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llvm / llvm-project / clang / refs/heads/main / . / lib / Format / UnwrappedLineFormatter.cpp
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//===--- UnwrappedLineFormatter.cpp - Format C++ code ---------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "UnwrappedLineFormatter.h"
#include "FormatToken.h"
#include "NamespaceEndCommentsFixer.h"
#include "WhitespaceManager.h"
#include "llvm/Support/Debug.h"
#include <queue>
#define DEBUG_TYPE "format-formatter"
namespace clang {
namespace format {
namespace {
bool startsExternCBlock(const AnnotatedLine &Line) {
const FormatToken *Next = Line.First->getNextNonComment();
const FormatToken *NextNext = Next ? Next->getNextNonComment() : nullptr;
return Line.startsWith(tok::kw_extern) && Next && Next->isStringLiteral() &&
NextNext && NextNext->is(tok::l_brace);
}
bool isRecordLBrace(const FormatToken &Tok) {
return Tok.isOneOf(TT_ClassLBrace, TT_EnumLBrace, TT_RecordLBrace,
TT_StructLBrace, TT_UnionLBrace);
}
/// Tracks the indent level of \c AnnotatedLines across levels.
///
/// \c nextLine must be called for each \c AnnotatedLine, after which \c
/// getIndent() will return the indent for the last line \c nextLine was called
/// with.
/// If the line is not formatted (and thus the indent does not change), calling
/// \c adjustToUnmodifiedLine after the call to \c nextLine will cause
/// subsequent lines on the same level to be indented at the same level as the
/// given line.
class LevelIndentTracker {
public:
LevelIndentTracker(const FormatStyle &Style,
const AdditionalKeywords &Keywords, unsigned StartLevel,
int AdditionalIndent)
: Style(Style), Keywords(Keywords), AdditionalIndent(AdditionalIndent) {
for (unsigned i = 0; i != StartLevel; ++i)
IndentForLevel.push_back(Style.IndentWidth * i + AdditionalIndent);
}
/// Returns the indent for the current line.
unsigned getIndent() const { return Indent; }
/// Update the indent state given that \p Line is going to be formatted
/// next.
void nextLine(const AnnotatedLine &Line) {
Offset = getIndentOffset(*Line.First);
// Update the indent level cache size so that we can rely on it
// having the right size in adjustToUnmodifiedline.
if (Line.Level >= IndentForLevel.size())
IndentForLevel.resize(Line.Level + 1, -1);
if (Style.IndentPPDirectives != FormatStyle::PPDIS_None &&
(Line.InPPDirective ||
(Style.IndentPPDirectives == FormatStyle::PPDIS_BeforeHash &&
Line.Type == LT_CommentAbovePPDirective))) {
unsigned PPIndentWidth =
(Style.PPIndentWidth >= 0) ? Style.PPIndentWidth : Style.IndentWidth;
Indent = Line.InMacroBody
? Line.PPLevel * PPIndentWidth +
(Line.Level - Line.PPLevel) * Style.IndentWidth
: Line.Level * PPIndentWidth;
Indent += AdditionalIndent;
} else {
// When going to lower levels, forget previous higher levels so that we
// recompute future higher levels. But don't forget them if we enter a PP
// directive, since these do not terminate a C++ code block.
if (!Line.InPPDirective) {
assert(Line.Level <= IndentForLevel.size());
IndentForLevel.resize(Line.Level + 1);
}
Indent = getIndent(Line.Level);
}
if (static_cast<int>(Indent) + Offset >= 0)
Indent += Offset;
if (Line.IsContinuation)
Indent = Line.Level * Style.IndentWidth + Style.ContinuationIndentWidth;
}
/// Update the level indent to adapt to the given \p Line.
///
/// When a line is not formatted, we move the subsequent lines on the same
/// level to the same indent.
/// Note that \c nextLine must have been called before this method.
void adjustToUnmodifiedLine(const AnnotatedLine &Line) {
if (Line.InPPDirective || Line.IsContinuation)
return;
assert(Line.Level < IndentForLevel.size());
if (Line.First->is(tok::comment) && IndentForLevel[Line.Level] != -1)
return;
unsigned LevelIndent = Line.First->OriginalColumn;
if (static_cast<int>(LevelIndent) - Offset >= 0)
LevelIndent -= Offset;
IndentForLevel[Line.Level] = LevelIndent;
}
private:
/// Get the offset of the line relatively to the level.
///
/// For example, 'public:' labels in classes are offset by 1 or 2
/// characters to the left from their level.
int getIndentOffset(const FormatToken &RootToken) {
if (Style.Language == FormatStyle::LK_Java || Style.isJavaScript() ||
Style.isCSharp()) {
return 0;
}
auto IsAccessModifier = [this, &RootToken]() {
if (RootToken.isAccessSpecifier(Style.isCpp())) {
return true;
} else if (RootToken.isObjCAccessSpecifier()) {
return true;
}
// Handle Qt signals.
else if (RootToken.isOneOf(Keywords.kw_signals, Keywords.kw_qsignals) &&
RootToken.Next && RootToken.Next->is(tok::colon)) {
return true;
} else if (RootToken.Next &&
RootToken.Next->isOneOf(Keywords.kw_slots,
Keywords.kw_qslots) &&
RootToken.Next->Next && RootToken.Next->Next->is(tok::colon)) {
return true;
}
// Handle malformed access specifier e.g. 'private' without trailing ':'.
else if (!RootToken.Next && RootToken.isAccessSpecifier(false)) {
return true;
}
return false;
};
if (IsAccessModifier()) {
// The AccessModifierOffset may be overridden by IndentAccessModifiers,
// in which case we take a negative value of the IndentWidth to simulate
// the upper indent level.
return Style.IndentAccessModifiers ? -Style.IndentWidth
: Style.AccessModifierOffset;
}
return 0;
}
/// Get the indent of \p Level from \p IndentForLevel.
///
/// \p IndentForLevel must contain the indent for the level \c l
/// at \p IndentForLevel[l], or a value < 0 if the indent for
/// that level is unknown.
unsigned getIndent(unsigned Level) const {
assert(Level < IndentForLevel.size());
if (IndentForLevel[Level] != -1)
return IndentForLevel[Level];
if (Level == 0)
return 0;
return getIndent(Level - 1) + Style.IndentWidth;
}
const FormatStyle &Style;
const AdditionalKeywords &Keywords;
const unsigned AdditionalIndent;
/// The indent in characters for each level. It remembers the indent of
/// previous lines (that are not PP directives) of equal or lower levels. This
/// is used to align formatted lines to the indent of previous non-formatted
/// lines. Think about the --lines parameter of clang-format.
SmallVector<int> IndentForLevel;
/// Offset of the current line relative to the indent level.
