Initial implementation of a code-completion interface in Clang. In
essence, code completion is triggered by a magic "code completion"
token produced by the lexer [*], which the parser recognizes at
certain points in the grammar. The parser then calls into the Action
object with the appropriate CodeCompletionXXX action.
Sema implements the CodeCompletionXXX callbacks by performing minimal
translation, then forwarding them to a CodeCompletionConsumer
subclass, which uses the results of semantic analysis to provide
code-completion results. At present, only a single, "printing" code
completion consumer is available, for regression testing and
debugging. However, the design is meant to permit other
code-completion consumers.
This initial commit contains two code-completion actions: one for
member access, e.g., "x." or "p->", and one for
nested-name-specifiers, e.g., "std::". More code-completion actions
will follow, along with improved gathering of code-completion results
for the various contexts.
[*] In the current -code-completion-dump testing/debugging mode, the
file is truncated at the completion point and EOF is translated into
"code completion".
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@82166 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/CodeCompleteConsumer.cpp b/lib/Sema/CodeCompleteConsumer.cpp
new file mode 100644
index 0000000..7464bc1
--- /dev/null
+++ b/lib/Sema/CodeCompleteConsumer.cpp
@@ -0,0 +1,314 @@
+//===---- CodeCompleteConsumer.h - Code Completion Interface ----*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the CodeCompleteConsumer class.
+//
+//===----------------------------------------------------------------------===//
+#include "clang/Sema/CodeCompleteConsumer.h"
+#include "clang/Lex/Preprocessor.h"
+#include "Sema.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/Support/Compiler.h"
+#include "llvm/Support/raw_ostream.h"
+#include <algorithm>
+#include <string.h>
+using namespace clang;
+
+CodeCompleteConsumer::CodeCompleteConsumer(Sema &S) : SemaRef(S) {
+ SemaRef.setCodeCompleteConsumer(this);
+}
+
+CodeCompleteConsumer::~CodeCompleteConsumer() {
+ SemaRef.setCodeCompleteConsumer(0);
+}
+
+void
+CodeCompleteConsumer::CodeCompleteMemberReferenceExpr(Scope *S,
+ QualType BaseType,
+ bool IsArrow) {
+ if (IsArrow) {
+ if (const PointerType *Ptr = BaseType->getAs<PointerType>())
+ BaseType = Ptr->getPointeeType();
+ else if (BaseType->isObjCObjectPointerType())
+ /*Do nothing*/ ;
+ else
+ return;
+ }
+
+ ResultSet Results;
+ unsigned NextRank = 0;
+
+ if (const RecordType *Record = BaseType->getAs<RecordType>()) {
+ NextRank = CollectMemberResults(Record->getDecl(), NextRank, Results);
+
+ if (getSema().getLangOptions().CPlusPlus) {
+ if (!Results.empty())
+ // The "template" keyword can follow "->" or "." in the grammar.
+ Results.MaybeAddResult(Result("template", NextRank++));
+
+ // FIXME: For C++, we also need to look into the current scope, since
+ // we could have the start of a nested-name-specifier.
+ }
+
+ // Hand off the results found for code completion.
+ ProcessCodeCompleteResults(Results.data(), Results.size());
+
+ // We're done!
+ return;
+ }
+}
+
+void
+CodeCompleteConsumer::CodeCompleteQualifiedId(Scope *S,
+ NestedNameSpecifier *NNS,
+ bool EnteringContext) {
+ CXXScopeSpec SS;
+ SS.setScopeRep(NNS);
+ DeclContext *Ctx = getSema().computeDeclContext(SS, EnteringContext);
+ if (!Ctx)
+ return;
+
+ ResultSet Results;
+ unsigned NextRank = CollectMemberResults(Ctx, 0, Results);
+
+ // The "template" keyword can follow "::" in the grammar
+ if (!Results.empty())
+ Results.MaybeAddResult(Result("template", NextRank));
+
+ ProcessCodeCompleteResults(Results.data(), Results.size());
+}
+
+void CodeCompleteConsumer::ResultSet::MaybeAddResult(Result R) {
+ if (R.Kind != Result::RK_Declaration) {
+ // For non-declaration results, just add the result.
