From: Dmitry Stogov <dmitry@zend.com>
Date: Fri, 4 Apr 2014 11:22:41 +0000 (+0400)
Subject: Tergets of ASSIGN and ASSIGN_REF don't have to be initialized
X-Git-Tag: POST_PHPNG_MERGE~412^2~168
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=cea26aa2ebb172d3afa0f22a5eb1af1c3b0c703f;p=php

Tergets of ASSIGN and ASSIGN_REF don't have to be initialized
---

diff --git a/Zend/zend_vm_def.h b/Zend/zend_vm_def.h
index 75ced021bb..613a82de83 100644
--- a/Zend/zend_vm_def.h
+++ b/Zend/zend_vm_def.h
@@ -1738,7 +1738,7 @@ ZEND_VM_HANDLER(38, ZEND_ASSIGN, VAR|CV, CONST|TMP|VAR|CV)
 
 	SAVE_OPLINE();
 	value = GET_OP2_ZVAL_PTR(BP_VAR_R);
-	variable_ptr = GET_OP1_ZVAL_PTR_PTR(BP_VAR_W);
+	variable_ptr = GET_OP1_ZVAL_PTR_PTR_UNDEF(BP_VAR_W);
 
 	if (OP1_TYPE == IS_VAR && UNEXPECTED(Z_TYPE_P(variable_ptr) == IS_STR_OFFSET)) {
 		zend_assign_to_string_offset(variable_ptr, value, OP2_TYPE, (RETURN_VALUE_USED(opline) ? EX_VAR(opline->result.var) : NULL) TSRMLS_CC);
@@ -1781,10 +1781,9 @@ ZEND_VM_HANDLER(39, ZEND_ASSIGN_REF, VAR|CV, VAR|CV)
 	value_ptr = GET_OP2_ZVAL_PTR_PTR(BP_VAR_W);
 
 	if (OP2_TYPE == IS_VAR &&
-	    value_ptr &&
-	    !Z_ISREF_P(value_ptr) &&
 	    opline->extended_value == ZEND_RETURNS_FUNCTION &&
-	    !(Z_VAR_FLAGS_P(value_ptr) & IS_VAR_RET_REF)) {
+	    !(Z_VAR_FLAGS_P(value_ptr) & IS_VAR_RET_REF) &&
+	    !Z_ISREF_P(value_ptr)) {
 		if (!OP2_FREE) {
 			PZVAL_LOCK(value_ptr); /* undo the effect of get_zval_ptr_ptr() */
 		}
@@ -1799,13 +1798,13 @@ ZEND_VM_HANDLER(39, ZEND_ASSIGN_REF, VAR|CV, VAR|CV)
 			PZVAL_LOCK(value_ptr);
 		}
 	}
+
+	variable_ptr = GET_OP1_ZVAL_PTR_PTR_UNDEF(BP_VAR_W);
 	if (OP1_TYPE == IS_VAR &&
 	    UNEXPECTED(Z_TYPE_P(EX_VAR(opline->op1.var)) != IS_INDIRECT) &&
 	    UNEXPECTED(!Z_ISREF_P(variable_ptr))) {
 		zend_error_noreturn(E_ERROR, "Cannot assign by reference to overloaded object");
 	}
-
-	variable_ptr = GET_OP1_ZVAL_PTR_PTR(BP_VAR_W);
 	if ((OP2_TYPE == IS_VAR && UNEXPECTED(Z_TYPE_P(value_ptr) == IS_STR_OFFSET)) ||
 	    (OP1_TYPE == IS_VAR && UNEXPECTED(Z_TYPE_P(variable_ptr) == IS_STR_OFFSET))) {
 		zend_error_noreturn(E_ERROR, "Cannot create references to/from string offsets nor overloaded objects");
diff --git a/Zend/zend_vm_execute.h b/Zend/zend_vm_execute.h
index a1360caeae..8187956cf6 100644
--- a/Zend/zend_vm_execute.h
+++ b/Zend/zend_vm_execute.h
@@ -19554,10 +19554,9 @@ static int ZEND_FASTCALL  ZEND_ASSIGN_REF_SPEC_VAR_VAR_HANDLER(ZEND_OPCODE_HANDL
 	value_ptr = _get_zval_ptr_ptr_var(opline->op2.var, execute_data, &free_op2 TSRMLS_CC);
 
