C++11 constexpr: Add note stacks containing backtraces if constant evaluation
fails within a call to a constexpr function. Add -fconstexpr-backtrace-limit
argument to driver and frontend, to control the maximum number of notes so
produced (default 10). Fix APValue printing to be able to pretty-print all
APValue types, and move the testing for this functionality from a unittest to
a -verify test now that it's visible in clang's output.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@146749 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/APValue.cpp b/lib/AST/APValue.cpp
index b99a662..0d4dea8 100644
--- a/lib/AST/APValue.cpp
+++ b/lib/AST/APValue.cpp
@@ -12,7 +12,11 @@
//===----------------------------------------------------------------------===//
#include "clang/AST/APValue.h"
+#include "clang/AST/ASTContext.h"
#include "clang/AST/CharUnits.h"
+#include "clang/AST/DeclCXX.h"
+#include "clang/AST/Expr.h"
+#include "clang/AST/Type.h"
#include "clang/Basic/Diagnostic.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/Support/raw_ostream.h"
@@ -203,7 +207,7 @@
}
void APValue::dump() const {
- print(llvm::errs());
+ dump(llvm::errs());
llvm::errs() << '\n';
}
@@ -215,7 +219,7 @@
return V.convertToDouble();
}
-void APValue::print(raw_ostream &OS) const {
+void APValue::dump(raw_ostream &OS) const {
switch (getKind()) {
case Uninitialized:
OS << "Uninitialized";
@@ -227,9 +231,12 @@
OS << "Float: " << GetApproxValue(getFloat());
return;
case Vector:
- OS << "Vector: " << getVectorElt(0);
- for (unsigned i = 1; i != getVectorLength(); ++i)
- OS << ", " << getVectorElt(i);
+ OS << "Vector: ";
+ getVectorElt(0).dump(OS);
+ for (unsigned i = 1; i != getVectorLength(); ++i) {
+ OS << ", ";
+ getVectorElt(i).dump(OS);
+ }
return;
case ComplexInt:
OS << "ComplexInt: " << getComplexIntReal() << ", " << getComplexIntImag();
@@ -244,28 +251,36 @@
case Array:
OS << "Array: ";
for (unsigned I = 0, N = getArrayInitializedElts(); I != N; ++I) {
- OS << getArrayInitializedElt(I);
+ getArrayInitializedElt(I).dump(OS);
if (I != getArraySize() - 1) OS << ", ";
}
- if (hasArrayFiller())
- OS << getArraySize() - getArrayInitializedElts() << " x "
- << getArrayFiller();
+ if (hasArrayFiller()) {
+ OS << getArraySize() - getArrayInitializedElts() << " x ";
+ getArrayFiller().dump(OS);
+ }
return;
case Struct:
OS << "Struct ";
if (unsigned N = getStructNumBases()) {
- OS << " bases: " << getStructBase(0);
- for (unsigned I = 1; I != N; ++I)
- OS << ", " << getStructBase(I);
+ OS << " bases: ";
+ getStructBase(0).dump(OS);
+ for (unsigned I = 1; I != N; ++I) {
+ OS << ", ";
+ getStructBase(I).dump(OS);
+ }
}
if (unsigned N = getStructNumFields()) {
- OS << " fields: " << getStructField(0);
- for (unsigned I = 1; I != N; ++I)
- OS << ", " << getStructField(I);
+ OS << " fields: ";
+ getStructField(0).dump(OS);
+ for (unsigned I = 1; I != N; ++I) {
+ OS << ", ";
+ getStructField(I).dump(OS);
+ }
}
return;
case Union:
- OS << "Union: " << getUnionValue();
+ OS << "Union: ";
+ getUnionValue().dump(OS);
return;
case MemberPointer:
OS << "MemberPointer: <todo>";
@@ -274,78 +289,198 @@
llvm_unreachable("Unknown APValue kind!");
}
-static void WriteShortAPValueToStream(raw_ostream& Out,
- const APValue& V) {
- switch (V.getKind()) {
+void APValue::printPretty(raw_ostream &Out, ASTContext &Ctx, QualType Ty) const{
+ switch (getKind()) {
case APValue::Uninitialized:
