declare the builtin if needed

Signed-off-by: Sarnie, Nick <[email protected]>

Author: sarnex

clang/include/clang/Sema/Sema.h

@@ -1825,11 +1825,6 @@ class Sema final : public SemaBase {
   /// Set of no-builtin functions listed by \#pragma function.
   llvm::SmallSetVector<StringRef, 4> MSFunctionNoBuiltins;
 
-  /// Map of BuiltinIDs to source locations that have #pragma intrinsic calls
-  /// that refer to them.
-  llvm::DenseMap<unsigned, llvm::SmallSetVector<SourceLocation, 4>>
-      PragmaIntrinsicBuiltinIDMap;
-
   /// AddAlignmentAttributesForRecord - Adds any needed alignment attributes to
   /// a the record decl, to handle '\#pragma pack' and '\#pragma options align'.
   void AddAlignmentAttributesForRecord(RecordDecl *RD);
@@ -4350,11 +4345,6 @@ class Sema final : public SemaBase {
   /// contain non-field names.
   Scope *getNonFieldDeclScope(Scope *S);
 
-  // Determine if the given builtin usage at the given source location
-  // was previously specified in a #pragma intrinsic.
-  bool isBuiltinSpecifiedInPragmaIntrinsic(unsigned BuiltinID,
-                                           SourceLocation UsageLoc) const;
-
   FunctionDecl *CreateBuiltin(IdentifierInfo *II, QualType Type, unsigned ID,
                               SourceLocation Loc);
 

clang/lib/Parse/ParsePragma.cpp

@@ -3807,10 +3807,15 @@ void PragmaMSIntrinsicHandler::HandlePragma(Preprocessor &PP,
     if (!II->getBuiltinID())
       PP.Diag(Tok.getLocation(), diag::warn_pragma_intrinsic_builtin)
           << II << SuggestIntrinH;
-    /// Store the location at which the builtin was used in a #pragma intrinsic
-    /// so we don't emit a missing header warning later.
-    Actions.PragmaIntrinsicBuiltinIDMap[II->getBuiltinID()].insert(
-        Tok.getLocation());
+    // If the builtin hasn't already been declared, declare it now.
+    DeclarationNameInfo NameInfo(II, Tok.getLocation());
+    LookupResult Previous(Actions, NameInfo, Sema::LookupOrdinaryName,
+                          Actions.forRedeclarationInCurContext());
+    Actions.LookupName(Previous, Actions.getCurScope(),
+                       /*CreateBuiltins*/ false);
+    if (Previous.empty())
+      Actions.LazilyCreateBuiltin(II, II->getBuiltinID(), Actions.getCurScope(),
+                                  /*ForRedeclaration*/ true, Tok.getLocation());
     PP.Lex(Tok);
     if (Tok.isNot(tok::comma))
       break;

clang/lib/Sema/SemaDecl.cpp

@@ -2299,21 +2299,6 @@ static StringRef getHeaderName(Builtin::Context &BuiltinInfo, unsigned ID,
   llvm_unreachable("unhandled error kind");
 }
 
-bool Sema::isBuiltinSpecifiedInPragmaIntrinsic(unsigned BuiltinID,
-                                               SourceLocation UsageLoc) const {
-  assert(Context.BuiltinInfo(BuiltinID) && "Invalid builtin id");
-  assert(UsageLoc.isValid() && "Invalid source location");
-  auto It = PragmaIntrinsicBuiltinIDMap.find(BuiltinID);
-  if (It == PragmaIntrinsicBuiltinIDMap.end())
-    return false;
-  for (const SourceLocation &PragmaIntrinLoc : It->second) {
-    if (Context.getSourceManager().isBeforeInTranslationUnit(PragmaIntrinLoc,
-                                                             UsageLoc))
-      return true;
-  }
-  return false;
-}
-
 FunctionDecl *Sema::CreateBuiltin(IdentifierInfo *II, QualType Type,
                                   unsigned ID, SourceLocation Loc) {
   DeclContext *Parent = Context.getTranslationUnitDecl();
@@ -2385,17 +2370,15 @@ NamedDecl *Sema::LazilyCreateBuiltin(IdentifierInfo *II, unsigned ID,
 
     // Generally, we emit a warning that the declaration requires the
     // appropriate header.
-    if (!isBuiltinSpecifiedInPragmaIntrinsic(ID, Loc))
-      Diag(Loc, diag::warn_implicit_decl_requires_sysheader)
-          << getHeaderName(Context.BuiltinInfo, ID, Error)
-          << Context.BuiltinInfo.getName(ID);
+    Diag(Loc, diag::warn_implicit_decl_requires_sysheader)
+        << getHeaderName(Context.BuiltinInfo, ID, Error)
+        << Context.BuiltinInfo.getName(ID);
     return nullptr;
   }
 
   if (!ForRedeclaration &&
       (Context.BuiltinInfo.isPredefinedLibFunction(ID) ||
-       Context.BuiltinInfo.isHeaderDependentFunction(ID)) &&
-      !isBuiltinSpecifiedInPragmaIntrinsic(ID, Loc)) {
+       Context.BuiltinInfo.isHeaderDependentFunction(ID))) {
     Diag(Loc, LangOpts.C99 ? diag::ext_implicit_lib_function_decl_c99
                            : diag::ext_implicit_lib_function_decl)
         << Context.BuiltinInfo.getName(ID) << R;