CppEditor: Revert changes to parseExpressionStatement()

Amends c8f29b9e0148202ab1959466e14fa23411fd8214.
It turns out that there are contexts where we want to parse an
expression statement even with the semicolon missing (e.g. completion on
incomplete code).
So leave the existing functions unchanged and do the thorough check
afterwards in parseIfStatement().

Change-Id: Id6209ef1abfe9d155c5b9381e6ae655cc721feb2
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

6 files changed, 23 insertions, 24 deletions

diff --git a/src/libs/3rdparty/cplusplus/AST.h b/src/libs/3rdparty/cplusplus/AST.h
index 6a5da23306..3f48e192b9 100644
--- a/src/libs/3rdparty/cplusplus/AST.h
+++ b/src/libs/3rdparty/cplusplus/AST.h
@@ -1779,7 +1779,6 @@ public:
     int if_token = 0;
     int constexpr_token = 0;
     int lparen_token = 0;
-    DeclarationAST *initDecl = nullptr;
     StatementAST *initStmt = nullptr;
     ExpressionAST *condition = nullptr;
     int rparen_token = 0;
diff --git a/src/libs/3rdparty/cplusplus/ASTClone.cpp b/src/libs/3rdparty/cplusplus/ASTClone.cpp
index 57617bb118..c9c2fc8294 100644
--- a/src/libs/3rdparty/cplusplus/ASTClone.cpp
+++ b/src/libs/3rdparty/cplusplus/ASTClone.cpp
@@ -785,8 +785,6 @@ IfStatementAST *IfStatementAST::clone(MemoryPool *pool) const
     ast->if_token = if_token;
     ast->constexpr_token = constexpr_token;
     ast->lparen_token = lparen_token;
-    if (initDecl)
-        ast->initDecl = initDecl->clone(pool);
     if (initStmt)
         ast->initStmt = initStmt->clone(pool);
     if (condition)
diff --git a/src/libs/3rdparty/cplusplus/ASTMatcher.cpp b/src/libs/3rdparty/cplusplus/ASTMatcher.cpp
index 6f12efb8ac..b264098a96 100644
--- a/src/libs/3rdparty/cplusplus/ASTMatcher.cpp
+++ b/src/libs/3rdparty/cplusplus/ASTMatcher.cpp
@@ -1318,11 +1318,6 @@ bool ASTMatcher::match(IfStatementAST *node, IfStatementAST *pattern)
 
     pattern->lparen_token = node->lparen_token;
 
-    if (!pattern->initDecl)
-        pattern->initDecl = node->initDecl;
-    else if (!AST::match(node->initDecl, pattern->initDecl, this))
-        return false;
-
     if (!pattern->initStmt)
         pattern->initStmt = node->initStmt;
     else if (!AST::match(node->initStmt, pattern->initStmt, this))
diff --git a/src/libs/3rdparty/cplusplus/ASTVisit.cpp b/src/libs/3rdparty/cplusplus/ASTVisit.cpp
index 7e8f75f233..5b0ef3ce33 100644
--- a/src/libs/3rdparty/cplusplus/ASTVisit.cpp
+++ b/src/libs/3rdparty/cplusplus/ASTVisit.cpp
@@ -563,7 +563,6 @@ void ForStatementAST::accept0(ASTVisitor *visitor)
 void IfStatementAST::accept0(ASTVisitor *visitor)
 {
     if (visitor->visit(this)) {
-        accept(initDecl, visitor);
         accept(initStmt, visitor);
         accept(condition, visitor);
         accept(statement, visitor);
diff --git a/src/libs/3rdparty/cplusplus/Bind.cpp b/src/libs/3rdparty/cplusplus/Bind.cpp
index e3d38a09a8..c85d401c49 100644
--- a/src/libs/3rdparty/cplusplus/Bind.cpp
+++ b/src/libs/3rdparty/cplusplus/Bind.cpp
@@ -1528,9 +1528,7 @@ bool Bind::visit(IfStatementAST *ast)
     ast->symbol = block;
 
     Scope *previousScope = switchScope(block);
-    if (ast->initDecl)
-        this->declaration(ast->initDecl);
-    else if (ast->initStmt)
+    if (ast->initStmt)
         this->statement(ast->initStmt);
     /*ExpressionTy condition =*/ this->expression(ast->condition);
     this->statement(ast->statement);
diff --git a/src/libs/3rdparty/cplusplus/Parser.cpp b/src/libs/3rdparty/cplusplus/Parser.cpp
index 31e290d1ad..6bf19f5982 100644
--- a/src/libs/3rdparty/cplusplus/Parser.cpp
+++ b/src/libs/3rdparty/cplusplus/Parser.cpp
@@ -3511,14 +3511,12 @@ bool Parser::parseExpressionStatement(StatementAST *&node)
 
     ExpressionAST *expression = nullptr;
     if (parseExpression(expression)) {
-        if (LA() == T_SEMICOLON) {
-            ExpressionStatementAST *ast = new (previousPool) ExpressionStatementAST;
-            ast->semicolon_token = consumeToken();
-            if (expression)
-                ast->expression = expression->clone(previousPool);
-            node = ast;
-            parsed = true;
-        }
+        ExpressionStatementAST *ast = new (previousPool) ExpressionStatementAST;
+        if (expression)
+            ast->expression = expression->clone(previousPool);
+        match(T_SEMICOLON, &ast->semicolon_token);
+        node = ast;
+        parsed = true;
     }
 
     _inExpressionStatement = wasInExpressionStatement;
@@ -4079,14 +4077,26 @@ bool Parser::parseIfStatement(StatementAST *&node)
         if (_languageFeatures.cxx17Enabled) {
             const int savedCursor = cursor();
             const bool savedBlockErrors = _translationUnit->blockErrors(true);
-            if (!parseSimpleDeclaration(ast->initDecl)) {
+            bool foundInitStmt = parseExpressionOrDeclarationStatement(ast->initStmt);
+            if (foundInitStmt)
+                foundInitStmt = ast->initStmt;
+            if (foundInitStmt) {
+                if (const auto exprStmt = ast->initStmt->asExpressionStatement()) {
+                    foundInitStmt = exprStmt->semicolon_token;
+                } else if (const auto declStmt = ast->initStmt->asDeclarationStatement()) {
+                    foundInitStmt = declStmt->declaration
+                            && declStmt->declaration->asSimpleDeclaration()
+                            && declStmt->declaration->asSimpleDeclaration()->semicolon_token;
+                } else {
+                    foundInitStmt = false;
+                }
+            }
+            if (!foundInitStmt) {
+                ast->initStmt = nullptr;
                 rewind(savedCursor);
-                if (!parseExpressionStatement(ast->initStmt))
-                    rewind(savedCursor);
             }
             _translationUnit->blockErrors(savedBlockErrors);
         }
-
         parseCondition(ast->condition);
         match(T_RPAREN, &ast->rparen_token);
         if (! parseStatement(ast->statement))