--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/tools/qdoc3/yyindent.cpp Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,1190 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the tools applications of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the Technology Preview License Agreement accompanying
+** this package.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights. These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+/*
+ This file is a self-contained interactive indenter for C++ and Qt
+ Script.
+
+ The general problem of indenting a C++ program is ill posed. On
+ the one hand, an indenter has to analyze programs written in a
+ free-form formal language that is best described in terms of
+ tokens, not characters, not lines. On the other hand, indentation
+ applies to lines and white space characters matter, and otherwise
+ the programs to indent are formally invalid in general, as they
+ are begin edited.
+
+ The approach taken here works line by line. We receive a program
+ consisting of N lines or more, and we want to compute the
+ indentation appropriate for the Nth line. Lines beyond the Nth
+ lines are of no concern to us, so for simplicity we pretend the
+ program has exactly N lines and we call the Nth line the "bottom
+ line". Typically, we have to indent the bottom line when it's
+ still empty, so we concentrate our analysis on the N - 1 lines
+ that precede.
+
+ By inspecting the (N - 1)-th line, the (N - 2)-th line, ...
+ backwards, we determine the kind of the bottom line and indent it
+ accordingly.
+
+ * The bottom line is a comment line. See
+ bottomLineStartsInCComment() and
+ indentWhenBottomLineStartsInCComment().
+ * The bottom line is a continuation line. See isContinuationLine()
+ and indentForContinuationLine().
+ * The bottom line is a standalone line. See
+ indentForStandaloneLine().
+
+ Certain tokens that influence the indentation, notably braces,
+ are looked for in the lines. This is done by simple string
+ comparison, without a real tokenizer. Confusing constructs such
+ as comments and string literals are removed beforehand.
+*/
+
+#include <qregexp.h>
+#include <qstringlist.h>
+
+QT_BEGIN_NAMESPACE
+
+/* qmake ignore Q_OBJECT */
+
+/*
+ The indenter avoids getting stuck in almost infinite loops by
+ imposing arbitrary limits on the number of lines it analyzes when
+ looking for a construct.
+
+ For example, the indenter never considers more than BigRoof lines
+ backwards when looking for the start of a C-style comment.
+*/
+static const int SmallRoof = 40;
+static const int BigRoof = 400;
+
+/*
+ The indenter supports a few parameters:
+
+ * ppHardwareTabSize is the size of a '\t' in your favorite editor.
+ * ppIndentSize is the size of an indentation, or software tab
+ size.
+ * ppContinuationIndentSize is the extra indent for a continuation
+ line, when there is nothing to align against on the previous
+ line.
+ * ppCommentOffset is the indentation within a C-style comment,
+ when it cannot be picked up.
+*/
+
+static int ppHardwareTabSize = 8;
+static int ppIndentSize = 4;
+static int ppContinuationIndentSize = 8;
+
+static const int ppCommentOffset = 2;
+
+void setTabSize( int size )
+{
+ ppHardwareTabSize = size;
+}
+
+void setIndentSize( int size )
+{
+ ppIndentSize = size;
+ ppContinuationIndentSize = 2 * size;
+}
+
+static QRegExp *literal = 0;
+static QRegExp *label = 0;
+static QRegExp *inlineCComment = 0;
+static QRegExp *braceX = 0;
+static QRegExp *iflikeKeyword = 0;
+
+/*
+ Returns the first non-space character in the string t, or
+ QChar::Null if the string is made only of white space.
+*/
+static QChar firstNonWhiteSpace( const QString& t )
+{
+ int i = 0;
+ while ( i < (int) t.length() ) {
+ if ( !t[i].isSpace() )
+ return t[i];
+ i++;
+ }
+ return QChar::Null;
+}
+
+/*
+ Returns true if string t is made only of white space; otherwise
+ returns false.
+*/
+static bool isOnlyWhiteSpace( const QString& t )
+{
+ return firstNonWhiteSpace( t ).isNull();
+}
+
+/*
+ Assuming string t is a line, returns the column number of a given
+ index. Column numbers and index are identical for strings that don't
+ contain '\t's.
