Rework Microsoft __if_exists/__if_not_exists parsing and semantic
analysis to separate dependent names from non-dependent names. For
dependent names, we'll behave differently from Visual C++:
- For __if_exists/__if_not_exists at class scope, we'll just warn
and then ignore them.
- For __if_exists/__if_not_exists in statements, we'll treat the
inner statement as a compound statement, which we only instantiate
in templates where the dependent name (after instantiation)
exists. This behavior is different from VC++, but it's as close as
we can get without encroaching ridiculousness.
The latter part (dependent statements) is not yet implemented.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@142864 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Parse/ParseDeclCXX.cpp b/lib/Parse/ParseDeclCXX.cpp
index 7583cca..3d3d7c2 100644
--- a/lib/Parse/ParseDeclCXX.cpp
+++ b/lib/Parse/ParseDeclCXX.cpp
@@ -2757,25 +2757,32 @@
void Parser::ParseMicrosoftIfExistsClassDeclaration(DeclSpec::TST TagType,
AccessSpecifier& CurAS) {
- bool Result;
+ IfExistsCondition Result;
if (ParseMicrosoftIfExistsCondition(Result))
return;
- if (Tok.isNot(tok::l_brace)) {
+ BalancedDelimiterTracker Braces(*this, tok::l_brace);
+ if (Braces.consumeOpen()) {
Diag(Tok, diag::err_expected_lbrace);
return;
}
- ConsumeBrace();
- // Condition is false skip all inside the {}.
- if (!Result) {
- SkipUntil(tok::r_brace, false);
+ switch (Result.Behavior) {
+ case IEB_Parse:
+ // Parse the declarations below.
+ break;
+
+ case IEB_Dependent:
+ Diag(Result.KeywordLoc, diag::warn_microsoft_dependent_exists)
+ << Result.IsIfExists;
+ // Fall through to skip.
+
+ case IEB_Skip:
+ Braces.skipToEnd();
return;
}
- // Condition is true, parse the declaration.
- while (Tok.isNot(tok::r_brace)) {
-
+ while (Tok.isNot(tok::r_brace) && Tok.isNot(tok::eof)) {
// __if_exists, __if_not_exists can nest.
if ((Tok.is(tok::kw___if_exists) || Tok.is(tok::kw___if_not_exists))) {
ParseMicrosoftIfExistsClassDeclaration((DeclSpec::TST)TagType, CurAS);
@@ -2808,10 +2815,6 @@
// Parse all the comma separated declarators.
ParseCXXClassMemberDeclaration(CurAS, 0);
}
-
- if (Tok.isNot(tok::r_brace)) {
- Diag(Tok, diag::err_expected_rbrace);
- return;
- }
- ConsumeBrace();
+
+ Braces.consumeClose();
}
diff --git a/lib/Parse/ParseStmt.cpp b/lib/Parse/ParseStmt.cpp
index 8968a43..5c2ed4e 100644
--- a/lib/Parse/ParseStmt.cpp
+++ b/lib/Parse/ParseStmt.cpp
@@ -2136,19 +2136,43 @@
}
void Parser::ParseMicrosoftIfExistsStatement(StmtVector &Stmts) {
- bool Result;
+ IfExistsCondition Result;
if (ParseMicrosoftIfExistsCondition(Result))
return;
- if (Tok.isNot(tok::l_brace)) {
+ // Handle dependent statements by parsing the braces as a compound statement.
+ // This is not the same behavior as Visual C++, which don't treat this as a
+ // compound statement, but for Clang's type checking we can't have anything
+ // inside these braces escaping to the surrounding code.
+ if (Result.Behavior == IEB_Dependent) {
+ if (!Tok.is(tok::l_brace)) {
+ Diag(Tok, diag::err_expected_lbrace);
+ return;
+ }
+
+ ParsedAttributes Attrs(AttrFactory);
+ StmtResult Compound = ParseCompoundStatement(Attrs);
+ // FIXME: We're dropping these statements on the floor.
