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-rw-r--r--Help/dev/experimental.rst42
-rw-r--r--Source/cmGlobalNinjaGenerator.cxx32
-rw-r--r--Source/cmGlobalNinjaGenerator.h4
-rw-r--r--Source/cmNinjaTargetGenerator.cxx84
-rw-r--r--Source/cmNinjaTargetGenerator.h4
-rw-r--r--Source/cmRulePlaceholderExpander.cxx5
-rw-r--r--Source/cmRulePlaceholderExpander.h1
7 files changed, 150 insertions, 22 deletions
diff --git a/Help/dev/experimental.rst b/Help/dev/experimental.rst
index 4d2b076..4cf1c62 100644
--- a/Help/dev/experimental.rst
+++ b/Help/dev/experimental.rst
@@ -7,4 +7,44 @@ See documentation on `CMake Development`_ for more information.
.. _`CMake Development`: README.rst
-No experimental features are under development in this version of CMake.
+C++20 Module Dependencies
+=========================
+
+The Ninja generator has experimental infrastructure supporting C++20 module
+dependency scanning. This is similar to the Fortran modules support, but
+relies on external tools to scan C++20 translation units for module
+dependencies. The approach is described by Kitware's `D1483r1`_ paper.
+
+The ``CMAKE_EXPERIMENTAL_CXX_MODULE_DYNDEP`` variable can be set to ``1``
+in order to activate this undocumented experimental infrastructure. This
+is **intended to make the functionality available to compiler writers** so
+they can use it to develop and test their dependency scanning tool.
+The ``CMAKE_EXPERIMENTAL_CXX_SCANDEP_SOURCE`` variable must also be set
+to tell CMake how to invoke the C++20 module dependency scanning tool.
+
+For example, add code like the following to a test project:
+
+.. code-block:: cmake
+
+ set(CMAKE_EXPERIMENTAL_CXX_MODULE_DYNDEP 1)
+ string(CONCAT CMAKE_EXPERIMENTAL_CXX_SCANDEP_SOURCE
+ "<CMAKE_CXX_COMPILER> <DEFINES> <INCLUDES> <FLAGS> <SOURCE>"
+ " -MT <DYNDEP_FILE> -MD -MF <DEP_FILE>"
+ " ${flags_to_scan_deps} -fdep-file=<DYNDEP_FILE> -fdep-output=<OBJECT>"
+ )
+
+The tool specified by ``CMAKE_EXPERIMENTAL_CXX_SCANDEP_SOURCE`` is
+expected to process the translation unit, write preprocessor dependencies
+to the file specified by the ``<DEP_FILE>`` placeholder, and write module
+dependencies to the file specified by the ``<DYNDEP_FILE>`` placeholder.
+
+The module dependencies should be written in the format described
+by the `P1689r3`_ paper.
+
+Compiler writers may try out their scanning functionality using
+the `cxx-modules-sandbox`_ test project, modified to set variables
+as above for their compiler.
