File indexing completed on 2024-05-19 15:42:37

 /*
     SPDX-FileCopyrightText: 2013-2015 Sven Brauch <mail@svenbrauch.de>
     SPDX-FileCopyrightText: 2016-2017 Francis Herne <mail@flherne.uk>
 
     SPDX-License-Identifier: LGPL-2.0-or-later
 */
 
 #include "rangefixvisitor.h"
 
 namespace Python {
 
 class NextAstFindVisitor : public AstDefaultVisitor {
 public:
     KTextEditor::Cursor findNext(Python::Ast* node) {
         m_root = node;
         auto parent = node;
         while ( parent->parent && parent->parent->isExpression() ) {
             parent = parent->parent;
         }
         visitNode(parent);
 
         while ( ! m_next.isValid() && parent->parent ) {
             // no next expression found in that statement, advance to the next statement
             parent = parent->parent;
             visitNode(parent);
         }
 
         return m_next;
     };
     void visitNode(Python::Ast* node) override {
         if ( ! node ) {
             return;
         }
         AstDefaultVisitor::visitNode(node);
         if ( node->start() > m_root->start() && ! node->isChildOf(m_root) ) {
             m_next = (m_next < node->start() && m_next.isValid()) ? m_next : node->start();
         }
     }
 
 private:
     KTextEditor::Cursor m_next{-1, -1};
     Ast* m_root;
 };
 
 
 //BEGIN RangeFixVisitor
 void RangeFixVisitor::visitNode(Ast* node) {
     AstDefaultVisitor::visitNode(node);
     if ( node && node->parent && node->parent->astType != Ast::AttributeAstType ) {
         if ( ( node->parent->endLine <= node->endLine && node->parent->endCol <= node->endCol )
                 || node->parent->endLine < node->endLine )
         {
             node->parent->endLine = node->endLine;
             node->parent->endCol = node->endCol;
         }
     }
 };
 
 void RangeFixVisitor::visitCode(CodeAst* node) {
     node->startLine = node->startCol = 0;
     AstDefaultVisitor::visitCode(node);
 }
 
 void RangeFixVisitor::visitFunctionDefinition(FunctionDefinitionAst* node) {
     cutDefinitionPreamble(node->name, node->async ? "asyncdef" : "def");
     AstDefaultVisitor::visitFunctionDefinition(node);
 };
 
 void RangeFixVisitor::visitClassDefinition(ClassDefinitionAst* node) {
     cutDefinitionPreamble(node->name, "class");
     AstDefaultVisitor::visitClassDefinition(node);
 };
 
 void RangeFixVisitor::visitAttribute(AttributeAst* node) {
     // Work around the weird way to count columns in Python's AST module.
 
     // Find where the next expression (of any kind) behind this one starts
     NextAstFindVisitor v;
     auto next_start = v.findNext(node);
     if ( ! next_start.isValid() ) {
         // use end of document as reference
         next_start = {lines.size() - 1, lines.last().size() - 1};
     }
 
     // take only the portion of the line up to that next expression
     auto endLine = next_start.line();
     auto endCol = next_start.column();
     if ( ! (next_start > node->start()) ) {
         endLine = node->startLine;
         endCol = -1;
     }
 
     const QString& name(node->attribute->value);
 
     QString line;
     for ( int n = node->startLine,
                 pos = node->value->endCol + 1,
                 dotFound = false,
                 nameFound = false;
             n <= endLine; ++n, pos = 0 ) {
         line = lines.at(n);
         if ( n == endLine && endCol != -1 ) {
             // Never look at the next expression.
             line = line.left(endCol);
         }
         if ( !dotFound ) {
             // The real attr name can never be before a dot.
             // Nor can the start of a comment.
             // (Don't be misled by `foo["bar"].bar` or `foo["#"].bar`)
             pos = line.indexOf('.', pos);
             if ( pos == -1 ) continue;
             dotFound = true;
         }
         if ( !nameFound ) {
             // Track if the attr name has appeared at least once.
             // This helps avoid RangeFixVisitor::interpreting '#'s in strings as comments -
             //   there can never be a comment before the real attr name.
             pos = line.indexOf(name, pos + 1);
             if ( pos == -1 ) continue;
             nameFound = true;
         }
         if ( dotFound && nameFound &&
                 (pos = line.indexOf('#', pos + name.length())) != -1) {
             // Remove the comment after a '#' iff we're certain it can't
             //  be inside a string literal (e.g. `foo["#"].bar`).
             line = line.left(pos);
         }
         // Take the last occurrence, any others are in string literals.
         pos = line.lastIndexOf(name);
         if ( pos != -1 ) {
             node->startLine = n;
             node->startCol = pos;
         }
         // N.B. we do this for all lines, the last non-comment occurrence
         //  is the real one.
     }
     // This fails (only, AFAIK) in a very limited case:
     // If the value expression (`foo` in `foo.bar`) contains a dot, the
     //   attr name, _and_ a hash in that order (may not be consecutive),
     //   and the hash is on the same line as the real attr name,
     //   we wrongly interpret the hash as the start of a comment.
     // e.g `foo["...barrier#"].bar` will highlight part of the string.
 