///
/// For example, the 'public' keywords is often indented with a negative
/// offset.
int Offset = 0;
/// The current line's indent.
unsigned Indent = 0;
};
const FormatToken *getMatchingNamespaceToken(
const AnnotatedLine *Line,
const SmallVectorImpl<AnnotatedLine *> &AnnotatedLines) {
if (!Line->startsWith(tok::r_brace))
return nullptr;
size_t StartLineIndex = Line->MatchingOpeningBlockLineIndex;
if (StartLineIndex == UnwrappedLine::kInvalidIndex)
return nullptr;
assert(StartLineIndex < AnnotatedLines.size());
return AnnotatedLines[StartLineIndex]->First->getNamespaceToken();
}
StringRef getNamespaceTokenText(const AnnotatedLine *Line) {
const FormatToken *NamespaceToken = Line->First->getNamespaceToken();
return NamespaceToken ? NamespaceToken->TokenText : StringRef();
}
StringRef getMatchingNamespaceTokenText(
const AnnotatedLine *Line,
const SmallVectorImpl<AnnotatedLine *> &AnnotatedLines) {
const FormatToken *NamespaceToken =
getMatchingNamespaceToken(Line, AnnotatedLines);
return NamespaceToken ? NamespaceToken->TokenText : StringRef();
}
class LineJoiner {
public:
LineJoiner(const FormatStyle &Style, const AdditionalKeywords &Keywords,
const SmallVectorImpl<AnnotatedLine *> &Lines)
: Style(Style), Keywords(Keywords), End(Lines.end()), Next(Lines.begin()),
AnnotatedLines(Lines) {}
/// Returns the next line, merging multiple lines into one if possible.
const AnnotatedLine *getNextMergedLine(bool DryRun,
LevelIndentTracker &IndentTracker) {
if (Next == End)
return nullptr;
const AnnotatedLine *Current = *Next;
IndentTracker.nextLine(*Current);
unsigned MergedLines = tryFitMultipleLinesInOne(IndentTracker, Next, End);
if (MergedLines > 0 && Style.ColumnLimit == 0) {
// Disallow line merging if there is a break at the start of one of the
// input lines.
for (unsigned i = 0; i < MergedLines; ++i)
if (Next[i + 1]->First->NewlinesBefore > 0)
MergedLines = 0;
}
if (!DryRun)
for (unsigned i = 0; i < MergedLines; ++i)
join(*Next[0], *Next[i + 1]);
Next = Next + MergedLines + 1;
return Current;
}
private:
/// Calculates how many lines can be merged into 1 starting at \p I.
unsigned
tryFitMultipleLinesInOne(LevelIndentTracker &IndentTracker,
SmallVectorImpl<AnnotatedLine *>::const_iterator I,
SmallVectorImpl<AnnotatedLine *>::const_iterator E) {
const unsigned Indent = IndentTracker.getIndent();
// Can't join the last line with anything.
if (I + 1 == E)
return 0;
// We can never merge stuff if there are trailing line comments.
const AnnotatedLine *TheLine = *I;
if (TheLine->Last->is(TT_LineComment))
return 0;
const auto &NextLine = *I[1];
if (NextLine.Type == LT_Invalid || NextLine.First->MustBreakBefore)
return 0;
if (TheLine->InPPDirective &&
(!NextLine.InPPDirective || NextLine.First->HasUnescapedNewline)) {
return 0;
}
if (Style.ColumnLimit > 0 && Indent > Style.ColumnLimit)
return 0;
unsigned Limit =
Style.ColumnLimit == 0 ? UINT_MAX : Style.ColumnLimit - Indent;
// If we already exceed the column limit, we set 'Limit' to 0. The different
// tryMerge..() functions can then decide whether to still do merging.
Limit = TheLine->Last->TotalLength > Limit
? 0
: Limit - TheLine->Last->TotalLength;
if (TheLine->Last->is(TT_FunctionLBrace) &&
TheLine->First == TheLine->Last &&
!Style.BraceWrapping.SplitEmptyFunction &&
NextLine.First->is(tok::r_brace)) {
return tryMergeSimpleBlock(I, E, Limit);
}
const auto *PreviousLine = I != AnnotatedLines.begin() ? I[-1] : nullptr;
// Handle empty record blocks where the brace has already been wrapped.
if (PreviousLine && TheLine->Last->is(tok::l_brace) &&
TheLine->First == TheLine->Last) {
bool EmptyBlock = NextLine.First->is(tok::r_brace);
const FormatToken *Tok = PreviousLine->First;
if (Tok && Tok->is(tok::comment))
Tok = Tok->getNextNonComment();
if (Tok && Tok->getNamespaceToken()) {
return !Style.BraceWrapping.SplitEmptyNamespace && EmptyBlock
? tryMergeSimpleBlock(I, E, Limit)
: 0;
}
if (Tok && Tok->is(tok::kw_typedef))
Tok = Tok->getNextNonComment();
if (Tok && Tok->isOneOf(tok::kw_class, tok::kw_struct, tok::kw_union,
tok::kw_extern, Keywords.kw_interface)) {
return !Style.BraceWrapping.SplitEmptyRecord && EmptyBlock
? tryMergeSimpleBlock(I, E, Limit)
: 0;
}
if (Tok && Tok->is(tok::kw_template) &&
Style.BraceWrapping.SplitEmptyRecord && EmptyBlock) {
return 0;
}
}
auto ShouldMergeShortFunctions = [this, &I, &NextLine, PreviousLine,
TheLine]() {
if (Style.AllowShortFunctionsOnASingleLine == FormatStyle::SFS_All)
return true;
if (Style.AllowShortFunctionsOnASingleLine >= FormatStyle::SFS_Empty &&
NextLine.First->is(tok::r_brace)) {
return true;
}
if (Style.AllowShortFunctionsOnASingleLine &
FormatStyle::SFS_InlineOnly) {
// Just checking TheLine->Level != 0 is not enough, because it
// provokes treating functions inside indented namespaces as short.
if (Style.isJavaScript() && TheLine->Last->is(TT_FunctionLBrace))
return true;
if (TheLine->Level != 0) {
if (!PreviousLine)
return false;
// TODO: Use IndentTracker to avoid loop?
// Find the last line with lower level.
const AnnotatedLine *Line = nullptr;
for (auto J = I - 1; J >= AnnotatedLines.begin(); --J) {
assert(*J);
if (!(*J)->InPPDirective && !(*J)->isComment() &&
(*J)->Level < TheLine->Level) {
Line = *J;
break;
}
}
if (!Line)
return false;
// Check if the found line starts a record.
const auto *LastNonComment = Line->getLastNonComment();
// There must be another token (usually `{`), because we chose a
// non-PPDirective and non-comment line that has a smaller level.
assert(LastNonComment);
return isRecordLBrace(*LastNonComment);
}
}
return false;
};
bool MergeShortFunctions = ShouldMergeShortFunctions();
const auto *FirstNonComment = TheLine->getFirstNonComment();
if (!FirstNonComment)
return 0;
// FIXME: There are probably cases where we should use FirstNonComment
// instead of TheLine->First.
if (Style.CompactNamespaces) {
if (const auto *NSToken = TheLine->First->getNamespaceToken()) {
int J = 1;
assert(TheLine->MatchingClosingBlockLineIndex > 0);
for (auto ClosingLineIndex = TheLine->MatchingClosingBlockLineIndex - 1;
I + J != E && NSToken->TokenText == getNamespaceTokenText(I[J]) &&
ClosingLineIndex == I[J]->MatchingClosingBlockLineIndex &&
I[J]->Last->TotalLength < Limit;
++J, --ClosingLineIndex) {
Limit -= I[J]->Last->TotalLength;
// Reduce indent level for bodies of namespaces which were compacted,
// but only if their content was indented in the first place.
auto *ClosingLine = AnnotatedLines.begin() + ClosingLineIndex + 1;
const int OutdentBy = I[J]->Level - TheLine->Level;
assert(OutdentBy >= 0);
for (auto *CompactedLine = I + J; CompactedLine <= ClosingLine;
++CompactedLine) {
if (!(*CompactedLine)->InPPDirective) {
const int Level = (*CompactedLine)->Level;
(*CompactedLine)->Level = std::max(Level - OutdentBy, 0);
}
}
}
return J - 1;
}
if (auto nsToken = getMatchingNamespaceToken(TheLine, AnnotatedLines)) {
int i = 0;
unsigned openingLine = TheLine->MatchingOpeningBlockLineIndex - 1;
for (; I + 1 + i != E &&
nsToken->TokenText ==
getMatchingNamespaceTokenText(I[i + 1], AnnotatedLines) &&
openingLine == I[i + 1]->MatchingOpeningBlockLineIndex;
i++, --openingLine) {
// No space between consecutive braces.
I[i + 1]->First->SpacesRequiredBefore =
I[i]->Last->isNot(tok::r_brace);
// Indent like the outer-most namespace.