+
+.. _`D1483r1`: https://mathstuf.fedorapeople.org/fortran-modules/fortran-modules.html
+.. _`P1689r3`: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2020/p1689r3.html
+.. _`cxx-modules-sandbox`: https://github.com/mathstuf/cxx-modules-sandbox
diff --git a/Source/cmGlobalNinjaGenerator.cxx b/Source/cmGlobalNinjaGenerator.cxx
index b0b0cd6..16cdcd3 100644
--- a/Source/cmGlobalNinjaGenerator.cxx
+++ b/Source/cmGlobalNinjaGenerator.cxx
@@ -555,6 +555,7 @@ void cmGlobalNinjaGenerator::Generate()
this->TargetAll = this->NinjaOutputPath("all");
this->CMakeCacheFile = this->NinjaOutputPath("CMakeCache.txt");
this->DisableCleandead = false;
+ this->DiagnosedCxxModuleSupport = false;
this->PolicyCMP0058 =
this->LocalGenerators[0]->GetMakefile()->GetPolicyStatus(
@@ -755,6 +756,37 @@ bool cmGlobalNinjaGenerator::CheckLanguages(
return true;
}
+bool cmGlobalNinjaGenerator::CheckCxxModuleSupport()
+{
+ bool const diagnose = !this->DiagnosedCxxModuleSupport &&
+ !this->CMakeInstance->GetIsInTryCompile();
+ if (diagnose) {
+ this->DiagnosedCxxModuleSupport = true;
+ this->GetCMakeInstance()->IssueMessage(
+ MessageType::AUTHOR_WARNING,
+ "C++20 modules support via CMAKE_EXPERIMENTAL_CXX_MODULE_DYNDEP "
+ "is experimental. It is meant only for compiler developers to try.");
+ }
+ if (this->NinjaSupportsDyndeps) {
+ return true;
+ }
+ if (diagnose) {
+ std::ostringstream e;
+ /* clang-format off */
+ e <<
+ "The Ninja generator does not support C++20 modules "
+ "using Ninja version \n"
+ " " << this->NinjaVersion << "\n"
+ "due to lack of required features. "
+ "Ninja " << RequiredNinjaVersionForDyndeps() << " or higher is required."
+ ;
+ /* clang-format on */
+ this->GetCMakeInstance()->IssueMessage(MessageType::FATAL_ERROR, e.str());
+ cmSystemTools::SetFatalErrorOccured();
+ }
+ return false;
+}
+
bool cmGlobalNinjaGenerator::CheckFortran(cmMakefile* mf) const
{
if (this->NinjaSupportsDyndeps) {
diff --git a/Source/cmGlobalNinjaGenerator.h b/Source/cmGlobalNinjaGenerator.h
index 5e9defe..b21586b 100644
--- a/Source/cmGlobalNinjaGenerator.h
+++ b/Source/cmGlobalNinjaGenerator.h
@@ -445,6 +445,8 @@ public:
bool IsSingleConfigUtility(cmGeneratorTarget const* target) const;
+ bool CheckCxxModuleSupport();
+
protected:
void Generate() override;
@@ -565,6 +567,8 @@ private:
bool NinjaSupportsMultipleOutputs = false;
bool NinjaSupportsMetadataOnRegeneration = false;
+ bool DiagnosedCxxModuleSupport = false;
+
private:
void InitOutputPathPrefix();
diff --git a/Source/cmNinjaTargetGenerator.cxx b/Source/cmNinjaTargetGenerator.cxx
index d3f4a00..124e885 100644
--- a/Source/cmNinjaTargetGenerator.cxx
+++ b/Source/cmNinjaTargetGenerator.cxx
@@ -35,6 +35,7 @@
#include "cmRange.h"
#include "cmRulePlaceholderExpander.h"
#include "cmSourceFile.h"
+#include "cmStandardLevelResolver.h"
#include "cmState.h"
#include "cmStateTypes.h"
#include "cmStringAlgorithms.h"
@@ -146,9 +147,26 @@ std::string cmNinjaTargetGenerator::LanguageDyndepRule(
'_', config);
}
-bool cmNinjaTargetGenerator::NeedDyndep(std::string const& lang) const
+bool cmNinjaTargetGenerator::NeedCxxModuleSupport(
+ std::string const& lang, std::string const& config) const
{
- return lang == "Fortran";
+ if (lang != "CXX") {
+ return false;
+ }
+ if (!this->Makefile->IsOn("CMAKE_EXPERIMENTAL_CXX_MODULE_DYNDEP")) {
+ return false;
+ }
+ cmGeneratorTarget const* tgt = this->GetGeneratorTarget();
+ cmStandardLevelResolver standardResolver(this->Makefile);
+ bool const uses_cxx20 =
+ standardResolver.HaveStandardAvailable(tgt, "CXX", config, "cxx_std_20");
+ return uses_cxx20 && this->GetGlobalGenerator()->CheckCxxModuleSupport();
+}
+
+bool cmNinjaTargetGenerator::NeedDyndep(std::string const& lang,
+ std::string const& config) const
+{
+ return lang == "Fortran" || this->NeedCxxModuleSupport(lang, config);
}
std::string cmNinjaTargetGenerator::OrderDependsTargetForTarget(
@@ -531,6 +549,7 @@ cmNinjaRule GetScanRule(
scanVars.Language = vars.Language;
scanVars.Object = "$OBJ_FILE";
scanVars.PreprocessedSource = "$out";
+ scanVars.DynDepFile = "$DYNDEP_INTERMEDIATE_FILE";
scanVars.DependencyFile = rule.DepFile.c_str();
scanVars.DependencyTarget = "$out";
@@ -585,7 +604,7 @@ void cmNinjaTargetGenerator::WriteCompileRule(const std::string& lang,
cmMakefile* mf = this->GetMakefile();
// For some cases we scan to dynamically discover dependencies.