+ Results.push_back(R);
+ return;
+ }
+
+ // FIXME: Using declarations
+
+ Decl *CanonDecl = R.Declaration->getCanonicalDecl();
+ unsigned IDNS = CanonDecl->getIdentifierNamespace();
+
+ // Friend declarations and declarations introduced due to friends are never
+ // added as results.
+ if (isa<FriendDecl>(CanonDecl) ||
+ (IDNS & (Decl::IDNS_OrdinaryFriend | Decl::IDNS_TagFriend)))
+ return;
+
+ ShadowMap &SMap = ShadowMaps.back();
+ ShadowMap::iterator I, IEnd;
+ for (llvm::tie(I, IEnd) = SMap.equal_range(R.Declaration->getDeclName());
+ I != IEnd; ++I) {
+ NamedDecl *ND = I->second.first;
+ unsigned Index = I->second.second;
+ if (ND->getCanonicalDecl() == CanonDecl) {
+ // This is a redeclaration. Always pick the newer declaration.
+ I->second.first = R.Declaration;
+ Results[Index].Declaration = R.Declaration;
+
+ // Pick the best rank of the two.
+ Results[Index].Rank = std::min(Results[Index].Rank, R.Rank);
+
+ // We're done.
+ return;
+ }
+ }
+
+ // This is a new declaration in this scope. However, check whether this
+ // declaration name is hidden by a similarly-named declaration in an outer
+ // scope.
+ std::list<ShadowMap>::iterator SM, SMEnd = ShadowMaps.end();
+ --SMEnd;
+ for (SM = ShadowMaps.begin(); SM != SMEnd; ++SM) {
+ for (llvm::tie(I, IEnd) = SM->equal_range(R.Declaration->getDeclName());
+ I != IEnd; ++I) {
+ // A tag declaration does not hide a non-tag declaration.
+ if (I->second.first->getIdentifierNamespace() == Decl::IDNS_Tag &&
+ (IDNS & (Decl::IDNS_Member | Decl::IDNS_Ordinary |
+ Decl::IDNS_ObjCProtocol)))
+ continue;
+
+ // Protocols are in distinct namespaces from everything else.
+ if (((I->second.first->getIdentifierNamespace() & Decl::IDNS_ObjCProtocol)
+ || (IDNS & Decl::IDNS_ObjCProtocol)) &&
+ I->second.first->getIdentifierNamespace() != IDNS)
+ continue;
+
+ // The newly-added result is hidden by an entry in the shadow map.
+ R.Hidden = true;
+ break;
+ }
+ }
+
+ // Insert this result into the set of results and into the current shadow
+ // map.
+ SMap.insert(std::make_pair(R.Declaration->getDeclName(),
+ std::make_pair(R.Declaration, Results.size())));
+ Results.push_back(R);
+}
+
+/// \brief Enter into a new scope.
+void CodeCompleteConsumer::ResultSet::EnterNewScope() {
+ ShadowMaps.push_back(ShadowMap());
+}
+
+/// \brief Exit from the current scope.
+void CodeCompleteConsumer::ResultSet::ExitScope() {
+ ShadowMaps.pop_back();
+}
+
+/// \brief Collect the results of searching for members within the given
+/// declaration context.
+///
+/// \param Ctx the declaration context from which we will gather results.
+///
+/// \param InitialRank the initial rank given to results in this tag
+/// declaration. Larger rank values will be used for, e.g., members found
+/// in base classes.
+///
+/// \param Results the result set that will be extended with any results
+/// found within this declaration context (and, for a C++ class, its bases).
+///
+/// \returns the next higher rank value, after considering all of the
+/// names within this declaration context.
+unsigned CodeCompleteConsumer::CollectMemberResults(DeclContext *Ctx,
+ unsigned InitialRank,
+ ResultSet &Results) {
+ // Enumerate all of the results in this context.
