https://github.com/llvmbot created https://github.com/llvm/llvm-project/pull/163919
Backport d7921de8027eec19a9d272bf445944973e6758b1 059f2df74898ff7f394dc8e60f746323499ae32b Requested by: @owenca >From a30385efc12acbe53a040a327600349d7d6ac04b Mon Sep 17 00:00:00 2001 From: owenca <[email protected]> Date: Thu, 25 Sep 2025 00:44:33 -0700 Subject: [PATCH 1/2] [clang-format] Correctly handle backward compatibility of C headers (#159908) This in effect reverts 05fb8408de23c3ccb6125b6886742177755bd757 and 7e1a88b9d1431e263258e3ff0f729c1fdce342d3, the latter of which erroneously changed the behavior of formatting `ObjC` header files when both the default and `ObjC` styles were absent. Now the previous behavior of treating that as an error is restored. Fixes #158704 (cherry picked from commit d7921de8027eec19a9d272bf445944973e6758b1) --- clang/lib/Format/Format.cpp | 91 +++++++++++++--------- clang/unittests/Format/ConfigParseTest.cpp | 9 ++- 2 files changed, 59 insertions(+), 41 deletions(-) diff --git a/clang/lib/Format/Format.cpp b/clang/lib/Format/Format.cpp index 161a6c4b47e7f..d4e3a1989cd71 100644 --- a/clang/lib/Format/Format.cpp +++ b/clang/lib/Format/Format.cpp @@ -2133,47 +2133,68 @@ std::error_code parseConfiguration(llvm::MemoryBufferRef Config, if (Input.error()) return Input.error(); - for (unsigned i = 0; i < Styles.size(); ++i) { - // Ensures that only the first configuration can skip the Language option. - if (Styles[i].Language == FormatStyle::LK_None && i != 0) + assert(!Styles.empty()); + const auto StyleCount = Styles.size(); + + // Start from the second style as (only) the first one may be the default. + for (unsigned I = 1; I < StyleCount; ++I) { + const auto Lang = Styles[I].Language; + if (Lang == FormatStyle::LK_None) return make_error_code(ParseError::Error); // Ensure that each language is configured at most once. - for (unsigned j = 0; j < i; ++j) { - if (Styles[i].Language == Styles[j].Language) { + for (unsigned J = 0; J < I; ++J) { + if (Lang == Styles[J].Language) { LLVM_DEBUG(llvm::dbgs() << "Duplicate languages in the config file on positions " - << j << " and " << i << "\n"); + << J << " and " << I << '\n'); return make_error_code(ParseError::Error); } } } - // Look for a suitable configuration starting from the end, so we can - // find the configuration for the specific language first, and the default - // configuration (which can only be at slot 0) after it. - FormatStyle::FormatStyleSet StyleSet; - bool LanguageFound = false; - for (const FormatStyle &Style : llvm::reverse(Styles)) { - const auto Lang = Style.Language; - if (Lang != FormatStyle::LK_None) - StyleSet.Add(Style); - if (Lang == Language || - // For backward compatibility. - (Lang == FormatStyle::LK_Cpp && Language == FormatStyle::LK_C)) { - LanguageFound = true; - } else if (IsDotHFile && Language == FormatStyle::LK_Cpp && - (Lang == FormatStyle::LK_C || Lang == FormatStyle::LK_ObjC)) { - Language = Lang; - LanguageFound = true; + + int LanguagePos = -1; // Position of the style for Language. + int CppPos = -1; // Position of the style for C++. + int CPos = -1; // Position of the style for C. + + // Search Styles for Language and store the positions of C++ and C styles in + // case Language is not found. + for (unsigned I = 0; I < StyleCount; ++I) { + const auto Lang = Styles[I].Language; + if (Lang == Language) { + LanguagePos = I; + break; } - } - if (!LanguageFound) { - if (Styles.empty() || Styles[0].Language != FormatStyle::LK_None) + if (Lang == FormatStyle::LK_Cpp) + CppPos = I; + else if (Lang == FormatStyle::LK_C) + CPos = I; + } + + // If Language is not found, use the default style if there is one. Otherwise, + // use the C style for C++ .h files and for backward compatibility, the C++ + // style for .c files. + if (LanguagePos < 0) { + if (Styles[0].Language == FormatStyle::LK_None) // Default style. + LanguagePos = 0; + else if (IsDotHFile && Language == FormatStyle::LK_Cpp) + LanguagePos = CPos; + else if (!IsDotHFile && Language == FormatStyle::LK_C) + LanguagePos = CppPos; + if (LanguagePos < 0) return make_error_code(ParseError::Unsuitable); - FormatStyle DefaultStyle = Styles[0]; - DefaultStyle.Language = Language; - StyleSet.Add(std::move(DefaultStyle)); } - *Style = *StyleSet.Get(Language); + + for (const auto &S : llvm::reverse(llvm::drop_begin(Styles))) + Style->StyleSet.Add(S); + + *Style = Styles[LanguagePos]; + + if (LanguagePos == 0) { + if (Style->Language == FormatStyle::LK_None) // Default style. + Style->Language = Language; + Style->StyleSet.Add(*Style); + } + if (Style->InsertTrailingCommas != FormatStyle::TCS_None && Style->BinPackArguments) { // See comment on FormatStyle::TSC_Wrapped. @@ -2204,14 +2225,8 @@ FormatStyle::FormatStyleSet::Get(FormatStyle::LanguageKind Language) const { if (!Styles) return std::nullopt; auto It = Styles->find(Language); - if (It == Styles->end()) { - if (Language != FormatStyle::LK_C) - return std::nullopt; - // For backward compatibility. - It = Styles->find(FormatStyle::LK_Cpp); - if (It == Styles->end()) - return std::nullopt; - } + if (It == Styles->end()) + return std::nullopt; FormatStyle Style = It->second; Style.StyleSet = *this; return Style; diff --git a/clang/unittests/Format/ConfigParseTest.cpp b/clang/unittests/Format/ConfigParseTest.cpp index 2b17c36f6aa84..bbe1923e19ee1 100644 --- a/clang/unittests/Format/ConfigParseTest.cpp +++ b/clang/unittests/Format/ConfigParseTest.cpp @@ -1269,7 +1269,7 @@ TEST(ConfigParseTest, AllowCppForC) { ParseError::Success); } -TEST(ConfigParseTest, HandleNonCppDotHFile) { +TEST(ConfigParseTest, HandleDotHFile) { FormatStyle Style = {}; Style.Language = FormatStyle::LK_Cpp; EXPECT_EQ(parseConfiguration("Language: C", &Style, @@ -1280,11 +1280,14 @@ TEST(ConfigParseTest, HandleNonCppDotHFile) { Style = {}; Style.Language = FormatStyle::LK_Cpp; - EXPECT_EQ(parseConfiguration("Language: ObjC", &Style, + EXPECT_EQ(parseConfiguration("Language: Cpp\n" + "...\n" + "Language: C", + &Style, /*AllowUnknownOptions=*/false, /*IsDotHFile=*/true), ParseError::Success); - EXPECT_EQ(Style.Language, FormatStyle::LK_ObjC); + EXPECT_EQ(Style.Language, FormatStyle::LK_Cpp); } TEST(ConfigParseTest, UsesLanguageForBasedOnStyle) { >From 61cd0a0125d08e3352833250c23706d68f06582d Mon Sep 17 00:00:00 2001 From: owenca <[email protected]> Date: Thu, 16 Oct 2025 21:40:59 -0700 Subject: [PATCH 2/2] [clang-format] Fix an assertion failure on comment-only config files (#163111) (cherry picked from commit 059f2df74898ff7f394dc8e60f746323499ae32b) --- clang/lib/Format/Format.cpp | 3 ++- clang/unittests/Format/ConfigParseTest.cpp | 7 +++++++ 2 files changed, 9 insertions(+), 1 deletion(-) diff --git a/clang/lib/Format/Format.cpp b/clang/lib/Format/Format.cpp index d4e3a1989cd71..5bdb810a3925b 100644 --- a/clang/lib/Format/Format.cpp +++ b/clang/lib/Format/Format.cpp @@ -2132,8 +2132,9 @@ std::error_code parseConfiguration(llvm::MemoryBufferRef Config, Input >> Styles; if (Input.error()) return Input.error(); + if (Styles.empty()) + return make_error_code(ParseError::Success); - assert(!Styles.empty()); const auto StyleCount = Styles.size(); // Start from the second style as (only) the first one may be the default. diff --git a/clang/unittests/Format/ConfigParseTest.cpp b/clang/unittests/Format/ConfigParseTest.cpp index bbe1923e19ee1..ff42f09b90cf3 100644 --- a/clang/unittests/Format/ConfigParseTest.cpp +++ b/clang/unittests/Format/ConfigParseTest.cpp @@ -1249,6 +1249,13 @@ TEST(ConfigParseTest, ParsesConfigurationWithLanguages) { IndentWidth, 56u); } +TEST(ConfigParseTest, AllowCommentOnlyConfigFile) { + FormatStyle Style = {}; + Style.Language = FormatStyle::LK_Cpp; + EXPECT_EQ(parseConfiguration("#Language: C", &Style), ParseError::Success); + EXPECT_EQ(Style.Language, FormatStyle::LK_Cpp); +} + TEST(ConfigParseTest, AllowCppForC) { FormatStyle Style = {}; Style.Language = FormatStyle::LK_C; _______________________________________________ llvm-branch-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
