install: Add EXCLUDE_FROM_ALL option (#14921)

Let us take an example of a project that has some tests in a component
that need to be installed into a dedicated test package.  The user
expectation is that the result could be achieved by typing the
following:

    make
    make tests
    make install
    DESTDIR=/testpkgs make install-tests

However this results in test components in the default installation as
well as the testpkg.

Add an EXCLUDE_FROM_ALL option to the install() command to tell it that
the installation rule should not be included unless its component is
explicitly specified for installation.

1 files changed, 12 insertions, 6 deletions

diff --git a/Source/cmInstallGenerator.cxx b/Source/cmInstallGenerator.cxx
index 2e1c5f0..660e44f 100644
--- a/Source/cmInstallGenerator.cxx
+++ b/Source/cmInstallGenerator.cxx
@@ -19,11 +19,13 @@ cmInstallGenerator
 ::cmInstallGenerator(const char* destination,
                      std::vector<std::string> const& configurations,
                      const char* component,
-                     MessageLevel message):
+                     MessageLevel message,
+                     bool exclude_from_all):
   cmScriptGenerator("CMAKE_INSTALL_CONFIG_NAME", configurations),
   Destination(destination? destination:""),
   Component(component? component:""),
-  Message(message)
+  Message(message),
+  ExcludeFromAll(exclude_from_all)
 {
 }
 
@@ -146,12 +148,16 @@ void cmInstallGenerator
 
 //----------------------------------------------------------------------------
 std::string
-cmInstallGenerator::CreateComponentTest(const char* component)
+cmInstallGenerator::CreateComponentTest(const char* component,
+                                        bool exclude_from_all)
 {
-  std::string result = "NOT CMAKE_INSTALL_COMPONENT OR "
-    "\"${CMAKE_INSTALL_COMPONENT}\" STREQUAL \"";
+  std::string result = "\"${CMAKE_INSTALL_COMPONENT}\" STREQUAL \"";
   result += component;
   result += "\"";
+  if(!exclude_from_all)
+    {
+    result += " OR NOT CMAKE_INSTALL_COMPONENT";
+    }
   return result;
 }
 
@@ -163,7 +169,7 @@ void cmInstallGenerator::GenerateScript(std::ostream& os)
 
   // Begin this block of installation.
   std::string component_test =
-    this->CreateComponentTest(this->Component.c_str());
+    this->CreateComponentTest(this->Component.c_str(),this->ExcludeFromAll);
   os << indent << "if(" << component_test << ")\n";
 
   // Generate the script possibly with per-configuration code.