IndentTracker.nextLine(*I[i + 1]);
}
return i;
}
}
const auto *LastNonComment = TheLine->getLastNonComment();
assert(LastNonComment);
// FIXME: There are probably cases where we should use LastNonComment
// instead of TheLine->Last.
// Try to merge a function block with left brace unwrapped.
if (LastNonComment->is(TT_FunctionLBrace) &&
TheLine->First != LastNonComment) {
return MergeShortFunctions ? tryMergeSimpleBlock(I, E, Limit) : 0;
}
// Try to merge a control statement block with left brace unwrapped.
if (TheLine->Last->is(tok::l_brace) && FirstNonComment != TheLine->Last &&
FirstNonComment->isOneOf(tok::kw_if, tok::kw_while, tok::kw_for,
TT_ForEachMacro)) {
return Style.AllowShortBlocksOnASingleLine != FormatStyle::SBS_Never
? tryMergeSimpleBlock(I, E, Limit)
: 0;
}
// Try to merge a control statement block with left brace wrapped.
if (NextLine.First->is(tok::l_brace)) {
if ((TheLine->First->isOneOf(tok::kw_if, tok::kw_else, tok::kw_while,
tok::kw_for, tok::kw_switch, tok::kw_try,
tok::kw_do, TT_ForEachMacro) ||
(TheLine->First->is(tok::r_brace) && TheLine->First->Next &&
TheLine->First->Next->isOneOf(tok::kw_else, tok::kw_catch))) &&
Style.BraceWrapping.AfterControlStatement ==
FormatStyle::BWACS_MultiLine) {
// If possible, merge the next line's wrapped left brace with the
// current line. Otherwise, leave it on the next line, as this is a
// multi-line control statement.
return (Style.ColumnLimit == 0 || TheLine->Level * Style.IndentWidth +
TheLine->Last->TotalLength <=
Style.ColumnLimit)
? 1
: 0;
}
if (TheLine->First->isOneOf(tok::kw_if, tok::kw_else, tok::kw_while,
tok::kw_for, TT_ForEachMacro)) {
return (Style.BraceWrapping.AfterControlStatement ==
FormatStyle::BWACS_Always)
? tryMergeSimpleBlock(I, E, Limit)
: 0;
}
if (TheLine->First->isOneOf(tok::kw_else, tok::kw_catch) &&
Style.BraceWrapping.AfterControlStatement ==
FormatStyle::BWACS_MultiLine) {
// This case if different from the upper BWACS_MultiLine processing
// in that a preceding r_brace is not on the same line as else/catch
// most likely because of BeforeElse/BeforeCatch set to true.
// If the line length doesn't fit ColumnLimit, leave l_brace on the
// next line to respect the BWACS_MultiLine.
return (Style.ColumnLimit == 0 ||
TheLine->Last->TotalLength <= Style.ColumnLimit)
? 1
: 0;
}
}
if (PreviousLine && TheLine->First->is(tok::l_brace)) {
switch (PreviousLine->First->Tok.getKind()) {
case tok::at:
// Don't merge block with left brace wrapped after ObjC special blocks.
if (PreviousLine->First->Next) {
tok::ObjCKeywordKind kwId =
PreviousLine->First->Next->Tok.getObjCKeywordID();
if (kwId == tok::objc_autoreleasepool ||
kwId == tok::objc_synchronized) {
return 0;
}
}
break;
case tok::kw_case:
case tok::kw_default:
// Don't merge block with left brace wrapped after case labels.
return 0;
default:
break;
}
}
// Don't merge an empty template class or struct if SplitEmptyRecords
// is defined.
if (PreviousLine && Style.BraceWrapping.SplitEmptyRecord &&
TheLine->Last->is(tok::l_brace) && PreviousLine->Last) {
const FormatToken *Previous = PreviousLine->Last;
if (Previous) {
if (Previous->is(tok::comment))
Previous = Previous->getPreviousNonComment();
if (Previous) {
if (Previous->is(tok::greater) && !PreviousLine->InPPDirective)
return 0;
if (Previous->is(tok::identifier)) {
const FormatToken *PreviousPrevious =
Previous->getPreviousNonComment();
if (PreviousPrevious &&
PreviousPrevious->isOneOf(tok::kw_class, tok::kw_struct)) {
return 0;
}
}
}
}
}
if (TheLine->Last->is(tok::l_brace)) {
bool ShouldMerge = false;
// Try to merge records.
if (TheLine->Last->is(TT_EnumLBrace)) {
ShouldMerge = Style.AllowShortEnumsOnASingleLine;
} else if (TheLine->Last->is(TT_RequiresExpressionLBrace)) {
ShouldMerge = Style.AllowShortCompoundRequirementOnASingleLine;
} else if (TheLine->Last->isOneOf(TT_ClassLBrace, TT_StructLBrace)) {
// NOTE: We use AfterClass (whereas AfterStruct exists) for both classes
// and structs, but it seems that wrapping is still handled correctly
// elsewhere.
ShouldMerge = !Style.BraceWrapping.AfterClass ||
(NextLine.First->is(tok::r_brace) &&
!Style.BraceWrapping.SplitEmptyRecord);
} else if (TheLine->InPPDirective ||
!TheLine->First->isOneOf(tok::kw_class, tok::kw_enum,
tok::kw_struct)) {
// Try to merge a block with left brace unwrapped that wasn't yet
// covered.
ShouldMerge = !Style.BraceWrapping.AfterFunction ||
(NextLine.First->is(tok::r_brace) &&
!Style.BraceWrapping.SplitEmptyFunction);
}
return ShouldMerge ? tryMergeSimpleBlock(I, E, Limit) : 0;
}
// Try to merge a function block with left brace wrapped.
if (NextLine.First->is(TT_FunctionLBrace) &&
Style.BraceWrapping.AfterFunction) {
if (NextLine.Last->is(TT_LineComment))
return 0;
// Check for Limit <= 2 to account for the " {".
if (Limit <= 2 || (Style.ColumnLimit == 0 && containsMustBreak(TheLine)))
return 0;
Limit -= 2;
unsigned MergedLines = 0;
if (MergeShortFunctions ||
(Style.AllowShortFunctionsOnASingleLine >= FormatStyle::SFS_Empty &&
NextLine.First == NextLine.Last && I + 2 != E &&
I[2]->First->is(tok::r_brace))) {
MergedLines = tryMergeSimpleBlock(I + 1, E, Limit);
// If we managed to merge the block, count the function header, which is
// on a separate line.
if (MergedLines > 0)
++MergedLines;
}
return MergedLines;
}
auto IsElseLine = [&TheLine]() -> bool {
const FormatToken *First = TheLine->First;
if (First->is(tok::kw_else))
return true;
return First->is(tok::r_brace) && First->Next &&
First->Next->is(tok::kw_else);
};
if (TheLine->First->is(tok::kw_if) ||
(IsElseLine() && (Style.AllowShortIfStatementsOnASingleLine ==
FormatStyle::SIS_AllIfsAndElse))) {
return Style.AllowShortIfStatementsOnASingleLine
? tryMergeSimpleControlStatement(I, E, Limit)
: 0;
}
if (TheLine->First->isOneOf(tok::kw_for, tok::kw_while, tok::kw_do,
TT_ForEachMacro)) {
return Style.AllowShortLoopsOnASingleLine
? tryMergeSimpleControlStatement(I, E, Limit)
: 0;
}
if (TheLine->First->isOneOf(tok::kw_case, tok::kw_default)) {
return Style.AllowShortCaseLabelsOnASingleLine
? tryMergeShortCaseLabels(I, E, Limit)
: 0;
}
if (TheLine->InPPDirective &&
(TheLine->First->HasUnescapedNewline || TheLine->First->IsFirst)) {
return tryMergeSimplePPDirective(I, E, Limit);
}
return 0;
}
unsigned
tryMergeSimplePPDirective(SmallVectorImpl<AnnotatedLine *>::const_iterator I,
SmallVectorImpl<AnnotatedLine *>::const_iterator E,
unsigned Limit) {
if (Limit == 0)
return 0;
if (I + 2 != E && I[2]->InPPDirective && !I[2]->First->HasUnescapedNewline)
return 0;
if (1 + I[1]->Last->TotalLength > Limit)
return 0;
return 1;
}
unsigned tryMergeSimpleControlStatement(
SmallVectorImpl<AnnotatedLine *>::const_iterator I,
SmallVectorImpl<AnnotatedLine *>::const_iterator E, unsigned Limit) {
if (Limit == 0)
return 0;
if (Style.BraceWrapping.AfterControlStatement ==
FormatStyle::BWACS_Always &&
I[1]->First->is(tok::l_brace) &&
Style.AllowShortBlocksOnASingleLine == FormatStyle::SBS_Never) {
return 0;
}
if (I[1]->InPPDirective != (*I)->InPPDirective ||
(I[1]->InPPDirective && I[1]->First->HasUnescapedNewline)) {
return 0;
}
Limit = limitConsideringMacros(I + 1, E, Limit);
AnnotatedLine &Line = **I;
if (Line.First->isNot(tok::kw_do) && Line.First->isNot(tok::kw_else) &&
Line.Last->isNot(tok::kw_else) && Line.Last->isNot(tok::r_paren)) {
return 0;
}
// Only merge `do while` if `do` is the only statement on the line.
if (Line.First->is(tok::kw_do) && Line.Last->isNot(tok::kw_do))
return 0;
if (1 + I[1]->Last->TotalLength > Limit)
return 0;
// Don't merge with loops, ifs, a single semicolon or a line comment.
if (I[1]->First->isOneOf(tok::semi, tok::kw_if, tok::kw_for, tok::kw_while,
TT_ForEachMacro, TT_LineComment)) {
return 0;
}
// Only inline simple if's (no nested if or else), unless specified
if (Style.AllowShortIfStatementsOnASingleLine ==
FormatStyle::SIS_WithoutElse) {
if (I + 2 != E && Line.startsWith(tok::kw_if) &&
I[2]->First->is(tok::kw_else)) {
return 0;
}
}
return 1;
}
unsigned
tryMergeShortCaseLabels(SmallVectorImpl<AnnotatedLine *>::const_iterator I,
SmallVectorImpl<AnnotatedLine *>::const_iterator E,
unsigned Limit) {
if (Limit == 0 || I + 1 == E ||
I[1]->First->isOneOf(tok::kw_case, tok::kw_default)) {
return 0;
}
if (I[0]->Last->is(tok::l_brace) || I[1]->First->is(tok::l_brace))
return 0;
unsigned NumStmts = 0;
unsigned Length = 0;
bool EndsWithComment = false;
bool InPPDirective = I[0]->InPPDirective;
bool InMacroBody = I[0]->InMacroBody;
const unsigned Level = I[0]->Level;
for (; NumStmts < 3; ++NumStmts) {
if (I + 1 + NumStmts == E)
break;
const AnnotatedLine *Line = I[1 + NumStmts];
if (Line->InPPDirective != InPPDirective)
break;
if (Line->InMacroBody != InMacroBody)
break;
if (Line->First->isOneOf(tok::kw_case, tok::kw_default, tok::r_brace))
break;
if (Line->First->isOneOf(tok::kw_if, tok::kw_for, tok::kw_switch,
tok::kw_while) ||
EndsWithComment) {
return 0;
}
if (Line->First->is(tok::comment)) {
if (Level != Line->Level)
return 0;
SmallVectorImpl<AnnotatedLine *>::const_iterator J = I + 2 + NumStmts;
for (; J != E; ++J) {
Line = *J;
if (Line->InPPDirective != InPPDirective)
break;
if (Line->First->isOneOf(tok::kw_case, tok::kw_default, tok::r_brace))
break;
if (Line->First->isNot(tok::comment) || Level != Line->Level)
return 0;
}
break;
}
if (Line->Last->is(tok::comment))
EndsWithComment = true;
Length += I[1 + NumStmts]->Last->TotalLength + 1; // 1 for the space.
}
if (NumStmts == 0 || NumStmts == 3 || Length > Limit)
return 0;
return NumStmts;
}
unsigned
tryMergeSimpleBlock(SmallVectorImpl<AnnotatedLine *>::const_iterator I,
SmallVectorImpl<AnnotatedLine *>::const_iterator E,
unsigned Limit) {
// Don't merge with a preprocessor directive.
if (I[1]->Type == LT_PreprocessorDirective)
return 0;
AnnotatedLine &Line = **I;
// Don't merge ObjC @ keywords and methods.
// FIXME: If an option to allow short exception handling clauses on a single
// line is added, change this to not return for @try and friends.
if (Style.Language != FormatStyle::LK_Java &&
Line.First->isOneOf(tok::at, tok::minus, tok::plus)) {
return 0;
}
// Check that the current line allows merging. This depends on whether we
// are in a control flow statements as well as several style flags.
if (Line.First->is(tok::kw_case) ||
(Line.First->Next && Line.First->Next->is(tok::kw_else))) {
return 0;
}
// default: in switch statement
if (Line.First->is(tok::kw_default)) {
const FormatToken *Tok = Line.First->getNextNonComment();
if (Tok && Tok->is(tok::colon))
return 0;
}
auto IsCtrlStmt = [](const auto &Line) {
return Line.First->isOneOf(tok::kw_if, tok::kw_else, tok::kw_while,
tok::kw_do, tok::kw_for, TT_ForEachMacro);
};
const bool IsSplitBlock =
Style.AllowShortBlocksOnASingleLine == FormatStyle::SBS_Never ||
(Style.AllowShortBlocksOnASingleLine == FormatStyle::SBS_Empty &&
I[1]->First->isNot(tok::r_brace));
if (IsCtrlStmt(Line) ||
Line.First->isOneOf(tok::kw_try, tok::kw___try, tok::kw_catch,
tok::kw___finally, tok::r_brace,
Keywords.kw___except)) {
if (IsSplitBlock)
return 0;
// Don't merge when we can't except the case when
// the control statement block is empty
if (!Style.AllowShortIfStatementsOnASingleLine &&
Line.First->isOneOf(tok::kw_if, tok::kw_else) &&
!Style.BraceWrapping.AfterControlStatement &&
I[1]->First->isNot(tok::r_brace)) {
return 0;
}
if (!Style.AllowShortIfStatementsOnASingleLine &&
Line.First->isOneOf(tok::kw_if, tok::kw_else) &&
Style.BraceWrapping.AfterControlStatement ==
FormatStyle::BWACS_Always &&
I + 2 != E && I[2]->First->isNot(tok::r_brace)) {
return 0;
}
if (!Style.AllowShortLoopsOnASingleLine &&
Line.First->isOneOf(tok::kw_while, tok::kw_do, tok::kw_for,
TT_ForEachMacro) &&
!Style.BraceWrapping.AfterControlStatement &&
I[1]->First->isNot(tok::r_brace)) {
return 0;
}
if (!Style.AllowShortLoopsOnASingleLine &&
Line.First->isOneOf(tok::kw_while, tok::kw_do, tok::kw_for,
TT_ForEachMacro) &&
Style.BraceWrapping.AfterControlStatement ==
FormatStyle::BWACS_Always &&
I + 2 != E && I[2]->First->isNot(tok::r_brace)) {
return 0;
}
// FIXME: Consider an option to allow short exception handling clauses on
// a single line.
// FIXME: This isn't covered by tests.
