C++: Improve file accuracy when finding symbols

This patch introduces a priority-based mechanism when searching for certains
symbols in the snapshot. The priority corresponds to how similar the file path
from the "reference" symbol is to the file path from the "candidate" symbol.
This solves a variety of issues when matching "equivalent" symbols but that
are in another file/project, such as when following a function declaration,
a forward class declaration, or adding a definition through a quickfix.

There's now a symbol finder which will compute the "best" search order and cache
the most recent results. A consequence is that following symbols in some cases
is slower, but not apparently significatly.

Note: The "find" functions were moved from the Snapshot to the new SymbolFinder
class.

Task-number: QTCREATORBUG-6697
Task-number: QTCREATORBUG-6792

Change-Id: Ia518f014275fec1f4d0cb3224bd4e06a9df6d557
Reviewed-by: Roberto Raggi <roberto.raggi@nokia.com>
This commit is contained in:
Leandro Melo
2012-01-20 14:43:21 +01:00
parent 271ec63a10
commit 466ea4842c
12 changed files with 451 additions and 269 deletions

View File

@@ -37,7 +37,8 @@ HEADERS += completionsettingspage.h \
cppcodestylepreferences.h \
cpptoolsreuse.h \
doxygengenerator.h \
commentssettings.h
commentssettings.h \
symbolfinder.h
SOURCES += completionsettingspage.cpp \
cppclassesfilter.cpp \
@@ -66,7 +67,8 @@ SOURCES += completionsettingspage.cpp \
cppcodestylepreferences.cpp \
cpptoolsreuse.cpp \
doxygengenerator.cpp \
commentssettings.cpp
commentssettings.cpp \
symbolfinder.cpp
FORMS += completionsettingspage.ui \
cppfilesettingspage.ui \

View File

@@ -33,6 +33,7 @@
#include "cpptoolsplugin.h"
#include "cpprefactoringchanges.h"
#include "insertionpointlocator.h"
#include "symbolfinder.h"
#include <AST.h>
#include <ASTVisitor.h>
@@ -516,7 +517,10 @@ static InsertionLocation nextToSurroundingDefinitions(Declaration *declaration,
}
// find the declaration's definition
Symbol *definition = changes.snapshot().findMatchingDefinition(surroundingFunctionDecl);
CppTools::SymbolFinder symbolFinder(surroundingFunctionDecl->fileName(),
surroundingFunctionDecl->fileNameLength());
Symbol *definition = symbolFinder.findMatchingDefinition(surroundingFunctionDecl,
changes.snapshot());
if (!definition)
return noResult;
@@ -555,7 +559,10 @@ QList<InsertionLocation> InsertionPointLocator::methodDefinition(
if (!declaration)
return result;
if (Symbol *s = m_refactoringChanges.snapshot().findMatchingDefinition(declaration, true)) {
CppTools::SymbolFinder symbolFinder(declaration->fileName(), declaration->fileNameLength());
if (Symbol *s = symbolFinder.findMatchingDefinition(declaration,
m_refactoringChanges.snapshot(),
true)) {
if (Function *f = s->asFunction()) {
if (f->isConst() == declaration->type().isConst()
&& f->isVolatile() == declaration->type().isVolatile())

