Add support for C++ default arguments, and rework Parse-Sema
interaction for function parameters, fixing PR2046.
Patch by Doug Gregor!
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@49369 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Parse/ParseDecl.cpp b/lib/Parse/ParseDecl.cpp
index 0eb5c1f..0eb95fa 100644
--- a/lib/Parse/ParseDecl.cpp
+++ b/lib/Parse/ParseDecl.cpp
@@ -1232,8 +1232,10 @@
///
/// parameter-declaration: [C99 6.7.5]
/// declaration-specifiers declarator
+/// [C++] declaration-specifiers declarator '=' assignment-expression
/// [GNU] declaration-specifiers declarator attributes
/// declaration-specifiers abstract-declarator[opt]
+/// [C++] declaration-specifiers abstract-declarator[opt] '=' assignment-expression
/// [GNU] declaration-specifiers abstract-declarator[opt] attributes
///
void Parser::ParseFunctionDeclarator(SourceLocation LParenLoc, Declarator &D) {
@@ -1265,11 +1267,9 @@
// Build up an array of information about the parsed arguments.
llvm::SmallVector<DeclaratorChunk::ParamInfo, 16> ParamInfo;
- llvm::SmallSet<const IdentifierInfo*, 16> ParamsSoFar;
-
- // Enter function-declaration scope, limiting any declarators for struct
- // tags to the function prototype scope.
- // FIXME: is this needed?
+
+ // Enter function-declaration scope, limiting any declarators to the
+ // function prototype scope, including parameter declarators.
EnterScope(Scope::DeclScope);
bool IsVariadic = false;
@@ -1307,14 +1307,6 @@
// Remember this parsed parameter in ParamInfo.
IdentifierInfo *ParmII = ParmDecl.getIdentifier();
- // Verify that the argument identifier has not already been mentioned.
- if (ParmII && !ParamsSoFar.insert(ParmII)) {
- Diag(ParmDecl.getIdentifierLoc(), diag::err_param_redefinition,
- ParmII->getName());
- ParmII = 0;
- ParmDecl.setInvalidType(true);
- }
-
// If no parameter was specified, verify that *something* was specified,
// otherwise we have a missing type and identifier.
if (DS.getParsedSpecifiers() == DeclSpec::PQ_None &&
@@ -1327,12 +1319,37 @@
// Inform the actions module about the parameter declarator, so it gets
// added to the current scope.
- Action::TypeResult ParamTy =
- Actions.ActOnParamDeclaratorType(CurScope, ParmDecl);
+ DeclTy *Param = Actions.ActOnParamDeclarator(CurScope, ParmDecl);
+
+ // Parse the default argument, if any. We parse the default
+ // arguments in all dialects; the semantic analysis in
+ // ActOnParamDefaultArgument will reject the default argument in
+ // C.
+ if (Tok.is(tok::equal)) {
+ SourceLocation EqualLoc = Tok.getLocation();
+
+ // Consume the '='.
+ ConsumeToken();
+
+ // Parse the default argument
+ // FIXME: For C++, name lookup from within the default argument
+ // should be able to find parameter names, but we haven't put them
+ // in the scope. This means that we will accept ill-formed code
+ // such as:
+ //
+ // int x;
+ // void f(int x = x) { }
+ ExprResult DefArgResult = ParseAssignmentExpression();
+ if (DefArgResult.isInvalid) {
+ SkipUntil(tok::comma, tok::r_paren, true, true);
+ } else {
+ // Inform the actions module about the default argument
+ Actions.ActOnParamDefaultArgument(Param, EqualLoc, DefArgResult.Val);
+ }
+ }
ParamInfo.push_back(DeclaratorChunk::ParamInfo(ParmII,
- ParmDecl.getIdentifierLoc(), ParamTy.Val, ParmDecl.getInvalidType(),
- ParmDecl.getDeclSpec().TakeAttributes()));
+ ParmDecl.getIdentifierLoc(), Param));
}
// If the next token is a comma, consume it and keep reading arguments.
@@ -1354,7 +1371,6 @@
MatchRHSPunctuation(tok::r_paren, LParenLoc);
}
-
/// ParseFunctionDeclaratorIdentifierList - While parsing a function declarator
/// we found a K&R-style identifier list instead of a type argument list. The
/// current token is known to be the first identifier in the list.
diff --git a/lib/Parse/Parser.cpp b/lib/Parse/Parser.cpp
index cd99fc0..7e41bcc 100644
--- a/lib/Parse/Parser.cpp
+++ b/lib/Parse/Parser.cpp
@@ -509,6 +509,10 @@
// We know that the top-level of this declarator is a function.
DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun;
+ // Enter function-declaration scope, limiting any declarators to the
+ // function prototype scope, including parameter declarators.
+ EnterScope(Scope::DeclScope);
+
// Read all the argument declarations.
while (isDeclarationSpecifier()) {
SourceLocation DSStart = Tok.getLocation();
@@ -555,10 +559,10 @@
AttrList = ParseAttributes();
// Ask the actions module to compute the type for this declarator.
- Action::TypeResult TR =
- Actions.ActOnParamDeclaratorType(CurScope, ParmDeclarator);
+ Action::DeclTy *Param =
+ Actions.ActOnParamDeclarator(CurScope, ParmDeclarator);
- if (!TR.isInvalid &&
+ if (Param &&
// A missing identifier has already been diagnosed.
ParmDeclarator.getIdentifier()) {
@@ -575,12 +579,12 @@
if (FTI.ArgInfo[i].Ident == ParmDeclarator.getIdentifier()) {
// Reject redefinitions of parameters.
- if (FTI.ArgInfo[i].TypeInfo) {
+ if (FTI.ArgInfo[i].Param) {
Diag(ParmDeclarator.getIdentifierLoc(),
diag::err_param_redefinition,
ParmDeclarator.getIdentifier()->getName());
} else {
- FTI.ArgInfo[i].TypeInfo = TR.Val;
+ FTI.ArgInfo[i].Param = Param;
}
break;
}
@@ -611,6 +615,9 @@
}
}
+ // Leave prototype scope.
+ ExitScope();
+
// The actions module must verify that all arguments were declared.
}