+*/
+int columnForIndex( const QString& t, int index )
+{
+ int col = 0;
+ if ( index > (int) t.length() )
+ index = t.length();
+
+ for ( int i = 0; i < index; i++ ) {
+ if ( t[i] == QChar('\t') ) {
+ col = ( (col / ppHardwareTabSize) + 1 ) * ppHardwareTabSize;
+ } else {
+ col++;
+ }
+ }
+ return col;
+}
+
+/*
+ Returns the indentation size of string t.
+*/
+int indentOfLine( const QString& t )
+{
+ return columnForIndex( t, t.indexOf(firstNonWhiteSpace(t)) );
+}
+
+/*
+ Replaces t[k] by ch, unless t[k] is '\t'. Tab characters are better
+ left alone since they break the "index equals column" rule. No
+ provisions are taken against '\n' or '\r', which shouldn't occur in
+ t anyway.
+*/
+static inline void eraseChar( QString& t, int k, QChar ch )
+{
+ if ( t[k] != '\t' )
+ t[k] = ch;
+}
+
+/*
+ Removes some nefast constructs from a code line and returns the
+ resulting line.
+*/
+static QString trimmedCodeLine( const QString& t )
+{
+ QString trimmed = t;
+ int k;
+
+ /*
+ Replace character and string literals by X's, since they may
+ contain confusing characters (such as '{' and ';'). "Hello!" is
+ replaced by XXXXXXXX. The literals are rigourously of the same
+ length before and after; otherwise, we would break alignment of
+ continuation lines.
+ */
+ k = 0;
+ while ( (k = trimmed.indexOf(*literal, k)) != -1 ) {
+ for ( int i = 0; i < literal->matchedLength(); i++ )
+ eraseChar( trimmed, k + i, 'X' );
+ k += literal->matchedLength();
+ }
+
+ /*
+ Replace inline C-style comments by spaces. Other comments are
+ handled elsewhere.
+ */
+ k = 0;
+ while ( (k = trimmed.indexOf(*inlineCComment, k)) != -1 ) {
+ for ( int i = 0; i < inlineCComment->matchedLength(); i++ )
+ eraseChar( trimmed, k + i, ' ' );
+ k += inlineCComment->matchedLength();
+ }
+
+ /*
+ Replace goto and switch labels by whitespace, but be careful
+ with this case:
+
+ foo1: bar1;
+ bar2;
+ */
+ while ( trimmed.lastIndexOf(':') != -1 && trimmed.indexOf(*label) != -1 ) {
+ QString cap1 = label->cap( 1 );
+ int pos1 = label->pos( 1 );
+ int stop = cap1.length();
+
+ if ( pos1 + stop < (int) trimmed.length() && ppIndentSize < stop )
+ stop = ppIndentSize;
+
+ int i = 0;
+ while ( i < stop ) {
+ eraseChar( trimmed, pos1 + i, ' ' );
+ i++;
+ }
+ while ( i < (int) cap1.length() ) {
+ eraseChar( trimmed, pos1 + i, ';' );
+ i++;
+ }
+ }
+
+ /*
+ Remove C++-style comments.
+ */
+ k = trimmed.indexOf( "//" );
+ if ( k != -1 )
+ trimmed.truncate( k );
+
+ return trimmed;
+}
+
+/*
+ Returns '(' if the last parenthesis is opening, ')' if it is
+ closing, and QChar::Null if there are no parentheses in t.
+*/
+static inline QChar lastParen( const QString& t )
+{
+ int i = t.length();
+ while ( i > 0 ) {
+ i--;
+ if ( t[i] == QChar('(') || t[i] == QChar(')') )
+ return t[i];
+ }
+ return QChar::Null;
+}
+
+/*
+ Returns true if typedIn the same as okayCh or is null; otherwise
+ returns false.
+*/
+static inline bool okay( QChar typedIn, QChar okayCh )
+{
+ return typedIn == QChar::Null || typedIn == okayCh;
+}
+
+/*
+ The "linizer" is a group of functions and variables to iterate
+ through the source code of the program to indent. The program is
+ given as a list of strings, with the bottom line being the line
+ to indent. The actual program might contain extra lines, but
+ those are uninteresting and not passed over to us.
