[clang-format] Fix a bug in annotating function declaration names

[owenca]

Annotates function declaration names having unnamed parameters.

[llvmbot]

@llvm/pr-subscribers-clang-format

Author: Owen Pan (owenca)

Changes

Annotates function declaration names having unnamed parameters.

---

Full diff: https://github.com/llvm/llvm-project/pull/76206.diff

2 Files Affected:

• (modified) clang/lib/Format/TokenAnnotator.cpp (+2-1)
• (modified) clang/unittests/Format/TokenAnnotatorTest.cpp (+7)

diff --git a/clang/lib/Format/TokenAnnotator.cpp b/clang/lib/Format/TokenAnnotator.cpp
index f3551af3424396..3ac3aa3c5e3a22 100644
--- a/clang/lib/Format/TokenAnnotator.cpp
+++ b/clang/lib/Format/TokenAnnotator.cpp
@@ -3403,7 +3403,8 @@ static bool isFunctionDeclarationName(bool IsCpp, const FormatToken &Current,
       continue;
     }
     if (Tok->is(tok::kw_const) || Tok->isSimpleTypeSpecifier() ||
-        Tok->isOneOf(TT_PointerOrReference, TT_StartOfName, tok::ellipsis)) {
+        Tok->isOneOf(TT_PointerOrReference, TT_StartOfName, tok::ellipsis,
+                     TT_TypeName)) {
       return true;
     }
     if (Tok->isOneOf(tok::l_brace, TT_ObjCMethodExpr) || Tok->Tok.isLiteral())
diff --git a/clang/unittests/Format/TokenAnnotatorTest.cpp b/clang/unittests/Format/TokenAnnotatorTest.cpp
index 8e6935319b2f3d..2cafc0438ffb46 100644
--- a/clang/unittests/Format/TokenAnnotatorTest.cpp
+++ b/clang/unittests/Format/TokenAnnotatorTest.cpp
@@ -1718,6 +1718,13 @@ TEST_F(TokenAnnotatorTest, UnderstandsFunctionDeclarationNames) {
   ASSERT_EQ(Tokens.size(), 14u) << Tokens;
   EXPECT_TOKEN(Tokens[3], tok::identifier, TT_Unknown);
   EXPECT_TOKEN(Tokens[4], tok::l_paren, TT_FunctionTypeLParen);
+
+  auto Style = getLLVMStyle();
+  Style.TypeNames.push_back("time_t");
+  Tokens = annotate("int iso_time(time_t);", Style);
+  ASSERT_EQ(Tokens.size(), 7u) << Tokens;
+  EXPECT_TOKEN(Tokens[1], tok::identifier, TT_FunctionDeclarationName);
+  EXPECT_TOKEN(Tokens[3], tok::identifier, TT_TypeName);
 }
 
 TEST_F(TokenAnnotatorTest, UnderstandsCtorAndDtorDeclNames) {

[owenca]

See here for background info.

[mattmundell]

Thanks for doing this. Does it mean we would have to add every type we use to our config? It would be much more convenient if clang-format treated the argument list the same way that it treats in definitions. For example

printf "int\niso_time(time_t) { return 1; }\n" | clang-format -style='{ AlwaysBreakAfterReturnType: All }'

gives

int
iso_time(time_t) {
  return 1;
}

whereas

printf "int\niso_time(time_t);\n" | clang-format -style='{ AlwaysBreakAfterReturnType: All }'

will need a config edit to work.

Other examples that are currently failing to line break:

printf "int\niso_time(struct example);\n" | clang-format -style='{ AlwaysBreakAfterReturnType: All }'
printf "typedef long long int rowid_t;\nint\niso_time(rowid_t);\n" | clang-format -style='{ AlwaysBreakAfterReturnType: All }'

[HazardyKnusperkeks]

Thanks for doing this. Does it mean we would have to add every type we use to our config? It would be much more convenient if clang-format treated the argument list the same way that it treats in definitions. For example

printf "int\niso_time(time_t) { return 1; }\n" | clang-format -style='{ AlwaysBreakAfterReturnType: All }'

gives

int
iso_time(time_t) {
  return 1;
}

whereas

printf "int\niso_time(time_t);\n" | clang-format -style='{ AlwaysBreakAfterReturnType: All }'

will need a config edit to work.

clang-format doesn't know what are types, except for the keywords. So there is no way to decide if this is a function declaration without naming the parameters, or a variable declaration with a constructor call.

[mattmundell]

clang-format doesn't know what are types, except for the keywords. So there is no way to decide if this is a function declaration without naming the parameters, or a variable declaration with a constructor call.

This is C so I guess it can only be a function declaration. Anyway, it's minor to work around, thanks again.

[HazardyKnusperkeks]

clang-format doesn't know what are types, except for the keywords. So there is no way to decide if this is a function declaration without naming the parameters, or a variable declaration with a constructor call.

This is C so I guess it can only be a function declaration. Anyway, it's minor to work around, thanks again.

This boils down to, that for clang-format C doesn't exist. It's all parsed as C++.

[owenca]

Thanks for doing this. Does it mean we would have to add every type we use to our config? It would be much more convenient if clang-format treated the argument list the same way that it treats in definitions. For example

printf "int\niso_time(time_t) { return 1; }\n" | clang-format -style='{ AlwaysBreakAfterReturnType: All }'

gives

int
iso_time(time_t) {
  return 1;
}

whereas

printf "int\niso_time(time_t);\n" | clang-format -style='{ AlwaysBreakAfterReturnType: All }'

will need a config edit to work.

@mattmundell you don't need to add time_t and other common C/C++ types to TypeNames after 0baef3b.

[mattmundell]

Thanks @owenca, I added an argument name instead (cb983df).