Author: Qiongsi Wu Date: 2025-08-22T09:18:01-07:00 New Revision: 538e9e8ebd09233b3900ed2dfd23e4e1ca5c9fc0
URL: https://github.com/llvm/llvm-project/commit/538e9e8ebd09233b3900ed2dfd23e4e1ca5c9fc0 DIFF: https://github.com/llvm/llvm-project/commit/538e9e8ebd09233b3900ed2dfd23e4e1ca5c9fc0.diff LOG: [clang][Modules] Reporting Errors for Duplicating Link Declarations in `modulemap`s (#148959) This PR teaches the modulemap parsing logic to report warnings that default to errors if the parsing logic sees duplicating link declarations in the same module. Specifically, duplicating link declarations means multiple link declarations with the same string-literal in the same module. No errors are reported if a same link declaration exist in a submodule and its enclosing module. The warning can be disabled with `-Wno-module-link-redeclaration`. rdar://155880064 Added: clang/test/ClangScanDeps/link-libraries-diag-dup.c Modified: clang/include/clang/Basic/DiagnosticLexKinds.td clang/lib/Lex/ModuleMapFile.cpp Removed: ################################################################################ diff --git a/clang/include/clang/Basic/DiagnosticLexKinds.td b/clang/include/clang/Basic/DiagnosticLexKinds.td index c7fe6e1db6d1f..c03c4033cd3a6 100644 --- a/clang/include/clang/Basic/DiagnosticLexKinds.td +++ b/clang/include/clang/Basic/DiagnosticLexKinds.td @@ -912,6 +912,11 @@ def err_mmap_nested_submodule_id : Error< "qualified module name can only be used to define modules at the top level">; def err_mmap_expected_feature : Error<"expected a feature name">; def err_mmap_expected_attribute : Error<"expected an attribute name">; +def warn_mmap_link_redeclaration : Warning<"redeclaration of link library '%0'">, + InGroup<DiagGroup<"module-link-redeclaration">>, DefaultError; +def note_mmap_prev_link_declaration : Note<"previously declared here">; +def err_mmap_submodule_link_decl + : Error<"link declaration is not allowed in submodules">; def warn_mmap_unknown_attribute : Warning<"unknown attribute '%0'">, InGroup<IgnoredAttributes>; def warn_mmap_mismatched_private_submodule : Warning< diff --git a/clang/lib/Lex/ModuleMapFile.cpp b/clang/lib/Lex/ModuleMapFile.cpp index 183e919d14c22..f0cd9d2bee82a 100644 --- a/clang/lib/Lex/ModuleMapFile.cpp +++ b/clang/lib/Lex/ModuleMapFile.cpp @@ -118,7 +118,8 @@ struct ModuleMapFileParser { std::optional<ExcludeDecl> parseExcludeDecl(clang::SourceLocation LeadingLoc); std::optional<UmbrellaDirDecl> parseUmbrellaDirDecl(SourceLocation UmbrellaLoc); - std::optional<LinkDecl> parseLinkDecl(); + std::optional<LinkDecl> + parseLinkDecl(llvm::StringMap<SourceLocation> &SeenLinkDecl, bool Allowed); SourceLocation consumeToken(); void skipUntil(MMToken::TokenKind K); @@ -325,6 +326,7 @@ std::optional<ModuleDecl> ModuleMapFileParser::parseModuleDecl(bool TopLevel) { SourceLocation LBraceLoc = consumeToken(); bool Done = false; + llvm::StringMap<SourceLocation> SeenLinkDecl; do { std::optional<Decl> SubDecl; switch (Tok.Kind) { @@ -405,7 +407,9 @@ std::optional<ModuleDecl> ModuleMapFileParser::parseModuleDecl(bool TopLevel) { break; case MMToken::LinkKeyword: - SubDecl = parseLinkDecl(); + // Link decls are only allowed in top level modules or explicit + // submodules. + SubDecl = parseLinkDecl(SeenLinkDecl, TopLevel || MDecl.Explicit); break; default: @@ -822,7 +826,8 @@ ModuleMapFileParser::parseUmbrellaDirDecl(clang::SourceLocation UmbrellaLoc) { /// /// module-declaration: /// 'link' 'framework'[opt] string-literal -std::optional<LinkDecl> ModuleMapFileParser::parseLinkDecl() { +std::optional<LinkDecl> ModuleMapFileParser::parseLinkDecl( + llvm::StringMap<SourceLocation> &SeenLinkDecl, bool Allowed) { assert(Tok.is(MMToken::LinkKeyword)); LinkDecl LD; LD.Location = consumeToken(); @@ -838,12 +843,33 @@ std::optional<LinkDecl> ModuleMapFileParser::parseLinkDecl() { if (!Tok.is(MMToken::StringLiteral)) { Diags.Report(Tok.getLocation(), diag::err_mmap_expected_library_name) << LD.Framework << SourceRange(LD.Location); + consumeToken(); HadError = true; return std::nullopt; } - LD.Library = Tok.getString(); + StringRef Library = Tok.getString(); + + LD.Library = Library; consumeToken(); + + // Make sure we eat all the tokens when we report the errors so parsing + // can continue. + if (!Allowed) { + Diags.Report(LD.Location, diag::err_mmap_submodule_link_decl); + HadError = true; + return std::nullopt; + } + + auto [It, Inserted] = + SeenLinkDecl.insert(std::make_pair(Library, LD.Location)); + if (!Inserted) { + Diags.Report(LD.Location, diag::warn_mmap_link_redeclaration) << Library; + Diags.Report(It->second, diag::note_mmap_prev_link_declaration); + HadError = true; + return std::nullopt; + } + return std::move(LD); } diff --git a/clang/test/ClangScanDeps/link-libraries-diag-dup.c b/clang/test/ClangScanDeps/link-libraries-diag-dup.c new file mode 100644 index 0000000000000..e6612ca7bd216 --- /dev/null +++ b/clang/test/ClangScanDeps/link-libraries-diag-dup.c @@ -0,0 +1,57 @@ +// RUN: rm -rf %t +// RUN: mkdir %t +// RUN: split-file %s %t + +//--- module.modulemap +module A { + umbrella header "A.h" + + module B { + header "B.h" + link "libraryB" + } + + explicit module D { + header "D.h" + link "libraryD" + } + + link "libraryA" + link "libraryA" +} + +module C { + header "C.h" + link "libraryA" +} + +//--- A.h +#include "B.h" +//--- B.h +// empty +//--- C.h +// empty +//--- D.h +// empty +//--- TU.c +#include "A.h" +#include "C.h" +#include "D.h" + +//--- cdb.json.template +[{ + "file": "DIR/TU.c", + "directory": "DIR", + "command": "clang -fmodules -fmodules-cache-path=DIR/cache -I DIR -c DIR/TU.c" +}] + +// RUN: sed "s|DIR|%/t|g" %t/cdb.json.template > %t/cdb.json +// RUN: not clang-scan-deps -compilation-database %t/cdb.json -format \ +// RUN: experimental-full 2>&1 | FileCheck %s + +// Note that module D does not report an error because it is explicit. +// Therefore we can use CHECK-NEXT for the redeclaration error on line 15. +// CHECK: module.modulemap:6:5: error: link declaration is not allowed in submodules +// CHECK-NEXT: module.modulemap:15:3: error: redeclaration of link library 'libraryA' [-Wmodule-link-redeclaration] +// CHECK-NEXT: module.modulemap:14:3: note: previously declared here +// CHECK-NOT: module.modulemap:20:3: error: redeclaration of link library 'libraryA' _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
