Implement support for conditional expressions

Change-Id: Ifcd57713e1cfa9514d3955e26f739a359cdaa8e5
Reviewed-by: Erik Verbruggen <erik.verbruggen@qt.io>
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

4 files changed, 44 insertions, 38 deletions

diff --git a/src/qml/compiler/qv4bytecodegenerator.cpp b/src/qml/compiler/qv4bytecodegenerator.cpp
index 0073cb4598..444d8385d4 100644
--- a/src/qml/compiler/qv4bytecodegenerator.cpp
+++ b/src/qml/compiler/qv4bytecodegenerator.cpp
@@ -70,12 +70,15 @@ QByteArray BytecodeGenerator::finalize()
     }
 
     // resolve jumps
+//    qDebug() << "resolving jumps";
     for (const auto &j : jumps) {
         Q_ASSERT(j.linkedInstruction != -1);
         int offset = instructionOffsets.at(j.instructionIndex) + j.offset;
+//        qDebug() << "offset data is at" << offset;
         char *c = code.data() + offset;
-        int linkedInstruction = instructionOffsets.at(j.linkedInstruction) - offset;
-        memcpy(c, &linkedInstruction, sizeof(int));
+        ptrdiff_t linkedInstruction = instructionOffsets.at(j.linkedInstruction) - offset;
+//        qDebug() << "linked instruction" << j.linkedInstruction << "at " << instructionOffsets.at(j.linkedInstruction);
+        memcpy(c, &linkedInstruction, sizeof(ptrdiff_t));
     }
 
     return code;
diff --git a/src/qml/compiler/qv4bytecodegenerator_p.h b/src/qml/compiler/qv4bytecodegenerator_p.h
index 5c7480fc89..384fb22aa3 100644
--- a/src/qml/compiler/qv4bytecodegenerator_p.h
+++ b/src/qml/compiler/qv4bytecodegenerator_p.h
@@ -92,26 +92,33 @@ public:
         addInstructionHelper(InstrMeta<InstrT>::Size, genericInstr);
     }
 
-    Q_REQUIRED_RESULT Jump addInstruction(const Instruction::Jump &data)
+    Q_REQUIRED_RESULT Jump jump()
     {
+        Instruction::Jump data;
         return addJumpInstruction(data);
     }
 
-    Q_REQUIRED_RESULT Jump addInstruction(const Instruction::SetExceptionHandler &data)
+    Q_REQUIRED_RESULT Jump jumpEq(const QV4::Moth::Param &cond)
     {
+        Instruction::JumpEq data;
+        data.condition = cond;
         return addJumpInstruction(data);
     }
 
-    Q_REQUIRED_RESULT Jump addInstruction(const Instruction::JumpEq &data)
+    Q_REQUIRED_RESULT Jump jumpNe(const QV4::Moth::Param &cond)
     {
+        Instruction::JumpNe data;
+        data.condition = cond;
         return addJumpInstruction(data);
     }
 
-    Q_REQUIRED_RESULT Jump addInstruction(const Instruction::JumpNe &data)
+    Q_REQUIRED_RESULT Jump setExceptionHandler()
     {
+        Instruction::SetExceptionHandler data;
         return addJumpInstruction(data);
     }
 
+
     unsigned newTemp();
 
 
diff --git a/src/qml/compiler/qv4codegen.cpp b/src/qml/compiler/qv4codegen.cpp
index 921556ddf8..b16d28518d 100644
--- a/src/qml/compiler/qv4codegen.cpp
+++ b/src/qml/compiler/qv4codegen.cpp
@@ -1638,32 +1638,26 @@ bool Codegen::visit(ConditionalExpression *ast)
     if (hasError)
         return true;
 
-    IR::BasicBlock *iftrue = _function->newBasicBlock(exceptionHandler());
-    IR::BasicBlock *iffalse = _function->newBasicBlock(exceptionHandler());
-    IR::BasicBlock *endif = _function->newBasicBlock(exceptionHandler());
-
     const unsigned t = _block->newTemp();
+    _expr = Reference::fromTemp(this, t);
+
     TempScope scope(_function);
 