+*/
+
+struct LinizerState
+{
+ QString line;
+ int braceDepth;
+ bool leftBraceFollows;
+
+ QStringList::ConstIterator iter;
+ bool inCComment;
+ bool pendingRightBrace;
+};
+
+static QStringList *yyProgram = 0;
+static LinizerState *yyLinizerState = 0;
+
+// shorthands
+static const QString *yyLine = 0;
+static const int *yyBraceDepth = 0;
+static const bool *yyLeftBraceFollows = 0;
+
+/*
+ Saves and restores the state of the global linizer. This enables
+ backtracking.
+*/
+#define YY_SAVE() \
+ LinizerState savedState = *yyLinizerState
+#define YY_RESTORE() \
+ *yyLinizerState = savedState
+
+/*
+ Advances to the previous line in yyProgram and update yyLine
+ accordingly. yyLine is cleaned from comments and other damageable
+ constructs. Empty lines are skipped.
+*/
+static bool readLine()
+{
+ int k;
+
+ yyLinizerState->leftBraceFollows =
+ ( firstNonWhiteSpace(yyLinizerState->line) == QChar('{') );
+
+ do {
+ if ( yyLinizerState->iter == yyProgram->begin() ) {
+ yyLinizerState->line.clear();
+ return false;
+ }
+
+ --yyLinizerState->iter;
+ yyLinizerState->line = *yyLinizerState->iter;
+
+ yyLinizerState->line = trimmedCodeLine( yyLinizerState->line );
+
+ /*
+ Remove C-style comments that span multiple lines. If the
+ bottom line starts in a C-style comment, we are not aware
+ of that and eventually yyLine will contain a slash-aster.
+
+ Notice that both if's can be executed, since
+ yyLinizerState->inCComment is potentially set to false in
+ the first if. The order of the if's is also important.
+ */
+
+ if ( yyLinizerState->inCComment ) {
+ QString slashAster( "/*" );
+
+ k = yyLinizerState->line.indexOf( slashAster );
+ if ( k == -1 ) {
+ yyLinizerState->line.clear();
+ } else {
+ yyLinizerState->line.truncate( k );
+ yyLinizerState->inCComment = false;
+ }
+ }
+
+ if ( !yyLinizerState->inCComment ) {
+ QString asterSlash( "*/" );
+
+ k = yyLinizerState->line.indexOf( asterSlash );
+ if ( k != -1 ) {
+ for ( int i = 0; i < k + 2; i++ )
+ eraseChar( yyLinizerState->line, i, ' ' );
+ yyLinizerState->inCComment = true;
+ }
+ }
+
+ /*
+ Remove preprocessor directives.
+ */
+ k = 0;
+ while ( k < (int) yyLinizerState->line.length() ) {
+ QChar ch = yyLinizerState->line[k];
+ if ( ch == QChar('#') ) {
+ yyLinizerState->line.clear();
+ } else if ( !ch.isSpace() ) {
+ break;
+ }
+ k++;
+ }
+
+ /*
+ Remove trailing spaces.
+ */
+ k = yyLinizerState->line.length();
+ while ( k > 0 && yyLinizerState->line[k - 1].isSpace() )
+ k--;
+ yyLinizerState->line.truncate( k );
+
+ /*
+ '}' increment the brace depth and '{' decrements it and not
+ the other way around, as we are parsing backwards.
+ */
+ yyLinizerState->braceDepth +=
+ yyLinizerState->line.count( '}' ) -
+ yyLinizerState->line.count( '{' );
+
+ /*
+ We use a dirty trick for
+
+ } else ...
+
+ We don't count the '}' yet, so that it's more or less
+ equivalent to the friendly construct
+
+ }
+ else ...
+ */
+ if ( yyLinizerState->pendingRightBrace )
+ yyLinizerState->braceDepth++;
+ yyLinizerState->pendingRightBrace =
+ ( yyLinizerState->line.indexOf(*braceX) == 0 );
+ if ( yyLinizerState->pendingRightBrace )
+ yyLinizerState->braceDepth--;
+ } while ( yyLinizerState->line.isEmpty() );
+
+ return true;
+}
+
+/*
+ Resets the linizer to its initial state, with yyLine containing the
+ line above the bottom line of the program.