View File

@@ -0,0 +1,338 @@
#if defined(_MSC_VER)
#pragma warning(disable:4996)
#endif
#include "symbolfinder.h"
#include <Symbols.h>
#include <Names.h>
#include <Literals.h>
#include <SymbolVisitor.h>
#include <Control.h>
#include <LookupContext.h>
#include <QtCore/QDebug>
#include <algorithm>
#include <utility>
using namespace CPlusPlus;
using namespace CppTools;
namespace {
class FindMatchingDefinition: public SymbolVisitor
{
Symbol *_declaration;
const OperatorNameId *_oper;
QList<Function *> _result;
public:
FindMatchingDefinition(Symbol *declaration)
: _declaration(declaration)
, _oper(0)
{
if (_declaration->name())
_oper = _declaration->name()->asOperatorNameId();
}
QList<Function *> result() const { return _result; }
using SymbolVisitor::visit;
virtual bool visit(Function *fun)
{
if (_oper) {
if (const Name *name = fun->unqualifiedName()) {
if (_oper->isEqualTo(name))
_result.append(fun);
}
} else if (const Identifier *id = _declaration->identifier()) {
if (id->isEqualTo(fun->identifier()))
_result.append(fun);
}
return false;
}
virtual bool visit(Block *)
{
return false;
}
};
} // end of anonymous namespace
SymbolFinder::SymbolFinder(const QString &referenceFileName)
: m_referenceFile(referenceFileName)
{}
SymbolFinder::SymbolFinder(const char *referenceFileName, unsigned referenceFileLength)
: m_referenceFile(QString::fromUtf8(referenceFileName, referenceFileLength))
{}
// strict means the returned symbol has to match exactly,
// including argument count and argument types
Symbol *SymbolFinder::findMatchingDefinition(Symbol *declaration,
const Snapshot &snapshot,
bool strict)
{
if (!declaration)
return 0;
QString declFile = QString::fromUtf8(declaration->fileName(), declaration->fileNameLength());
Q_ASSERT(declFile == m_referenceFile);
Document::Ptr thisDocument = snapshot.document(declFile);
if (! thisDocument) {
qWarning() << "undefined document:" << declaration->fileName();
return 0;
}
Function *declarationTy = declaration->type()->asFunctionType();
if (! declarationTy) {
qWarning() << "not a function:" << declaration->fileName()
<< declaration->line() << declaration->column();
return 0;
}
foreach (const QString &fileName, fileIterationOrder(snapshot)) {
Document::Ptr doc = snapshot.document(fileName);
if (!doc) {
clear(fileName);
continue;
}
const Identifier *id = declaration->identifier();
if (id && ! doc->control()->findIdentifier(id->chars(), id->size()))
continue;
if (!id) {
if (!declaration->name())
continue;
const OperatorNameId *oper = declaration->name()->asOperatorNameId();
if (!oper)
continue;
if (!doc->control()->findOperatorNameId(oper->kind()))
continue;
}
FindMatchingDefinition candidates(declaration);
candidates.accept(doc->globalNamespace());
const QList<Function *> result = candidates.result();
if (! result.isEmpty()) {
LookupContext context(doc, snapshot);
QList<Function *> viableFunctions;
ClassOrNamespace *enclosingType = context.lookupType(declaration);
if (! enclosingType)
continue; // nothing to do
foreach (Function *fun, result) {
const QList<LookupItem> declarations = context.lookup(fun->name(), fun->enclosingScope());
if (declarations.isEmpty())
continue;
const LookupItem best = declarations.first();
if (enclosingType == context.lookupType(best.declaration()))
viableFunctions.append(fun);
}
if (viableFunctions.isEmpty())
continue;
else if (! strict && viableFunctions.length() == 1)
return viableFunctions.first();
Function *best = 0;
foreach (Function *fun, viableFunctions) {
if (! (fun->unqualifiedName() && fun->unqualifiedName()->isEqualTo(declaration->unqualifiedName())))
continue;
else if (fun->argumentCount() == declarationTy->argumentCount()) {
if (! strict && ! best)
best = fun;
unsigned argc = 0;
for (; argc < declarationTy->argumentCount(); ++argc) {
Symbol *arg = fun->argumentAt(argc);
Symbol *otherArg = declarationTy->argumentAt(argc);
if (! arg->type().isEqualTo(otherArg->type()))
break;
}
if (argc == declarationTy->argumentCount())
best = fun;
}
}
if (strict && ! best)
continue;
if (! best)
best = viableFunctions.first();
return best;
}
}
return 0;
}
Class *SymbolFinder::findMatchingClassDeclaration(Symbol *declaration, const Snapshot &snapshot)
{
if (! declaration->identifier())
return 0;
QString declFile = QString::fromUtf8(declaration->fileName(), declaration->fileNameLength());
Q_ASSERT(declFile == m_referenceFile);
foreach (const QString &file, fileIterationOrder(snapshot)) {
Document::Ptr doc = snapshot.document(file);
if (!doc) {
clear(file);
continue;
}
if (! doc->control()->findIdentifier(declaration->identifier()->chars(),
declaration->identifier()->size()))
continue;
LookupContext context(doc, snapshot);
ClassOrNamespace *type = context.lookupType(declaration);
if (!type)
continue;
foreach (Symbol *s, type->symbols()) {
if (Class *c = s->asClass())
return c;
}
}
return 0;
}
void SymbolFinder::findMatchingDeclaration(const LookupContext &context,
Function *functionType,
QList<Declaration *> *typeMatch,
QList<Declaration *> *argumentCountMatch,
QList<Declaration *> *nameMatch)
{
Scope *enclosingScope = functionType->enclosingScope();
while (! (enclosingScope->isNamespace() || enclosingScope->isClass()))
enclosingScope = enclosingScope->enclosingScope();
Q_ASSERT(enclosingScope != 0);
const Name *functionName = functionType->name();
if (! functionName)
return; // anonymous function names are not valid c++
ClassOrNamespace *binding = 0;
const QualifiedNameId *qName = functionName->asQualifiedNameId();
if (qName) {
if (qName->base())
binding = context.lookupType(qName->base(), enclosingScope);
else
binding = context.globalNamespace();
functionName = qName->name();
}
if (!binding) { // declaration for a global function
binding = context.lookupType(enclosingScope);
if (!binding)
return;
}
const Identifier *funcId = functionName->identifier();
if (!funcId) // E.g. operator, which we might be able to handle in the future...
return;
foreach (Symbol *s, binding->symbols()) {
Scope *scope = s->asScope();
if (!scope)
continue;
for (Symbol *s = scope->find(funcId); s; s = s->next()) {
if (! s->name())
continue;
else if (! funcId->isEqualTo(s->identifier()))
continue;
else if (! s->type()->isFunctionType())
continue;
else if (Declaration *decl = s->asDeclaration()) {
if (Function *declFunTy = decl->type()->asFunctionType()) {
if (functionType->isEqualTo(declFunTy))
typeMatch->prepend(decl);
else if (functionType->argumentCount() == declFunTy->argumentCount())
argumentCountMatch->prepend(decl);
else
nameMatch->append(decl);
}
}
}
}
}
QList<Declaration *> SymbolFinder::findMatchingDeclaration(const LookupContext &context,
Function *functionType)
{
QList<Declaration *> result;
QList<Declaration *> nameMatch, argumentCountMatch, typeMatch;
findMatchingDeclaration(context, functionType, &typeMatch, &argumentCountMatch, &nameMatch);
result.append(typeMatch);
result.append(argumentCountMatch);
result.append(nameMatch);
return result;
}
#include <QtCore/QThread>
QStringList SymbolFinder::fileIterationOrder(const Snapshot &snapshot)
{
if (m_filePriorityCache.isEmpty()) {
foreach (const Document::Ptr &doc, snapshot)
insert(doc->fileName());
} else {
checkCacheConsistency(snapshot);
}
return m_filePriorityCache.values();
}
void SymbolFinder::checkCacheConsistency(const Snapshot &snapshot)
{
// We only check for "new" files, which which are in the snapshot but not in the cache.
// The counterpart validation for "old" files is done when one tries to access the
// corresponding document and notices it's now null.
foreach (const Document::Ptr &doc, snapshot) {
if (!m_fileMetaCache.contains(doc->fileName()))
insert(doc->fileName());
}
}
void SymbolFinder::clear(const QString &comparingFile)
{
m_filePriorityCache.remove(computeKey(m_referenceFile, comparingFile), comparingFile);
m_fileMetaCache.remove(comparingFile);
}
void SymbolFinder::insert(const QString &comparingFile)
{
// We want an ordering such that the documents with the most common path appear first.
m_filePriorityCache.insert(computeKey(m_referenceFile, comparingFile), comparingFile);
m_fileMetaCache.insert(comparingFile);
}
int SymbolFinder::computeKey(const QString &referenceFile, const QString &comparingFile)
{
// As similar the path from the comparing file is to the path from the reference file,
// the smaller the key is, which is then used for sorting the map.
std::pair<QString::const_iterator,
QString::const_iterator> r = std::mismatch(referenceFile.begin(),
referenceFile.end(),
comparingFile.begin());
return referenceFile.length() - (r.first - referenceFile.begin());
}

