[clang-format] Parse restrict as a pointer qualifier

[arichardson]

Summary

Before: void f() { MACRO(A * restrict a); }
After: void f() { MACRO(A *restrict a); }

Also check that the restrict and restrict__ aliases are handled.

[JakeMerdichAMD]

LGTM, assuming tests pass (automated checks failed to resolve your patch since you based it off of your other one). Looks like enabling C99 should have no other effects, right?

[arichardson]

In D86710#2242197, @JakeMerdichAMD wrote:

LGTM, assuming tests pass (automated checks failed to resolve your patch since you based it off of your other one). Looks like enabling C99 should have no other effects, right?

Tests are passing locally. Looking at TokenKinds.def it seems the only thing setting C99 enables is restrict and inline (but we already get that via C++).

clang/lib/Format/Format.cpp

LangOptions getFormattingLangOpts(const FormatStyle &Style) {
 
   LangOpts.LineComment = 1;
   bool AlternativeOperators = Style.isCpp();
   LangOpts.CXXOperatorNames = AlternativeOperators ? 1 : 0;
   LangOpts.Bool = 1;
   LangOpts.ObjC = 1;
   LangOpts.MicrosoftExt = 1;    // To get kw___try, kw___finally.
   LangOpts.DeclSpecKeyword = 1; // To get __declspec.
+  LangOpts.C99 = 1; // To get kw_restrict for non-underscore-prefixed restrict.
   return LangOpts;
 }
 
 const char *StyleOptionHelpDescription =
     "Coding style, currently supports:\n"
     "  LLVM, GNU, Google, Chromium, Microsoft, Mozilla, WebKit.\n"
     "Use -style=file to load style configuration from\n"
     ".clang-format file located in one of the parent\n"

clang/lib/Format/TokenAnnotator.cpp

TokenType determineStarAmpUsage(const FormatToken &Tok, bool IsExpression,
 
     const FormatToken *PrevToken = Tok.getPreviousNonComment();
     if (!PrevToken)
       return TT_UnaryOperator;
 
     const FormatToken *NextToken = Tok.getNextNonComment();
     if (!NextToken ||
         NextToken->isOneOf(tok::arrow, tok::equal, tok::kw_const,
-                           tok::kw_volatile, tok::kw_noexcept) ||
+                           tok::kw_restrict, tok::kw_volatile,
+                           tok::kw_noexcept) ||
         (NextToken->is(tok::l_brace) && !NextToken->getNextNonComment()))
       return TT_PointerOrReference;
 
     if (PrevToken->is(tok::coloncolon))
       return TT_PointerOrReference;
 
     if (PrevToken->isOneOf(tok::l_paren, tok::l_square, tok::l_brace,
                            tok::comma, tok::semi, tok::kw_return, tok::colon,

clang/unittests/Format/FormatTest.cpp

verifyFormat(
       "              ::std::is_array<T>{} && ::std::is_array<T>{}>::type>\n"
       "void F();",
       getGoogleStyleWithColumns(68));
 
   verifyIndependentOfContext("MACRO(int *i);");
   verifyIndependentOfContext("MACRO(auto *a);");
   verifyIndependentOfContext("MACRO(const A *a);");
   verifyIndependentOfContext("MACRO(A *const a);");
+  verifyIndependentOfContext("MACRO(A *restrict a);");
+  verifyIndependentOfContext("MACRO(A *__restrict__ a);");
+  verifyIndependentOfContext("MACRO(A *__restrict a);");
   verifyIndependentOfContext("MACRO(A *volatile a);");
   verifyIndependentOfContext("MACRO(A *__volatile a);");
   verifyIndependentOfContext("MACRO(A *__volatile__ a);");
   verifyIndependentOfContext("MACRO('0' <= c && c <= '9');");
   verifyFormat("void f() { f(float{1}, a * a); }");
   // FIXME: Is there a way to make this work?
   // verifyIndependentOfContext("MACRO(A *a);");