fix signed int64 LEB bug with large negative values (#719)

4 files changed, 55 insertions, 7 deletions

diff --git a/src/wasm-binary.h b/src/wasm-binary.h
index 70af27856..35f84c6b4 100644
--- a/src/wasm-binary.h
+++ b/src/wasm-binary.h
@@ -48,7 +48,7 @@ struct LEB {
 
   bool hasMore(T temp, MiniT byte) {
     // for signed, we must ensure the last bit has the right sign, as it will zero extend
-    return std::is_signed<T>::value ? (temp != 0 && int32_t(temp) != -1) || (value >= 0 && (byte & 64)) || (value < 0 && !(byte & 64)): (temp != 0);
+    return std::is_signed<T>::value ? (temp != 0 && temp != -1) || (value >= 0 && (byte & 64)) || (value < 0 && !(byte & 64)) : (temp != 0);
   }
 
   void write(std::vector<uint8_t>* out) {
@@ -165,23 +165,59 @@ public:
     return *this;
   }
   BufferWithRandomAccess& operator<<(U32LEB x) {
-    if (debug) std::cerr << "writeU32LEB: " << x.value << " (at " << size() << ")" << std::endl;
+    size_t before = -1;
+    if (debug) {
+      before = size();
+      std::cerr << "writeU32LEB: " << x.value << " (at " << before << ")" << std::endl;
+    }
     x.write(this);
+    if (debug) {
+      for (size_t i = before; i < size(); i++) {
+        std::cerr << "  " << (int)at(i) << " (at " << i << ")\n";
+      }
+    }
     return *this;
   }
   BufferWithRandomAccess& operator<<(U64LEB x) {
-    if (debug) std::cerr << "writeU64LEB: " << x.value << " (at " << size() << ")" << std::endl;
+    size_t before = -1;
+    if (debug) {
+      before = size();
+      std::cerr << "writeU64LEB: " << x.value << " (at " << before << ")" << std::endl;
+    }
     x.write(this);
+    if (debug) {
+      for (size_t i = before; i < size(); i++) {
+        std::cerr << "  " << (int)at(i) << " (at " << i << ")\n";
+      }
+    }
     return *this;
   }
   BufferWithRandomAccess& operator<<(S32LEB x) {
-    if (debug) std::cerr << "writeS32LEB: " << x.value << " (at " << size() << ")" << std::endl;
+    size_t before = -1;
+    if (debug) {
+      before = size();
+      std::cerr << "writeS32LEB: " << x.value << " (at " << before << ")" << std::endl;
+    }
     x.write(this);
+    if (debug) {
+      for (size_t i = before; i < size(); i++) {
+        std::cerr << "  " << (int)at(i) << " (at " << i << ")\n";
+      }
+    }
     return *this;
   }
   BufferWithRandomAccess& operator<<(S64LEB x) {
-    if (debug) std::cerr << "writeS64LEB: " << x.value << " (at " << size() << ")" << std::endl;
+    size_t before = -1;
+    if (debug) {
+      before = size();
+      std::cerr << "writeS64LEB: " << x.value << " (at " << before << ")" << std::endl;
+    }
     x.write(this);
+    if (debug) {
+      for (size_t i = before; i < size(); i++) {
+        std::cerr << "  " << (int)at(i) << " (at " << i << ")\n";
+      }
+    }
     return *this;
   }
 
@@ -1420,7 +1456,7 @@ public:
     ret.read([&]() {
       return (int8_t)getInt8();
     });
-    if (debug) std::cerr << "getU32LEB: " << ret.value << " ==>" << std::endl;
+    if (debug) std::cerr << "getS32LEB: " << ret.value << " ==>" << std::endl;
     return ret.value;
   }
   int64_t getS64LEB() {
@@ -1429,7 +1465,7 @@ public:
     ret.read([&]() {
       return (int8_t)getInt8();
     });
-    if (debug) std::cerr << "getU64LEB: " << ret.value << " ==>" << std::endl;
+    if (debug) std::cerr << "getS64LEB: " << ret.value << " ==>" << std::endl;
     return ret.value;
   }
   WasmType getWasmType() {
diff --git a/test/unit.wast b/test/unit.wast
index 2ba0f6612..90fab25f3 100644
--- a/test/unit.wast
+++ b/test/unit.wast
@@ -9,6 +9,7 @@
   (type $5 (func (result i32)))
   (type $6 (func (param i32) (result i32)))
   (type $7 (func (param f64) (result f64)))
+  (type $8 (func (result i64)))
   (import "env" "_emscripten_asm_const_vi" (func $_emscripten_asm_const_vi))
   (import "asm2wasm" "f64-to-int" (func $f64-to-int (param f64) (result i32)))
   (import "asm2wasm" "f64-rem" (func $f64-rem (param f64 f64) (result f64)))
@@ -436,4 +437,7 @@
       (get_local $0)
     )
   )
+  (func $big-i64 (type $8) (result i64)
+    (i64.const -9218868437227405313)
+  )
 )
diff --git a/test/unit.wast.fromBinary b/test/unit.wast.fromBinary
index 8516d1775..4ff9f0d73 100644
--- a/test/unit.wast.fromBinary
+++ b/test/unit.wast.fromBinary
@@ -9,6 +9,7 @@
   (type $5 (func (result i32)))
   (type $6 (func (param i32) (result i32)))
   (type $7 (func (param f64) (result f64)))
+  (type $8 (func (result i64)))
   (import "env" "_emscripten_asm_const_vi" (func $import$0))
   (import "asm2wasm" "f64-to-int" (func $import$1 (param f64) (result i32)))
   (import "asm2wasm" "f64-rem" (func $import$2 (param f64 f64) (result f64)))
@@ -446,5 +447,8 @@
       (get_local $var$0)
     )
   )
+  (func $big-i64 (type $8) (result i64)
+    (i64.const -9218868437227405313)
+  )
 )
 
diff --git a/test/unit.wast.fromBinary.noDebugInfo b/test/unit.wast.fromBinary.noDebugInfo
index d6980b9be..04448e90b 100644
--- a/test/unit.wast.fromBinary.noDebugInfo
+++ b/test/unit.wast.fromBinary.noDebugInfo
@@ -9,6 +9,7 @@
   (type $5 (func (result i32)))
   (type $6 (func (param i32) (result i32)))
   (type $7 (func (param f64) (result f64)))
+  (type $8 (func (result i64)))
   (import "env" "_emscripten_asm_const_vi" (func $import$0))
   (import "asm2wasm" "f64-to-int" (func $import$1 (param f64) (result i32)))
   (import "asm2wasm" "f64-rem" (func $import$2 (param f64 f64) (result f64)))
@@ -446,5 +447,8 @@
       (get_local $var$0)
     )
   )
+  (func $21 (type $8) (result i64)
+    (i64.const -9218868437227405313)
+  )
 )