[clang] [clang-format] Add support for absl nullability macros (PR #130346)

[Jan Voung via cfe-commits]

https://github.com/jvoung created https://github.com/llvm/llvm-project/pull/130346

None

>From 10df1857532a6a27b0e5286e10c9f0724d6d7e1d Mon Sep 17 00:00:00 2001
From: Jan Voung <jvoung at gmail.com>
Date: Fri, 7 Mar 2025 21:02:16 +0000
Subject: [PATCH] [clang-format] Add support for absl nullability macros

---
 clang/lib/Format/Format.cpp                |  4 ++++
 clang/unittests/Format/ConfigParseTest.cpp |  4 +++-
 clang/unittests/Format/FormatTest.cpp      | 19 +++++++++++++++++--
 3 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/clang/lib/Format/Format.cpp b/clang/lib/Format/Format.cpp
index b5f1241321891..1401b51586d03 100644
--- a/clang/lib/Format/Format.cpp
+++ b/clang/lib/Format/Format.cpp
@@ -1508,6 +1508,10 @@ FormatStyle getLLVMStyle(FormatStyle::LanguageKind Language) {
   LLVMStyle.AlwaysBreakAfterDefinitionReturnType = FormatStyle::DRTBS_None;
   LLVMStyle.AlwaysBreakBeforeMultilineStrings = false;
   LLVMStyle.AttributeMacros.push_back("__capability");
+  // Abseil aliases to clang's `_Nonnull`, `_Nullable` and `_Null_unspecified`.
+  LLVMStyle.AttributeMacros.push_back("absl_nonnull");
+  LLVMStyle.AttributeMacros.push_back("absl_nullable");
+  LLVMStyle.AttributeMacros.push_back("absl_nullability_unknown");
   LLVMStyle.BinPackArguments = true;
   LLVMStyle.BinPackLongBracedList = true;
   LLVMStyle.BinPackParameters = FormatStyle::BPPS_BinPack;
diff --git a/clang/unittests/Format/ConfigParseTest.cpp b/clang/unittests/Format/ConfigParseTest.cpp
index 273bab87b1ee1..2cc2a45a7a590 100644
--- a/clang/unittests/Format/ConfigParseTest.cpp
+++ b/clang/unittests/Format/ConfigParseTest.cpp
@@ -908,7 +908,9 @@ TEST(ConfigParseTest, ParsesConfiguration) {
 
   Style.AttributeMacros.clear();
   CHECK_PARSE("BasedOnStyle: LLVM", AttributeMacros,
-              std::vector<std::string>{"__capability"});
+      std::vector<std::string>({"__capability", "absl_nonnull", "absl_nullable",
+                                "absl_nullability_unknown"}));
+  Style.AttributeMacros.clear();
   CHECK_PARSE("AttributeMacros: [attr1, attr2]", AttributeMacros,
               std::vector<std::string>({"attr1", "attr2"}));
 
diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
index bd335f4b6a21b..a17cad0b67b08 100644
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -12375,6 +12375,9 @@ TEST_F(FormatTest, UnderstandsUsesOfStarAndAmp) {
   verifyFormat("vector<a *_Nonnull> v;");
   verifyFormat("vector<a *_Nullable> v;");
   verifyFormat("vector<a *_Null_unspecified> v;");
+  verifyFormat("vector<a *absl_nonnull> v;");
+  verifyFormat("vector<a *absl_nullable> v;");
+  verifyFormat("vector<a *absl_nullability_unknown> v;");
   verifyFormat("vector<a *__ptr32> v;");
   verifyFormat("vector<a *__ptr64> v;");
   verifyFormat("vector<a *__capability> v;");
@@ -12518,6 +12521,9 @@ TEST_F(FormatTest, UnderstandsUsesOfStarAndAmp) {
   verifyIndependentOfContext("MACRO(A *_Nonnull a);");
   verifyIndependentOfContext("MACRO(A *_Nullable a);");
   verifyIndependentOfContext("MACRO(A *_Null_unspecified a);");
+  verifyIndependentOfContext("MACRO(A *absl_nonnull a);");
+  verifyIndependentOfContext("MACRO(A *absl_nullable a);");
+  verifyIndependentOfContext("MACRO(A *absl_nullability_unknown a);");
   verifyIndependentOfContext("MACRO(A *__attribute__((foo)) a);");
   verifyIndependentOfContext("MACRO(A *__attribute((foo)) a);");
   verifyIndependentOfContext("MACRO(A *[[clang::attr]] a);");
@@ -12674,6 +12680,12 @@ TEST_F(FormatTest, UnderstandsAttributes) {
   verifyFormat("SomeType *__unused s{InitValue};", CustomAttrs);
   verifyFormat("SomeType s __unused(InitValue);", CustomAttrs);
   verifyFormat("SomeType s __unused{InitValue};", CustomAttrs);
+  verifyFormat("SomeType *absl_nonnull s(InitValue);", CustomAttrs);
+  verifyFormat("SomeType *absl_nonnull s{InitValue};", CustomAttrs);
+  verifyFormat("SomeType *absl_nullable s(InitValue);", CustomAttrs);
+  verifyFormat("SomeType *absl_nullable s{InitValue};", CustomAttrs);
+  verifyFormat("SomeType *absl_nullability_unknown s(InitValue);", CustomAttrs);
+  verifyFormat("SomeType *absl_nullability_unknown s{InitValue};", CustomAttrs);
   verifyFormat("SomeType *__capability s(InitValue);", CustomAttrs);
   verifyFormat("SomeType *__capability s{InitValue};", CustomAttrs);
 }
@@ -12687,7 +12699,9 @@ TEST_F(FormatTest, UnderstandsPointerQualifiersInCast) {
   verifyFormat("x = (foo *_Nonnull)*v;");
   verifyFormat("x = (foo *_Nullable)*v;");
   verifyFormat("x = (foo *_Null_unspecified)*v;");
-  verifyFormat("x = (foo *_Nonnull)*v;");
+  verifyFormat("x = (foo *absl_nonnull)*v;");
+  verifyFormat("x = (foo *absl_nullable)*v;");
+  verifyFormat("x = (foo *absl_nullability_unknown)*v;");
   verifyFormat("x = (foo *[[clang::attr]])*v;");
   verifyFormat("x = (foo *[[clang::attr(\"foo\")]])*v;");
   verifyFormat("x = (foo *__ptr32)*v;");
@@ -12701,7 +12715,8 @@ TEST_F(FormatTest, UnderstandsPointerQualifiersInCast) {
   LongPointerLeft.PointerAlignment = FormatStyle::PAS_Left;
   StringRef AllQualifiers =
       "const volatile restrict __attribute__((foo)) _Nonnull _Null_unspecified "
-      "_Nonnull [[clang::attr]] __ptr32 __ptr64 __capability";
+      "_Nullable absl_nonnull absl_nullable absl_nullability_unknown "
+      "[[clang::attr]] __ptr32 __ptr64 __capability";
   verifyFormat(("x = (foo *" + AllQualifiers + ")*v;").str(), LongPointerRight);
   verifyFormat(("x = (foo* " + AllQualifiers + ")*v;").str(), LongPointerLeft);