+ return;
+ }
+
+ BalancedDelimiterTracker Braces(*this, tok::l_brace);
+ if (Braces.consumeOpen()) {
Diag(Tok, diag::err_expected_lbrace);
return;
}
- ConsumeBrace();
- // Condition is false skip all inside the {}.
- if (!Result) {
- SkipUntil(tok::r_brace, false);
+ switch (Result.Behavior) {
+ case IEB_Parse:
+ // Parse the statements below.
+ break;
+
+ case IEB_Dependent:
+ llvm_unreachable("Dependent case handled above");
+ break;
+
+ case IEB_Skip:
+ Braces.skipToEnd();
return;
}
@@ -2158,10 +2182,5 @@
if (R.isUsable())
Stmts.push_back(R.release());
}
-
- if (Tok.isNot(tok::r_brace)) {
- Diag(Tok, diag::err_expected_rbrace);
- return;
- }
- ConsumeBrace();
+ Braces.consumeClose();
}
diff --git a/lib/Parse/Parser.cpp b/lib/Parse/Parser.cpp
index 2face30..90bed04 100644
--- a/lib/Parse/Parser.cpp
+++ b/lib/Parse/Parser.cpp
@@ -1470,81 +1470,91 @@
Actions.CodeCompleteNaturalLanguage();
}
-bool Parser::ParseMicrosoftIfExistsCondition(bool& Result) {
+bool Parser::ParseMicrosoftIfExistsCondition(IfExistsCondition& Result) {
assert((Tok.is(tok::kw___if_exists) || Tok.is(tok::kw___if_not_exists)) &&
"Expected '__if_exists' or '__if_not_exists'");
- Token Condition = Tok;
- SourceLocation IfExistsLoc = ConsumeToken();
+ Result.IsIfExists = Tok.is(tok::kw___if_exists);
+ Result.KeywordLoc = ConsumeToken();
BalancedDelimiterTracker T(*this, tok::l_paren);
if (T.consumeOpen()) {
- Diag(Tok, diag::err_expected_lparen_after) << IfExistsLoc;
- SkipUntil(tok::semi);
+ Diag(Tok, diag::err_expected_lparen_after)
+ << (Result.IsIfExists? "__if_exists" : "__if_not_exists");
return true;
}
// Parse nested-name-specifier.
- CXXScopeSpec SS;
- ParseOptionalCXXScopeSpecifier(SS, ParsedType(), false);
+ ParseOptionalCXXScopeSpecifier(Result.SS, ParsedType(), false);
// Check nested-name specifier.
- if (SS.isInvalid()) {
- SkipUntil(tok::semi);
+ if (Result.SS.isInvalid()) {
+ T.skipToEnd();
return true;
}
// Parse the unqualified-id.
- UnqualifiedId Name;
- if (ParseUnqualifiedId(SS, false, true, true, ParsedType(), Name)) {
- SkipUntil(tok::semi);
+ if (ParseUnqualifiedId(Result.SS, false, true, true, ParsedType(),
+ Result.Name)) {
+ T.skipToEnd();
return true;
}
- T.consumeClose();
- if (T.getCloseLocation().isInvalid())
+ if (T.consumeClose())
return true;
-
+
// Check if the symbol exists.
- bool Exist = Actions.CheckMicrosoftIfExistsSymbol(SS, Name);
+ switch (Actions.CheckMicrosoftIfExistsSymbol(getCurScope(), Result.SS,
+ Result.Name)) {
+ case Sema::IER_Exists:
+ Result.Behavior = Result.IsIfExists ? IEB_Parse : IEB_Skip;
+ break;
- Result = ((Condition.is(tok::kw___if_exists) && Exist) ||
- (Condition.is(tok::kw___if_not_exists) && !Exist));
+ case Sema::IER_DoesNotExist:
+ Result.Behavior = !Result.IsIfExists ? IEB_Parse : IEB_Skip;
+ break;
+
+ case Sema::IER_Dependent:
+ Result.Behavior = IEB_Dependent;
+ break;
+ }
return false;
}
void Parser::ParseMicrosoftIfExistsExternalDeclaration() {
- bool Result;
+ IfExistsCondition Result;
if (ParseMicrosoftIfExistsCondition(Result))
return;
- if (Tok.isNot(tok::l_brace)) {
+ BalancedDelimiterTracker Braces(*this, tok::l_brace);
+ if (Braces.consumeOpen()) {
Diag(Tok, diag::err_expected_lbrace);
return;
}
- ConsumeBrace();
- // Condition is false skip all inside the {}.
