For DR712: store on a DeclRefExpr whether it constitutes an odr-use.
Begin restructuring to support the forms of non-odr-use reference
permitted by DR712.
llvm-svn: 363086
diff --git a/clang/lib/AST/ASTImporter.cpp b/clang/lib/AST/ASTImporter.cpp
index e0a9da5..c4ae3b8 100644
--- a/clang/lib/AST/ASTImporter.cpp
+++ b/clang/lib/AST/ASTImporter.cpp
@@ -6189,7 +6189,7 @@
auto *ToE = DeclRefExpr::Create(
Importer.getToContext(), ToQualifierLoc, ToTemplateKeywordLoc, ToDecl,
E->refersToEnclosingVariableOrCapture(), ToLocation, ToType,
- E->getValueKind(), ToFoundD, ToResInfo);
+ E->getValueKind(), ToFoundD, ToResInfo, E->isNonOdrUse());
if (E->hadMultipleCandidates())
ToE->setHadMultipleCandidates(true);
return ToE;
diff --git a/clang/lib/AST/Decl.cpp b/clang/lib/AST/Decl.cpp
index 8b77e01..1b744c8 100644
--- a/clang/lib/AST/Decl.cpp
+++ b/clang/lib/AST/Decl.cpp
@@ -2245,12 +2245,16 @@
Init = I;
}
-bool VarDecl::isUsableInConstantExpressions(ASTContext &C) const {
+bool VarDecl::mightBeUsableInConstantExpressions(ASTContext &C) const {
const LangOptions &Lang = C.getLangOpts();
if (!Lang.CPlusPlus)
return false;
+ // Function parameters are never usable in constant expressions.
+ if (isa<ParmVarDecl>(this))
+ return false;
+
// In C++11, any variable of reference type can be used in a constant
// expression if it is initialized by a constant expression.
if (Lang.CPlusPlus11 && getType()->isReferenceType())
@@ -2272,6 +2276,22 @@
return Lang.CPlusPlus11 && isConstexpr();
}
+bool VarDecl::isUsableInConstantExpressions(ASTContext &Context) const {
+ // C++2a [expr.const]p3:
+ // A variable is usable in constant expressions after its initializing
+ // declaration is encountered...
+ const VarDecl *DefVD = nullptr;
+ const Expr *Init = getAnyInitializer(DefVD);
+ if (!Init || Init->isValueDependent())
+ return false;
+ // ... if it is a constexpr variable, or it is of reference type or of
+ // const-qualified integral or enumeration type, ...
+ if (!DefVD->mightBeUsableInConstantExpressions(Context))
+ return false;
+ // ... and its initializer is a constant initializer.
+ return DefVD->checkInitIsICE();
+}
+
/// Convert the initializer for this declaration to the elaborated EvaluatedStmt
/// form, which contains extra information on the evaluated value of the
/// initializer.
diff --git a/clang/lib/AST/Expr.cpp b/clang/lib/AST/Expr.cpp
index ee9d853..b772518f 100644
--- a/clang/lib/AST/Expr.cpp
+++ b/clang/lib/AST/Expr.cpp
@@ -344,7 +344,8 @@
DeclRefExpr::DeclRefExpr(const ASTContext &Ctx, ValueDecl *D,
bool RefersToEnclosingVariableOrCapture, QualType T,
ExprValueKind VK, SourceLocation L,
- const DeclarationNameLoc &LocInfo)
+ const DeclarationNameLoc &LocInfo,
+ NonOdrUseReason NOUR)
: Expr(DeclRefExprClass, T, VK, OK_Ordinary, false, false, false, false),
D(D), DNLoc(LocInfo) {
DeclRefExprBits.HasQualifier = false;
@@ -353,6 +354,7 @@
DeclRefExprBits.HadMultipleCandidates = false;
DeclRefExprBits.RefersToEnclosingVariableOrCapture =
RefersToEnclosingVariableOrCapture;
+ DeclRefExprBits.NonOdrUseReason = NOUR;
DeclRefExprBits.Loc = L;
computeDependence(Ctx);
}
@@ -363,7 +365,7 @@
bool RefersToEnclosingVariableOrCapture,
const DeclarationNameInfo &NameInfo, NamedDecl *FoundD,
const TemplateArgumentListInfo *TemplateArgs,
- QualType T, ExprValueKind VK)
+ QualType T, ExprValueKind VK, NonOdrUseReason NOUR)