 	if (IS_VAR == IS_VAR &&
-	    value_ptr &&
-	    !Z_ISREF_P(value_ptr) &&
 	    opline->extended_value == ZEND_RETURNS_FUNCTION &&
-	    !(Z_VAR_FLAGS_P(value_ptr) & IS_VAR_RET_REF)) {
+	    !(Z_VAR_FLAGS_P(value_ptr) & IS_VAR_RET_REF) &&
+	    !Z_ISREF_P(value_ptr)) {
 		if (!(free_op2.var != NULL)) {
 			PZVAL_LOCK(value_ptr); /* undo the effect of get_zval_ptr_ptr() */
 		}
@@ -19572,13 +19571,13 @@ static int ZEND_FASTCALL  ZEND_ASSIGN_REF_SPEC_VAR_VAR_HANDLER(ZEND_OPCODE_HANDL
 			PZVAL_LOCK(value_ptr);
 		}
 	}
+
+	variable_ptr = _get_zval_ptr_ptr_var(opline->op1.var, execute_data, &free_op1 TSRMLS_CC);
 	if (IS_VAR == IS_VAR &&
 	    UNEXPECTED(Z_TYPE_P(EX_VAR(opline->op1.var)) != IS_INDIRECT) &&
 	    UNEXPECTED(!Z_ISREF_P(variable_ptr))) {
 		zend_error_noreturn(E_ERROR, "Cannot assign by reference to overloaded object");
 	}
-
-	variable_ptr = _get_zval_ptr_ptr_var(opline->op1.var, execute_data, &free_op1 TSRMLS_CC);
 	if ((IS_VAR == IS_VAR && UNEXPECTED(Z_TYPE_P(value_ptr) == IS_STR_OFFSET)) ||
 	    (IS_VAR == IS_VAR && UNEXPECTED(Z_TYPE_P(variable_ptr) == IS_STR_OFFSET))) {
 		zend_error_noreturn(E_ERROR, "Cannot create references to/from string offsets nor overloaded objects");
@@ -22904,10 +22903,9 @@ static int ZEND_FASTCALL  ZEND_ASSIGN_REF_SPEC_VAR_CV_HANDLER(ZEND_OPCODE_HANDLE
 	value_ptr = _get_zval_ptr_cv_BP_VAR_W(execute_data, opline->op2.var TSRMLS_CC);
 
 	if (IS_CV == IS_VAR &&
-	    value_ptr &&
-	    !Z_ISREF_P(value_ptr) &&
 	    opline->extended_value == ZEND_RETURNS_FUNCTION &&
-	    !(Z_VAR_FLAGS_P(value_ptr) & IS_VAR_RET_REF)) {
+	    !(Z_VAR_FLAGS_P(value_ptr) & IS_VAR_RET_REF) &&
+	    !Z_ISREF_P(value_ptr)) {
 		if (!0) {
 			PZVAL_LOCK(value_ptr); /* undo the effect of get_zval_ptr_ptr() */
 		}
@@ -22922,13 +22920,13 @@ static int ZEND_FASTCALL  ZEND_ASSIGN_REF_SPEC_VAR_CV_HANDLER(ZEND_OPCODE_HANDLE
 			PZVAL_LOCK(value_ptr);
 		}
 	}
+
+	variable_ptr = _get_zval_ptr_ptr_var(opline->op1.var, execute_data, &free_op1 TSRMLS_CC);
 	if (IS_VAR == IS_VAR &&
 	    UNEXPECTED(Z_TYPE_P(EX_VAR(opline->op1.var)) != IS_INDIRECT) &&
 	    UNEXPECTED(!Z_ISREF_P(variable_ptr))) {
 		zend_error_noreturn(E_ERROR, "Cannot assign by reference to overloaded object");
 	}
-
-	variable_ptr = _get_zval_ptr_ptr_var(opline->op1.var, execute_data, &free_op1 TSRMLS_CC);
 	if ((IS_CV == IS_VAR && UNEXPECTED(Z_TYPE_P(value_ptr) == IS_STR_OFFSET)) ||
 	    (IS_VAR == IS_VAR && UNEXPECTED(Z_TYPE_P(variable_ptr) == IS_STR_OFFSET))) {
 		zend_error_noreturn(E_ERROR, "Cannot create references to/from string offsets nor overloaded objects");
@@ -32050,7 +32048,7 @@ static int ZEND_FASTCALL  ZEND_ASSIGN_SPEC_CV_CONST_HANDLER(ZEND_OPCODE_HANDLER_
 