+*/
+static void startLinizer()
+{
+ yyLinizerState->braceDepth = 0;
+ yyLinizerState->inCComment = false;
+ yyLinizerState->pendingRightBrace = false;
+
+ yyLine = &yyLinizerState->line;
+ yyBraceDepth = &yyLinizerState->braceDepth;
+ yyLeftBraceFollows = &yyLinizerState->leftBraceFollows;
+
+ yyLinizerState->iter = yyProgram->end();
+ --yyLinizerState->iter;
+ yyLinizerState->line = *yyLinizerState->iter;
+ readLine();
+}
+
+/*
+ Returns true if the start of the bottom line of yyProgram (and
+ potentially the whole line) is part of a C-style comment;
+ otherwise returns false.
+*/
+static bool bottomLineStartsInCComment()
+{
+ QString slashAster( "/*" );
+ QString asterSlash( "*/" );
+
+ /*
+ We could use the linizer here, but that would slow us down
+ terribly. We are better to trim only the code lines we need.
+ */
+ QStringList::ConstIterator p = yyProgram->end();
+ --p; // skip bottom line
+
+ for ( int i = 0; i < BigRoof; i++ ) {
+ if ( p == yyProgram->begin() )
+ return false;
+ --p;
+
+ if ( (*p).indexOf(slashAster) != -1 || (*p).indexOf(asterSlash) != -1 ) {
+ QString trimmed = trimmedCodeLine( *p );
+
+ if ( trimmed.indexOf(slashAster) != -1 ) {
+ return true;
+ } else if ( trimmed.indexOf(asterSlash) != -1 ) {
+ return false;
+ }
+ }
+ }
+ return false;
+}
+
+/*
+ Returns the recommended indent for the bottom line of yyProgram
+ assuming that it starts in a C-style comment, a condition that is
+ tested elsewhere.
+
+ Essentially, we're trying to align against some text on the
+ previous line.
+*/
+static int indentWhenBottomLineStartsInCComment()
+{
+ int k = yyLine->lastIndexOf( "/*" );
+ if ( k == -1 ) {
+ /*
+ We found a normal text line in a comment. Align the
+ bottom line with the text on this line.
+ */
+ return indentOfLine( *yyLine );
+ } else {
+ /*
+ The C-style comment starts on this line. If there is
+ text on the same line, align with it. Otherwise, align
+ with the slash-aster plus a given offset.
+ */
+ int indent = columnForIndex( *yyLine, k );
+ k += 2;
+ while ( k < (int) yyLine->length() ) {
+ if ( !(*yyLine)[k].isSpace() )
+ return columnForIndex( *yyLine, k );
+ k++;
+ }
+ return indent + ppCommentOffset;
+ }
+}
+
+/*
+ A function called match...() modifies the linizer state. If it
+ returns true, yyLine is the top line of the matched construct;
+ otherwise, the linizer is left in an unknown state.
+
+ A function called is...() keeps the linizer state intact.
+*/
+
+/*
+ Returns true if the current line (and upwards) forms a braceless
+ control statement; otherwise returns false.
+
+ The first line of the following example is a "braceless control
+ statement":
+
+ if ( x )
+ y;
+*/
+static bool matchBracelessControlStatement()
+{
+ int delimDepth = 0;
+
+ if ( yyLine->endsWith("else") )
+ return true;
+
+ if ( !yyLine->endsWith(")") )
+ return false;
+
+ for ( int i = 0; i < SmallRoof; i++ ) {
+ int j = yyLine->length();
+ while ( j > 0 ) {
+ j--;
+ QChar ch = (*yyLine)[j];
+
+ switch ( ch.unicode() ) {
+ case ')':
+ delimDepth++;
+ break;
+ case '(':
+ delimDepth--;
+ if ( delimDepth == 0 ) {
+ if ( yyLine->indexOf(*iflikeKeyword) != -1 ) {
+ /*
+ We have
+
+ if ( x )
+ y
+
+ "if ( x )" is not part of the statement
+ "y".