: Expr(DeclRefExprClass, T, VK, OK_Ordinary, false, false, false, false),
D(D), DNLoc(NameInfo.getInfo()) {
DeclRefExprBits.Loc = NameInfo.getLoc();
@@ -384,6 +386,7 @@
= (TemplateArgs || TemplateKWLoc.isValid()) ? 1 : 0;
DeclRefExprBits.RefersToEnclosingVariableOrCapture =
RefersToEnclosingVariableOrCapture;
+ DeclRefExprBits.NonOdrUseReason = NOUR;
if (TemplateArgs) {
bool Dependent = false;
bool InstantiationDependent = false;
@@ -405,30 +408,27 @@
DeclRefExpr *DeclRefExpr::Create(const ASTContext &Context,
NestedNameSpecifierLoc QualifierLoc,
- SourceLocation TemplateKWLoc,
- ValueDecl *D,
+ SourceLocation TemplateKWLoc, ValueDecl *D,
bool RefersToEnclosingVariableOrCapture,
- SourceLocation NameLoc,
- QualType T,
- ExprValueKind VK,
- NamedDecl *FoundD,
- const TemplateArgumentListInfo *TemplateArgs) {
+ SourceLocation NameLoc, QualType T,
+ ExprValueKind VK, NamedDecl *FoundD,
+ const TemplateArgumentListInfo *TemplateArgs,
+ NonOdrUseReason NOUR) {
return Create(Context, QualifierLoc, TemplateKWLoc, D,
RefersToEnclosingVariableOrCapture,
DeclarationNameInfo(D->getDeclName(), NameLoc),
- T, VK, FoundD, TemplateArgs);
+ T, VK, FoundD, TemplateArgs, NOUR);
}
DeclRefExpr *DeclRefExpr::Create(const ASTContext &Context,
NestedNameSpecifierLoc QualifierLoc,
- SourceLocation TemplateKWLoc,
- ValueDecl *D,
+ SourceLocation TemplateKWLoc, ValueDecl *D,
bool RefersToEnclosingVariableOrCapture,
const DeclarationNameInfo &NameInfo,
- QualType T,
- ExprValueKind VK,
+ QualType T, ExprValueKind VK,
NamedDecl *FoundD,
- const TemplateArgumentListInfo *TemplateArgs) {
+ const TemplateArgumentListInfo *TemplateArgs,
+ NonOdrUseReason NOUR) {
// Filter out cases where the found Decl is the same as the value refenenced.
if (D == FoundD)
FoundD = nullptr;
@@ -443,8 +443,8 @@
void *Mem = Context.Allocate(Size, alignof(DeclRefExpr));
return new (Mem) DeclRefExpr(Context, QualifierLoc, TemplateKWLoc, D,
- RefersToEnclosingVariableOrCapture,
- NameInfo, FoundD, TemplateArgs, T, VK);
+ RefersToEnclosingVariableOrCapture, NameInfo,
+ FoundD, TemplateArgs, T, VK, NOUR);
}
DeclRefExpr *DeclRefExpr::CreateEmpty(const ASTContext &Context,
diff --git a/clang/lib/AST/JSONNodeDumper.cpp b/clang/lib/AST/JSONNodeDumper.cpp
index 991cf09..1290847 100644
--- a/clang/lib/AST/JSONNodeDumper.cpp
+++ b/clang/lib/AST/JSONNodeDumper.cpp
@@ -805,6 +805,12 @@
if (DRE->getDecl() != DRE->getFoundDecl())
JOS.attribute("foundReferencedDecl",
createBareDeclRef(DRE->getFoundDecl()));
+ switch (DRE->isNonOdrUse()) {
+ case NOUR_None: break;
+ case NOUR_Unevaluated: JOS.attribute("nonOdrUseReason", "unevaluated"); break;
+ case NOUR_Constant: JOS.attribute("nonOdrUseReason", "constant"); break;
+ case NOUR_Discarded: JOS.attribute("nonOdrUseReason", "discarded"); break;
+ }
}
void JSONNodeDumper::VisitPredefinedExpr(const PredefinedExpr *PE) {
diff --git a/clang/lib/AST/TextNodeDumper.cpp b/clang/lib/AST/TextNodeDumper.cpp
index c15713b..3b8c8f2 100644
--- a/clang/lib/AST/TextNodeDumper.cpp
+++ b/clang/lib/AST/TextNodeDumper.cpp
@@ -715,6 +715,12 @@
dumpBareDeclRef(Node->getFoundDecl());
OS << ")";
}
+ switch (Node->isNonOdrUse()) {
+ case NOUR_None: break;
+ case NOUR_Unevaluated: OS << " non_odr_use_unevaluated"; break;
+ case NOUR_Constant: OS << " non_odr_use_constant"; break;
+ case NOUR_Discarded: OS << " non_odr_use_discarded"; break;
+ }
}
void TextNodeDumper::VisitUnresolvedLookupExpr(