From 0fb923c46041d67110c8e0907afdf66b3b25f25a Mon Sep 17 00:00:00 2001 From: Ben Boeckel Date: Sat, 14 Jan 2023 23:58:28 -0500 Subject: cmGeneratorExpressionNode: implement `COMPILE_ONLY` genex This generator expression is the inverse of `LINK_ONLY` and only coveys usage requirements for the purposes of compilation. Its intended use is to avoid needing to export targets that do not have link usage requirements (e.g., header-only libraries) when used by another target. It will also be used to represent private usage requirements on exported C++ module-containing targets in the future. Eventually there should be logic to collapse nesting of `$` and `$` when generating instances of either. A TODO is left in the code for this case. See: #15415 --- Help/manual/cmake-generator-expressions.7.rst | 19 +++++++++++++++- Help/release/dev/genex-compile-only.rst | 5 +++++ Source/cmExportFileGenerator.cxx | 16 ++++++++++++++ Source/cmGeneratorExpressionNode.cxx | 25 ++++++++++++++++++++++ Source/cmTargetLinkLibrariesCommand.cxx | 1 + .../COMPILE_ONLY-not-compiling-result.txt | 1 + .../COMPILE_ONLY-not-compiling-stderr.txt | 8 +++++++ .../COMPILE_ONLY-not-compiling.cmake | 1 + .../GeneratorExpression/RunCMakeTest.cmake | 1 + 9 files changed, 76 insertions(+), 1 deletion(-) create mode 100644 Help/release/dev/genex-compile-only.rst create mode 100644 Tests/RunCMake/GeneratorExpression/COMPILE_ONLY-not-compiling-result.txt create mode 100644 Tests/RunCMake/GeneratorExpression/COMPILE_ONLY-not-compiling-stderr.txt create mode 100644 Tests/RunCMake/GeneratorExpression/COMPILE_ONLY-not-compiling.cmake diff --git a/Help/manual/cmake-generator-expressions.7.rst b/Help/manual/cmake-generator-expressions.7.rst index 9da37999b1..186a9d25f9 100644 --- a/Help/manual/cmake-generator-expressions.7.rst +++ b/Help/manual/cmake-generator-expressions.7.rst @@ -959,6 +959,22 @@ Compile Features :manual:`cmake-compile-features(7)` manual for information on compile features and a list of supported compilers. +Compile Context +^^^^^^^^^^^^^^^ + +.. genex:: $ + + .. versionadded:: 3.27 + + Content of ``...``, except while collecting :ref:`Target Usage Requirements`, + in which case it is the empty string. This is intended for use in an + :prop_tgt:`INTERFACE_LINK_LIBRARIES` target property, typically populated + via the :command:`target_link_libraries` command, to specify private + compilation requirements without other usage requirements. + + Use cases include header-only usage where all usages are known to not have + linking requirements (e.g., all-``inline`` or C++ template libraries). + Linker Language And ID ^^^^^^^^^^^^^^^^^^^^^^ @@ -1339,7 +1355,8 @@ Link Context in which case it is the empty string. This is intended for use in an :prop_tgt:`INTERFACE_LINK_LIBRARIES` target property, typically populated via the :command:`target_link_libraries` command, to specify private link - dependencies without other usage requirements. + dependencies without other usage requirements such as include directories or + compile options. .. versionadded:: 3.24 ``LINK_ONLY`` may also be used in a :prop_tgt:`LINK_LIBRARIES` target diff --git a/Help/release/dev/genex-compile-only.rst b/Help/release/dev/genex-compile-only.rst new file mode 100644 index 0000000000..1f898d8620 --- /dev/null +++ b/Help/release/dev/genex-compile-only.rst @@ -0,0 +1,5 @@ +genex-compile-only +------------------ + +* The :genex:`COMPILE_ONLY` generator expression has been added which provides + compilation usage requirements without any linking requirements. diff --git a/Source/cmExportFileGenerator.cxx b/Source/cmExportFileGenerator.cxx index 6e7ef4e735..e997158c3e 100644 --- a/Source/cmExportFileGenerator.cxx +++ b/Source/cmExportFileGenerator.cxx @@ -734,6 +734,22 @@ void cmExportFileGenerator::ResolveTargetsInGeneratorExpression( lastPos = nameStartPos + libName.size() + 1; } + while (errorString.empty() && + (pos = input.find("$', nameStartPos); + if (endPos == std::string::npos) { + errorString = "$ expression incomplete"; + break; + } + std::string libName = input.substr(nameStartPos, endPos - nameStartPos); + if (cmGeneratorExpression::IsValidTargetName(libName) && + this->AddTargetNamespace(libName, target, lg)) { + input.replace(nameStartPos, endPos - nameStartPos, libName); + } + lastPos = nameStartPos + libName.size() + 1; + } + this->ReplaceInstallPrefix(input); if (!errorString.empty()) { diff --git a/Source/cmGeneratorExpressionNode.cxx b/Source/cmGeneratorExpressionNode.cxx index a47366b4a1..a221498fda 100644 --- a/Source/cmGeneratorExpressionNode.cxx +++ b/Source/cmGeneratorExpressionNode.cxx @@ -1351,6 +1351,29 @@ static const VersionNode versionLessNode; static const VersionNode versionLessEqNode; static const VersionNode versionEqualNode; +static const struct CompileOnlyNode : public cmGeneratorExpressionNode +{ + CompileOnlyNode() {} // NOLINT(modernize-use-equals-default) + + std::string Evaluate( + const std::vector& parameters, + cmGeneratorExpressionContext* context, + const GeneratorExpressionContent* content, + cmGeneratorExpressionDAGChecker* dagChecker) const override + { + if (!dagChecker) { + reportError(context, content->GetOriginalExpression(), + "$ may only be used via linking"); + return std::string(); + } + // Linking checks for the inverse, so compiling is the opposite. + if (dagChecker->GetTransitivePropertiesOnly()) { + return parameters.front(); + } + return std::string(); + } +} compileOnlyNode; + static const struct LinkOnlyNode : public cmGeneratorExpressionNode { LinkOnlyNode() {} // NOLINT(modernize-use-equals-default) @@ -1366,6 +1389,7 @@ static const struct LinkOnlyNode : public cmGeneratorExpressionNode "$ may only be used for linking"); return std::string(); } + // Compile-only checks for the inverse, so linking is the opposite. if (!dagChecker->GetTransitivePropertiesOnly()) { return parameters.front(); } @@ -3805,6 +3829,7 @@ const cmGeneratorExpressionNode* cmGeneratorExpressionNode::GetNode( { "BUILD_LOCAL_INTERFACE", &buildLocalInterfaceNode }, { "INSTALL_PREFIX", &installPrefixNode }, { "JOIN", &joinNode }, + { "COMPILE_ONLY", &compileOnlyNode }, { "LINK_ONLY", &linkOnlyNode }, { "COMPILE_LANG_AND_ID", &languageAndIdNode }, { "COMPILE_LANGUAGE", &languageNode }, diff --git a/Source/cmTargetLinkLibrariesCommand.cxx b/Source/cmTargetLinkLibrariesCommand.cxx index 0b123b2d61..03d7c9fea9 100644 --- a/Source/cmTargetLinkLibrariesCommand.cxx +++ b/Source/cmTargetLinkLibrariesCommand.cxx @@ -552,6 +552,7 @@ bool TLL::HandleLibrary(ProcessingState currentProcessingState, currentProcessingState == ProcessingPlainPrivateInterface) { if (this->Target->GetType() == cmStateEnums::STATIC_LIBRARY || this->Target->GetType() == cmStateEnums::OBJECT_LIBRARY) { + // TODO: Detect and no-op `$` genexes here. std::string configLib = this->Target->GetDebugGeneratorExpressions(lib, llt); if (cmGeneratorExpression::IsValidTargetName(lib) || diff --git a/Tests/RunCMake/GeneratorExpression/COMPILE_ONLY-not-compiling-result.txt b/Tests/RunCMake/GeneratorExpression/COMPILE_ONLY-not-compiling-result.txt new file mode 100644 index 0000000000..d00491fd7e --- /dev/null +++ b/Tests/RunCMake/GeneratorExpression/COMPILE_ONLY-not-compiling-result.txt @@ -0,0 +1 @@ +1 diff --git a/Tests/RunCMake/GeneratorExpression/COMPILE_ONLY-not-compiling-stderr.txt b/Tests/RunCMake/GeneratorExpression/COMPILE_ONLY-not-compiling-stderr.txt new file mode 100644 index 0000000000..5e7fce2a1b --- /dev/null +++ b/Tests/RunCMake/GeneratorExpression/COMPILE_ONLY-not-compiling-stderr.txt @@ -0,0 +1,8 @@ +CMake Error at COMPILE_ONLY-not-compiling.cmake:1 \(add_custom_target\): + Error evaluating generator expression: + + \$ + + \$ may only be used via linking +Call Stack \(most recent call first\): + CMakeLists.txt:3 \(include\) diff --git a/Tests/RunCMake/GeneratorExpression/COMPILE_ONLY-not-compiling.cmake b/Tests/RunCMake/GeneratorExpression/COMPILE_ONLY-not-compiling.cmake new file mode 100644 index 0000000000..1bc75f98e5 --- /dev/null +++ b/Tests/RunCMake/GeneratorExpression/COMPILE_ONLY-not-compiling.cmake @@ -0,0 +1 @@ +add_custom_target(Custom ALL COMMAND ${CMAKE_COMMAND} -E echo $) diff --git a/Tests/RunCMake/GeneratorExpression/RunCMakeTest.cmake b/Tests/RunCMake/GeneratorExpression/RunCMakeTest.cmake index b139210d72..3fd994721b 100644 --- a/Tests/RunCMake/GeneratorExpression/RunCMakeTest.cmake +++ b/Tests/RunCMake/GeneratorExpression/RunCMakeTest.cmake @@ -22,6 +22,7 @@ run_cmake(NonValidTarget-CXX_COMPILER_VERSION) run_cmake(NonValidTarget-Fortran_COMPILER_VERSION) run_cmake(NonValidTarget-TARGET_PROPERTY) run_cmake(NonValidTarget-TARGET_POLICY) +run_cmake(COMPILE_ONLY-not-compiling) run_cmake(LINK_ONLY-not-linking) run_cmake(TARGET_EXISTS-no-arg) run_cmake(TARGET_EXISTS-empty-arg) -- cgit v1.2.1