     node->endLine = node->startLine;
     node->endCol = node->startCol + name.length() - 1;
     node->attribute->copyRange(node);
 
     AstDefaultVisitor::visitAttribute(node);
 };
 
 // alias for imports (import foo as bar, baz as bang)
 // no strings, brackets, or whatever are allowed here, so the "parser"
 // can be very straightforward.
 void RangeFixVisitor::visitImport(ImportAst* node) {
     AstDefaultVisitor::visitImport(node);
     int aliasIndex = 0;
     foreach ( AliasAst* alias, node->names ) {
         fixAlias(alias->name, alias->asName, node->startLine, aliasIndex);
         aliasIndex += 1;
     }
 };
 
 // alias for exceptions (except FooBarException as somethingterriblehappened: ...)
 void RangeFixVisitor::visitExceptionHandler(ExceptionHandlerAst* node) {
     AstDefaultVisitor::visitExceptionHandler(node);
     if ( ! node->name ) {
         return;
     }
     const QString& line = lines.at(node->startLine);
     const int end = line.count() - 1;
     int back = backtrackDottedName(line, end);
     node->name->startCol = end - back;
     node->name->endCol = end;
 }
 
 void RangeFixVisitor::visitString(Python::StringAst* node) {
     AstDefaultVisitor::visitString(node);
     auto match = findString.match(lines.at(node->startLine), node->startCol);
     if ( match.capturedLength() > 0 ) {
         node->endCol += match.capturedLength() - 1; // Ranges are inclusive.
     }
 }
 void RangeFixVisitor::visitBytes(Python::BytesAst* node) {
     AstDefaultVisitor::visitBytes(node);
     auto match = findString.match(lines.at(node->startLine), node->startCol + 1);
     if ( match.capturedLength() > 0 ) {
         node->endCol += match.capturedLength(); // -1 then +1, because of the 'b'.
     }
 }
 void RangeFixVisitor::visitFormattedValue(Python::FormattedValueAst * node) {
     AstDefaultVisitor::visitFormattedValue(node);
     auto match = findString.match(lines.at(node->startLine), node->startCol + 1);
     if ( match.capturedLength() > 0 ) {
         node->endCol += match.capturedLength();
     }
 }
 
 void RangeFixVisitor::visitNumber(Python::NumberAst* node) {
     AstDefaultVisitor::visitNumber(node);
     auto match = findNumber.match(lines.at(node->startLine), node->startCol);
     if ( match.capturedLength() > 0 ) {
         node->endCol += match.capturedLength() - 1; // Ranges are inclusive.
     }
 }
 
 // Add one column after the last child to cover the closing bracket: `[1,2,3]`
 // TODO This is still wrong if the last child is followed by parens or whitespace.
 // endCol matters most in single-line expressions, so this isn't a huge problem.
 void RangeFixVisitor::visitSubscript(Python::SubscriptAst* node) {
     AstDefaultVisitor::visitSubscript(node);
     node->endCol++;
 }
 void RangeFixVisitor::visitComprehension(Python::ComprehensionAst* node) {
     AstDefaultVisitor::visitComprehension(node);
     node->endCol++;
 }
 void RangeFixVisitor::visitList(Python::ListAst* node) {
     AstDefaultVisitor::visitList(node);
     node->endCol++;
 }
 void RangeFixVisitor::visitTuple(Python::TupleAst* node) {
     AstDefaultVisitor::visitTuple(node);
     node->endCol++;
 }
 
 // skip the decorators and the "def" at the beginning
 // of a class or function declaration and modify @arg node
 // example:
 //  @decorate(foo)
 //  @decorate(bar)
 //  class myclass(parent): pass
 // before: start of class->name is [0, 0]
 // after: start of class->name is [2, 5]
 // line continuation characters are not supported,
 // because code needing those in this case is not worth being supported.
 void RangeFixVisitor::cutDefinitionPreamble(Ast* fixNode, const QString& defKeyword) {
     if ( ! fixNode ) {
         return;
     }
     int currentLine = fixNode->startLine;
 
     // cut away decorators
     while ( currentLine < lines.size() ) {
         if ( lines.at(currentLine).trimmed().remove(' ').remove('\t').startsWith(defKeyword) ) {
             // it's not a decorator, so stop skipping lines.
             break;
         }
         currentLine += 1;
     }
 //         qDebug() << "FIX:" << fixNode->range();
     fixNode->startLine = currentLine;
     fixNode->endLine = currentLine;
 //         qDebug() << "FIXED:" << fixNode->range() << fixNode->astType;
 
