[clang] 063e3fe - [clang-format] Skip PP directives when determining brace kind (#69473)

[via cfe-commits]

Author: Emilia Kond
Date: 2023-11-03T05:51:20+02:00
New Revision: 063e3fe648533004e6970ab767ece845e3c0afb1

URL: https://github.com/llvm/llvm-project/commit/063e3fe648533004e6970ab767ece845e3c0afb1
DIFF: https://github.com/llvm/llvm-project/commit/063e3fe648533004e6970ab767ece845e3c0afb1.diff

LOG: [clang-format] Skip PP directives when determining brace kind (#69473)

Pull request #65409 changed the brace kind heuristic to not treat a
preprocessor if directive as a in statement, however, this caused some
regressions.

If the contents of a brace don't immediately determine the brace kind,
the heuristic will look at the characters immediately before and after
the closing brace to determine the brace type.

Unfortunately, if the closing brace was preceded by a preprocessor
directive, for example `#endif`, the preceding token was `endif`, seen
as just an identifier, so the braces were understood as a braced list.

This patch fixes this behaviour by skipping all preprocessor directives
when calculating brace types. Comments were already being skipped, so
now preprocessor lines are skipped alongside comments.

Fixes https://github.com/llvm/llvm-project/issues/68404

Added: 
    

Modified: 
    clang/lib/Format/UnwrappedLineParser.cpp
    clang/unittests/Format/TokenAnnotatorTest.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/Format/UnwrappedLineParser.cpp b/clang/lib/Format/UnwrappedLineParser.cpp
index 94e238039c2a707..018bc6c165485e2 100644
--- a/clang/lib/Format/UnwrappedLineParser.cpp
+++ b/clang/lib/Format/UnwrappedLineParser.cpp
@@ -491,11 +491,18 @@ void UnwrappedLineParser::calculateBraceTypes(bool ExpectClassBody) {
   SmallVector<StackEntry, 8> LBraceStack;
   assert(Tok->is(tok::l_brace));
   do {
-    // Get next non-comment token.
+    // Get next non-comment, non-preprocessor token.
     FormatToken *NextTok;
     do {
       NextTok = Tokens->getNextToken();
     } while (NextTok->is(tok::comment));
+    while (NextTok->is(tok::hash)) {
+      NextTok = Tokens->getNextToken();
+      do {
+        NextTok = Tokens->getNextToken();
+      } while (NextTok->is(tok::comment) ||
+               (NextTok->NewlinesBefore == 0 && NextTok->isNot(tok::eof)));
+    }
 
     switch (Tok->Tok.getKind()) {
     case tok::l_brace:
@@ -611,12 +618,9 @@ void UnwrappedLineParser::calculateBraceTypes(bool ExpectClassBody) {
       if (Tok->isNot(TT_StatementMacro))
         break;
       [[fallthrough]];
-    case tok::kw_if:
-      if (PrevTok->is(tok::hash))
-        break;
-      [[fallthrough]];
     case tok::at:
     case tok::semi:
+    case tok::kw_if:
     case tok::kw_while:
     case tok::kw_for:
     case tok::kw_switch:

diff  --git a/clang/unittests/Format/TokenAnnotatorTest.cpp b/clang/unittests/Format/TokenAnnotatorTest.cpp
index c9f1439e212b0ff..ed730307074963f 100644
--- a/clang/unittests/Format/TokenAnnotatorTest.cpp
+++ b/clang/unittests/Format/TokenAnnotatorTest.cpp
@@ -2152,6 +2152,7 @@ TEST_F(TokenAnnotatorTest, UnderstandConstructors) {
   EXPECT_TOKEN(Tokens[11], tok::l_paren, TT_Unknown);
   EXPECT_TOKEN(Tokens[12], tok::r_paren, TT_Unknown);
   EXPECT_TOKEN(Tokens[13], tok::l_brace, TT_FunctionLBrace);
+  EXPECT_BRACE_KIND(Tokens[13], BK_Block);
 
   Tokens = annotate("Class::Class() : BaseClass{}, Member{} {}");
   ASSERT_EQ(Tokens.size(), 16u) << Tokens;
@@ -2164,6 +2165,20 @@ TEST_F(TokenAnnotatorTest, UnderstandConstructors) {
   EXPECT_TOKEN(Tokens[11], tok::l_brace, TT_Unknown);
   EXPECT_TOKEN(Tokens[12], tok::r_brace, TT_Unknown);
   EXPECT_TOKEN(Tokens[13], tok::l_brace, TT_FunctionLBrace);
+  EXPECT_BRACE_KIND(Tokens[13], BK_Block);
+
+  Tokens = annotate("class Class {\n"
+                    "  Class() : BaseClass() {\n"
+                    "#if 0\n"
+                    "    // comment\n"
+                    "#endif\n"
+                    "  }\n"
+                    "  Class f();\n"
+                    "}");
+  ASSERT_EQ(Tokens.size(), 25u) << Tokens;
+  EXPECT_TOKEN(Tokens[6], tok::colon, TT_CtorInitializerColon);
+  EXPECT_TOKEN(Tokens[10], tok::l_brace, TT_FunctionLBrace);
+  EXPECT_BRACE_KIND(Tokens[10], BK_Block);
 }
 
 TEST_F(TokenAnnotatorTest, UnderstandsConditionParens) {