+ */
+ return true;
+ }
+ }
+ if ( delimDepth == -1 ) {
+ /*
+ We have
+
+ if ( (1 +
+ 2)
+
+ and not
+
+ if ( 1 +
+ 2 )
+ */
+ return false;
+ }
+ break;
+ case '{':
+ case '}':
+ case ';':
+ /*
+ We met a statement separator, but not where we
+ expected it. What follows is probably a weird
+ continuation line. Be careful with ';' in for,
+ though.
+ */
+ if ( ch != QChar(';') || delimDepth == 0 )
+ return false;
+ }
+ }
+
+ if ( !readLine() )
+ break;
+ }
+ return false;
+}
+
+/*
+ Returns true if yyLine is an unfinished line; otherwise returns
+ false.
+
+ In many places we'll use the terms "standalone line", "unfinished
+ line" and "continuation line". The meaning of these should be
+ evident from this code example:
+
+ a = b; // standalone line
+ c = d + // unfinished line
+ e + // unfinished continuation line
+ f + // unfinished continuation line
+ g; // continuation line
+*/
+static bool isUnfinishedLine()
+{
+ bool unf = false;
+
+ YY_SAVE();
+
+ if ( yyLine->isEmpty() )
+ return false;
+
+ QChar lastCh = (*yyLine)[(int) yyLine->length() - 1];
+ if ( QString("{};").indexOf(lastCh) == -1 && !yyLine->endsWith("...") ) {
+ /*
+ It doesn't end with ';' or similar. If it's neither
+ "Q_OBJECT" nor "if ( x )", it must be an unfinished line.
+ */
+ unf = ( yyLine->indexOf("Q_OBJECT") == -1 &&
+ !matchBracelessControlStatement() );
+ } else if ( lastCh == QChar(';') ) {
+ if ( lastParen(*yyLine) == QChar('(') ) {
+ /*
+ Exception:
+
+ for ( int i = 1; i < 10;
+ */
+ unf = true;
+ } else if ( readLine() && yyLine->endsWith(";") &&
+ lastParen(*yyLine) == QChar('(') ) {
+ /*
+ Exception:
+
+ for ( int i = 1;
+ i < 10;
+ */
+ unf = true;
+ }
+ }
+
+ YY_RESTORE();
+ return unf;
+}
+
+/*
+ Returns true if yyLine is a continuation line; otherwise returns
+ false.
+*/
+static bool isContinuationLine()
+{
+ bool cont = false;
+
+ YY_SAVE();
+ if ( readLine() )
+ cont = isUnfinishedLine();
+ YY_RESTORE();
+ return cont;
+}
+
+/*
+ Returns the recommended indent for the bottom line of yyProgram,
+ assuming it's a continuation line.
+
+ We're trying to align the continuation line against some parenthesis
+ or other bracked left opened on a previous line, or some interesting
+ operator such as '='.
+*/
+static int indentForContinuationLine()
+{
+ int braceDepth = 0;
+ int delimDepth = 0;
+
+ bool leftBraceFollowed = *yyLeftBraceFollows;
+
+ for ( int i = 0; i < SmallRoof; i++ ) {
+ int hook = -1;
+
+ int j = yyLine->length();
+ while ( j > 0 && hook < 0 ) {
+ j--;
+ QChar ch = (*yyLine)[j];
+
+ switch ( ch.unicode() ) {
+ case ')':
+ case ']':
+ delimDepth++;
+ break;
+ case '}':
+ braceDepth++;
+ break;
+ case '(':
+ case '[':
+ delimDepth--;
+ /*
+ An unclosed delimiter is a good place to align at,
+ at least for some styles (including Qt's).
+ */
+ if ( delimDepth == -1 )
+ hook = j;
+ break;
+ case '{':
+ braceDepth--;
+ /*
+ A left brace followed by other stuff on the same
+ line is typically for an enum or an initializer.
+ Such a brace must be treated just like the other
+ delimiters.
