cmGlobalGenerator: add a query to represent support for short object names

Help/release/dev/short-object-names.rst

@@ -0,0 +1,7 @@
+short-object-names
+------------------
+
+* There is now the :variable:`CMAKE_INTERMEDIATE_DIR_STRATEGY` variable (and
+  associated environment variable :envvar:`CMAKE_INTERMEDIATE_DIR_STRATEGY`)
+  that may be used to change the strategy used to name intermediate
+  directories used for object files (and other associated target metadata).

Source/cmGlobalGenerator.cxx

@@ -1440,6 +1440,20 @@ bool cmGlobalGenerator::Compute()
     return false;
   }
 
+  if (cmValue v = this->CMakeInstance->GetCacheDefinition(
+        "CMAKE_INTERMEDIATE_DIR_STRATEGY")) {
+    if (*v == "FULL") {
+      this->IntDirStrategy = IntermediateDirStrategy::Full;
+    } else if (*v == "SHORT") {
+      this->IntDirStrategy = IntermediateDirStrategy::Short;
+    } else {
+      this->GetCMakeInstance()->IssueMessage(
+        MessageType::FATAL_ERROR,
+        cmStrCat("Unsupported intermediate directory strategy '", *v, '\''));
+      return false;
+    }
+  }
+
   // Some generators track files replaced during the Generate.
   // Start with an empty vector:
   this->FilesReplacedDuringGenerate.clear();
@@ -1981,6 +1995,17 @@ void cmGlobalGenerator::ClearGeneratorMembers()
   this->WarnedExperimental.clear();
 }
 
+bool cmGlobalGenerator::SupportsShortObjectNames() const
+{
+  return false;
+}
+
+bool cmGlobalGenerator::UseShortObjectNames() const
+{
+  return this->SupportsShortObjectNames() &&
+    this->IntDirStrategy == IntermediateDirStrategy::Short;
+}
+
 void cmGlobalGenerator::ComputeTargetObjectDirectory(
   cmGeneratorTarget* /*unused*/) const
 {

Source/cmGlobalGenerator.h

@@ -629,6 +629,9 @@ public:
     std::string const& filename) const;
   void AddCMP0068WarnTarget(std::string const& target);
 
+  virtual bool SupportsShortObjectNames() const;
+  bool UseShortObjectNames() const;
+
   virtual void ComputeTargetObjectDirectory(cmGeneratorTarget* gt) const;
 
   bool GenerateCPackPropertiesFile();
@@ -941,6 +944,13 @@ private:
   PerConfigModuleDatabases PerConfigModuleDbs;
   PerLanguageModuleDatabases PerLanguageModuleDbs;
 
+  enum class IntermediateDirStrategy
+  {
+    Full,
+    Short,
+  };
+  IntermediateDirStrategy IntDirStrategy = IntermediateDirStrategy::Full;
+
 protected:
   float FirstTimeProgress;
   bool NeedSymbolicMark;

Source/cmLocalGenerator.cxx

@@ -4287,6 +4287,11 @@ std::string cmLocalGenerator::GetObjectFileNameWithoutTarget(
   return this->CreateSafeUniqueObjectFileName(objectName, dir_max);
 }
 
+bool cmLocalGenerator::UseShortObjectNames() const
+{
+  return this->GlobalGenerator->UseShortObjectNames();
+}
+
 std::string cmLocalGenerator::GetObjectOutputRoot() const
 {
   return cmStrCat(this->GetCurrentBinaryDirectory(), "/CMakeFiles");

Source/cmLocalGenerator.h

@@ -438,6 +438,7 @@ public:
   std::string const& GetCurrentBinaryDirectory() const;
   std::string const& GetCurrentSourceDirectory() const;
 
+  bool UseShortObjectNames() const;
   virtual std::string GetObjectOutputRoot() const;
   virtual bool AlwaysUsesCMFPaths() const;
 

Source/cmake.cxx

@@ -2607,7 +2607,7 @@ int cmake::ActualConfigure()
       this->IntermediateDirStrategy) {
     this->AddCacheEntry(
       "CMAKE_INTERMEDIATE_DIR_STRATEGY", *this->IntermediateDirStrategy,
-      "Select the intermediate directory strategy", cmStateEnums::STRING);
+      "Select the intermediate directory strategy", cmStateEnums::INTERNAL);
   }
 
   if (!this->State->GetInitializedCacheValue("CMAKE_TEST_LAUNCHER")) {

Tests/RunCMake/CMakeLists.txt

@@ -794,6 +794,7 @@ add_RunCMake_test(CMP0004)
 add_RunCMake_test(TargetPolicies)
 add_RunCMake_test(alias_targets)
 add_RunCMake_test(InterfaceLibrary)
+add_RunCMake_test(IntermediateDirStrategy)
 add_RunCMake_test(no_install_prefix)
 add_RunCMake_test(configure_file)
 if(CTestTestTimeout_TIME)

Tests/RunCMake/IntermediateDirStrategy/CMakeLists.txt

@@ -0,0 +1,2 @@
+cmake_minimum_required(VERSION 3.10)
+project(${RunCMake_TEST} NONE)

Tests/RunCMake/IntermediateDirStrategy/IntDirStrategyCacheINVALID-result.txt

@@ -0,0 +1 @@
+1

Tests/RunCMake/IntermediateDirStrategy/IntDirStrategyCacheINVALID-stderr.txt

@@ -0,0 +1,5 @@
+CMake Error:
+  Unsupported intermediate directory strategy 'INVALID'
+
+
+CMake Generate step failed.  Build files cannot be regenerated correctly.

Tests/RunCMake/IntermediateDirStrategy/IntDirStrategyEnvINVALID-result.txt

@@ -0,0 +1 @@
+1

Tests/RunCMake/IntermediateDirStrategy/IntDirStrategyEnvINVALID-stderr.txt

@@ -0,0 +1,5 @@
+CMake Error:
+  Unsupported intermediate directory strategy 'INVALID'
+
+
+CMake Generate step failed.  Build files cannot be regenerated correctly.

Tests/RunCMake/IntermediateDirStrategy/RunCMakeTest.cmake

@@ -0,0 +1,20 @@
+include(RunCMake)
+
+function(run_cmake_intdir_strategy base strategy)
+  unset(ENV{CMAKE_INTERMEDIATE_DIR_STRATEGY})
+
+  if (base STREQUAL "IntDirStrategyCache")
+    set(RunCMake_TEST_OPTIONS -DCMAKE_INTERMEDIATE_DIR_STRATEGY=${strategy})
+  elseif (base STREQUAL "IntDirStrategyEnv")
+    set(ENV{CMAKE_INTERMEDIATE_DIR_STRATEGY} "${strategy}")
+  else ()
+    message(FATAL_ERROR "unsupported base: ${base}")
+  endif ()
+  set(RunCMake_TEST_BINARY_DIR ${RunCMake_BINARY_DIR}/${base}${strategy}-build)
+  run_cmake(${base}${strategy})
+endfunction()
+
+foreach (strategy IN ITEMS INVALID FULL SHORT)
+  run_cmake_intdir_strategy(IntDirStrategyCache ${strategy})
+  run_cmake_intdir_strategy(IntDirStrategyEnv ${strategy})
+endforeach ()