cmFileAPI: Add "toolchains" object kind.

Fixes #19514

5 files changed, 233 insertions, 0 deletions

diff --git a/Source/CMakeLists.txt b/Source/CMakeLists.txt
index c5b67c0..dca94ee 100644
--- a/Source/CMakeLists.txt
+++ b/Source/CMakeLists.txt
@@ -268,6 +268,8 @@ set(SRCS
   cmFileAPICodemodel.h
   cmFileAPICMakeFiles.cxx
   cmFileAPICMakeFiles.h
+  cmFileAPIToolchains.cxx
+  cmFileAPIToolchains.h
   cmFileCopier.cxx
   cmFileCopier.h
   cmFileInstaller.cxx
diff --git a/Source/cmFileAPI.cxx b/Source/cmFileAPI.cxx
index c2ab2f1..d2a9bec 100644
--- a/Source/cmFileAPI.cxx
+++ b/Source/cmFileAPI.cxx
@@ -18,6 +18,7 @@
 #include "cmFileAPICMakeFiles.h"
 #include "cmFileAPICache.h"
 #include "cmFileAPICodemodel.h"
+#include "cmFileAPIToolchains.h"
 #include "cmGlobalGenerator.h"
 #include "cmStringAlgorithms.h"
 #include "cmSystemTools.h"
@@ -262,6 +263,17 @@ bool cmFileAPI::ReadQuery(std::string const& query,
     objects.push_back(o);
     return true;
   }
+  if (kindName == ObjectKindName(ObjectKind::Toolchains)) {
+    Object o;
+    o.Kind = ObjectKind::Toolchains;
+    if (verStr == "v1") {
+      o.Version = 1;
+    } else {
+      return false;
+    }
+    objects.push_back(o);
+    return true;
+  }
   if (kindName == ObjectKindName(ObjectKind::InternalTest)) {
     Object o;
     o.Kind = ObjectKind::InternalTest;
@@ -402,6 +414,7 @@ const char* cmFileAPI::ObjectKindName(ObjectKind kind)
     "codemodel",  //
     "cache",      //
     "cmakeFiles", //
+    "toolchains", //
     "__test"      //
   };
   return objectKindNames[size_t(kind)];
@@ -435,6 +448,9 @@ Json::Value cmFileAPI::BuildObject(Object const& object)
     case ObjectKind::CMakeFiles:
       value = this->BuildCMakeFiles(object);
       break;
+    case ObjectKind::Toolchains:
+      value = this->BuildToolchains(object);
+      break;
     case ObjectKind::InternalTest:
       value = this->BuildInternalTest(object);
       break;
@@ -491,6 +507,8 @@ cmFileAPI::ClientRequest cmFileAPI::BuildClientRequest(
     r.Kind = ObjectKind::Cache;
   } else if (kindName == this->ObjectKindName(ObjectKind::CMakeFiles)) {
     r.Kind = ObjectKind::CMakeFiles;
+  } else if (kindName == this->ObjectKindName(ObjectKind::Toolchains)) {
+    r.Kind = ObjectKind::Toolchains;
   } else if (kindName == this->ObjectKindName(ObjectKind::InternalTest)) {
     r.Kind = ObjectKind::InternalTest;
   } else {
@@ -518,6 +536,9 @@ cmFileAPI::ClientRequest cmFileAPI::BuildClientRequest(
     case ObjectKind::CMakeFiles:
       this->BuildClientRequestCMakeFiles(r, versions);
       break;
+    case ObjectKind::Toolchains:
+      this->BuildClientRequestToolchains(r, versions);
+      break;
     case ObjectKind::InternalTest:
       this->BuildClientRequestInternalTest(r, versions);
       break;
@@ -765,6 +786,40 @@ Json::Value cmFileAPI::BuildCMakeFiles(Object const& object)
   return cmakeFiles;
 }
 
