Merge topic 'avoid-LIB_DEPENDS'

7723e9a058 Do not produce legacy _LIB_DEPENDS cache entries
2124a1364a cmTarget: Remove unnecessary RecordDependencies member
1c5bfab532 cmTarget: Simplify ClearDependencyInformation implementation
910a9d608e cmTarget: Simplify ClearDependencyInformation signature

Acked-by: Kitware Robot <kwrobot@kitware.com>
Acked-by: Pavel Solodovnikov <hellyeahdominate@gmail.com>
Merge-request: !1828

12 files changed, 77 insertions, 33 deletions

diff --git a/Help/manual/cmake-policies.7.rst b/Help/manual/cmake-policies.7.rst
index 96d5c7d..254656a 100644
--- a/Help/manual/cmake-policies.7.rst
+++ b/Help/manual/cmake-policies.7.rst
@@ -51,6 +51,14 @@ The :variable:`CMAKE_MINIMUM_REQUIRED_VERSION` variable may also be used
 to determine whether to report an error on use of deprecated macros or
 functions.
 
+Policies Introduced by CMake 3.12
+=================================
+
+.. toctree::
+   :maxdepth: 1
+
+   CMP0073: Do not produce legacy _LIB_DEPENDS cache entries. </policy/CMP0073>
+
 Policies Introduced by CMake 3.11
 =================================
 
diff --git a/Help/policy/CMP0073.rst b/Help/policy/CMP0073.rst
new file mode 100644
index 0000000..9bfa0e9
--- /dev/null
+++ b/Help/policy/CMP0073.rst
@@ -0,0 +1,25 @@
+CMP0073
+-------
+
+Do not produce legacy ``_LIB_DEPENDS`` cache entries.
+
+Ancient CMake versions once used ``<tgt>_LIB_DEPENDS`` cache entries to
+propagate library link dependencies.  This has long been done by other
+means, leaving the :command:`export_library_dependencies` command as the
+only user of these values.  That command has long been disallowed by
+policy :policy:`CMP0033`, but the ``<tgt>_LIB_DEPENDS`` cache entries
+were left for compatibility with possible non-standard uses by projects.
+
+CMake 3.12 and above now prefer to not produce these cache entries
+at all.  This policy provides compatibility with projects that have
+not been updated to avoid using them.
+
+The ``OLD`` behavior for this policy is to set ``<tgt>_LIB_DEPENDS`` cache
+entries.  The ``NEW`` behavior for this policy is to not set them.
+
+This policy was introduced in CMake version 3.12.  Use the
+:command:`cmake_policy` command to set it to ``OLD`` or ``NEW`` explicitly.
+Unlike most policies, CMake version |release| does *not* warn
+when this policy is not set and simply uses ``OLD`` behavior.
+
+.. include:: DEPRECATED.txt
diff --git a/Help/release/dev/avoid-LIB_DEPENDS.rst b/Help/release/dev/avoid-LIB_DEPENDS.rst
new file mode 100644
index 0000000..b89d8f9
--- /dev/null
+++ b/Help/release/dev/avoid-LIB_DEPENDS.rst
@@ -0,0 +1,5 @@
+avoid-LIB_DEPENDS
+-----------------
+
+* CMake no longer produces ``<tgt>_LIB_DEPENDS`` cache entries
+  for library targets.  See policy :policy:`CMP0073`.
diff --git a/Source/cmMakefile.cxx b/Source/cmMakefile.cxx
index 47d75af..a69f75f 100644
--- a/Source/cmMakefile.cxx
+++ b/Source/cmMakefile.cxx
@@ -1867,7 +1867,7 @@ cmTarget* cmMakefile::AddLibrary(const std::string& lname,
   // Clear its dependencies. Otherwise, dependencies might persist
   // over changes in CMakeLists.txt, making the information stale and
   // hence useless.
-  target->ClearDependencyInformation(*this, lname);
+  target->ClearDependencyInformation(*this);
   if (excludeFromAll) {
     target->SetProperty("EXCLUDE_FROM_ALL", "TRUE");
   }
diff --git a/Source/cmPolicies.h b/Source/cmPolicies.h
index c39f927..a784f98 100644
--- a/Source/cmPolicies.h
+++ b/Source/cmPolicies.h
@@ -214,6 +214,9 @@ class cmMakefile;
          3, 10, 0, cmPolicies::WARN)                                          \
   SELECT(POLICY, CMP0072,                                                     \
          "FindOpenGL prefers GLVND by default when available.", 3, 11, 0,     \
+         cmPolicies::WARN)                                                    \
+  SELECT(POLICY, CMP0073,                                                     \
+         "Do not produce legacy _LIB_DEPENDS cache entries.", 3, 12, 0,       \
          cmPolicies::WARN)
 
 #define CM_SELECT_ID(F, A1, A2, A3, A4, A5, A6) F(A1)
@@ -238,7 +241,8 @@ class cmMakefile;
   F(CMP0063)                                                                  \
   F(CMP0065)                                                                  \
   F(CMP0068)                                                                  \
-  F(CMP0069)
+  F(CMP0069)                                                                  \
+  F(CMP0073)
 
