[clang-format] Correctly handle SpaceBeforeParens for builtins.

[curdeius]

Summary

That's a partial fix for https://github.com/llvm/llvm-project/issues/55292.

Before, known builtins behaved differently from other identifiers:

void f () { return F (__builtin_LINE() + __builtin_FOO ()); }

After:

void f () { return F (__builtin_LINE () + __builtin_FOO ()); }

[urnathan]

cool

[owenpan]

clang/lib/Format/TokenAnnotator.cpp

3439–3441

Any identifiers and keywords are covered now.

[curdeius]

Address comment: simplify.

[owenpan]

LGTM

clang/lib/Format/TokenAnnotator.cpp

if (!Left.Previous || Left.Previous->isNot(tok::period)) {
                spaceRequiredBeforeParens(Right);
 
       if (Left.is(tok::r_square) && Left.MatchingParen &&
           Left.MatchingParen->Previous &&
           Left.MatchingParen->Previous->is(tok::kw_delete))
         return (Style.SpaceBeforeParens != FormatStyle::SBPO_Never) ||
                spaceRequiredBeforeParens(Right);
     }
+    // Handle builtins like identifiers.
     if (Line.Type != LT_PreprocessorDirective &&
-        (Left.is(tok::identifier) || Left.isFunctionLikeKeyword() ||
-         Left.is(tok::r_paren) || Left.isSimpleTypeSpecifier()))
+        (Left.is(tok::identifier) || Left.Tok.getIdentifierInfo() ||
+         Left.isFunctionLikeKeyword() || Left.is(tok::r_paren) ||
+         Left.isSimpleTypeSpecifier()))
       return spaceRequiredBeforeParens(Right);
     return false;
   }
   if (Left.is(tok::at) && Right.Tok.getObjCKeywordID() != tok::objc_not_keyword)
     return false;
   if (Right.is(TT_UnaryOperator))
     return !Left.isOneOf(tok::l_paren, tok::l_square, tok::at) &&
            (Left.isNot(tok::colon) || Left.isNot(TT_ObjCMethodExpr));

clang/unittests/Format/FormatTest.cpp

TEST_F(FormatTest, ConfigurableSpaceBeforeParens) {
   verifyFormat("static_assert (sizeof (char) == 1, \"Impossible!\");", Space);
   verifyFormat("int f () throw (Deprecated);", Space);
   verifyFormat("typedef void (*cb) (int);", Space);
   // FIXME these tests regressed behaviour.
   // verifyFormat("T A::operator() ();", Space);
   // verifyFormat("X A::operator++ (T);", Space);
   verifyFormat("auto lambda = [] () { return 0; };", Space);
   verifyFormat("int x = int (y);", Space);
+  verifyFormat("#define F(...) __VA_OPT__ (__VA_ARGS__)", Space);
+  verifyFormat("__builtin_LINE ()", Space);
+  verifyFormat("__builtin_UNKNOWN ()", Space);
 
   FormatStyle SomeSpace = getLLVMStyle();
   SomeSpace.SpaceBeforeParens = FormatStyle::SBPO_NonEmptyParentheses;
 
   verifyFormat("[]() -> float {}", SomeSpace);
   verifyFormat("[] (auto foo) {}", SomeSpace);
   verifyFormat("[foo]() -> int {}", SomeSpace);
   verifyFormat("int f();", SomeSpace);