// FIXME: For catch, __except, __finally the first token on the line
// is '}', so this isn't correct here.
if (Line.First->isOneOf(tok::kw_try, tok::kw___try, tok::kw_catch,
Keywords.kw___except, tok::kw___finally)) {
return 0;
}
}
if (Line.endsWith(tok::l_brace)) {
if (Style.AllowShortBlocksOnASingleLine == FormatStyle::SBS_Never &&
Line.First->is(TT_BlockLBrace)) {
return 0;
}
if (IsSplitBlock && Line.First == Line.Last &&
I > AnnotatedLines.begin() &&
(I[-1]->endsWith(tok::kw_else) || IsCtrlStmt(*I[-1]))) {
return 0;
}
FormatToken *Tok = I[1]->First;
auto ShouldMerge = [Tok]() {
if (Tok->isNot(tok::r_brace) || Tok->MustBreakBefore)
return false;
const FormatToken *Next = Tok->getNextNonComment();
return !Next || Next->is(tok::semi);
};
if (ShouldMerge()) {
// We merge empty blocks even if the line exceeds the column limit.
Tok->SpacesRequiredBefore =
(Style.SpaceInEmptyBlock || Line.Last->is(tok::comment)) ? 1 : 0;
Tok->CanBreakBefore = true;
return 1;
} else if (Limit != 0 && !Line.startsWithNamespace() &&
!startsExternCBlock(Line)) {
// We don't merge short records.
if (isRecordLBrace(*Line.Last))
return 0;
// Check that we still have three lines and they fit into the limit.
if (I + 2 == E || I[2]->Type == LT_Invalid)
return 0;
Limit = limitConsideringMacros(I + 2, E, Limit);
if (!nextTwoLinesFitInto(I, Limit))
return 0;
// Second, check that the next line does not contain any braces - if it
// does, readability declines when putting it into a single line.
if (I[1]->Last->is(TT_LineComment))
return 0;
do {
if (Tok->is(tok::l_brace) && Tok->isNot(BK_BracedInit))
return 0;
Tok = Tok->Next;
} while (Tok);
// Last, check that the third line starts with a closing brace.
Tok = I[2]->First;
if (Tok->isNot(tok::r_brace))
return 0;
// Don't merge "if (a) { .. } else {".
if (Tok->Next && Tok->Next->is(tok::kw_else))
return 0;
// Don't merge a trailing multi-line control statement block like:
// } else if (foo &&
// bar)
// { <-- current Line
// baz();
// }
if (Line.First == Line.Last && Line.First->isNot(TT_FunctionLBrace) &&
Style.BraceWrapping.AfterControlStatement ==
FormatStyle::BWACS_MultiLine) {
return 0;
}
return 2;
}
} else if (I[1]->First->is(tok::l_brace)) {
if (I[1]->Last->is(TT_LineComment))
return 0;
// Check for Limit <= 2 to account for the " {".
if (Limit <= 2 || (Style.ColumnLimit == 0 && containsMustBreak(*I)))
return 0;
Limit -= 2;
unsigned MergedLines = 0;
if (Style.AllowShortBlocksOnASingleLine != FormatStyle::SBS_Never ||
(I[1]->First == I[1]->Last && I + 2 != E &&
I[2]->First->is(tok::r_brace))) {
MergedLines = tryMergeSimpleBlock(I + 1, E, Limit);
// If we managed to merge the block, count the statement header, which
// is on a separate line.
if (MergedLines > 0)
++MergedLines;
}
return MergedLines;
}
return 0;
}
/// Returns the modified column limit for \p I if it is inside a macro and
/// needs a trailing '\'.
unsigned
limitConsideringMacros(SmallVectorImpl<AnnotatedLine *>::const_iterator I,
SmallVectorImpl<AnnotatedLine *>::const_iterator E,
unsigned Limit) {
if (I[0]->InPPDirective && I + 1 != E &&
!I[1]->First->HasUnescapedNewline && I[1]->First->isNot(tok::eof)) {
return Limit < 2 ? 0 : Limit - 2;
}
return Limit;
}
bool nextTwoLinesFitInto(SmallVectorImpl<AnnotatedLine *>::const_iterator I,
unsigned Limit) {
if (I[1]->First->MustBreakBefore || I[2]->First->MustBreakBefore)
return false;
return 1 + I[1]->Last->TotalLength + 1 + I[2]->Last->TotalLength <= Limit;
}
bool containsMustBreak(const AnnotatedLine *Line) {
assert(Line->First);
// Ignore the first token, because in this situation, it applies more to the
// last token of the previous line.
for (const FormatToken *Tok = Line->First->Next; Tok; Tok = Tok->Next)
if (Tok->MustBreakBefore)
return true;
return false;
}
void join(AnnotatedLine &A, const AnnotatedLine &B) {
assert(!A.Last->Next);
assert(!B.First->Previous);
if (B.Affected)
A.Affected = true;
A.Last->Next = B.First;
B.First->Previous = A.Last;
B.First->CanBreakBefore = true;
unsigned LengthA = A.Last->TotalLength + B.First->SpacesRequiredBefore;
for (FormatToken *Tok = B.First; Tok; Tok = Tok->Next) {
Tok->TotalLength += LengthA;
A.Last = Tok;
}
}
const FormatStyle &Style;
const AdditionalKeywords &Keywords;
const SmallVectorImpl<AnnotatedLine *>::const_iterator End;
SmallVectorImpl<AnnotatedLine *>::const_iterator Next;
const SmallVectorImpl<AnnotatedLine *> &AnnotatedLines;
};
static void markFinalized(FormatToken *Tok) {
if (Tok->is(tok::hash) && !Tok->Previous && Tok->Next &&
Tok->Next->isOneOf(tok::pp_if, tok::pp_ifdef, tok::pp_ifndef,
tok::pp_elif, tok::pp_elifdef, tok::pp_elifndef,
tok::pp_else, tok::pp_endif)) {
Tok = Tok->Next;
}
for (; Tok; Tok = Tok->Next) {
if (Tok->MacroCtx && Tok->MacroCtx->Role == MR_ExpandedArg) {
// In the first pass we format all macro arguments in the expanded token
// stream. Instead of finalizing the macro arguments, we mark that they
// will be modified as unexpanded arguments (as part of the macro call
// formatting) in the next pass.
Tok->MacroCtx->Role = MR_UnexpandedArg;
// Reset whether spaces or a line break are required before this token, as
// that is context dependent, and that context may change when formatting
// the macro call. For example, given M(x) -> 2 * x, and the macro call
// M(var), the token 'var' will have SpacesRequiredBefore = 1 after being
// formatted as part of the expanded macro, but SpacesRequiredBefore = 0
// for its position within the macro call.
Tok->SpacesRequiredBefore = 0;
if (!Tok->MustBreakBeforeFinalized)
Tok->MustBreakBefore = 0;
} else {
Tok->Finalized = true;
}
}
}
#ifndef NDEBUG
static void printLineState(const LineState &State) {
llvm::dbgs() << "State: ";
for (const ParenState &P : State.Stack) {
llvm::dbgs() << (P.Tok ? P.Tok->TokenText : "F") << "|" << P.Indent << "|"
<< P.LastSpace << "|" << P.NestedBlockIndent << " ";
}
llvm::dbgs() << State.NextToken->TokenText << "\n";
}
#endif
/// Base class for classes that format one \c AnnotatedLine.
class LineFormatter {
public:
LineFormatter(ContinuationIndenter *Indenter, WhitespaceManager *Whitespaces,
const FormatStyle &Style,
UnwrappedLineFormatter *BlockFormatter)
: Indenter(Indenter), Whitespaces(Whitespaces), Style(Style),
BlockFormatter(BlockFormatter) {}
virtual ~LineFormatter() {}
/// Formats an \c AnnotatedLine and returns the penalty.
///
/// If \p DryRun is \c false, directly applies the changes.
virtual unsigned formatLine(const AnnotatedLine &Line, unsigned FirstIndent,
unsigned FirstStartColumn, bool DryRun) = 0;
protected:
/// If the \p State's next token is an r_brace closing a nested block,
/// format the nested block before it.