- bool const needDyndep = this->NeedDyndep(lang);
+ bool const needDyndep = this->NeedDyndep(lang, config);
bool const compilationPreprocesses = !this->NeedExplicitPreprocessing(lang);
std::string flags = "$FLAGS";
@@ -623,16 +642,26 @@ void cmNinjaTargetGenerator::WriteCompileRule(const std::string& lang,
// Rule to scan dependencies of sources that need preprocessing.
{
std::vector<std::string> scanCommands;
- std::string const& scanRuleName =
- this->LanguagePreprocessAndScanRule(lang, config);
- std::string const& ppCommmand = mf->GetRequiredDefinition(
- cmStrCat("CMAKE_", lang, "_PREPROCESS_SOURCE"));
- cmExpandList(ppCommmand, scanCommands);
- for (std::string& i : scanCommands) {
- i = cmStrCat(launcher, i);
+ std::string scanRuleName;
+ if (compilationPreprocesses) {
+ scanRuleName = this->LanguageScanRule(lang, config);
+ std::string const& scanCommand = mf->GetRequiredDefinition(
+ cmStrCat("CMAKE_EXPERIMENTAL_", lang, "_SCANDEP_SOURCE"));
+ cmExpandList(scanCommand, scanCommands);
+ for (std::string& i : scanCommands) {
+ i = cmStrCat(launcher, i);
+ }
+ } else {
+ scanRuleName = this->LanguagePreprocessAndScanRule(lang, config);
+ std::string const& ppCommmand = mf->GetRequiredDefinition(
+ cmStrCat("CMAKE_", lang, "_PREPROCESS_SOURCE"));
+ cmExpandList(ppCommmand, scanCommands);
+ for (std::string& i : scanCommands) {
+ i = cmStrCat(launcher, i);
+ }
+ scanCommands.emplace_back(GetScanCommand(cmakeCmd, tdi, lang, "$out",
+ "$DYNDEP_INTERMEDIATE_FILE"));
}
- scanCommands.emplace_back(GetScanCommand(cmakeCmd, tdi, lang, "$out",
- "$DYNDEP_INTERMEDIATE_FILE"));
auto scanRule = GetScanRule(
scanRuleName, vars, responseFlag, flags, rulePlaceholderExpander.get(),
@@ -640,12 +669,18 @@ void cmNinjaTargetGenerator::WriteCompileRule(const std::string& lang,
scanRule.Comment =
cmStrCat("Rule for generating ", lang, " dependencies.");
- scanRule.Description = cmStrCat("Building ", lang, " preprocessed $out");
+ if (compilationPreprocesses) {
+ scanRule.Description =
+ cmStrCat("Scanning $in for ", lang, " dependencies");
+ } else {
+ scanRule.Description =
+ cmStrCat("Building ", lang, " preprocessed $out");
+ }
this->GetGlobalGenerator()->AddRule(scanRule);
}
- {
+ if (!compilationPreprocesses) {
// Compilation will not preprocess, so it does not need the defines
// unless the compiler wants them for some other purpose.
if (!this->CompileWithDefines(lang)) {
@@ -1258,7 +1293,7 @@ void cmNinjaTargetGenerator::WriteObjectBuildStatement(
}
// For some cases we scan to dynamically discover dependencies.