 	SAVE_OPLINE();
 	value = opline->op2.zv;
-	variable_ptr = _get_zval_ptr_cv_BP_VAR_W(execute_data, opline->op1.var TSRMLS_CC);
+	variable_ptr = _get_zval_ptr_cv_undef_BP_VAR_W(execute_data, opline->op1.var TSRMLS_CC);
 
 	if (IS_CV == IS_VAR && UNEXPECTED(Z_TYPE_P(variable_ptr) == IS_STR_OFFSET)) {
 		zend_assign_to_string_offset(variable_ptr, value, IS_CONST, (RETURN_VALUE_USED(opline) ? EX_VAR(opline->result.var) : NULL) TSRMLS_CC);
@@ -34094,7 +34092,7 @@ static int ZEND_FASTCALL  ZEND_ASSIGN_SPEC_CV_TMP_HANDLER(ZEND_OPCODE_HANDLER_AR
 
 	SAVE_OPLINE();
 	value = _get_zval_ptr_tmp(opline->op2.var, execute_data, &free_op2 TSRMLS_CC);
-	variable_ptr = _get_zval_ptr_cv_BP_VAR_W(execute_data, opline->op1.var TSRMLS_CC);
+	variable_ptr = _get_zval_ptr_cv_undef_BP_VAR_W(execute_data, opline->op1.var TSRMLS_CC);
 
 	if (IS_CV == IS_VAR && UNEXPECTED(Z_TYPE_P(variable_ptr) == IS_STR_OFFSET)) {
 		zend_assign_to_string_offset(variable_ptr, value, IS_TMP_VAR, (RETURN_VALUE_USED(opline) ? EX_VAR(opline->result.var) : NULL) TSRMLS_CC);
@@ -36172,7 +36170,7 @@ static int ZEND_FASTCALL  ZEND_ASSIGN_SPEC_CV_VAR_HANDLER(ZEND_OPCODE_HANDLER_AR
 
 	SAVE_OPLINE();
 	value = _get_zval_ptr_var(opline->op2.var, execute_data, &free_op2 TSRMLS_CC);
-	variable_ptr = _get_zval_ptr_cv_BP_VAR_W(execute_data, opline->op1.var TSRMLS_CC);
+	variable_ptr = _get_zval_ptr_cv_undef_BP_VAR_W(execute_data, opline->op1.var TSRMLS_CC);
 
 	if (IS_CV == IS_VAR && UNEXPECTED(Z_TYPE_P(variable_ptr) == IS_STR_OFFSET)) {
 		zend_assign_to_string_offset(variable_ptr, value, IS_VAR, (RETURN_VALUE_USED(opline) ? EX_VAR(opline->result.var) : NULL) TSRMLS_CC);
@@ -36215,10 +36213,9 @@ static int ZEND_FASTCALL  ZEND_ASSIGN_REF_SPEC_CV_VAR_HANDLER(ZEND_OPCODE_HANDLE
 	value_ptr = _get_zval_ptr_ptr_var(opline->op2.var, execute_data, &free_op2 TSRMLS_CC);
 