+ */
+ if ( braceDepth == -1 ) {
+ if ( j < (int) yyLine->length() - 1 ) {
+ hook = j;
+ } else {
+ return 0; // shouldn't happen
+ }
+ }
+ break;
+ case '=':
+ /*
+ An equal sign is a very natural alignment hook
+ because it's usually the operator with the lowest
+ precedence in statements it appears in. Case in
+ point:
+
+ int x = 1 +
+ 2;
+
+ However, we have to beware of constructs such as
+ default arguments and explicit enum constant
+ values:
+
+ void foo( int x = 0,
+ int y = 0 );
+
+ And not
+
+ void foo( int x = 0,
+ int y = 0 );
+
+ These constructs are caracterized by a ',' at the
+ end of the unfinished lines or by unbalanced
+ parentheses.
+ */
+ if ( QString("!=<>").indexOf((*yyLine)[j - 1]) == -1 &&
+ (*yyLine)[j + 1] != '=' ) {
+ if ( braceDepth == 0 && delimDepth == 0 &&
+ j < (int) yyLine->length() - 1 &&
+ !yyLine->endsWith(",") &&
+ (yyLine->contains('(') == yyLine->contains(')')) )
+ hook = j;
+ }
+ }
+ }
+
+ if ( hook >= 0 ) {
+ /*
+ Yes, we have a delimiter or an operator to align
+ against! We don't really align against it, but rather
+ against the following token, if any. In this example,
+ the following token is "11":
+
+ int x = ( 11 +
+ 2 );
+
+ If there is no such token, we use a continuation indent:
+
+ static QRegExp foo( QString(
+ "foo foo foo foo foo foo foo foo foo") );
+ */
+ hook++;
+ while ( hook < (int) yyLine->length() ) {
+ if ( !(*yyLine)[hook].isSpace() )
+ return columnForIndex( *yyLine, hook );
+ hook++;
+ }
+ return indentOfLine( *yyLine ) + ppContinuationIndentSize;
+ }
+
+ if ( braceDepth != 0 )
+ break;
+
+ /*
+ The line's delimiters are balanced. It looks like a
+ continuation line or something.
+ */
+ if ( delimDepth == 0 ) {
+ if ( leftBraceFollowed ) {
+ /*
+ We have
+
+ int main()
+ {
+
+ or
+
+ Bar::Bar()
+ : Foo( x )
+ {
+
+ The "{" should be flush left.
+ */
+ if ( !isContinuationLine() )
+ return indentOfLine( *yyLine );
+ } else if ( isContinuationLine() || yyLine->endsWith(",") ) {
+ /*
+ We have
+
+ x = a +
+ b +
+ c;
+
+ or
+
+ int t[] = {
+ 1, 2, 3,
+ 4, 5, 6
+
+ The "c;" should fall right under the "b +", and the
+ "4, 5, 6" right under the "1, 2, 3,".
+ */
+ return indentOfLine( *yyLine );
+ } else {
+ /*
+ We have
+
+ stream << 1 +
+ 2;
+
+ We could, but we don't, try to analyze which
+ operator has precedence over which and so on, to
+ obtain the excellent result
+
+ stream << 1 +
+ 2;
+
+ We do have a special trick above for the assignment
+ operator above, though.
+ */
+ return indentOfLine( *yyLine ) + ppContinuationIndentSize;
+ }
+ }
+
+ if ( !readLine() )
+ break;
+ }
+ return 0;
+}
+
+/*
+ Returns the recommended indent for the bottom line of yyProgram if
+ that line is standalone (or should be indented likewise).
+
+ Indenting a standalone line is tricky, mostly because of braceless
+ control statements. Grossly, we are looking backwards for a special
+ line, a "hook line", that we can use as a starting point to indent,
+ and then modify the indentation level according to the braces met
+ along the way to that hook.
+
+ Let's consider a few examples. In all cases, we want to indent the
+ bottom line.
+
+ Example 1:
+
+ x = 1;
+ y = 2;
+
+ The hook line is "x = 1;". We met 0 opening braces and 0 closing
+ braces. Therefore, "y = 2;" inherits the indent of "x = 1;".
+
+ Example 2:
+
+ if ( x ) {
+ y;
+
+ The hook line is "if ( x ) {". No matter what precedes it, "y;" has
+ to be indented one level deeper than the hook line, since we met one
+ opening brace along the way.
+
+ Example 3:
+
+ if ( a )
+ while ( b ) {
+ c;
+ }
+ d;
+
+ To indent "d;" correctly, we have to go as far as the "if ( a )".
