlTransfer::kPushVoid}},  // --
+                 {5, {1, 2, ControlTransfer::kPopAndRepush}});
+}
+
+TEST_F(ControlTransferTest, Br0c) {
+  byte code[] = {
+      kExprBlock,  // @0
+      kExprBr,     // @1
+      ARITY_0,     //   +1
+      0,           //   +1
+      kExprNop,    // @4
+      kExprNop,    // @5
+      kExprEnd     // @6
+  };
+  EXPECT_TARGETS({1, {6, 0, ControlTransfer::kPushVoid}},  // --
+                 {6, {1, 3, ControlTransfer::kPopAndRepush}});
+}
+
+TEST_F(ControlTransferTest, SimpleLoop1) {
+  byte code[] = {
+      kExprLoop,  // @0
+      kExprBr,    // @1
+      ARITY_0,    //   +1
+      0,          //   +1
+      kExprEnd    // @4
+  };
+  EXPECT_TARGETS({1, {-1, 0, ControlTransfer::kNoAction}},  // --
+                 {4, {1, 1, ControlTransfer::kPopAndRepush}});
+}
+
+TEST_F(ControlTransferTest, SimpleLoop2) {
+  byte code[] = {
+      kExprLoop,  // @0
+      kExprNop,   // @1
+      kExprBr,    // @2
+      ARITY_0,    //   +1
+      0,          //   +1
+      kExprEnd    // @5
+  };
+  EXPECT_TARGETS({2, {-2, 1, ControlTransfer::kNoAction}},  // --
+                 {5, {1, 2, ControlTransfer::kPopAndRepush}});
+}
+
+TEST_F(ControlTransferTest, SimpleLoopExit1) {
+  byte code[] = {
+      kExprLoop,  // @0
+      kExprBr,    // @1
+      ARITY_0,    //   +1
+      1,          //   +1
+      kExprEnd    // @4
+  };
+  EXPECT_TARGETS({1, {4, 0, ControlTransfer::kPushVoid}},  // --
+                 {4, {1, 1, ControlTransfer::kPopAndRepush}});
+}
+
+TEST_F(ControlTransferTest, SimpleLoopExit2) {
+  byte code[] = {
+      kExprLoop,  // @0
+      kExprNop,   // @1
+      kExprBr,    // @2
+      ARITY_0,    //   +1
+      1,          //   +1
+      kExprEnd    // @5
+  };
+  EXPECT_TARGETS({2, {4, 1, ControlTransfer::kPopAndRepush}},  // --
+                 {5, {1, 2, ControlTransfer::kPopAndRepush}});
+}
+
+TEST_F(ControlTransferTest, BrTable0) {
+  byte code[] = {
+      kExprBlock,    // @0
+      kExprI8Const,  // @1
+      0,             //   +1
+      kExprBrTable,  // @3
+      ARITY_0,       //   +1
+      0,             //   +1
+      U32_LE(0),     //   +4
+      kExprEnd       // @10
+  };
+  EXPECT_TARGETS({3, {8, 0, ControlTransfer::kPushVoid}},  // --
+                 {10, {1, 1, ControlTransfer::kPopAndRepush}});
+}
+
+TEST_F(ControlTransferTest, BrTable1) {
+  byte code[] = {
+      kExprBlock,    // @0
+      kExprI8Const,  // @1
+      0,             //   +1
+      kExprBrTable,  // @3
+      ARITY_0,       //   +1
+      1,             //   +1
+      U32_LE(0),     //   +4
+      U32_LE(0),     //   +4
+      kExprEnd       // @14
+  };
+  EXPECT_TARGETS({3, {12, 0, ControlTransfer::kPushVoid}},  // --
+                 {4, {11, 0, ControlTransfer::kPushVoid}},  // --
+                 {14, {1, 1, ControlTransfer::kPopAndRepush}});
+}
+
+TEST_F(ControlTransferTest, BrTable2) {
+  byte code[] = {
+      kExprBlock,    // @0
+      kExprBlock,    // @1
+      kExprI8Const,  // @2
+      0,             //   +1
+      kExprBrTable,  // @4
+      ARITY_0,       //   +1
+      2,             //   +1
+      U32_LE(0),     //   +4
+      U32_LE(0),     //   +4
+      U32_LE(1),     //   +4
+      kExprEnd,      // @19
+      kExprEnd       // @19
+  };
+  EXPECT_TARGETS({4, {16, 0, ControlTransfer::kPushVoid}},      // --
+                 {5, {15, 0, ControlTransfer::kPushVoid}},      // --
+                 {6, {15, 0, ControlTransfer::kPushVoid}},      // --
+                 {19, {1, 1, ControlTransfer::kPopAndRepush}},  // --
+                 {20, {1, 1, ControlTransfer::kPopAndRepush}});
+}
+
+}  // namespace wasm
+}  // namespace internal
+}  // namespace v8