- Out << "Uninitialized";
+ Out << "<uninitialized>";
return;
case APValue::Int:
- Out << V.getInt();
+ Out << getInt();
return;
case APValue::Float:
- Out << GetApproxValue(V.getFloat());
+ Out << GetApproxValue(getFloat());
return;
- case APValue::Vector:
- Out << '[';
- WriteShortAPValueToStream(Out, V.getVectorElt(0));
- for (unsigned i = 1; i != V.getVectorLength(); ++i) {
+ case APValue::Vector: {
+ Out << '{';
+ QualType ElemTy = Ty->getAs<VectorType>()->getElementType();
+ getVectorElt(0).printPretty(Out, Ctx, ElemTy);
+ for (unsigned i = 1; i != getVectorLength(); ++i) {
Out << ", ";
- WriteShortAPValueToStream(Out, V.getVectorElt(i));
+ getVectorElt(i).printPretty(Out, Ctx, ElemTy);
}
- Out << ']';
+ Out << '}';
return;
+ }
case APValue::ComplexInt:
- Out << V.getComplexIntReal() << "+" << V.getComplexIntImag() << "i";
+ Out << getComplexIntReal() << "+" << getComplexIntImag() << "i";
return;
case APValue::ComplexFloat:
- Out << GetApproxValue(V.getComplexFloatReal()) << "+"
- << GetApproxValue(V.getComplexFloatImag()) << "i";
+ Out << GetApproxValue(getComplexFloatReal()) << "+"
+ << GetApproxValue(getComplexFloatImag()) << "i";
return;
- case APValue::LValue:
- Out << "LValue: <todo>";
- return;
- case APValue::Array:
- Out << '{';
- if (unsigned N = V.getArrayInitializedElts()) {
- Out << V.getArrayInitializedElt(0);
- for (unsigned I = 1; I != N; ++I)
- Out << ", " << V.getArrayInitializedElt(I);
+ case APValue::LValue: {
+ LValueBase Base = getLValueBase();
+ if (!Base) {
+ Out << "0";
+ return;
}
- Out << '}';
+
+ bool IsReference = Ty->isReferenceType();
+ QualType InnerTy
+ = IsReference ? Ty.getNonReferenceType() : Ty->getPointeeType();
+
+ if (!hasLValuePath()) {
+ // No lvalue path: just print the offset.
+ CharUnits O = getLValueOffset();
+ CharUnits S = Ctx.getTypeSizeInChars(InnerTy);
+ if (!O.isZero()) {
+ if (IsReference)
+ Out << "*(";
+ if (O % S) {
+ Out << "(char*)";
+ S = CharUnits::One();
+ }
+ Out << '&';
+ } else if (!IsReference)
+ Out << '&';
+
+ if (const ValueDecl *VD = Base.dyn_cast<const ValueDecl*>())
+ Out << *VD;
+ else
+ Base.get<const Expr*>()->printPretty(Out, Ctx, 0,
+ Ctx.getPrintingPolicy());
+ if (!O.isZero()) {
+ Out << " + " << (O / S);
+ if (IsReference)
+ Out << ')';
+ }
+ return;
+ }
+
+ // We have an lvalue path. Print it out nicely.
+ if (!IsReference)
+ Out << '&';
+ else if (isLValueOnePastTheEnd())
+ Out << "*(&";
+
+ QualType ElemTy;
+ if (const ValueDecl *VD = Base.dyn_cast<const ValueDecl*>()) {
+ Out << *VD;
+ ElemTy = VD->getType();
+ } else {
+ const Expr *E = Base.get<const Expr*>();
+ E->printPretty(Out, Ctx, 0,Ctx.getPrintingPolicy());
+ ElemTy = E->getType();
+ }
+
+ ArrayRef<LValuePathEntry> Path = getLValuePath();
+ const CXXRecordDecl *CastToBase = 0;
+ for (unsigned I = 0, N = Path.size(); I != N; ++I) {
+ if (ElemTy->getAs<RecordType>()) {
+ // The lvalue refers to a class type, so the next path entry is a base
+ // or member.
+ const Decl *BaseOrMember =
+ BaseOrMemberType::getFromOpaqueValue(Path[I].BaseOrMember).getPointer();
+ if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(BaseOrMember)) {
+ CastToBase = RD;
+ ElemTy = Ctx.getRecordType(RD);
+ } else {
+ const ValueDecl *VD = cast<ValueDecl>(BaseOrMember);
+ Out << ".";
+ if (CastToBase)
+ Out << *CastToBase << "::";
+ Out << *VD;
+ ElemTy = VD->getType();
+ }
+ } else {
+ // The lvalue must refer to an array.
