Issue a nicer error message on wasm components. (#2515)

Decode just enough of the component binary format to recognize when the
input is a component, and issue a dedicated error message for it.

Before:

0000008: error: bad wasm file version: 0x1000d (expected 0x1)

After:

0000008: error: wasm components are not yet supported in this tool

8 files changed, 70 insertions, 31 deletions

diff --git a/include/wabt/binary.h b/include/wabt/binary.h
index 98575f96..a8c768f3 100644
--- a/include/wabt/binary.h
+++ b/include/wabt/binary.h
@@ -21,6 +21,8 @@
 
 #define WABT_BINARY_MAGIC 0x6d736100
 #define WABT_BINARY_VERSION 1
+#define WABT_BINARY_LAYER_MODULE 0
+#define WABT_BINARY_LAYER_COMPONENT 1
 #define WABT_BINARY_LIMITS_HAS_MAX_FLAG 0x1
 #define WABT_BINARY_LIMITS_IS_SHARED_FLAG 0x2
 #define WABT_BINARY_LIMITS_IS_64_FLAG 0x4
diff --git a/src/binary-reader.cc b/src/binary-reader.cc
index 7b0b4187..e1859a1c 100644
--- a/src/binary-reader.cc
+++ b/src/binary-reader.cc
@@ -37,12 +37,17 @@
 #include <alloca.h>
 #endif
 
-#define ERROR_IF(expr, ...)    \
-  do {                         \
-    if (expr) {                \
-      PrintError(__VA_ARGS__); \
-      return Result::Error;    \
-    }                          \
+#define ERROR(...)           \
+  do {                       \
+    PrintError(__VA_ARGS__); \
+    return Result::Error;    \
+  } while (0)
+
+#define ERROR_IF(expr, ...) \
+  do {                      \
+    if (expr) {             \
+      ERROR(__VA_ARGS__);   \
+    }                       \
   } while (0)
 
 #define ERROR_UNLESS(expr, ...) ERROR_IF(!(expr), __VA_ARGS__)
@@ -100,6 +105,7 @@ class BinaryReader {
                              const char* type_name,
                              const char* desc);
   [[nodiscard]] Result ReadU8(uint8_t* out_value, const char* desc);
+  [[nodiscard]] Result ReadU16(uint16_t* out_value, const char* desc);
   [[nodiscard]] Result ReadU32(uint32_t* out_value, const char* desc);
   [[nodiscard]] Result ReadF32(uint32_t* out_value, const char* desc);
   [[nodiscard]] Result ReadF64(uint64_t* out_value, const char* desc);
@@ -300,6 +306,10 @@ Result BinaryReader::ReadU8(uint8_t* out_value, const char* desc) {
   return ReadT(out_value, "uint8_t", desc);
 }
 
+Result BinaryReader::ReadU16(uint16_t* out_value, const char* desc) {
+  return ReadT(out_value, "uint16_t", desc);
+}
+
 Result BinaryReader::ReadU32(uint32_t* out_value, const char* desc) {
   return ReadT(out_value, "uint32_t", desc);
 }
@@ -3086,11 +3096,24 @@ Result BinaryReader::ReadModule(const ReadModuleOptions& options) {
   uint32_t magic = 0;
   CHECK_RESULT(ReadU32(&magic, "magic"));
   ERROR_UNLESS(magic == WABT_BINARY_MAGIC, "bad magic value");
-  uint32_t version = 0;
-  CHECK_RESULT(ReadU32(&version, "version"));
-  ERROR_UNLESS(version == WABT_BINARY_VERSION,
-               "bad wasm file version: %#x (expected %#x)", version,
-               WABT_BINARY_VERSION);
+
+  uint16_t version = 0, layer = 0;
+  CHECK_RESULT(ReadU16(&version, "version"));
+  CHECK_RESULT(ReadU16(&layer, "layer"));
+
+  switch (layer) {
+    case WABT_BINARY_LAYER_MODULE:
+      ERROR_UNLESS(version == WABT_BINARY_VERSION,
+                   "bad wasm file version: %#x (expected %#x)", version,
+                   WABT_BINARY_VERSION);
+      break;
+    case WABT_BINARY_LAYER_COMPONENT:
+      ERROR("wasm components are not yet supported in this tool");
+      break;
+    default:
+      ERROR("unsupported wasm layer: %#x", layer);
+      break;
+  }
 