+// The "toolchains" object kind.
+
+static unsigned int const ToolchainsV1Minor = 0;
+
+void cmFileAPI::BuildClientRequestToolchains(
+  ClientRequest& r, std::vector<RequestVersion> const& versions)
+{
+  // Select a known version from those requested.
+  for (RequestVersion const& v : versions) {
+    if ((v.Major == 1 && v.Minor <= ToolchainsV1Minor)) {
+      r.Version = v.Major;
+      break;
+    }
+  }
+  if (!r.Version) {
+    r.Error = NoSupportedVersion(versions);
+  }
+}
+
+Json::Value cmFileAPI::BuildToolchains(Object const& object)
+{
+  Json::Value toolchains = cmFileAPIToolchainsDump(*this, object.Version);
+  toolchains["kind"] = this->ObjectKindName(object.Kind);
+
+  Json::Value& version = toolchains["version"];
+  if (object.Version == 1) {
+    version = BuildVersion(1, ToolchainsV1Minor);
+  } else {
+    return toolchains; // should be unreachable
+  }
+
+  return toolchains;
+}
+
 // The "__test" object kind is for internal testing of CMake.
 
 static unsigned int const InternalTestV1Minor = 3;
@@ -828,5 +883,13 @@ Json::Value cmFileAPI::ReportCapabilities()
     requests.append(std::move(request)); // NOLINT(*)
   }
 
+  {
+    Json::Value request = Json::objectValue;
+    request["kind"] = ObjectKindName(ObjectKind::Toolchains);
+    Json::Value& versions = request["version"] = Json::arrayValue;
+    versions.append(BuildVersion(1, ToolchainsV1Minor));
+    requests.append(std::move(request)); // NOLINT(*)
+  }
+
   return capabilities;
 }
diff --git a/Source/cmFileAPI.h b/Source/cmFileAPI.h
index 086a92a..22302b4 100644
--- a/Source/cmFileAPI.h
+++ b/Source/cmFileAPI.h
@@ -56,6 +56,7 @@ private:
     CodeModel,
     Cache,
     CMakeFiles,
+    Toolchains,
     InternalTest
   };
 
@@ -200,6 +201,10 @@ private:
     ClientRequest& r, std::vector<RequestVersion> const& versions);
   Json::Value BuildCMakeFiles(Object const& object);
 
+  void BuildClientRequestToolchains(
+    ClientRequest& r, std::vector<RequestVersion> const& versions);
+  Json::Value BuildToolchains(Object const& object);
+
   void BuildClientRequestInternalTest(
     ClientRequest& r, std::vector<RequestVersion> const& versions);
   Json::Value BuildInternalTest(Object const& object);
diff --git a/Source/cmFileAPIToolchains.cxx b/Source/cmFileAPIToolchains.cxx
new file mode 100644
index 0000000..722c114
--- /dev/null
+++ b/Source/cmFileAPIToolchains.cxx
@@ -0,0 +1,151 @@
+/* Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
+   file Copyright.txt or https://cmake.org/licensing for details.  */
+#include "cmFileAPIToolchains.h"
+
+#include <memory>
+#include <string>
+#include <vector>
+
+#include <cm3p/json/value.h>
+
+#include "cmFileAPI.h"
+#include "cmGlobalGenerator.h"
+#include "cmMakefile.h"
+#include "cmProperty.h"
+#include "cmState.h"
+#include "cmStringAlgorithms.h"
+#include "cmake.h"
+
+namespace {
+
+struct ToolchainVariable
+{
+  std::string ObjectKey;
+  std::string VariableSuffix;
+  bool IsList;
+};
+
+class Toolchains
+{
+  cmFileAPI& FileAPI;
+  unsigned long Version;
+
+  static const std::vector<ToolchainVariable> CompilerVariables;
+  static const std::vector<ToolchainVariable> CompilerImplicitVariables;
+  static const ToolchainVariable SourceFileExtensionsVariable;
+
+  Json::Value DumpToolchains();
+  Json::Value DumpToolchain(std::string const& lang);
+  Json::Value DumpToolchainVariables(
+    cmMakefile const* mf, std::string const& lang,
+    std::vector<ToolchainVariable> const& variables);
+  void DumpToolchainVariable(cmMakefile const* mf, Json::Value& object,
+                             std::string const& lang,
+                             ToolchainVariable const& variable);
+
+public:
+  Toolchains(cmFileAPI& fileAPI, unsigned long version);
+  Json::Value Dump();
+};
+
+const std::vector<ToolchainVariable> Toolchains::CompilerVariables{
+  { "path", "COMPILER", false },
+  { "id", "COMPILER_ID", false },
+  { "version", "COMPILER_VERSION", false },
+  { "target", "COMPILER_TARGET", false },
+};
+
+const std::vector<ToolchainVariable> Toolchains::CompilerImplicitVariables{
+  { "includeDirectories", "IMPLICIT_INCLUDE_DIRECTORIES", true },
+  { "linkDirectories", "IMPLICIT_LINK_DIRECTORIES", true },
+  { "linkFrameworkDirectories", "IMPLICIT_LINK_FRAMEWORK_DIRECTORIES", true },
+  { "linkLibraries", "IMPLICIT_LINK_LIBRARIES", true },
+};
+
+const ToolchainVariable Toolchains::SourceFileExtensionsVariable{
+  "sourceFileExtensions", "SOURCE_FILE_EXTENSIONS", true
+};
+
+Toolchains::Toolchains(cmFileAPI& fileAPI, unsigned long version)
+  : FileAPI(fileAPI)
+  , Version(version)
+{
+  static_cast<void>(this->Version);
+}
+
+Json::Value Toolchains::Dump()
+{
+  Json::Value toolchains = Json::objectValue;
+  toolchains["toolchains"] = this->DumpToolchains();
+  return toolchains;
+}
+
+Json::Value Toolchains::DumpToolchains()
+{
+  Json::Value toolchains = Json::arrayValue;
+
+  for (std::string const& lang :
+       this->FileAPI.GetCMakeInstance()->GetState()->GetEnabledLanguages()) {
+    toolchains.append(this->DumpToolchain(lang));
+  }
+
+  return toolchains;
+}
+
+Json::Value Toolchains::DumpToolchain(std::string const& lang)
+{
+  const auto& mf =
+    this->FileAPI.GetCMakeInstance()->GetGlobalGenerator()->GetMakefiles()[0];
+  Json::Value toolchain = Json::objectValue;
+  toolchain["language"] = lang;
+  toolchain["compiler"] =
+    this->DumpToolchainVariables(mf.get(), lang, CompilerVariables);
+  toolchain["compiler"]["implicit"] =
+    this->DumpToolchainVariables(mf.get(), lang, CompilerImplicitVariables);
+  this->DumpToolchainVariable(mf.get(), toolchain, lang,
+                              SourceFileExtensionsVariable);
+  return toolchain;
+}
+
+Json::Value Toolchains::DumpToolchainVariables(
+  cmMakefile const* mf, std::string const& lang,
+  std::vector<ToolchainVariable> const& variables)
+{
+  Json::Value object = Json::objectValue;
+  for (const auto& variable : variables) {
+    this->DumpToolchainVariable(mf, object, lang, variable);
+  }
+  return object;
+}
+
+void Toolchains::DumpToolchainVariable(cmMakefile const* mf,
+                                       Json::Value& object,
+                                       std::string const& lang,
+                                       ToolchainVariable const& variable)
+{
+  std::string const variableName =
+    cmStrCat("CMAKE_", lang, "_", variable.VariableSuffix);
+
+  if (variable.IsList) {
+    std::vector<std::string> values;
+    if (mf->GetDefExpandList(variableName, values)) {
+      Json::Value jsonArray = Json::arrayValue;
+      for (std::string const& value : values) {
+        jsonArray.append(value);
+      }
+      object[variable.ObjectKey] = jsonArray;
+    }
+  } else {
+    cmProp def = mf->GetDefinition(variableName);
+    if (def) {
+      object[variable.ObjectKey] = *def;
+    }
+  }
+}
+}
+
+Json::Value cmFileAPIToolchainsDump(cmFileAPI& fileAPI, unsigned long version)
+{
+  Toolchains toolchains(fileAPI, version);
+  return toolchains.Dump();
+}
diff --git a/Source/cmFileAPIToolchains.h b/Source/cmFileAPIToolchains.h
new file mode 100644
index 0000000..c188807
--- /dev/null
+++ b/Source/cmFileAPIToolchains.h
@@ -0,0 +1,12 @@
+/* Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
+   file Copyright.txt or https://cmake.org/licensing for details.  */
+#pragma once
+
+#include "cmConfigure.h" // IWYU pragma: keep
+
+#include <cm3p/json/value.h>
+
+class cmFileAPI;
+
+extern Json::Value cmFileAPIToolchainsDump(cmFileAPI& fileAPI,
+                                           unsigned long version);