Author: Ilya Biryukov Date: 2025-08-01T14:26:17+02:00 New Revision: 803a50aa0547fdbcd661c54f19de0c155a23d50d
URL: https://github.com/llvm/llvm-project/commit/803a50aa0547fdbcd661c54f19de0c155a23d50d DIFF: https://github.com/llvm/llvm-project/commit/803a50aa0547fdbcd661c54f19de0c155a23d50d.diff LOG: [Clang] Dump minimization hints for namespaces (#151534) Unlike other declarations, these cover two ranges: - from `namespace/inline namespace` to the opening `{`, - the closing `}`. This allows to mark the declarations inside the namespace itself independently. Added: Modified: clang/lib/Frontend/FrontendAction.cpp clang/test/Frontend/dump-minimization-hints.cpp Removed: ################################################################################ diff --git a/clang/lib/Frontend/FrontendAction.cpp b/clang/lib/Frontend/FrontendAction.cpp index 12b5c1837ded6..87cc2fc0cdd17 100644 --- a/clang/lib/Frontend/FrontendAction.cpp +++ b/clang/lib/Frontend/FrontendAction.cpp @@ -9,6 +9,7 @@ #include "clang/Frontend/FrontendAction.h" #include "clang/AST/ASTConsumer.h" #include "clang/AST/ASTContext.h" +#include "clang/AST/Decl.h" #include "clang/AST/DeclGroup.h" #include "clang/Basic/Builtins.h" #include "clang/Basic/DiagnosticOptions.h" @@ -39,6 +40,7 @@ #include "clang/Serialization/ASTReader.h" #include "clang/Serialization/GlobalModuleIndex.h" #include "llvm/ADT/ScopeExit.h" +#include "llvm/ADT/SmallPtrSet.h" #include "llvm/ADT/StringRef.h" #include "llvm/Support/BuryPointer.h" #include "llvm/Support/ErrorHandling.h" @@ -87,12 +89,25 @@ class DeserializedDeclsSourceRangePrinter : public ASTConsumer, // reducing the granularity and making the output less useful. return; } - if (auto *DC = D->getDeclContext(); !DC || !DC->isFileContext()) { + auto *DC = D->getLexicalDeclContext(); + if (!DC || !DC->isFileContext()) { // We choose to work at namespace level to reduce complexity and the // number of cases we care about. return; } + PendingDecls.push_back(D); + if (auto *NS = dyn_cast<NamespaceDecl>(DC)) { + // Add any namespaces we have not seen before. + // Note that we filter out namespaces from DeclRead as it includes too + // all redeclarations and we only want the ones that had other used + // declarations. + while (NS && ProcessedNamespaces.insert(NS).second) { + PendingDecls.push_back(NS); + + NS = dyn_cast<NamespaceDecl>(NS->getLexicalParent()); + } + } } struct Position { @@ -141,23 +156,25 @@ class DeserializedDeclsSourceRangePrinter : public ASTConsumer, OptionalFileEntryRef Ref; }; llvm::DenseMap<const FileEntry *, FileData> FileToRanges; + for (const Decl *D : PendingDecls) { - CharSourceRange R = SM.getExpansionRange(D->getSourceRange()); - if (!R.isValid()) - continue; + for (CharSourceRange R : getRangesToMark(D)) { + if (!R.isValid()) + continue; - auto *F = SM.getFileEntryForID(SM.getFileID(R.getBegin())); - if (F != SM.getFileEntryForID(SM.getFileID(R.getEnd()))) { - // Such cases are rare and diff icult to handle. - continue; - } + auto *F = SM.getFileEntryForID(SM.getFileID(R.getBegin())); + if (F != SM.getFileEntryForID(SM.getFileID(R.getEnd()))) { + // Such cases are rare and diff icult to handle. + continue; + } - auto &Data = FileToRanges[F]; - if (!Data.Ref) - Data.Ref = SM.getFileEntryRefForID(SM.getFileID(R.getBegin())); - Data.FromTo.push_back( - {Position::GetBeginSpelling(SM, R), - Position::GetEndSpelling(SM, R, D->getLangOpts())}); + auto &Data = FileToRanges[F]; + if (!Data.Ref) + Data.Ref = SM.getFileEntryRefForID(SM.getFileID(R.getBegin())); + Data.FromTo.push_back( + {Position::GetBeginSpelling(SM, R), + Position::GetEndSpelling(SM, R, D->getLangOpts())}); + } } // To simplify output, merge consecutive and intersecting