   CALLBACK(BeginModule, version);
   CHECK_RESULT(ReadSections(ReadSectionsOptions{options.stop_on_first_error}));
diff --git a/test/binary/unrecognized-layer.txt b/test/binary/unrecognized-layer.txt
new file mode 100644
index 00000000..3ba231dc
--- /dev/null
+++ b/test/binary/unrecognized-layer.txt
@@ -0,0 +1,7 @@
+;;; TOOL: run-gen-wasm-bad
+magic
+0xe 0 0x2 0
+(;; STDERR ;;;
+0000008: error: unsupported wasm layer: 0x2
+0000008: error: unsupported wasm layer: 0x2
+;;; STDERR ;;)
diff --git a/test/binary/unsupported-component.txt b/test/binary/unsupported-component.txt
new file mode 100644
index 00000000..c1167f0d
--- /dev/null
+++ b/test/binary/unsupported-component.txt
@@ -0,0 +1,7 @@
+;;; TOOL: run-gen-wasm-bad
+magic
+0xd 0 0x1 0
+(;; STDERR ;;;
+0000008: error: wasm components are not yet supported in this tool
+0000008: error: wasm components are not yet supported in this tool
+;;; STDERR ;;)
diff --git a/test/spec/binary.txt b/test/spec/binary.txt
index fd20a651..a4cfc29e 100644
--- a/test/spec/binary.txt
+++ b/test/spec/binary.txt
@@ -40,11 +40,11 @@ out/test/spec/binary.wast:31: assert_malformed passed:
 out/test/spec/binary.wast:34: assert_malformed passed:
   0000004: error: bad magic value
 out/test/spec/binary.wast:37: assert_malformed passed:
-  0000004: error: unable to read uint32_t: version
+  0000004: error: unable to read uint16_t: version
 out/test/spec/binary.wast:38: assert_malformed passed:
-  0000004: error: unable to read uint32_t: version
+  0000004: error: unable to read uint16_t: version
 out/test/spec/binary.wast:39: assert_malformed passed:
-  0000004: error: unable to read uint32_t: version
+  0000006: error: unable to read uint16_t: layer
 out/test/spec/binary.wast:40: assert_malformed passed:
   0000008: error: bad wasm file version: 0 (expected 0x1)
 out/test/spec/binary.wast:41: assert_malformed passed:
@@ -54,9 +54,9 @@ out/test/spec/binary.wast:42: assert_malformed passed:
 out/test/spec/binary.wast:43: assert_malformed passed:
   0000008: error: bad wasm file version: 0x100 (expected 0x1)
 out/test/spec/binary.wast:44: assert_malformed passed:
-  0000008: error: bad wasm file version: 0x10000 (expected 0x1)
+  0000008: error: wasm components are not yet supported in this tool
 out/test/spec/binary.wast:45: assert_malformed passed:
-  0000008: error: bad wasm file version: 0x1000000 (expected 0x1)
+  0000008: error: unsupported wasm layer: 0x100
 out/test/spec/binary.wast:48: assert_malformed passed:
   000000a: error: invalid section code: 14
 out/test/spec/binary.wast:49: assert_malformed passed:
diff --git a/test/spec/exception-handling/binary.txt b/test/spec/exception-handling/binary.txt
index 8d253cf7..a289d3be 100644
--- a/test/spec/exception-handling/binary.txt
+++ b/test/spec/exception-handling/binary.txt
@@ -41,11 +41,11 @@ out/test/spec/exception-handling/binary.wast:31: assert_malformed passed:
 out/test/spec/exception-handling/binary.wast:34: assert_malformed passed:
   0000004: error: bad magic value
 out/test/spec/exception-handling/binary.wast:37: assert_malformed passed:
-  0000004: error: unable to read uint32_t: version
+  0000004: error: unable to read uint16_t: version
 out/test/spec/exception-handling/binary.wast:38: assert_malformed passed:
-  0000004: error: unable to read uint32_t: version
+  0000004: error: unable to read uint16_t: version
 out/test/spec/exception-handling/binary.wast:39: assert_malformed passed:
-  0000004: error: unable to read uint32_t: version
+  0000006: error: unable to read uint16_t: layer
 out/test/spec/exception-handling/binary.wast:40: assert_malformed passed:
   0000008: error: bad wasm file version: 0 (expected 0x1)
 out/test/spec/exception-handling/binary.wast:41: assert_malformed passed:
@@ -55,9 +55,9 @@ out/test/spec/exception-handling/binary.wast:42: assert_malformed passed:
 out/test/spec/exception-handling/binary.wast:43: assert_malformed passed:
   0000008: error: bad wasm file version: 0x100 (expected 0x1)
 out/test/spec/exception-handling/binary.wast:44: assert_malformed passed:
-  0000008: error: bad wasm file version: 0x10000 (expected 0x1)
