Merge pull request '修复三元表达式 issue' (#45) from fix-bool-ternary-expr into master

Reviewed-on: #45

src/Parser/SelectionExpressionTrait.php

@@ -22,6 +22,9 @@ trait SelectionExpressionTrait
         $this->assertExprCanBeUsedAsCondition($expr->cond, 'ternary condition');
         $this->assertExprCanBeUsedAsValue($expr->if, 'ternary branch');
         $this->assertExprCanBeUsedAsValue($expr->else, 'ternary branch');
+        $ifType = $this->detectTypeOfExpr($expr->if);
+        $elseType = $this->detectTypeOfExpr($expr->else);
+        $typeChanged = $ifType !== $elseType;
         [$cond, $condBeforeStmts, $condAfterStmts] = $this->parseExprWithCapturedStmts($expr->cond);
         $ifBeforeStmtCount = count($this->context->beforeStmtLines);
         $ifAfterStmtCount = count($this->context->afterStmtLines);
@@ -40,13 +43,15 @@ trait SelectionExpressionTrait
         $this->context->afterStmtLines = array_slice($this->context->afterStmtLines, 0, $elseAfterStmtCount);
 
         $hasBranchStmts = $condBeforeStmts || $condAfterStmts || $ifBeforeStmts || $ifAfterStmts || $elseBeforeStmts || $elseAfterStmts;
-        $typeChanged = $this->detectTypeOfExpr($expr->if) !== $this->detectTypeOfExpr($expr->else);
         if (!$hasBranchStmts && $typeChanged) {
             $if = 'php::Var(' . $if . ')';
             $else = 'php::Var(' . $else . ')';
         }
         if ($hasBranchStmts) {
-            $code = '[&]() -> ' . Type::VAR . '{';
+            // REF and VOID are expression implementation types, not valid
+            // by-value result types for the materializing lambda.
+            $ternaryType = $this->getNormalAssignType($typeChanged ? Type::VAR : $ifType);
+            $code = '[&]() -> ' . $ternaryType . '{';
             $code .= $this->formatCapturedStmtLines($condBeforeStmts);
             if ($condAfterStmts) {
                 $condTmpVar = $this->addTmpVar(Type::VAR);
@@ -56,9 +61,9 @@ trait SelectionExpressionTrait
             }
             $cond = $this->convertConditionExpr($expr->cond, $cond);
             $code .= $this->getIndent() . 'if (' . $cond . ') {';
-            $code .= $this->formatTernaryReturn($if, $ifBeforeStmts, $ifAfterStmts);
+            $code .= $this->formatTernaryReturn($expr->if, $if, $ifBeforeStmts, $ifAfterStmts, $ternaryType, $ifType);
             $code .= $this->getIndent() . '} else {';
-            $code .= $this->formatTernaryReturn($else, $elseBeforeStmts, $elseAfterStmts);
+            $code .= $this->formatTernaryReturn($expr->else, $else, $elseBeforeStmts, $elseAfterStmts, $ternaryType, $elseType);
             $code .= $this->getIndent() . '}';
             $code .= $this->getIndent() . '}()';
             return $code;
@@ -67,16 +72,30 @@ trait SelectionExpressionTrait
         return '(' . $cond . ') ? (' . $if . ') : (' . $else . ')';
     }
 
-    protected function formatTernaryReturn(string $value, array $beforeStmts, array $afterStmts): string
+    protected function formatTernaryReturn(
+        NodeAbstract $valueExpr,
+        string $value,
+        array $beforeStmts,
+        array $afterStmts,
+        string $returnType,
+        string $valueType,
+    ): string
     {
         $code = $this->formatCapturedStmtLines($beforeStmts);
-        if ($afterStmts) {
-            $tmpVar = $this->addTmpVar(Type::VAR);
+        $returnsReference = $valueType === Type::REF
+            || ($valueExpr instanceof Expr\CallLike && $this->resolveRefReturningCall($valueExpr) !== false);
+        if ($returnType !== Type::VAR && ($beforeStmts || $afterStmts)) {
+            $value = $this->convertExprFromType($returnType, $value);
+        }
+        if ($afterStmts || $returnsReference) {
+            $tmpVar = $this->addTmpVar($returnType);
             $code .= $this->getIndent() . "{$tmpVar} = {$value};";
             $code .= $this->formatCapturedStmtLines($afterStmts);
             $code .= $this->getIndent() . 'return ' . $tmpVar . ';';
         } else {
-            $code .= $this->getIndent() . 'return php::Var(' . $value . ');';
+            $code .= $returnType === Type::VAR
+                ? $this->getIndent() . 'return php::Var(' . $value . ');'
+                : $this->getIndent() . 'return ' . $value . ';';
         }
         return $code;
     }

tests/compiler/ternary-ref-captured.phpt

@@ -0,0 +1,27 @@
+--TEST--
+Ternary with captured statements materializes reference returns as values
+--FILE--
+<?php
+function &ternary_ref_value(mixed &$value): mixed
+{
+    return $value;
+}
+
+function main(): void
+{
+    $first = 1;
+    $second = 2;
+    $values = [1];
+
+    $result = count($values) > 0
+        ? ternary_ref_value($first)
+        : ternary_ref_value($second);
+    $result = 9;
+
+    var_dump($first, $second, $result);
+}
+?>
+--EXPECT--
+int(1)
+int(2)
+int(9)

tests/compiler/ternary-typed-arg.phpt

@@ -0,0 +1,29 @@
+--TEST--
+Ternary with captured statements keeps its static type for typed arguments
+--FILE--
+<?php
+declare(strict_types=1);
+
+class TernaryBoolArg
+{
+    public function takeBool(bool $flag): bool
+    {
+        return $flag;
+    }
+}
+
+function main(): void
+{
+    $range = [1, 2, 3];
+    $obj = new TernaryBoolArg();
+
+    // The condition contains a function call, which forces the ternary into a
+    // captured-statement lambda. The lambda must still yield php::Bool so it
+    // can feed the typed parameter.
+    var_dump($obj->takeBool(count($range) > 1 ? true : false));
+    var_dump($obj->takeBool(count($range) > 5 ? true : false));
+}
+?>
+--EXPECT--
+bool(true)
+bool(false)

tests/compiler/ternary-void-captured.phpt

@@ -0,0 +1,26 @@
+--TEST--
+Ternary with captured statements preserves void expression semantics
+--FILE--
+<?php
+function ternary_void_side_effect(string $value): void
+{
+    echo $value, "\n";
+}
+
+function main(): void
+{
+    $values = [1, 2];
+
+    var_dump(count($values) > 1
+        ? ternary_void_side_effect('if')
+        : ternary_void_side_effect('else'));
+    var_dump(count($values) > 5
+        ? ternary_void_side_effect('if')
+        : ternary_void_side_effect('else'));
+}
+?>
+--EXPECT--
+if
+NULL
+else
+NULL