///
/// Returns \c true if all children could be placed successfully and adapts
/// \p Penalty as well as \p State. If \p DryRun is false, also directly
/// creates changes using \c Whitespaces.
///
/// The crucial idea here is that children always get formatted upon
/// encountering the closing brace right after the nested block. Now, if we
/// are currently trying to keep the "}" on the same line (i.e. \p NewLine is
/// \c false), the entire block has to be kept on the same line (which is only
/// possible if it fits on the line, only contains a single statement, etc.
///
/// If \p NewLine is true, we format the nested block on separate lines, i.e.
/// break after the "{", format all lines with correct indentation and the put
/// the closing "}" on yet another new line.
///
/// This enables us to keep the simple structure of the
/// \c UnwrappedLineFormatter, where we only have two options for each token:
/// break or don't break.
bool formatChildren(LineState &State, bool NewLine, bool DryRun,
unsigned &Penalty) {
const FormatToken *LBrace = State.NextToken->getPreviousNonComment();
bool HasLBrace = LBrace && LBrace->is(tok::l_brace) && LBrace->is(BK_Block);
FormatToken &Previous = *State.NextToken->Previous;
if (Previous.Children.size() == 0 || (!HasLBrace && !LBrace->MacroParent)) {
// The previous token does not open a block. Nothing to do. We don't
// assert so that we can simply call this function for all tokens.
return true;
}
if (NewLine || Previous.MacroParent) {
const ParenState &P = State.Stack.back();
int AdditionalIndent =
P.Indent - Previous.Children[0]->Level * Style.IndentWidth;
Penalty +=
BlockFormatter->format(Previous.Children, DryRun, AdditionalIndent,
/*FixBadIndentation=*/true);
return true;
}
if (Previous.Children[0]->First->MustBreakBefore)
return false;
// Cannot merge into one line if this line ends on a comment.
if (Previous.is(tok::comment))
return false;
// Cannot merge multiple statements into a single line.
if (Previous.Children.size() > 1)
return false;
const AnnotatedLine *Child = Previous.Children[0];
// We can't put the closing "}" on a line with a trailing comment.
if (Child->Last->isTrailingComment())
return false;
// If the child line exceeds the column limit, we wouldn't want to merge it.
// We add +2 for the trailing " }".
if (Style.ColumnLimit > 0 &&
Child->Last->TotalLength + State.Column + 2 > Style.ColumnLimit) {
return false;
}
if (!DryRun) {
Whitespaces->replaceWhitespace(
*Child->First, /*Newlines=*/0, /*Spaces=*/1,
/*StartOfTokenColumn=*/State.Column, /*IsAligned=*/false,
State.Line->InPPDirective);
}
Penalty +=
formatLine(*Child, State.Column + 1, /*FirstStartColumn=*/0, DryRun);
if (!DryRun)
markFinalized(Child->First);
State.Column += 1 + Child->Last->TotalLength;
return true;
}
ContinuationIndenter *Indenter;
private:
WhitespaceManager *Whitespaces;
const FormatStyle &Style;
UnwrappedLineFormatter *BlockFormatter;
};
/// Formatter that keeps the existing line breaks.
class NoColumnLimitLineFormatter : public LineFormatter {
public:
NoColumnLimitLineFormatter(ContinuationIndenter *Indenter,
WhitespaceManager *Whitespaces,
const FormatStyle &Style,
UnwrappedLineFormatter *BlockFormatter)
: LineFormatter(Indenter, Whitespaces, Style, BlockFormatter) {}
/// Formats the line, simply keeping all of the input's line breaking
/// decisions.
unsigned formatLine(const AnnotatedLine &Line, unsigned FirstIndent,
unsigned FirstStartColumn, bool DryRun) override {
assert(!DryRun);
LineState State = Indenter->getInitialState(FirstIndent, FirstStartColumn,
&Line, /*DryRun=*/false);
while (State.NextToken) {
bool Newline =
Indenter->mustBreak(State) ||
(Indenter->canBreak(State) && State.NextToken->NewlinesBefore > 0);
unsigned Penalty = 0;
formatChildren(State, Newline, /*DryRun=*/false, Penalty);
Indenter->addTokenToState(State, Newline, /*DryRun=*/false);
}
return 0;
}
};
/// Formatter that puts all tokens into a single line without breaks.
class NoLineBreakFormatter : public LineFormatter {
public:
NoLineBreakFormatter(ContinuationIndenter *Indenter,
WhitespaceManager *Whitespaces, const FormatStyle &Style,
UnwrappedLineFormatter *BlockFormatter)
: LineFormatter(Indenter, Whitespaces, Style, BlockFormatter) {}
/// Puts all tokens into a single line.
unsigned formatLine(const AnnotatedLine &Line, unsigned FirstIndent,
unsigned FirstStartColumn, bool DryRun) override {
unsigned Penalty = 0;
LineState State =
Indenter->getInitialState(FirstIndent, FirstStartColumn, &Line, DryRun);
while (State.NextToken) {
formatChildren(State, /*NewLine=*/false, DryRun, Penalty);
Indenter->addTokenToState(
State, /*Newline=*/State.NextToken->MustBreakBefore, DryRun);
}
return Penalty;
}
};
/// Finds the best way to break lines.
class OptimizingLineFormatter : public LineFormatter {
public:
OptimizingLineFormatter(ContinuationIndenter *Indenter,
WhitespaceManager *Whitespaces,
const FormatStyle &Style,
UnwrappedLineFormatter *BlockFormatter)
: LineFormatter(Indenter, Whitespaces, Style, BlockFormatter) {}
/// Formats the line by finding the best line breaks with line lengths
/// below the column limit.
unsigned formatLine(const AnnotatedLine &Line, unsigned FirstIndent,
unsigned FirstStartColumn, bool DryRun) override {
LineState State =
Indenter->getInitialState(FirstIndent, FirstStartColumn, &Line, DryRun);
// If the ObjC method declaration does not fit on a line, we should format
// it with one arg per line.
if (State.Line->Type == LT_ObjCMethodDecl)
State.Stack.back().BreakBeforeParameter = true;
// Find best solution in solution space.
return analyzeSolutionSpace(State, DryRun);
}
private:
struct CompareLineStatePointers {
bool operator()(LineState *obj1, LineState *obj2) const {
return *obj1 < *obj2;
}
};
/// A pair of <penalty, count> that is used to prioritize the BFS on.
///
/// In case of equal penalties, we want to prefer states that were inserted
/// first. During state generation we make sure that we insert states first
/// that break the line as late as possible.
typedef std::pair<unsigned, unsigned> OrderedPenalty;
/// An edge in the solution space from \c Previous->State to \c State,
/// inserting a newline dependent on the \c NewLine.
struct StateNode {
StateNode(const LineState &State, bool NewLine, StateNode *Previous)
: State(State), NewLine(NewLine), Previous(Previous) {}
LineState State;
bool NewLine;
StateNode *Previous;
};
/// An item in the prioritized BFS search queue. The \c StateNode's
/// \c State has the given \c OrderedPenalty.
typedef std::pair<OrderedPenalty, StateNode *> QueueItem;
/// The BFS queue type.
typedef std::priority_queue<QueueItem, SmallVector<QueueItem>,
std::greater<QueueItem>>
QueueType;
/// Analyze the entire solution space starting from \p InitialState.
///
/// This implements a variant of Dijkstra's algorithm on the graph that spans
/// the solution space (\c LineStates are the nodes). The algorithm tries to
/// find the shortest path (the one with lowest penalty) from \p InitialState
/// to a state where all tokens are placed. Returns the penalty.