+  0000008: error: wasm components are not yet supported in this tool
 out/test/spec/exception-handling/binary.wast:45: assert_malformed passed:
-  0000008: error: bad wasm file version: 0x1000000 (expected 0x1)
+  0000008: error: unsupported wasm layer: 0x100
 out/test/spec/exception-handling/binary.wast:48: assert_malformed passed:
   000000a: error: invalid section code: 14
 out/test/spec/exception-handling/binary.wast:49: assert_malformed passed:
diff --git a/test/spec/memory64/binary.txt b/test/spec/memory64/binary.txt
index e34a5f79..6b3bfef5 100644
--- a/test/spec/memory64/binary.txt
+++ b/test/spec/memory64/binary.txt
@@ -41,11 +41,11 @@ out/test/spec/memory64/binary.wast:31: assert_malformed passed:
 out/test/spec/memory64/binary.wast:34: assert_malformed passed:
   0000004: error: bad magic value
 out/test/spec/memory64/binary.wast:37: assert_malformed passed:
-  0000004: error: unable to read uint32_t: version
+  0000004: error: unable to read uint16_t: version
 out/test/spec/memory64/binary.wast:38: assert_malformed passed:
-  0000004: error: unable to read uint32_t: version
+  0000004: error: unable to read uint16_t: version
 out/test/spec/memory64/binary.wast:39: assert_malformed passed:
-  0000004: error: unable to read uint32_t: version
+  0000006: error: unable to read uint16_t: layer
 out/test/spec/memory64/binary.wast:40: assert_malformed passed:
   0000008: error: bad wasm file version: 0 (expected 0x1)
 out/test/spec/memory64/binary.wast:41: assert_malformed passed:
@@ -55,9 +55,9 @@ out/test/spec/memory64/binary.wast:42: assert_malformed passed:
 out/test/spec/memory64/binary.wast:43: assert_malformed passed:
   0000008: error: bad wasm file version: 0x100 (expected 0x1)
 out/test/spec/memory64/binary.wast:44: assert_malformed passed:
-  0000008: error: bad wasm file version: 0x10000 (expected 0x1)
+  0000008: error: wasm components are not yet supported in this tool
 out/test/spec/memory64/binary.wast:45: assert_malformed passed:
-  0000008: error: bad wasm file version: 0x1000000 (expected 0x1)
+  0000008: error: unsupported wasm layer: 0x100
 out/test/spec/memory64/binary.wast:48: assert_malformed passed:
   000000a: error: invalid section code: 14
 out/test/spec/memory64/binary.wast:49: assert_malformed passed:
diff --git a/test/spec/multi-memory/binary.txt b/test/spec/multi-memory/binary.txt
index d88e22f5..ed0842c9 100644
--- a/test/spec/multi-memory/binary.txt
+++ b/test/spec/multi-memory/binary.txt
@@ -41,11 +41,11 @@ out/test/spec/multi-memory/binary.wast:31: assert_malformed passed:
 out/test/spec/multi-memory/binary.wast:34: assert_malformed passed:
   0000004: error: bad magic value
 out/test/spec/multi-memory/binary.wast:37: assert_malformed passed:
-  0000004: error: unable to read uint32_t: version
+  0000004: error: unable to read uint16_t: version
 out/test/spec/multi-memory/binary.wast:38: assert_malformed passed:
-  0000004: error: unable to read uint32_t: version
+  0000004: error: unable to read uint16_t: version
 out/test/spec/multi-memory/binary.wast:39: assert_malformed passed:
-  0000004: error: unable to read uint32_t: version
+  0000006: error: unable to read uint16_t: layer
 out/test/spec/multi-memory/binary.wast:40: assert_malformed passed:
   0000008: error: bad wasm file version: 0 (expected 0x1)
 out/test/spec/multi-memory/binary.wast:41: assert_malformed passed:
@@ -55,9 +55,9 @@ out/test/spec/multi-memory/binary.wast:42: assert_malformed passed:
 out/test/spec/multi-memory/binary.wast:43: assert_malformed passed:
   0000008: error: bad wasm file version: 0x100 (expected 0x1)
 out/test/spec/multi-memory/binary.wast:44: assert_malformed passed:
-  0000008: error: bad wasm file version: 0x10000 (expected 0x1)
+  0000008: error: wasm components are not yet supported in this tool
 out/test/spec/multi-memory/binary.wast:45: assert_malformed passed:
-  0000008: error: bad wasm file version: 0x1000000 (expected 0x1)
+  0000008: error: unsupported wasm layer: 0x100
 out/test/spec/multi-memory/binary.wast:48: assert_malformed passed:
   000000a: error: invalid section code: 14
 out/test/spec/multi-memory/binary.wast:49: assert_malformed passed: