1 files changed, 36 insertions, 41 deletions

diff --git a/clang/lib/Sema/SemaTemplate.cpp b/clang/lib/Sema/SemaTemplate.cpp
index c7d67cde112..56302d62484 100644
--- a/clang/lib/Sema/SemaTemplate.cpp
+++ b/clang/lib/Sema/SemaTemplate.cpp
@@ -3052,42 +3052,30 @@ static Expr *lookThroughRangesV3Condition(Preprocessor &PP, Expr *Cond) {
   return Cond;
 }
 
-namespace {
-
-// A PrinterHelper that prints more helpful diagnostics for some sub-expressions
-// within failing boolean expression, such as substituting template parameters
-// for actual types.
-class FailedBooleanConditionPrinterHelper : public PrinterHelper {
-public:
-  explicit FailedBooleanConditionPrinterHelper(const PrintingPolicy &Policy)
-      : Policy(Policy) {}
-
-  bool handledStmt(Stmt *E, raw_ostream &OS) override {
-    const auto *DR = dyn_cast<DeclRefExpr>(E);
-    if (DR && DR->getQualifier()) {
-      // If this is a qualified name, expand the template arguments in nested
-      // qualifiers.
-      DR->getQualifier()->print(OS, Policy, true);
-      // Then print the decl itself.
-      const ValueDecl *VD = DR->getDecl();
-      OS << VD->getName();
-      if (const auto *IV = dyn_cast<VarTemplateSpecializationDecl>(VD)) {
-        // This is a template variable, print the expanded template arguments.
-        printTemplateArgumentList(OS, IV->getTemplateArgs().asArray(), Policy);
-      }
-      return true;
+// Print a diagnostic for the failing static_assert expression. Defaults to
+// pretty-printing the expression.
+static void prettyPrintFailedBooleanCondition(llvm::raw_string_ostream &OS,
+                                              const Expr *FailedCond,
+                                              const PrintingPolicy &Policy) {
+  const auto *DR = dyn_cast<DeclRefExpr>(FailedCond);
+  if (DR && DR->getQualifier()) {
+    // If this is a qualified name, expand the template arguments in nested
+    // qualifiers.
+    DR->getQualifier()->print(OS, Policy, true);
+    // Then print the decl itself.
+    const ValueDecl *VD = DR->getDecl();
+    OS << VD->getName();
+    if (const auto *IV = dyn_cast<VarTemplateSpecializationDecl>(VD)) {
+      // This is a template variable, print the expanded template arguments.
+      printTemplateArgumentList(OS, IV->getTemplateArgs().asArray(), Policy);
     }
-    return false;
+    return;
   }
-
-private:
-  const PrintingPolicy &Policy;
-};
-
-} // end anonymous namespace
+  FailedCond->printPretty(OS, nullptr, Policy);
+}
 
 std::pair<Expr *, std::string>
-Sema::findFailedBooleanCondition(Expr *Cond) {
+Sema::findFailedBooleanCondition(Expr *Cond, bool AllowTopLevelCond) {
   Cond = lookThroughRangesV3Condition(PP, Cond);
 
   // Separate out all of the terms in a conjunction.
@@ -3099,6 +3087,11 @@ Sema::findFailedBooleanCondition(Expr *Cond) {
   for (Expr *Term : Terms) {
     Expr *TermAsWritten = Term->IgnoreParenImpCasts();
 
+    // Literals are uninteresting.
+    if (isa<CXXBoolLiteralExpr>(TermAsWritten) ||
+        isa<IntegerLiteral>(TermAsWritten))
+      continue;
+
     // The initialization of the parameter from the argument is
     // a constant-evaluated context.
     EnterExpressionEvaluationContext ConstantEvaluated(
@@ -3111,18 +3104,18 @@ Sema::findFailedBooleanCondition(Expr *Cond) {
       break;
     }
   }
-  if (!FailedCond)
-    FailedCond = Cond->IgnoreParenImpCasts();
 
-  // Literals are uninteresting.
-  if (isa<CXXBoolLiteralExpr>(FailedCond) || isa<IntegerLiteral>(FailedCond))
-    return {nullptr, ""};
+  if (!FailedCond) {
+    if (!AllowTopLevelCond)
+      return { nullptr, "" };
+
+    FailedCond = Cond->IgnoreParenImpCasts();
+  }
 
   std::string Description;
   {
     llvm::raw_string_ostream Out(Description);
-    FailedBooleanConditionPrinterHelper Helper(getPrintingPolicy());
-    FailedCond->printPretty(Out, &Helper, getPrintingPolicy());
+    prettyPrintFailedBooleanCondition(Out, FailedCond, getPrintingPolicy());
   }
   return { FailedCond, Description };
 }
@@ -3206,7 +3199,9 @@ QualType Sema::CheckTemplateIdType(TemplateName Name,
             Expr *FailedCond;
             std::string FailedDescription;
             std::tie(FailedCond, FailedDescription) =
-              findFailedBooleanCondition(TemplateArgs[0].getSourceExpression());
+              findFailedBooleanCondition(
+                TemplateArgs[0].getSourceExpression(),
+                /*AllowTopLevelCond=*/true);
 
             // Remove the old SFINAE diagnostic.
             PartialDiagnosticAt OldDiag =
@@ -9654,7 +9649,7 @@ Sema::CheckTypenameType(ElaboratedTypeKeyword Keyword,
         Expr *FailedCond;
         std::string FailedDescription;
         std::tie(FailedCond, FailedDescription) =
-          findFailedBooleanCondition(Cond);
+          findFailedBooleanCondition(Cond, /*AllowTopLevelCond=*/true);
 
         Diag(FailedCond->getExprLoc(),
              diag::err_typename_nested_not_found_requirement)