+ Out << '[' << Path[I].ArrayIndex << ']';
+ ElemTy = Ctx.getAsArrayType(ElemTy)->getElementType();
+ }
+ }
+
+ // Handle formatting of one-past-the-end lvalues.
+ if (isLValueOnePastTheEnd()) {
+ // FIXME: If CastToBase is non-0, we should prefix the output with
+ // "(CastToBase*)".
+ Out << " + 1";
+ if (IsReference)
+ Out << ')';
+ }
return;
- case APValue::Struct:
+ }
+ case APValue::Array: {
+ const ArrayType *AT = Ctx.getAsArrayType(Ty);
+ QualType ElemTy = AT->getElementType();
Out << '{';
- if (unsigned N = V.getStructNumBases()) {
- Out << V.getStructBase(0);
- for (unsigned I = 1; I != N; ++I)
- Out << ", " << V.getStructBase(I);
- if (V.getStructNumFields())
+ if (unsigned N = getArrayInitializedElts()) {
+ getArrayInitializedElt(0).printPretty(Out, Ctx, ElemTy);
+ for (unsigned I = 1; I != N; ++I) {
Out << ", ";
- }
- if (unsigned N = V.getStructNumFields()) {
- Out << V.getStructField(0);
- for (unsigned I = 1; I != N; ++I)
- Out << ", " << V.getStructField(I);
+ if (I == 10) {
+ // Avoid printing out the entire contents of large arrays.
+ Out << "...";
+ break;
+ }
+ getArrayInitializedElt(I).printPretty(Out, Ctx, ElemTy);
+ }
}
Out << '}';
return;
+ }
+ case APValue::Struct: {
+ Out << '{';
+ const RecordDecl *RD = Ty->getAs<RecordType>()->getDecl();
+ bool First = true;
+ if (unsigned N = getStructNumBases()) {
+ const CXXRecordDecl *CD = cast<CXXRecordDecl>(RD);
+ CXXRecordDecl::base_class_const_iterator BI = CD->bases_begin();
+ for (unsigned I = 0; I != N; ++I, ++BI) {
+ assert(BI != CD->bases_end());
+ if (!First)
+ Out << ", ";
+ getStructBase(I).printPretty(Out, Ctx, BI->getType());
+ First = false;
+ }
+ }
+ for (RecordDecl::field_iterator FI = RD->field_begin();
+ FI != RD->field_end(); ++FI) {
+ if (!First)
+ Out << ", ";
+ if ((*FI)->isUnnamedBitfield()) continue;
+ getStructField((*FI)->getFieldIndex()).
+ printPretty(Out, Ctx, (*FI)->getType());
+ First = false;
+ }
+ Out << '}';
+ return;
+ }
case APValue::Union:
- Out << '{' << V.getUnionValue() << '}';
+ Out << '{';
+ if (const FieldDecl *FD = getUnionField()) {
+ Out << "." << *FD << " = ";
+ getUnionValue().printPretty(Out, Ctx, FD->getType());
+ }
+ Out << '}';
return;
case APValue::MemberPointer:
- Out << "MemberPointer: <todo>";
+ // FIXME: This is not enough to unambiguously identify the member in a
+ // multiple-inheritance scenario.
+ if (const ValueDecl *VD = getMemberPointerDecl()) {
+ Out << '&' << *cast<CXXRecordDecl>(VD->getDeclContext()) << "::" << *VD;
+ return;
+ }
+ Out << "0";
return;
}
llvm_unreachable("Unknown APValue kind!");
}
-const DiagnosticBuilder &clang::operator<<(const DiagnosticBuilder &DB,
- const APValue &V) {
- llvm::SmallString<64> Buffer;
- llvm::raw_svector_ostream Out(Buffer);
- WriteShortAPValueToStream(Out, V);
- return DB << Out.str();
+std::string APValue::getAsString(ASTContext &Ctx, QualType Ty) const {
+ std::string Result;
+ llvm::raw_string_ostream Out(Result);
+ printPretty(Out, Ctx, Ty);
+ return Result;
}
const APValue::LValueBase APValue::getLValueBase() const {
diff --git a/lib/AST/ExprConstant.cpp b/lib/AST/ExprConstant.cpp
index dd1110a..31b211e 100644
--- a/lib/AST/ExprConstant.cpp
+++ b/lib/AST/ExprConstant.cpp
@@ -231,6 +231,12 @@
/// Parent - The caller of this stack frame.
CallStackFrame *Caller;
+ /// CallLoc - The location of the call expression for this call.
+ SourceLocation CallLoc;
+
+ /// Callee - The function which was called.
+ const FunctionDecl *Callee;
+
/// This - The binding for the this pointer in this call, if any.
const LValue *This;
@@ -243,7 +249,8 @@
/// Temporaries - Temporary lvalues materialized within this stack frame.
MapTy Temporaries;
- CallStackFrame(EvalInfo &Info, const LValue *This,
+ CallStackFrame(EvalInfo &Info, SourceLocation CallLoc,
+ const FunctionDecl *Callee, const LValue *This,
const CCValue *Arguments);
~CallStackFrame();
};
@@ -300,8 +307,8 @@
EvalInfo(const ASTContext &C, Expr::EvalStatus &S)
: Ctx(const_cast<ASTContext&>(C)), EvalStatus(S), CurrentCall(0),
- CallStackDepth(0), BottomFrame(*this, 0, 0), EvaluatingDecl(0),
- EvaluatingDeclValue(0), HasActiveDiagnostic(false) {}
+ CallStackDepth(0), BottomFrame(*this, SourceLocation(), 0, 0, 0),
+ EvaluatingDecl(0), EvaluatingDeclValue(0), HasActiveDiagnostic(false) {}
const CCValue *getOpaqueValue(const OpaqueValueExpr *e) const {
MapTy::const_iterator i = OpaqueValues.find(e);
@@ -332,6 +339,9 @@
return EvalStatus.Diag->back().second;
}
+ /// Add notes containing a call stack to the current point of evaluation.
+ void addCallStack(unsigned Limit);
+
public:
/// Diagnose that the evaluation cannot be folded.
OptionalDiagnostic Diag(SourceLocation Loc, diag::kind DiagId,
@@ -340,11 +350,17 @@
// isn't a constant expression. This diagnostic is more important.
// FIXME: We might want to show both diagnostics to the user.
if (EvalStatus.Diag) {
+ unsigned CallStackNotes = CallStackDepth - 1;
+ unsigned Limit = Ctx.getDiagnostics().getConstexprBacktraceLimit();
+ if (Limit)
+ CallStackNotes = std::min(CallStackNotes, Limit + 1);
+
HasActiveDiagnostic = true;
EvalStatus.Diag->clear();
- EvalStatus.Diag->reserve(1 + ExtraNotes);
- // FIXME: Add a call stack for constexpr evaluation.
- return OptionalDiagnostic(&addDiag(Loc, DiagId));
+ EvalStatus.Diag->reserve(1 + ExtraNotes + CallStackNotes);
+ addDiag(Loc, DiagId);
+ addCallStack(Limit);
+ return OptionalDiagnostic(&(*EvalStatus.Diag)[0].second);
}
HasActiveDiagnostic = false;
return OptionalDiagnostic();
@@ -367,20 +383,87 @@
return OptionalDiagnostic(&addDiag(Loc, DiagId));
}
};
+}
- CallStackFrame::CallStackFrame(EvalInfo &Info, const LValue *This,
- const CCValue *Arguments)
- : Info(Info), Caller(Info.CurrentCall), This(This), Arguments(Arguments) {
- Info.CurrentCall = this;
- ++Info.CallStackDepth;
+CallStackFrame::CallStackFrame(EvalInfo &Info, SourceLocation CallLoc,
+ const FunctionDecl *Callee, const LValue *This,
+ const CCValue *Arguments)
+ : Info(Info), Caller(Info.CurrentCall), CallLoc(CallLoc), Callee(Callee),
+ This(This), Arguments(Arguments) {
+ Info.CurrentCall = this;
+ ++Info.CallStackDepth;
+}
+
+CallStackFrame::~CallStackFrame() {
+ assert(Info.CurrentCall == this && "calls retired out of order");
+ --Info.CallStackDepth;
+ Info.CurrentCall = Caller;
+}
+
+/// Produce a string describing the given constexpr call.
+static void describeCall(CallStackFrame *Frame, llvm::raw_ostream &Out) {
+ unsigned ArgIndex = 0;
+ bool IsMemberCall = isa<CXXMethodDecl>(Frame->Callee) &&
+ !isa<CXXConstructorDecl>(Frame->Callee);
+
+ if (!IsMemberCall)
+ Out << *Frame->Callee << '(';
+
+ for (FunctionDecl::param_const_iterator I = Frame->Callee->param_begin(),
+ E = Frame->Callee->param_end(); I != E; ++I, ++ArgIndex) {
+ if (ArgIndex > IsMemberCall)
+ Out << ", ";
+
+ const ParmVarDecl *Param = *I;
+ const CCValue &Arg = Frame->Arguments[ArgIndex];
+ if (!Arg.isLValue() || Arg.getLValueDesignator().Invalid)
+ Arg.printPretty(Out, Frame->Info.Ctx, Param->getType());
+ else {
+ // Deliberately slice off the frame to form an APValue we can print.
+ APValue Value(Arg.getLValueBase(), Arg.getLValueOffset(),
+ Arg.getLValueDesignator().Entries,
+ Arg.getLValueDesignator().OnePastTheEnd);
+ Value.printPretty(Out, Frame->Info.Ctx, Param->getType());
+ }
+
+ if (ArgIndex == 0 && IsMemberCall)
+ Out << "->" << *Frame->Callee << '(';
}
- CallStackFrame::~CallStackFrame() {
- assert(Info.CurrentCall == this && "calls retired out of order");
- --Info.CallStackDepth;
- Info.CurrentCall = Caller;
+ Out << ')';
+}
+
+void EvalInfo::addCallStack(unsigned Limit) {
+ // Determine which calls to skip, if any.
+ unsigned ActiveCalls = CallStackDepth - 1;
+ unsigned SkipStart = ActiveCalls, SkipEnd = SkipStart;
+ if (Limit && Limit < ActiveCalls) {
+ SkipStart = Limit / 2 + Limit % 2;
+ SkipEnd = ActiveCalls - Limit / 2;
}
+ // Walk the call stack and add the diagnostics.
+ unsigned CallIdx = 0;
+ for (CallStackFrame *Frame = CurrentCall; Frame != &BottomFrame;
+ Frame = Frame->Caller, ++CallIdx) {
+ // Skip this call?
+ if (CallIdx >= SkipStart && CallIdx < SkipEnd) {
+ if (CallIdx == SkipStart) {
+ // Note that we're skipping calls.
+ addDiag(Frame->CallLoc, diag::note_constexpr_calls_suppressed)
+ << unsigned(ActiveCalls - Limit);
+ }
+ continue;
+ }
+
+ llvm::SmallVector<char, 128> Buffer;
+ llvm::raw_svector_ostream Out(Buffer);
+ describeCall(Frame, Out);
+ addDiag(Frame->CallLoc, diag::note_constexpr_call_here) << Out.str();
+ }
+}
+
+namespace {
struct ComplexValue {
private:
bool IsInt;
@@ -1465,7 +1548,8 @@
}
/// Evaluate a function call.
-static bool HandleFunctionCall(const Expr *CallExpr, const LValue *This,
+static bool HandleFunctionCall(const Expr *CallExpr, const FunctionDecl *Callee,
+ const LValue *This,
ArrayRef<const Expr*> Args, const Stmt *Body,
EvalInfo &Info, APValue &Result) {
if (!Info.CheckCallLimit(CallExpr->getExprLoc()))
@@ -1475,7 +1559,8 @@
if (!EvaluateArgs(Args, ArgValues, Info))
return false;
- CallStackFrame Frame(Info, This, ArgValues.data());
+ CallStackFrame Frame(Info, CallExpr->getExprLoc(), Callee, This,
+ ArgValues.data());
return EvaluateStmt(Result, Info, Body) == ESR_Returned;
}
@@ -1492,7 +1577,8 @@
if (!EvaluateArgs(Args, ArgValues, Info))
return false;
- CallStackFrame Frame(Info, &This, ArgValues.data());
+ CallStackFrame Frame(Info, CallExpr->getExprLoc(), Definition,
+ &This, ArgValues.data());
// If it's a delegating constructor, just delegate.