 	if (IS_VAR == IS_VAR &&
-	    value_ptr &&
-	    !Z_ISREF_P(value_ptr) &&
 	    opline->extended_value == ZEND_RETURNS_FUNCTION &&
-	    !(Z_VAR_FLAGS_P(value_ptr) & IS_VAR_RET_REF)) {
+	    !(Z_VAR_FLAGS_P(value_ptr) & IS_VAR_RET_REF) &&
+	    !Z_ISREF_P(value_ptr)) {
 		if (!(free_op2.var != NULL)) {
 			PZVAL_LOCK(value_ptr); /* undo the effect of get_zval_ptr_ptr() */
 		}
@@ -36233,13 +36230,13 @@ static int ZEND_FASTCALL  ZEND_ASSIGN_REF_SPEC_CV_VAR_HANDLER(ZEND_OPCODE_HANDLE
 			PZVAL_LOCK(value_ptr);
 		}
 	}
+
+	variable_ptr = _get_zval_ptr_cv_undef_BP_VAR_W(execute_data, opline->op1.var TSRMLS_CC);
 	if (IS_CV == IS_VAR &&
 	    UNEXPECTED(Z_TYPE_P(EX_VAR(opline->op1.var)) != IS_INDIRECT) &&
 	    UNEXPECTED(!Z_ISREF_P(variable_ptr))) {
 		zend_error_noreturn(E_ERROR, "Cannot assign by reference to overloaded object");
 	}
-
-	variable_ptr = _get_zval_ptr_cv_BP_VAR_W(execute_data, opline->op1.var TSRMLS_CC);
 	if ((IS_VAR == IS_VAR && UNEXPECTED(Z_TYPE_P(value_ptr) == IS_STR_OFFSET)) ||
 	    (IS_CV == IS_VAR && UNEXPECTED(Z_TYPE_P(variable_ptr) == IS_STR_OFFSET))) {
 		zend_error_noreturn(E_ERROR, "Cannot create references to/from string offsets nor overloaded objects");
@@ -39257,7 +39254,7 @@ static int ZEND_FASTCALL  ZEND_ASSIGN_SPEC_CV_CV_HANDLER(ZEND_OPCODE_HANDLER_ARG
 
 	SAVE_OPLINE();
 	value = _get_zval_ptr_cv_BP_VAR_R(execute_data, opline->op2.var TSRMLS_CC);
-	variable_ptr = _get_zval_ptr_cv_BP_VAR_W(execute_data, opline->op1.var TSRMLS_CC);
+	variable_ptr = _get_zval_ptr_cv_undef_BP_VAR_W(execute_data, opline->op1.var TSRMLS_CC);
 
 	if (IS_CV == IS_VAR && UNEXPECTED(Z_TYPE_P(variable_ptr) == IS_STR_OFFSET)) {
 		zend_assign_to_string_offset(variable_ptr, value, IS_CV, (RETURN_VALUE_USED(opline) ? EX_VAR(opline->result.var) : NULL) TSRMLS_CC);
@@ -39299,10 +39296,9 @@ static int ZEND_FASTCALL  ZEND_ASSIGN_REF_SPEC_CV_CV_HANDLER(ZEND_OPCODE_HANDLER
 	value_ptr = _get_zval_ptr_cv_BP_VAR_W(execute_data, opline->op2.var TSRMLS_CC);
 
 	if (IS_CV == IS_VAR &&
-	    value_ptr &&
-	    !Z_ISREF_P(value_ptr) &&
 	    opline->extended_value == ZEND_RETURNS_FUNCTION &&
-	    !(Z_VAR_FLAGS_P(value_ptr) & IS_VAR_RET_REF)) {
+	    !(Z_VAR_FLAGS_P(value_ptr) & IS_VAR_RET_REF) &&
+	    !Z_ISREF_P(value_ptr)) {
 		if (!0) {
 			PZVAL_LOCK(value_ptr); /* undo the effect of get_zval_ptr_ptr() */
 		}
@@ -39317,13 +39313,13 @@ static int ZEND_FASTCALL  ZEND_ASSIGN_REF_SPEC_CV_CV_HANDLER(ZEND_OPCODE_HANDLER
 			PZVAL_LOCK(value_ptr);
 		}
 	}
+
+	variable_ptr = _get_zval_ptr_cv_undef_BP_VAR_W(execute_data, opline->op1.var TSRMLS_CC);
 	if (IS_CV == IS_VAR &&
 	    UNEXPECTED(Z_TYPE_P(EX_VAR(opline->op1.var)) != IS_INDIRECT) &&
 	    UNEXPECTED(!Z_ISREF_P(variable_ptr))) {
 		zend_error_noreturn(E_ERROR, "Cannot assign by reference to overloaded object");
 	}
-
-	variable_ptr = _get_zval_ptr_cv_BP_VAR_W(execute_data, opline->op1.var TSRMLS_CC);
 	if ((IS_CV == IS_VAR && UNEXPECTED(Z_TYPE_P(value_ptr) == IS_STR_OFFSET)) ||
 	    (IS_CV == IS_VAR && UNEXPECTED(Z_TYPE_P(variable_ptr) == IS_STR_OFFSET))) {
 		zend_error_noreturn(E_ERROR, "Cannot create references to/from string offsets nor overloaded objects");
diff --git a/Zend/zend_vm_gen.php b/Zend/zend_vm_gen.php
index 56a923b6a5..5614052520 100644
--- a/Zend/zend_vm_gen.php
+++ b/Zend/zend_vm_gen.php
@@ -171,6 +171,24 @@ $op2_get_zval_ptr_deref = array(
 	"CV"     => "_get_zval_ptr_cv_deref_\\1(execute_data, opline->op2.var TSRMLS_CC)",
 );
 