-    condition(ast->expression, iftrue, iffalse);
+    Reference r = expression(ast->expression);
 
-    _block = iftrue;
-    Result ok = expression(ast->ok);
-    if (hasError)
-        return false;
-    move(_block->TEMP(t), *ok);
-    _block->JUMP(endif);
+    // ### handle const Reference
 
-    _block = iffalse;
-    Result ko = expression(ast->ko);
-    if (hasError)
-        return false;
-    move(_block->TEMP(t), *ko);
-    _block->JUMP(endif);
+    Moth::BytecodeGenerator::Jump jump_else = bytecodeGenerator->jumpNe(r.asRValue());
 
-    _block = endif;
+    _expr.result.store(expression(ast->ok));
 
-    _expr.code = _block->TEMP(t);
+    Moth::BytecodeGenerator::Jump jump_endif = bytecodeGenerator->jump();
+
+    jump_else.link();
+
+    _expr.result.store(expression(ast->ko));
+
+    jump_endif.link();
 
     return false;
 }
@@ -1723,11 +1717,7 @@ bool Codegen::visit(FalseLiteral *)
     if (hasError)
         return false;
 
-    if (_expr.accept(cx)) {
-        _block->JUMP(_expr.iffalse);
-    } else {
-        _expr.result = Reference::fromConst(this, QV4::Encode(false));
-    }
+    _expr.result = Reference::fromConst(this, QV4::Encode(false));
     return false;
 }
 
@@ -2264,11 +2254,7 @@ bool Codegen::visit(TrueLiteral *)
     if (hasError)
         return false;
 
-    if (_expr.accept(cx)) {
-        _block->JUMP(_expr.iftrue);
-    } else {
-        _expr.result = Reference::fromConst(this, QV4::Encode(false));
-    }
+    _expr.result = Reference::fromConst(this, QV4::Encode(true));
     return false;
 }
 
diff --git a/src/qml/compiler/qv4instr_moth.cpp b/src/qml/compiler/qv4instr_moth.cpp
index e1a6a4395c..33ca111bf1 100644
--- a/src/qml/compiler/qv4instr_moth.cpp
+++ b/src/qml/compiler/qv4instr_moth.cpp
@@ -59,6 +59,16 @@ QByteArray alignedNumber(int n) {
     return number;
 }
 
+QString toString(QV4::ReturnedValue v)
+{
+#ifdef V4_BOOTSTRAP
+    return QStringLiteral("string-const(%1)").arg(v);
+#else // !V4_BOOTSTRAP
+    Value val = Value::fromReturnedValue(v);
+    return QLatin1String("const(") + val.toQStringNoThrow() + QLatin1String(")");
+#endif // V4_BOOTSTRAP
+}
+
 #define MOTH_BEGIN_INSTR(I) \
     case Instr::I: {\
     const InstrMeta<(int)Instr::I>::DataType &instr = InstrMeta<(int)Instr::I>::data(*genericInstr); \
@@ -104,7 +114,7 @@ void dumpBytecode(const char *code, int len)
         MOTH_END_INSTR(Move)
 
         MOTH_BEGIN_INSTR(MoveConst)
-            d << instr.result << ", " << instr.source;
+            d << instr.result << ", " << toString(instr.source).toUtf8().constData();
         MOTH_END_INSTR(MoveConst)
 
         MOTH_BEGIN_INSTR(SwapTemps)
@@ -349,11 +359,11 @@ void dumpBytecode(const char *code, int len)
         MOTH_END_INSTR(Jump)
 
         MOTH_BEGIN_INSTR(JumpEq)
-            d << instr.offset;
+            d << instr.condition << "  " << instr.offset;
         MOTH_END_INSTR(JumpEq)
 
         MOTH_BEGIN_INSTR(JumpNe)
-            d << instr.offset;
+            d << instr.condition << "  " << instr.offset;
         MOTH_END_INSTR(JumpNe)
 
         MOTH_BEGIN_INSTR(UNot)