- if (!Result) {
- SkipUntil(tok::r_brace, false);
+ switch (Result.Behavior) {
+ case IEB_Parse:
+ // Parse declarations below.
+ break;
+
+ case IEB_Dependent:
+ llvm_unreachable("Cannot have a dependent external declaration");
+
+ case IEB_Skip:
+ Braces.skipToEnd();
return;
}
- // Condition is true, parse the declaration.
- while (Tok.isNot(tok::r_brace)) {
+ // Parse the declarations.
+ while (Tok.isNot(tok::r_brace) && Tok.isNot(tok::eof)) {
ParsedAttributesWithRange attrs(AttrFactory);
MaybeParseCXX0XAttributes(attrs);
MaybeParseMicrosoftAttributes(attrs);
DeclGroupPtrTy Result = ParseExternalDeclaration(attrs);
if (Result && !getCurScope()->getParent())
Actions.getASTConsumer().HandleTopLevelDecl(Result.get());
- }
-
- if (Tok.isNot(tok::r_brace)) {
- Diag(Tok, diag::err_expected_rbrace);
- return;
- }
- ConsumeBrace();
+ }
+ Braces.consumeClose();
}
Parser::DeclGroupPtrTy Parser::ParseModuleImport() {
@@ -1629,3 +1639,8 @@
}
return true;
}
+
+void Parser::BalancedDelimiterTracker::skipToEnd() {
+ P.SkipUntil(Close, false);
+ Cleanup = false;
+}
diff --git a/lib/Sema/SemaExprCXX.cpp b/lib/Sema/SemaExprCXX.cpp
index 64a9dd9..c4571c9 100644
--- a/lib/Sema/SemaExprCXX.cpp
+++ b/lib/Sema/SemaExprCXX.cpp
@@ -4665,17 +4665,37 @@
return MaybeCreateStmtWithCleanups(FullStmt);
}
-bool Sema::CheckMicrosoftIfExistsSymbol(CXXScopeSpec &SS,
- UnqualifiedId &Name) {
+Sema::IfExistsResult Sema::CheckMicrosoftIfExistsSymbol(Scope *S,
+ CXXScopeSpec &SS,
+ UnqualifiedId &Name) {
DeclarationNameInfo TargetNameInfo = GetNameFromUnqualifiedId(Name);
DeclarationName TargetName = TargetNameInfo.getName();
if (!TargetName)
- return false;
+ return IER_DoesNotExist;
+ // If the name itself is dependent, then the result is dependent.
+ if (TargetName.isDependentName())
+ return IER_Dependent;
+
// Do the redeclaration lookup in the current scope.
LookupResult R(*this, TargetNameInfo, Sema::LookupAnyName,
Sema::NotForRedeclaration);
+ LookupParsedName(R, S, &SS);
R.suppressDiagnostics();
- LookupParsedName(R, getCurScope(), &SS);
- return !R.empty();
+
+ switch (R.getResultKind()) {
+ case LookupResult::Found:
+ case LookupResult::FoundOverloaded:
+ case LookupResult::FoundUnresolvedValue:
+ case LookupResult::Ambiguous:
+ return IER_Exists;
+
+ case LookupResult::NotFound:
+ return IER_DoesNotExist;
+
+ case LookupResult::NotFoundInCurrentInstantiation:
+ return IER_Dependent;
+ }
+
+ return IER_DoesNotExist;
}