+$op1_get_zval_ptr_ptr_undef = array(
+	"ANY"    => "get_zval_ptr_ptr_undef(opline->op1_type, &opline->op1, execute_data, &free_op1, \\1)",
+	"TMP"    => "NULL",
+	"VAR"    => "_get_zval_ptr_ptr_var(opline->op1.var, execute_data, &free_op1 TSRMLS_CC)",
+	"CONST"  => "NULL",
+	"UNUSED" => "NULL",
+	"CV"     => "_get_zval_ptr_cv_undef_\\1(execute_data, opline->op1.var TSRMLS_CC)",
+);
+
+$op2_get_zval_ptr_ptr_undef = array(
+	"ANY"    => "get_zval_ptr_ptr_undef(opline->op2_type, &opline->op2, execute_data, &free_op2, \\1)",
+	"TMP"    => "NULL",
+	"VAR"    => "_get_zval_ptr_ptr_var(opline->op2.var, execute_data, &free_op2 TSRMLS_CC)",
+	"CONST"  => "NULL",
+	"UNUSED" => "NULL",
+	"CV"     => "_get_zval_ptr_cv_undef_\\1(execute_data, opline->op2.var TSRMLS_CC)",
+);
+
 $op1_get_obj_zval_ptr = array(
 	"ANY"    => "get_obj_zval_ptr(opline->op1_type, &opline->op1, execute_data, &free_op1, \\1)",
 	"TMP"    => "_get_zval_ptr_tmp(opline->op1.var, execute_data, &free_op1 TSRMLS_CC)",
@@ -348,6 +366,7 @@ function gen_code($f, $spec, $kind, $export, $code, $op1, $op2, $name) {
 	global $op1_type, $op2_type, $op1_get_zval_ptr, $op2_get_zval_ptr,
 		$op1_get_zval_ptr_deref, $op2_get_zval_ptr_deref,
 		$op1_get_zval_ptr_ptr, $op2_get_zval_ptr_ptr,
+		$op1_get_zval_ptr_ptr_undef, $op2_get_zval_ptr_ptr_undef,
 		$op1_get_obj_zval_ptr, $op2_get_obj_zval_ptr,
 		$op1_get_obj_zval_ptr_deref, $op2_get_obj_zval_ptr_deref,
 		$op1_get_obj_zval_ptr_ptr, $op2_get_obj_zval_ptr_ptr,
@@ -369,6 +388,8 @@ function gen_code($f, $spec, $kind, $export, $code, $op1, $op2, $name) {
 			"/GET_OP2_ZVAL_PTR_DEREF\(([^)]*)\)/",
 			"/GET_OP1_ZVAL_PTR_PTR\(([^)]*)\)/",
 			"/GET_OP2_ZVAL_PTR_PTR\(([^)]*)\)/",
+			"/GET_OP1_ZVAL_PTR_PTR_UNDEF\(([^)]*)\)/",
+			"/GET_OP2_ZVAL_PTR_PTR_UNDEF\(([^)]*)\)/",
 			"/GET_OP1_OBJ_ZVAL_PTR\(([^)]*)\)/",
 			"/GET_OP2_OBJ_ZVAL_PTR\(([^)]*)\)/",
 			"/GET_OP1_OBJ_ZVAL_PTR_DEREF\(([^)]*)\)/",
@@ -407,6 +428,8 @@ function gen_code($f, $spec, $kind, $export, $code, $op1, $op2, $name) {
 			$op2_get_zval_ptr_deref[$op2],
 			$op1_get_zval_ptr_ptr[$op1],
 			$op2_get_zval_ptr_ptr[$op2],
+			$op1_get_zval_ptr_ptr_undef[$op1],
+			$op2_get_zval_ptr_ptr_undef[$op2],
 			$op1_get_obj_zval_ptr[$op1],
 			$op2_get_obj_zval_ptr[$op2],
 			$op1_get_obj_zval_ptr_deref[$op1],