     // cut away the "def" / "class"
     int currentColumn = -1;
     if ( currentLine > lines.size() ) {
         // whops?
         return;
     }
     const QString& lineData = lines.at(currentLine);
     bool keywordFound = false;
     while ( currentColumn < lineData.size() - 1 ) {
         currentColumn += 1;
         if ( lineData.at(currentColumn).isSpace() ) {
             // skip space at the beginning of the line
             continue;
         }
         else if ( keywordFound ) {
             // if the "def" / "class" was already found, and the current char is
             // non space, then this is indeed the start of the identifier we're looking for.
             break;
         }
         else {
             keywordFound = true;
             currentColumn += defKeyword.size();
         }
     }
     const int previousLength = fixNode->endCol - fixNode->startCol;
     fixNode->startCol = currentColumn;
     fixNode->endCol = currentColumn + previousLength;
 };
 
 int RangeFixVisitor::backtrackDottedName(const QString& data, const int start) {
     bool haveDot = true;
     bool previousWasSpace = true;
     for ( int i = start - 1; i >= 0; i-- ) {
         if ( data.at(i).isSpace() ) {
             previousWasSpace = true;
             continue;
         }
         if ( data.at(i) == ':' ) {
             // excepthandler
             continue;
         }
         if ( data.at(i) == '.' ) {
             haveDot = true;
         }
         else if ( haveDot ) {
             haveDot = false;
             previousWasSpace = false;
             continue;
         }
         if ( previousWasSpace && ! haveDot ) {
             return start-i-2;
         }
         previousWasSpace = false;
     }
     return 0;
 }
 
 void RangeFixVisitor::fixAlias(Ast* dotted, Ast* asname, const int startLine, int aliasIndex) {
     if ( ! asname && ! dotted ) {
         return;
     }
     QString line = lines.at(startLine);
     int lineno = startLine;
     for ( int i = 0; i < line.size(); i++ ) {
         const QChar& current = line.at(i);
         if ( current == '\\' ) {
             // line continuation character
             // splitting like "import foo as \ \n bar" is not supported.
             lineno += 1;
             line = lines.at(lineno);
             i = 0;
             continue;
         }
         if ( current == ',' ) {
             if ( aliasIndex == 0 ) {
                 // nothing found, continue below
                 line = line.left(i);
                 break;
             }
             // next alias expression
             aliasIndex -= 1;
         }
         if ( i > line.length() - 3 ) {
             continue;
         }
         if ( current.isSpace() && line.mid(i+1).startsWith("as") && ( line.at(i+3).isSpace() || line.at(i+3) == '\\' ) ) {
             // there's an "as"
             if ( aliasIndex == 0 ) {
                 // it's the one we're looking for
                 // find the expression
                 if ( dotted ) {
                     int dottedNameLength = backtrackDottedName(line, i);
                     dotted->startLine = lineno;
                     dotted->endLine = lineno;
                     dotted->startCol = i-dottedNameLength;
                     dotted->endCol = i;
                 }
                 // find the asname
                 if ( asname ) {
                     bool atStart = true;
                     int textStart = i+3;
                     for ( int j = i+3; j < line.size(); j++ ) {
                         if ( atStart && ! line.at(j).isSpace() ) {
                             atStart = false;
                             textStart = j;
                         }
                         if ( ! atStart && ( line.at(j).isSpace() || j == line.size() - 1 ) ) {
                             // found it
                             asname->startLine = lineno;
                             asname->endLine = lineno;
                             asname->startCol = textStart - 1;
                             asname->endCol = j;
                         }
                     }
                 }
                 return;
             }
         }
     }
     // no "as" found, use last dotted name in line
     const int end = line.count() - whitespaceAtEnd(line);
     int back = backtrackDottedName(line, end);
     dotted->startLine = lineno;
     dotted->endLine = lineno;
     dotted->startCol = end - back;
     dotted->endCol = end;
 };
 
 int RangeFixVisitor::whitespaceAtEnd(const QString& line) {
     for ( int i = 0; i < line.size(); i++ ) {
         if ( ! line.at(line.size() - i - 1).isSpace() ) {
             return i;
         }
     }
     return 0;
 };
 
 // FIXME This doesn't work for triple-quoted strings
 //  (it gives length 2, which is no worse than before).
 const QRegularExpression RangeFixVisitor::findString("\\G(['\"]).*?(?<!\\\\)\\g1");
 // Looser than the real spec, but since we know there *is* a valid number it finds the end ok.
 const QRegularExpression RangeFixVisitor::findNumber("\\G(?:[\\d_\\.bjoxBJOX]|[eE][+-]?)*");
 
 }