ranges. @@ -188,10 +205,49 @@ class DeserializedDeclsSourceRangePrinter : public ASTConsumer, private: std::vector<const Decl *> PendingDecls; + llvm::SmallPtrSet<const NamespaceDecl *, 0> ProcessedNamespaces; bool IsCollectingDecls = true; const SourceManager &SM; std::unique_ptr<llvm::raw_ostream> OS; + llvm::SmallVector<CharSourceRange, 2> getRangesToMark(const Decl *D) { + auto *NS = dyn_cast<NamespaceDecl>(D); + if (!NS) + return {SM.getExpansionRange(D->getSourceRange())}; + + SourceLocation LBraceLoc; + if (NS->isAnonymousNamespace()) { + LBraceLoc = NS->getLocation(); + } else { + // Start with the location of the identifier. + SourceLocation TokenBeforeLBrace = NS->getLocation(); + if (NS->hasAttrs()) { + for (auto *A : NS->getAttrs()) { + // But attributes may go after it. + if (SM.isBeforeInTranslationUnit(TokenBeforeLBrace, + A->getRange().getEnd())) { + // Give up, the attributes are often coming from macros and we + // cannot skip them reliably. + return {}; + } + } + } + auto &LangOpts = D->getLangOpts(); + // Now skip one token, the next should be the lbrace. + Token Tok; + if (Lexer::getRawToken(TokenBeforeLBrace, Tok, SM, LangOpts, true) || + Lexer::getRawToken(Tok.getEndLoc(), Tok, SM, LangOpts, true) || + Tok.getKind() != tok::l_brace) { + // On error or if we did not find the token we expected, avoid marking + // everything inside the namespace as used. + return {}; + } + LBraceLoc = Tok.getLocation(); + } + return {SM.getExpansionRange(SourceRange(NS->getBeginLoc(), LBraceLoc)), + SM.getExpansionRange(NS->getRBraceLoc())}; + } + void printJson(llvm::ArrayRef<RequiredRanges> Result) { *OS << "{\n"; *OS << R"( "required_ranges": [)" << "\n"; diff --git a/clang/test/Frontend/dump-minimization-hints.cpp b/clang/test/Frontend/dump-minimization-hints.cpp index 273fd7f4ecd63..4c5dfbc343cd4 100644 --- a/clang/test/Frontend/dump-minimization-hints.cpp +++ b/clang/test/Frontend/dump-minimization-hints.cpp @@ -59,6 +59,36 @@ // RANGE-NEXT: "line": 23, // RANGE-NEXT: "column": 2 // RANGE-NEXT: } +// RANGE-NEXT: }, +// RANGE-NEXT: { +// RANGE-NEXT: "from": { +// RANGE-NEXT: "line": 31, +// RANGE-NEXT: "column": 1 +// RANGE-NEXT: }, +// RANGE-NEXT: "to": { +// RANGE-NEXT: "line": 31, +// RANGE-NEXT: "column": 27 +// RANGE-NEXT: } +// RANGE-NEXT: }, +// RANGE-NEXT: { +// RANGE-NEXT: "from": { +// RANGE-NEXT: "line": 32, +// RANGE-NEXT: "column": 3 +// RANGE-NEXT: }, +// RANGE-NEXT: "to": { +// RANGE-NEXT: "line": 32, +// RANGE-NEXT: "column": 12 +// RANGE-NEXT: } +// RANGE-NEXT: }, +// RANGE-NEXT: { +// RANGE-NEXT: "from": { +// RANGE-NEXT: "line": 34, +// RANGE-NEXT: "column": 1 +// RANGE-NEXT: }, +// RANGE-NEXT: "to": { +// RANGE-NEXT: "line": 34, +// RANGE-NEXT: "column": 2 +// RANGE-NEXT: } // RANGE-NEXT: } // RANGE-NEXT: ] // RANGE-NEXT: } @@ -88,7 +118,7 @@ int multiply(int a, int b) { return a * b; } -inline int unused_by_foo() {} // line 17 +inline void unused_by_foo() {} // line 17 inline void recursively_used_by_foo() {} // line 19 inline int used_by_foo() { // line 20 @@ -98,6 +128,20 @@ inline int used_by_foo() { // line 20 struct UnusedByFoo {}; +namespace ns_unused_by_foo { + void x(); +} + +namespace ns_used_by_foo { // line 31 + void x(); // line 32 + void unused_y(); +} // line 34 + +// Does not have any declarations that are used, so +// will not be marked as used. +namespace ns_used_by_foo { + void unused_z(); +} //--- foo.cpp #include "foo.h" int global_value = 5; @@ -107,5 +151,6 @@ int main() { int doubled_value = multiply(current_value, 2); int final_result = doubled_value + global_value; - return used_by_foo(); + used_by_foo(); + ns_used_by_foo::x(); } _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