if (Definition->isDelegatingConstructor()) {
@@ -1855,7 +1941,7 @@
APValue Result;
if (!CheckConstexprFunction(Info, E->getExprLoc(), FD, Definition) ||
- !HandleFunctionCall(E, This, Args, Body, Info, Result))
+ !HandleFunctionCall(E, Definition, This, Args, Body, Info, Result))
return false;
return DerivedSuccess(CCValue(Result, CCValue::GlobalValue()), E);
diff --git a/lib/Basic/Diagnostic.cpp b/lib/Basic/Diagnostic.cpp
index 7ea2962..1643572 100644
--- a/lib/Basic/Diagnostic.cpp
+++ b/lib/Basic/Diagnostic.cpp
@@ -53,6 +53,7 @@
ErrorLimit = 0;
TemplateBacktraceLimit = 0;
+ ConstexprBacktraceLimit = 0;
Reset();
}
diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp
index 60e6d3d..798d787 100644
--- a/lib/Driver/Tools.cpp
+++ b/lib/Driver/Tools.cpp
@@ -1808,6 +1808,11 @@
CmdArgs.push_back(A->getValue(Args));
}
+ if (Arg *A = Args.getLastArg(options::OPT_fconstexpr_backtrace_limit_EQ)) {
+ CmdArgs.push_back("-fconstexpr-backtrace-limit");
+ CmdArgs.push_back(A->getValue(Args));
+ }
+
// Pass -fmessage-length=.
CmdArgs.push_back("-fmessage-length");
if (Arg *A = Args.getLastArg(options::OPT_fmessage_length_EQ)) {
diff --git a/lib/Frontend/CompilerInvocation.cpp b/lib/Frontend/CompilerInvocation.cpp
index 797147e5..3ad555b 100644
--- a/lib/Frontend/CompilerInvocation.cpp
+++ b/lib/Frontend/CompilerInvocation.cpp
@@ -354,6 +354,11 @@
Res.push_back("-ftemplate-backtrace-limit");
Res.push_back(llvm::utostr(Opts.TemplateBacktraceLimit));
}
+ if (Opts.ConstexprBacktraceLimit
+ != DiagnosticOptions::DefaultConstexprBacktraceLimit) {
+ Res.push_back("-fconstexpr-backtrace-limit");
+ Res.push_back(llvm::utostr(Opts.ConstexprBacktraceLimit));
+ }
if (Opts.TabStop != DiagnosticOptions::DefaultTabStop) {
Res.push_back("-ftabstop");
@@ -1229,6 +1234,10 @@
= Args.getLastArgIntValue(OPT_ftemplate_backtrace_limit,
DiagnosticOptions::DefaultTemplateBacktraceLimit,
Diags);
+ Opts.ConstexprBacktraceLimit
+ = Args.getLastArgIntValue(OPT_fconstexpr_backtrace_limit,
+ DiagnosticOptions::DefaultConstexprBacktraceLimit,
+ Diags);
Opts.TabStop = Args.getLastArgIntValue(OPT_ftabstop,
DiagnosticOptions::DefaultTabStop, Diags);
if (Opts.TabStop == 0 || Opts.TabStop > DiagnosticOptions::MaxTabStop) {
diff --git a/lib/Frontend/Warnings.cpp b/lib/Frontend/Warnings.cpp
index e63bc21..6f44111 100644
--- a/lib/Frontend/Warnings.cpp
+++ b/lib/Frontend/Warnings.cpp
@@ -58,6 +58,8 @@
Diags.setErrorLimit(Opts.ErrorLimit);
if (Opts.TemplateBacktraceLimit)
Diags.setTemplateBacktraceLimit(Opts.TemplateBacktraceLimit);
+ if (Opts.ConstexprBacktraceLimit)
+ Diags.setConstexprBacktraceLimit(Opts.ConstexprBacktraceLimit);
// If -pedantic or -pedantic-errors was specified, then we want to map all
// extension diagnostics onto WARNING or ERROR unless the user has futz'd
diff --git a/lib/Sema/SemaInit.cpp b/lib/Sema/SemaInit.cpp
index a95a257..7dbf830 100644
--- a/lib/Sema/SemaInit.cpp
+++ b/lib/Sema/SemaInit.cpp
@@ -5707,7 +5707,7 @@
? diag::err_init_list_constant_narrowing
: diag::warn_init_list_constant_narrowing)
<< InitE->getSourceRange()
- << ConstantValue
+ << ConstantValue.getAsString(S.getASTContext(), EntityType)
<< EntityType.getLocalUnqualifiedType();
} else
S.Diag(InitE->getLocStart(),