///
/// If \p DryRun is \c false, directly applies the changes.
unsigned analyzeSolutionSpace(LineState &InitialState, bool DryRun) {
std::set<LineState *, CompareLineStatePointers> Seen;
// Increasing count of \c StateNode items we have created. This is used to
// create a deterministic order independent of the container.
unsigned Count = 0;
QueueType Queue;
// Insert start element into queue.
StateNode *RootNode =
new (Allocator.Allocate()) StateNode(InitialState, false, nullptr);
Queue.push(QueueItem(OrderedPenalty(0, Count), RootNode));
++Count;
unsigned Penalty = 0;
// While not empty, take first element and follow edges.
while (!Queue.empty()) {
// Quit if we still haven't found a solution by now.
if (Count > 25'000'000)
return 0;
Penalty = Queue.top().first.first;
StateNode *Node = Queue.top().second;
if (!Node->State.NextToken) {
LLVM_DEBUG(llvm::dbgs()
<< "\n---\nPenalty for line: " << Penalty << "\n");
break;
}
Queue.pop();
// Cut off the analysis of certain solutions if the analysis gets too
// complex. See description of IgnoreStackForComparison.
if (Count > 50'000)
Node->State.IgnoreStackForComparison = true;
if (!Seen.insert(&Node->State).second) {
// State already examined with lower penalty.
continue;
}
FormatDecision LastFormat = Node->State.NextToken->getDecision();
if (LastFormat == FD_Unformatted || LastFormat == FD_Continue)
addNextStateToQueue(Penalty, Node, /*NewLine=*/false, &Count, &Queue);
if (LastFormat == FD_Unformatted || LastFormat == FD_Break)
addNextStateToQueue(Penalty, Node, /*NewLine=*/true, &Count, &Queue);
}
if (Queue.empty()) {
// We were unable to find a solution, do nothing.
// FIXME: Add diagnostic?
LLVM_DEBUG(llvm::dbgs() << "Could not find a solution.\n");
return 0;
}
// Reconstruct the solution.
if (!DryRun)
reconstructPath(InitialState, Queue.top().second);
LLVM_DEBUG(llvm::dbgs()
<< "Total number of analyzed states: " << Count << "\n");
LLVM_DEBUG(llvm::dbgs() << "---\n");
return Penalty;
}
/// Add the following state to the analysis queue \c Queue.
///
/// Assume the current state is \p PreviousNode and has been reached with a
/// penalty of \p Penalty. Insert a line break if \p NewLine is \c true.
void addNextStateToQueue(unsigned Penalty, StateNode *PreviousNode,
bool NewLine, unsigned *Count, QueueType *Queue) {
if (NewLine && !Indenter->canBreak(PreviousNode->State))
return;
if (!NewLine && Indenter->mustBreak(PreviousNode->State))
return;
StateNode *Node = new (Allocator.Allocate())
StateNode(PreviousNode->State, NewLine, PreviousNode);
if (!formatChildren(Node->State, NewLine, /*DryRun=*/true, Penalty))
return;
Penalty += Indenter->addTokenToState(Node->State, NewLine, true);
Queue->push(QueueItem(OrderedPenalty(Penalty, *Count), Node));
++(*Count);
}
/// Applies the best formatting by reconstructing the path in the
/// solution space that leads to \c Best.
void reconstructPath(LineState &State, StateNode *Best) {
llvm::SmallVector<StateNode *> Path;
// We do not need a break before the initial token.
while (Best->Previous) {
Path.push_back(Best);
Best = Best->Previous;
}
for (const auto &Node : llvm::reverse(Path)) {
unsigned Penalty = 0;
formatChildren(State, Node->NewLine, /*DryRun=*/false, Penalty);
Penalty += Indenter->addTokenToState(State, Node->NewLine, false);
LLVM_DEBUG({
printLineState(Node->Previous->State);
if (Node->NewLine) {
llvm::dbgs() << "Penalty for placing "
<< Node->Previous->State.NextToken->Tok.getName()
<< " on a new line: " << Penalty << "\n";
}
});
}
}
llvm::SpecificBumpPtrAllocator<StateNode> Allocator;
};
} // anonymous namespace
unsigned UnwrappedLineFormatter::format(
const SmallVectorImpl<AnnotatedLine *> &Lines, bool DryRun,
int AdditionalIndent, bool FixBadIndentation, unsigned FirstStartColumn,
unsigned NextStartColumn, unsigned LastStartColumn) {
LineJoiner Joiner(Style, Keywords, Lines);
// Try to look up already computed penalty in DryRun-mode.
std::pair<const SmallVectorImpl<AnnotatedLine *> *, unsigned> CacheKey(
&Lines, AdditionalIndent);
auto CacheIt = PenaltyCache.find(CacheKey);
if (DryRun && CacheIt != PenaltyCache.end())
return CacheIt->second;
assert(!Lines.empty());
unsigned Penalty = 0;
LevelIndentTracker IndentTracker(Style, Keywords, Lines[0]->Level,
AdditionalIndent);
const AnnotatedLine *PrevPrevLine = nullptr;
const AnnotatedLine *PreviousLine = nullptr;
const AnnotatedLine *NextLine = nullptr;
// The minimum level of consecutive lines that have been formatted.
unsigned RangeMinLevel = UINT_MAX;
bool FirstLine = true;
for (const AnnotatedLine *Line =
Joiner.getNextMergedLine(DryRun, IndentTracker);
Line; PrevPrevLine = PreviousLine, PreviousLine = Line, Line = NextLine,
FirstLine = false) {
assert(Line->First);
const AnnotatedLine &TheLine = *Line;
unsigned Indent = IndentTracker.getIndent();
// We continue formatting unchanged lines to adjust their indent, e.g. if a
// scope was added. However, we need to carefully stop doing this when we
// exit the scope of affected lines to prevent indenting the entire
// remaining file if it currently missing a closing brace.
bool PreviousRBrace =
PreviousLine && PreviousLine->startsWith(tok::r_brace);
bool ContinueFormatting =
TheLine.Level > RangeMinLevel ||
(TheLine.Level == RangeMinLevel && !PreviousRBrace &&
!TheLine.startsWith(tok::r_brace));
bool FixIndentation = (FixBadIndentation || ContinueFormatting) &&
Indent != TheLine.First->OriginalColumn;
bool ShouldFormat = TheLine.Affected || FixIndentation;
// We cannot format this line; if the reason is that the line had a
// parsing error, remember that.
if (ShouldFormat && TheLine.Type == LT_Invalid && Status) {
Status->FormatComplete = false;
Status->Line =
SourceMgr.getSpellingLineNumber(TheLine.First->Tok.getLocation());
}
if (ShouldFormat && TheLine.Type != LT_Invalid) {
if (!DryRun) {
bool LastLine = TheLine.First->is(tok::eof);
formatFirstToken(TheLine, PreviousLine, PrevPrevLine, Lines, Indent,
LastLine ? LastStartColumn : NextStartColumn + Indent);
}
NextLine = Joiner.getNextMergedLine(DryRun, IndentTracker);
unsigned ColumnLimit = getColumnLimit(TheLine.InPPDirective, NextLine);
bool FitsIntoOneLine =
!TheLine.ContainsMacroCall &&
(TheLine.Last->TotalLength + Indent <= ColumnLimit ||
(TheLine.Type == LT_ImportStatement &&
(!Style.isJavaScript() || !Style.JavaScriptWrapImports)) ||
(Style.isCSharp() &&
TheLine.InPPDirective)); // don't split #regions in C#
if (Style.ColumnLimit == 0) {
NoColumnLimitLineFormatter(Indenter, Whitespaces, Style, this)
.formatLine(TheLine, NextStartColumn + Indent,
FirstLine ? FirstStartColumn : 0, DryRun);
} else if (FitsIntoOneLine) {
Penalty += NoLineBreakFormatter(Indenter, Whitespaces, Style, this)
.formatLine(TheLine, NextStartColumn + Indent,
FirstLine ? FirstStartColumn : 0, DryRun);
} else {
Penalty += OptimizingLineFormatter(Indenter, Whitespaces, Style, this)
.formatLine(TheLine, NextStartColumn + Indent,
FirstLine ? FirstStartColumn : 0, DryRun);
}
RangeMinLevel = std::min(RangeMinLevel, TheLine.Level);
} else {
// If no token in the current line is affected, we still need to format
// affected children.