+ Results.EnterNewScope();
+ for (DeclContext *CurCtx = Ctx->getPrimaryContext(); CurCtx;
+ CurCtx = CurCtx->getNextContext()) {
+ for (DeclContext::decl_iterator D = CurCtx->decls_begin(),
+ DEnd = CurCtx->decls_end();
+ D != DEnd; ++D) {
+ if (NamedDecl *ND = dyn_cast<NamedDecl>(*D)) {
+ // FIXME: Apply a filter to the results
+ Results.MaybeAddResult(Result(ND, InitialRank));
+ }
+ }
+ }
+
+ // Traverse the contexts of inherited classes.
+ unsigned NextRank = InitialRank;
+ if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Ctx)) {
+ for (CXXRecordDecl::base_class_iterator B = Record->bases_begin(),
+ BEnd = Record->bases_end();
+ B != BEnd; ++B) {
+ QualType BaseType = B->getType();
+
+ // Don't look into dependent bases, because name lookup can't look
+ // there anyway.
+ if (BaseType->isDependentType())
+ continue;
+
+ const RecordType *Record = BaseType->getAs<RecordType>();
+ if (!Record)
+ continue;
+
+ // FIXME: We should keep track of the virtual bases we visit, so
+ // that we don't visit them more than once.
+
+ // FIXME: It would be nice to be able to determine whether referencing
+ // a particular member would be ambiguous. For example, given
+ //
+ // struct A { int member; };
+ // struct B { int member; };
+ // struct C : A, B { };
+ //
+ // void f(C *c) { c->### }
+ // accessing 'member' would result in an ambiguity. However, code
+ // completion could be smart enough to qualify the member with the
+ // base class, e.g.,
+ //
+ // c->B::member
+ //
+ // or
+ //
+ // c->A::member
+
+ // Collect results from this base class (and its bases).
+ NextRank = std::max(NextRank,
+ CollectMemberResults(Record->getDecl(),
+ InitialRank + 1,
+ Results));
+ }
+ }
+
+ // FIXME: Look into base classes in Objective-C!
+
+ Results.ExitScope();
+ return NextRank;
+}
+
+namespace {
+ struct VISIBILITY_HIDDEN SortCodeCompleteResult {
+ typedef CodeCompleteConsumer::Result Result;
+
+ bool operator()(const Result &X, const Result &Y) const {
+ // Sort first by rank.
+ if (X.Rank < Y.Rank)
+ return true;
+ else if (X.Rank > Y.Rank)
+ return false;
+
+ // Result kinds are ordered by decreasing importance.
+ if (X.Kind < Y.Kind)
+ return true;
+ else if (X.Kind > Y.Kind)
+ return false;
+
+ // Non-hidden names precede hidden names.
+ if (X.Hidden != Y.Hidden)
+ return !X.Hidden;
+
+ // Ordering depends on the kind of result.
+ switch (X.Kind) {
+ case Result::RK_Declaration:
+ // Order based on the declaration names.
+ return X.Declaration->getDeclName() < Y.Declaration->getDeclName();
+
+ case Result::RK_Keyword:
+ return strcmp(X.Keyword, Y.Keyword) == -1;
+ }
+
+ // If only our C++ compiler did control-flow warnings properly.
+ return false;
+ }
+ };
+}
+
+void
+PrintingCodeCompleteConsumer::ProcessCodeCompleteResults(Result *Results,
+ unsigned NumResults) {
+ // Sort the results by rank/kind/etc.
+ std::stable_sort(Results, Results + NumResults, SortCodeCompleteResult());
+
+ // Print the results.
+ for (unsigned I = 0; I != NumResults; ++I) {
+ switch (Results[I].Kind) {
+ case Result::RK_Declaration:
+ OS << Results[I].Declaration->getNameAsString() << " : "
+ << Results[I].Rank;
+ if (Results[I].Hidden)
+ OS << " (Hidden)";
+ OS << '\n';
+ break;
+
+ case Result::RK_Keyword:
+ OS << Results[I].Keyword << " : " << Results[I].Rank << '\n';
+ break;
+ }
+ }
+
+ // Once we've printed the code-completion results, suppress remaining
+ // diagnostics.
+ // FIXME: Move this somewhere else!
+ getSema().PP.getDiagnostics().setSuppressAllDiagnostics();
+}