2 files changed, 25 insertions, 26 deletions

diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
index f7d56231885..976f3a696df 100644
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -3867,7 +3867,8 @@ static void emitReplacement(Sema &S, SourceLocation Loc, SourceRange Range,
   if (!EmitHeaderHint)
     return;
 
-  S.Diag(Loc, diag::note_please_include_header) << HeaderName << FunctionName;
+  S.Diag(Loc, diag::note_include_header_or_declare) << HeaderName
+                                                    << FunctionName;
 }
 
 static bool IsFunctionStdAbs(const FunctionDecl *FDecl) {
@@ -3907,8 +3908,8 @@ void Sema::CheckAbsoluteValueFunction(const CallExpr *Call,
   QualType ArgType = Call->getArg(0)->IgnoreParenImpCasts()->getType();
   QualType ParamType = Call->getArg(0)->getType();
 
-  // Unsigned types can not be negative.  Suggest to drop the absolute value
-  // function.
+  // Unsigned types cannot be negative.  Suggest removing the absolute value
+  // function call.
   if (ArgType->isUnsignedIntegerType()) {
     const char *FunctionName =
         IsStdAbs ? "std::abs" : Context.BuiltinInfo.GetName(AbsKind);
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 253ec39a844..042fe264526 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -1602,6 +1602,20 @@ static void LookupPredefedObjCSuperType(Sema &ThisSema, Scope *S,
       Context.setObjCSuperType(Context.getTagDeclType(TD));
 }
 
+static StringRef getHeaderName(ASTContext::GetBuiltinTypeError Error) {
+  switch (Error) {
+  case ASTContext::GE_None:
+    return "";
+  case ASTContext::GE_Missing_stdio:
+    return "stdio.h";
+  case ASTContext::GE_Missing_setjmp:
+    return "setjmp.h";
+  case ASTContext::GE_Missing_ucontext:
+    return "ucontext.h";
+  }
+  llvm_unreachable("unhandled error kind");
+}
+
 /// LazilyCreateBuiltin - The specified Builtin-ID was first used at
 /// file scope.  lazily create a decl for it. ForRedeclaration is true
 /// if we're creating this built-in in anticipation of redeclaring the
@@ -1615,27 +1629,11 @@ NamedDecl *Sema::LazilyCreateBuiltin(IdentifierInfo *II, unsigned bid,
 
   ASTContext::GetBuiltinTypeError Error;
   QualType R = Context.GetBuiltinType(BID, Error);
-  switch (Error) {
-  case ASTContext::GE_None:
-    // Okay
-    break;
-
-  case ASTContext::GE_Missing_stdio:
-    if (ForRedeclaration)
-      Diag(Loc, diag::warn_implicit_decl_requires_stdio)
-        << Context.BuiltinInfo.GetName(BID);
-    return nullptr;
-
-  case ASTContext::GE_Missing_setjmp:
-    if (ForRedeclaration)
-      Diag(Loc, diag::warn_implicit_decl_requires_setjmp)
-        << Context.BuiltinInfo.GetName(BID);
-    return nullptr;
-
-  case ASTContext::GE_Missing_ucontext:
+  if (Error) {
     if (ForRedeclaration)
-      Diag(Loc, diag::warn_implicit_decl_requires_ucontext)
-        << Context.BuiltinInfo.GetName(BID);
+      Diag(Loc, diag::warn_implicit_decl_requires_sysheader)
+          << getHeaderName(Error)
+          << Context.BuiltinInfo.GetName(BID);
     return nullptr;
   }
 
@@ -1645,9 +1643,9 @@ NamedDecl *Sema::LazilyCreateBuiltin(IdentifierInfo *II, unsigned bid,
       << R;
     if (Context.BuiltinInfo.getHeaderName(BID) &&
         !Diags.isIgnored(diag::ext_implicit_lib_function_decl, Loc))
-      Diag(Loc, diag::note_please_include_header)
-        << Context.BuiltinInfo.getHeaderName(BID)
-        << Context.BuiltinInfo.GetName(BID);
+      Diag(Loc, diag::note_include_header_or_declare)
+          << Context.BuiltinInfo.getHeaderName(BID)
+          << Context.BuiltinInfo.GetName(BID);
   }
 
   DeclContext *Parent = Context.getTranslationUnitDecl();