+ Compare with
+
+ if ( a ) {
+ while ( b ) {
+ c;
+ }
+ d;
+
+ Still, we're striving to go back as little as possible to
+ accommodate people with irregular indentation schemes. A hook line
+ near at hand is much more reliable than a remote one.
+*/
+static int indentForStandaloneLine()
+{
+ for ( int i = 0; i < SmallRoof; i++ ) {
+ if ( !*yyLeftBraceFollows ) {
+ YY_SAVE();
+
+ if ( matchBracelessControlStatement() ) {
+ /*
+ The situation is this, and we want to indent "z;":
+
+ if ( x &&
+ y )
+ z;
+
+ yyLine is "if ( x &&".
+ */
+ return indentOfLine( *yyLine ) + ppIndentSize;
+ }
+ YY_RESTORE();
+ }
+
+ if ( yyLine->endsWith(";") || yyLine->contains('{') ) {
+ /*
+ The situation is possibly this, and we want to indent
+ "z;":
+
+ while ( x )
+ y;
+ z;
+
+ We return the indent of "while ( x )". In place of "y;",
+ any arbitrarily complex compound statement can appear.
+ */
+
+ if ( *yyBraceDepth > 0 ) {
+ do {
+ if ( !readLine() )
+ break;
+ } while ( *yyBraceDepth > 0 );
+ }
+
+ LinizerState hookState;
+
+ while ( isContinuationLine() )
+ readLine();
+ hookState = *yyLinizerState;
+
+ readLine();
+ if ( *yyBraceDepth <= 0 ) {
+ do {
+ if ( !matchBracelessControlStatement() )
+ break;
+ hookState = *yyLinizerState;
+ } while ( readLine() );
+ }
+
+ *yyLinizerState = hookState;
+
+ while ( isContinuationLine() )
+ readLine();
+
+ /*
+ Never trust lines containing only '{' or '}', as some
+ people (Richard M. Stallman) format them weirdly.
+ */
+ if ( yyLine->trimmed().length() > 1 )
+ return indentOfLine( *yyLine ) - *yyBraceDepth * ppIndentSize;
+ }
+
+ if ( !readLine() )
+ return -*yyBraceDepth * ppIndentSize;
+ }
+ return 0;
+}
+
+/*
+ Constructs global variables used by the indenter.
+*/
+static void initializeIndenter()
+{
+ literal = new QRegExp( "([\"'])(?:\\\\.|[^\\\\])*\\1" );
+ literal->setMinimal( true );
+ label = new QRegExp(
+ "^\\s*((?:case\\b([^:]|::)+|[a-zA-Z_0-9]+)(?:\\s+slots)?:)(?!:)" );
+ inlineCComment = new QRegExp( "/\\*.*\\*/" );
+ inlineCComment->setMinimal( true );
+ braceX = new QRegExp( "^\\s*\\}\\s*(?:else|catch)\\b" );
+ iflikeKeyword = new QRegExp( "\\b(?:catch|do|for|if|while)\\b" );
+
+ yyLinizerState = new LinizerState;
+}
+
+/*
+ Destroys global variables used by the indenter.
+*/
+static void terminateIndenter()
+{
+ delete literal;
+ delete label;
+ delete inlineCComment;
+ delete braceX;
+ delete iflikeKeyword;
+ delete yyLinizerState;
+}
+
+/*
+ Returns the recommended indent for the bottom line of program.
+ Unless null, typedIn stores the character of yyProgram that
+ triggered reindentation.
+
+ This function works better if typedIn is set properly; it is
+ slightly more conservative if typedIn is completely wild, and
+ slighly more liberal if typedIn is always null. The user might be
+ annoyed by the liberal behavior.
+*/
+int indentForBottomLine( const QStringList& program, QChar typedIn )
+{
+ if ( program.isEmpty() )
+ return 0;
+
+ initializeIndenter();
+
+ yyProgram = new QStringList( program );
+ startLinizer();
+
+ const QString& bottomLine = program.last();
+ QChar firstCh = firstNonWhiteSpace( bottomLine );
+ int indent;
+
+ if ( bottomLineStartsInCComment() ) {
+ /*
+ The bottom line starts in a C-style comment. Indent it
+ smartly, unless the user has already played around with it,
+ in which case it's better to leave her stuff alone.