- bool const needDyndep = this->NeedDyndep(language);
+ bool const needDyndep = this->NeedDyndep(language, config);
bool const compilationPreprocesses =
!this->NeedExplicitPreprocessing(language);
@@ -1440,17 +1475,26 @@ void cmNinjaTargetGenerator::WriteTargetDependInfo(std::string const& lang,
tdi["compiler-id"] = this->Makefile->GetSafeDefinition(
cmStrCat("CMAKE_", lang, "_COMPILER_ID"));
+ std::string mod_dir;
if (lang == "Fortran") {
- std::string mod_dir = this->GeneratorTarget->GetFortranModuleDirectory(
+ mod_dir = this->GeneratorTarget->GetFortranModuleDirectory(
this->Makefile->GetHomeOutputDirectory());
- if (mod_dir.empty()) {
- mod_dir = this->Makefile->GetCurrentBinaryDirectory();
- }
- tdi["module-dir"] = mod_dir;
+ } else if (lang == "CXX") {
+ mod_dir =
+ cmSystemTools::CollapseFullPath(this->GeneratorTarget->ObjectDirectory);
+ }
+ if (mod_dir.empty()) {
+ mod_dir = this->Makefile->GetCurrentBinaryDirectory();
+ }
+ tdi["module-dir"] = mod_dir;
+
+ if (lang == "Fortran") {
tdi["submodule-sep"] =
this->Makefile->GetSafeDefinition("CMAKE_Fortran_SUBMODULE_SEP");
tdi["submodule-ext"] =
this->Makefile->GetSafeDefinition("CMAKE_Fortran_SUBMODULE_EXT");
+ } else if (lang == "CXX") {
+ // No extra information necessary.
}
tdi["dir-cur-bld"] = this->Makefile->GetCurrentBinaryDirectory();
diff --git a/Source/cmNinjaTargetGenerator.h b/Source/cmNinjaTargetGenerator.h
index 83a4342..79dc622 100644
--- a/Source/cmNinjaTargetGenerator.h
+++ b/Source/cmNinjaTargetGenerator.h
@@ -71,9 +71,11 @@ protected:
const std::string& config) const;
std::string LanguageDyndepRule(std::string const& lang,
const std::string& config) const;
- bool NeedDyndep(std::string const& lang) const;
+ bool NeedDyndep(std::string const& lang, std::string const& config) const;
bool NeedExplicitPreprocessing(std::string const& lang) const;
bool CompileWithDefines(std::string const& lang) const;
+ bool NeedCxxModuleSupport(std::string const& lang,
+ std::string const& config) const;
std::string OrderDependsTargetForTarget(const std::string& config);
diff --git a/Source/cmRulePlaceholderExpander.cxx b/Source/cmRulePlaceholderExpander.cxx
index 5363fef..d00bbdf 100644
--- a/Source/cmRulePlaceholderExpander.cxx
+++ b/Source/cmRulePlaceholderExpander.cxx
@@ -44,6 +44,11 @@ std::string cmRulePlaceholderExpander::ExpandRuleVariable(
return replaceValues.Source;
}
}
+ if (replaceValues.DynDepFile) {
+ if (variable == "DYNDEP_FILE") {
+ return replaceValues.DynDepFile;
+ }
+ }
if (replaceValues.PreprocessedSource) {
if (variable == "PREPROCESSED_SOURCE") {
return replaceValues.PreprocessedSource;
diff --git a/Source/cmRulePlaceholderExpander.h b/Source/cmRulePlaceholderExpander.h
index 710f8a6..f8dc368 100644
--- a/Source/cmRulePlaceholderExpander.h
+++ b/Source/cmRulePlaceholderExpander.h
@@ -41,6 +41,7 @@ public:
const char* Source = nullptr;
const char* AssemblySource = nullptr;
const char* PreprocessedSource = nullptr;
+ const char* DynDepFile = nullptr;
const char* Output = nullptr;
const char* Object = nullptr;
const char* ObjectDir = nullptr;
generated by cgit v0.12 at 2024-09-24 06:20:48 (GMT)