View File

@@ -0,0 +1,55 @@
#ifndef SYMBOLFINDER_H
#define SYMBOLFINDER_H
#include "cpptools_global.h"
#include <CppDocument.h>
#include <CPlusPlusForwardDeclarations.h>
#include <QtCore/QHash>
#include <QtCore/QStringList>
#include <QtCore/QQueue>
#include <QtCore/QMultiMap>
namespace CppTools {
class CPPTOOLS_EXPORT SymbolFinder
{
public:
SymbolFinder(const QString &referenceFileName);
SymbolFinder(const char *referenceFileName, unsigned referenceFileLength);
CPlusPlus::Symbol *findMatchingDefinition(CPlusPlus::Symbol *symbol,
const CPlusPlus::Snapshot &snapshot,
bool strict = false);
CPlusPlus::Class *findMatchingClassDeclaration(CPlusPlus::Symbol *declaration,
const CPlusPlus::Snapshot &snapshot);
void findMatchingDeclaration(const CPlusPlus::LookupContext &context,
CPlusPlus::Function *functionType,
QList<CPlusPlus::Declaration *> *typeMatch,
QList<CPlusPlus::Declaration *> *argumentCountMatch,
QList<CPlusPlus::Declaration *> *nameMatch);
QList<CPlusPlus::Declaration *> findMatchingDeclaration(const CPlusPlus::LookupContext &context,
CPlusPlus::Function *functionType);
private:
QStringList fileIterationOrder(const CPlusPlus::Snapshot &snapshot);
void checkCacheConsistency(const CPlusPlus::Snapshot &snapshot);
void clear(const QString &comparingFile);
void insert(const QString &comparingFile);
static int computeKey(const QString &referenceFile, const QString &comparingFile);
QMultiMap<int, QString> m_filePriorityCache;
QSet<QString> m_fileMetaCache;
QString m_referenceFile;
};
} // namespace CppTools
#endif // SYMBOLFINDER_H