+ */
+ if ( isOnlyWhiteSpace(bottomLine) ) {
+ indent = indentWhenBottomLineStartsInCComment();
+ } else {
+ indent = indentOfLine( bottomLine );
+ }
+ } else if ( okay(typedIn, '#') && firstCh == QChar('#') ) {
+ /*
+ Preprocessor directives go flush left.
+ */
+ indent = 0;
+ } else {
+ if ( isUnfinishedLine() ) {
+ indent = indentForContinuationLine();
+ } else {
+ indent = indentForStandaloneLine();
+ }
+
+ if ( okay(typedIn, '}') && firstCh == QChar('}') ) {
+ /*
+ A closing brace is one level more to the left than the
+ code it follows.
+ */
+ indent -= ppIndentSize;
+ } else if ( okay(typedIn, ':') ) {
+ QRegExp caseLabel(
+ "\\s*(?:case\\b(?:[^:]|::)+"
+ "|(?:public|protected|private|signals|default)(?:\\s+slots)?\\s*"
+ ")?:.*" );
+
+ if ( caseLabel.exactMatch(bottomLine) ) {
+ /*
+ Move a case label (or the ':' in front of a
+ constructor initialization list) one level to the
+ left, but only if the user did not play around with
+ it yet. Some users have exotic tastes in the
+ matter, and most users probably are not patient
+ enough to wait for the final ':' to format their
+ code properly.
+
+ We don't attempt the same for goto labels, as the
+ user is probably the middle of "foo::bar". (Who
+ uses goto, anyway?)
+ */
+ if ( indentOfLine(bottomLine) <= indent )
+ indent -= ppIndentSize;
+ else
+ indent = indentOfLine( bottomLine );
+ }
+ }
+ }
+ delete yyProgram;
+ terminateIndenter();
+ return qMax( 0, indent );
+}
+
+QT_END_NAMESPACE
+
+#ifdef Q_TEST_YYINDENT
+/*
+ Test driver.
+*/
+
+#include <qfile.h>
+#include <qtextstream.h>
+
+#include <errno.h>
+
+QT_BEGIN_NAMESPACE
+
+static QString fileContents( const QString& fileName )
+{
+ QFile f( fileName );
+ if ( !f.open(QFile::ReadOnly) ) {
+ qWarning( "yyindent error: Cannot open file '%s' for reading: %s",
+ fileName.toLatin1().data(), strerror(errno) );
+ return QString();
+ }
+
+ QTextStream t( &f );
+ QString contents = t.read();
+ f.close();
+ if ( contents.isEmpty() )
+ qWarning( "yyindent error: File '%s' is empty", fileName.toLatin1().data() );
+ return contents;
+}
+
+QT_END_NAMESPACE
+
+int main( int argc, char **argv )
+{
+ QT_USE_NAMESPACE
+
+ if ( argc != 2 ) {
+ qWarning( "usage: yyindent file.cpp" );
+ return 1;
+ }
+
+ QString code = fileContents( argv[1] );
+ QStringList program = QStringList::split( '\n', code, true );
+ QStringList p;
+ QString out;
+
+ while ( !program.isEmpty() && program.last().trimmed().isEmpty() )
+ program.remove( program.fromLast() );
+
+ QStringList::ConstIterator line = program.begin();
+ while ( line != program.end() ) {
+ p.push_back( *line );
+ QChar typedIn = firstNonWhiteSpace( *line );
+ if ( p.last().endsWith(":") )
+ typedIn = ':';
+
+ int indent = indentForBottomLine( p, typedIn );
+
+ if ( !(*line).trimmed().isEmpty() ) {
+ for ( int j = 0; j < indent; j++ )
+ out += " ";
+ out += (*line).trimmed();
+ }
+ out += "\n";
+ ++line;
+ }
+
+ while ( out.endsWith("\n") )
+ out.truncate( out.length() - 1 );
+
+ printf( "%s\n", out.toLatin1().data() );
+ return 0;
+}
+
+#endif // Q_TEST_YYINDENT