[clang] e7b4fee - [Format/ObjC] Add NS_SWIFT_NAME() and CF_SWIFT_NAME() to WhitespaceSensitiveMacros

[Ben Hamilton via cfe-commits]

Author: Ben Hamilton
Date: 2020-10-14T15:42:51-06:00
New Revision: e7b4feea8e1bf520b34ad8c116abab6677344b74

URL: https://github.com/llvm/llvm-project/commit/e7b4feea8e1bf520b34ad8c116abab6677344b74
DIFF: https://github.com/llvm/llvm-project/commit/e7b4feea8e1bf520b34ad8c116abab6677344b74.diff

LOG: [Format/ObjC] Add NS_SWIFT_NAME() and CF_SWIFT_NAME() to WhitespaceSensitiveMacros

The argument passed to the preprocessor macros `NS_SWIFT_NAME(x)` and
`CF_SWIFT_NAME(x)` is stringified before passing to
`__attribute__((swift_name("x")))`.

ClangFormat didn't know about this stringification, so its custom parser
tried to parse the argument(s) passed to the macro as if they were
normal function arguments.

That means ClangFormat currently incorrectly inserts whitespace
between `NS_SWIFT_NAME` arguments with colons and dots, so:

```
extern UIWindow *MainWindow(void) NS_SWIFT_NAME(getter:MyHelper.mainWindow());
```

becomes:

```
extern UIWindow *MainWindow(void) NS_SWIFT_NAME(getter : MyHelper.mainWindow());
```

which clang treats as a parser error:

```
error: 'swift_name' attribute has invalid identifier for context name [-Werror,-Wswift-name-attribute]
```

Thankfully, D82620 recently added the ability to treat specific macros
as "whitespace sensitive", meaning their arguments are implicitly
treated as strings (so whitespace is not added anywhere inside).

This diff adds `NS_SWIFT_NAME` and `CF_SWIFT_NAME` to
`WhitespaceSensitiveMacros` so their arguments are implicitly treated
as whitespace-sensitive.

Test Plan:
  New tests added. Ran tests with:
  % ninja FormatTests && ./tools/clang/unittests/Format/FormatTests

Reviewed By: sammccall

Differential Revision: https://reviews.llvm.org/D89425

Added: 
    

Modified: 
    clang/lib/Format/Format.cpp
    clang/unittests/Format/FormatTestObjC.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/Format/Format.cpp b/clang/lib/Format/Format.cpp
index 8e4f65ace3f0..f2215e255c2b 100644
--- a/clang/lib/Format/Format.cpp
+++ b/clang/lib/Format/Format.cpp
@@ -964,6 +964,8 @@ FormatStyle getLLVMStyle(FormatStyle::LanguageKind Language) {
   LLVMStyle.WhitespaceSensitiveMacros.push_back("STRINGIZE");
   LLVMStyle.WhitespaceSensitiveMacros.push_back("PP_STRINGIZE");
   LLVMStyle.WhitespaceSensitiveMacros.push_back("BOOST_PP_STRINGIZE");
+  LLVMStyle.WhitespaceSensitiveMacros.push_back("NS_SWIFT_NAME");
+  LLVMStyle.WhitespaceSensitiveMacros.push_back("CF_SWIFT_NAME");
 
   // Defaults that 
diff er when not C++.
   if (Language == FormatStyle::LK_TableGen) {

diff  --git a/clang/unittests/Format/FormatTestObjC.cpp b/clang/unittests/Format/FormatTestObjC.cpp
index 28d33dcdaa54..f3be942ab913 100644
--- a/clang/unittests/Format/FormatTestObjC.cpp
+++ b/clang/unittests/Format/FormatTestObjC.cpp
@@ -1024,6 +1024,12 @@ TEST_F(FormatTestObjC, ObjCSnippets) {
   verifyFormat("@property(assign, nonatomic) CGFloat hoverAlpha;");
   verifyFormat("@property(assign, getter=isEditable) BOOL editable;");
 
+  verifyFormat("extern UIWindow *MainWindow(void) "
+               "NS_SWIFT_NAME(getter:MyHelper.mainWindow());");
+
+  verifyFormat("extern UIWindow *MainWindow(void) "
+               "CF_SWIFT_NAME(getter:MyHelper.mainWindow());");
+
   Style.ColumnLimit = 50;
   verifyFormat("@interface Foo\n"
                "- (void)doStuffWithFoo:(id)name\n"