if (TheLine.ChildrenAffected) {
for (const FormatToken *Tok = TheLine.First; Tok; Tok = Tok->Next)
if (!Tok->Children.empty())
format(Tok->Children, DryRun);
}
// Adapt following lines on the current indent level to the same level
// unless the current \c AnnotatedLine is not at the beginning of a line.
bool StartsNewLine =
TheLine.First->NewlinesBefore > 0 || TheLine.First->IsFirst;
if (StartsNewLine)
IndentTracker.adjustToUnmodifiedLine(TheLine);
if (!DryRun) {
bool ReformatLeadingWhitespace =
StartsNewLine && ((PreviousLine && PreviousLine->Affected) ||
TheLine.LeadingEmptyLinesAffected);
// Format the first token.
if (ReformatLeadingWhitespace) {
formatFirstToken(TheLine, PreviousLine, PrevPrevLine, Lines,
TheLine.First->OriginalColumn,
TheLine.First->OriginalColumn);
} else {
Whitespaces->addUntouchableToken(*TheLine.First,
TheLine.InPPDirective);
}
// Notify the WhitespaceManager about the unchanged whitespace.
for (FormatToken *Tok = TheLine.First->Next; Tok; Tok = Tok->Next)
Whitespaces->addUntouchableToken(*Tok, TheLine.InPPDirective);
}
NextLine = Joiner.getNextMergedLine(DryRun, IndentTracker);
RangeMinLevel = UINT_MAX;
}
if (!DryRun)
markFinalized(TheLine.First);
}
PenaltyCache[CacheKey] = Penalty;
return Penalty;
}
static auto computeNewlines(const AnnotatedLine &Line,
const AnnotatedLine *PreviousLine,
const AnnotatedLine *PrevPrevLine,
const SmallVectorImpl<AnnotatedLine *> &Lines,
const FormatStyle &Style) {
const auto &RootToken = *Line.First;
auto Newlines =
std::min(RootToken.NewlinesBefore, Style.MaxEmptyLinesToKeep + 1);
// Remove empty lines before "}" where applicable.
if (RootToken.is(tok::r_brace) &&
(!RootToken.Next ||
(RootToken.Next->is(tok::semi) && !RootToken.Next->Next)) &&
// Do not remove empty lines before namespace closing "}".
!getNamespaceToken(&Line, Lines)) {
Newlines = std::min(Newlines, 1u);
}
// Remove empty lines at the start of nested blocks (lambdas/arrow functions)
if (!PreviousLine && Line.Level > 0)
Newlines = std::min(Newlines, 1u);
if (Newlines == 0 && !RootToken.IsFirst)
Newlines = 1;
if (RootToken.IsFirst && !RootToken.HasUnescapedNewline)
Newlines = 0;
// Remove empty lines after "{".
if (!Style.KeepEmptyLinesAtTheStartOfBlocks && PreviousLine &&
PreviousLine->Last->is(tok::l_brace) &&
!PreviousLine->startsWithNamespace() &&
!(PrevPrevLine && PrevPrevLine->startsWithNamespace() &&
PreviousLine->startsWith(tok::l_brace)) &&
!startsExternCBlock(*PreviousLine)) {
Newlines = 1;
}
// Insert or remove empty line before access specifiers.
if (PreviousLine && RootToken.isAccessSpecifier()) {
switch (Style.EmptyLineBeforeAccessModifier) {
case FormatStyle::ELBAMS_Never:
if (Newlines > 1)
Newlines = 1;
break;
case FormatStyle::ELBAMS_Leave:
Newlines = std::max(RootToken.NewlinesBefore, 1u);
break;
case FormatStyle::ELBAMS_LogicalBlock:
if (PreviousLine->Last->isOneOf(tok::semi, tok::r_brace) && Newlines <= 1)
Newlines = 2;
if (PreviousLine->First->isAccessSpecifier())
Newlines = 1; // Previous is an access modifier remove all new lines.
break;
case FormatStyle::ELBAMS_Always: {
const FormatToken *previousToken;
if (PreviousLine->Last->is(tok::comment))
previousToken = PreviousLine->Last->getPreviousNonComment();
else
previousToken = PreviousLine->Last;
if ((!previousToken || previousToken->isNot(tok::l_brace)) &&
Newlines <= 1) {
Newlines = 2;
}
} break;
}
}
// Insert or remove empty line after access specifiers.
if (PreviousLine && PreviousLine->First->isAccessSpecifier() &&
(!PreviousLine->InPPDirective || !RootToken.HasUnescapedNewline)) {
// EmptyLineBeforeAccessModifier is handling the case when two access
// modifiers follow each other.
if (!RootToken.isAccessSpecifier()) {
switch (Style.EmptyLineAfterAccessModifier) {
case FormatStyle::ELAAMS_Never:
Newlines = 1;
break;
case FormatStyle::ELAAMS_Leave:
Newlines = std::max(Newlines, 1u);
break;
case FormatStyle::ELAAMS_Always:
if (RootToken.is(tok::r_brace)) // Do not add at end of class.
Newlines = 1u;
else
Newlines = std::max(Newlines, 2u);
break;
}
}
}
return Newlines;
}
void UnwrappedLineFormatter::formatFirstToken(
const AnnotatedLine &Line, const AnnotatedLine *PreviousLine,
const AnnotatedLine *PrevPrevLine,
const SmallVectorImpl<AnnotatedLine *> &Lines, unsigned Indent,
unsigned NewlineIndent) {
FormatToken &RootToken = *Line.First;
if (RootToken.is(tok::eof)) {
unsigned Newlines =
std::min(RootToken.NewlinesBefore,
Style.KeepEmptyLinesAtEOF ? Style.MaxEmptyLinesToKeep + 1 : 1);
unsigned TokenIndent = Newlines ? NewlineIndent : 0;
Whitespaces->replaceWhitespace(RootToken, Newlines, TokenIndent,
TokenIndent);
return;
}
if (RootToken.Newlines < 0) {
RootToken.Newlines =
computeNewlines(Line, PreviousLine, PrevPrevLine, Lines, Style);
assert(RootToken.Newlines >= 0);
}
if (RootToken.Newlines > 0)
Indent = NewlineIndent;
// Preprocessor directives get indented before the hash only if specified. In
// Javascript import statements are indented like normal statements.
if (!Style.isJavaScript() &&
Style.IndentPPDirectives != FormatStyle::PPDIS_BeforeHash &&
(Line.Type == LT_PreprocessorDirective ||
Line.Type == LT_ImportStatement)) {
Indent = 0;
}
Whitespaces->replaceWhitespace(RootToken, RootToken.Newlines, Indent, Indent,
/*IsAligned=*/false,
Line.InPPDirective &&
!RootToken.HasUnescapedNewline);
}
unsigned
UnwrappedLineFormatter::getColumnLimit(bool InPPDirective,
const AnnotatedLine *NextLine) const {
// In preprocessor directives reserve two chars for trailing " \" if the
// next line continues the preprocessor directive.
bool ContinuesPPDirective =
InPPDirective &&
// If there is no next line, this is likely a child line and the parent
// continues the preprocessor directive.
(!NextLine ||
(NextLine->InPPDirective &&
// If there is an unescaped newline between this line and the next, the
// next line starts a new preprocessor directive.
!NextLine->First->HasUnescapedNewline));
return Style.ColumnLimit - (ContinuesPPDirective ? 2 : 0);
}
} // namespace format
} // namespace clang