Add a fixit for _Noreturn main,

add tests for fixits removing static and inline from main

llvm-svn: 173024

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -390,6 +390,7 @@ def err_static_main : Error<"'main' is not allowed to be declared static">;
 def err_inline_main : Error<"'main' is not allowed to be declared inline">;
 def ext_noreturn_main : ExtWarn<
   "'main' is not allowed to be declared _Noreturn">, InGroup<Main>;
+def note_main_remove_noreturn : Note<"remove '_Noreturn'">;
 def err_constexpr_main : Error<
   "'main' is not allowed to be declared constexpr">;
 def err_main_template_decl : Error<"'main' cannot be a template">;

clang/lib/Sema/SemaDecl.cpp

@@ -6474,8 +6474,14 @@ void Sema::CheckMain(FunctionDecl* FD, const DeclSpec& DS) {
   if (FD->isInlineSpecified())
     Diag(DS.getInlineSpecLoc(), diag::err_inline_main) 
       << FixItHint::CreateRemoval(DS.getInlineSpecLoc());
-  if (DS.isNoreturnSpecified())
+  if (DS.isNoreturnSpecified()) {
-    Diag(DS.getNoreturnSpecLoc(), diag::ext_noreturn_main);
+    SourceLocation NoreturnLoc = DS.getNoreturnSpecLoc();
+    SourceRange NoreturnRange(NoreturnLoc,
+                              PP.getLocForEndOfToken(NoreturnLoc));
+    Diag(NoreturnLoc, diag::ext_noreturn_main);
+    Diag(NoreturnLoc, diag::note_main_remove_noreturn)
+      << FixItHint::CreateRemoval(NoreturnRange);
+  }
   if (FD->isConstexpr()) {
     Diag(DS.getConstexprSpecLoc(), diag::err_constexpr_main)
       << FixItHint::CreateRemoval(DS.getConstexprSpecLoc());

clang/test/Sema/warn-main.c

@@ -0,0 +1,32 @@
+// RUN: %clang_cc1 -fsyntax-only -verify %s
+// RUN: %clang_cc1 -fsyntax-only -fdiagnostics-parseable-fixits %s 2>&1 | FileCheck %s
+// RUN: %clang_cc1 -fsyntax-only -fdiagnostics-parseable-fixits -x c++ %s 2>&1 | FileCheck %s
+
+// expected-note@+1 2{{previous definition is here}}
+int main() {
+  return 0;
+}
+
+// expected-error@+2 {{static declaration of 'main' follows non-static declaration}}
+// expected-warning@+1 {{'main' should not be declared static}}
+static int main() {
+// CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:1-[[@LINE-1]]:8}:""
+  return 0;
+}
+
+// expected-error@+3 {{redefinition of 'main'}}
+// expected-error@+2 {{'main' is not allowed to be declared inline}}
+// expected-note@+1 {{previous definition is here}}
+inline int main() {
+// CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:1-[[@LINE-1]]:8}:""
+  return 0;
+}
+
+// expected-error@+3 {{redefinition of 'main'}}
+// expected-warning@+2 {{'main' is not allowed to be declared _Noreturn}}
+// expected-note@+1 {{remove '_Noreturn'}}
+_Noreturn int main() {
+// CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:1-[[@LINE-1]]:11}:""
+  return 0;
+}
+