 /** \class cmPolicies
  * \brief Handles changes in CMake behavior and policies
diff --git a/Source/cmTarget.cxx b/Source/cmTarget.cxx
index bb21022..70387ae 100644
--- a/Source/cmTarget.cxx
+++ b/Source/cmTarget.cxx
@@ -186,14 +186,6 @@ cmTarget::cmTarget(std::string const& name, cmStateEnums::TargetType type,
   this->ImportedGloballyVisible = vis == VisibilityImportedGlobally;
   this->BuildInterfaceIncludesAppended = false;
 
-  // only add dependency information for library targets
-  if (this->TargetTypeValue >= cmStateEnums::STATIC_LIBRARY &&
-      this->TargetTypeValue <= cmStateEnums::MODULE_LIBRARY) {
-    this->RecordDependencies = true;
-  } else {
-    this->RecordDependencies = false;
-  }
-
   // Check whether this is a DLL platform.
   this->DLLPlatform =
     (this->Makefile->IsOn("WIN32") || this->Makefile->IsOn("CYGWIN") ||
@@ -635,27 +627,11 @@ const std::vector<std::string>& cmTarget::GetLinkDirectories() const
   return this->LinkDirectories;
 }
 
-void cmTarget::ClearDependencyInformation(cmMakefile& mf,
-                                          const std::string& target)
+void cmTarget::ClearDependencyInformation(cmMakefile& mf)
 {
-  // Clear the dependencies. The cache variable must exist iff we are
-  // recording dependency information for this target.
-  std::string depname = target;
+  std::string depname = this->GetName();
   depname += "_LIB_DEPENDS";
-  if (this->RecordDependencies) {
-    mf.AddCacheDefinition(depname, "", "Dependencies for target",
-                          cmStateEnums::STATIC);
-  } else {
-    if (mf.GetDefinition(depname)) {
-      std::string message = "Target ";
-      message += target;
-      message += " has dependency information when it shouldn't.\n";
-      message += "Your cache is probably stale. Please remove the entry\n  ";
-      message += depname;
-      message += "\nfrom the cache.";
-      cmSystemTools::Error(message.c_str());
-    }
-  }
+  mf.RemoveCacheDefinition(depname);
 }
 
 std::string cmTarget::GetDebugGeneratorExpressions(
@@ -752,7 +728,7 @@ void cmTarget::AddLinkLibrary(cmMakefile& mf, const std::string& lib,
     this->OriginalLinkLibraries.emplace_back(lib, llt);
   }
 
-  // Add the explicit dependency information for this target. This is
+  // Add the explicit dependency information for libraries. This is
   // simply a set of libraries separated by ";". There should always
   // be a trailing ";". These library names are not canonical, in that
   // they may be "-framework x", "-ly", "/path/libz.a", etc.
@@ -760,7 +736,10 @@ void cmTarget::AddLinkLibrary(cmMakefile& mf, const std::string& lib,
   // may be purposefully duplicated to handle recursive dependencies,
   // and we removing one instance will break the link line. Duplicates
   // will be appropriately eliminated at emit time.
-  if (this->RecordDependencies) {
+  if (this->TargetTypeValue >= cmStateEnums::STATIC_LIBRARY &&
+      this->TargetTypeValue <= cmStateEnums::MODULE_LIBRARY &&
+      (this->GetPolicyStatusCMP0073() == cmPolicies::OLD ||
+       this->GetPolicyStatusCMP0073() == cmPolicies::WARN)) {
     std::string targetEntry = this->Name;
     targetEntry += "_LIB_DEPENDS";
     std::string dependencies;
diff --git a/Source/cmTarget.h b/Source/cmTarget.h
index 56f3e3a..62c4e22 100644
--- a/Source/cmTarget.h
+++ b/Source/cmTarget.h
@@ -137,7 +137,7 @@ public:
   /**
    * Clear the dependency information recorded for this target, if any.
    */
-  void ClearDependencyInformation(cmMakefile& mf, const std::string& target);
+  void ClearDependencyInformation(cmMakefile& mf);
 
   void AddLinkLibrary(cmMakefile& mf, const std::string& lib,
                       cmTargetLinkLibraryType llt);
@@ -310,7 +310,6 @@ private:
   cmTargetInternalPointer Internal;
   cmStateEnums::TargetType TargetTypeValue;
   bool HaveInstallRule;
-  bool RecordDependencies;
   bool DLLPlatform;
   bool IsAndroid;
   bool IsImportedTarget;
diff --git a/Tests/RunCMake/TargetPolicies/PolicyList-stderr.txt b/Tests/RunCMake/TargetPolicies/PolicyList-stderr.txt
index 8d5139d..5af6fcd 100644
--- a/Tests/RunCMake/TargetPolicies/PolicyList-stderr.txt
+++ b/Tests/RunCMake/TargetPolicies/PolicyList-stderr.txt
@@ -23,6 +23,7 @@
    \* CMP0065
    \* CMP0068
    \* CMP0069
+   \* CMP0073
 
 Call Stack \(most recent call first\):
   CMakeLists.txt:3 \(include\)
diff --git a/Tests/RunCMake/add_library/CMP0073-stdout.txt b/Tests/RunCMake/add_library/CMP0073-stdout.txt
new file mode 100644
index 0000000..84645b8
--- /dev/null
+++ b/Tests/RunCMake/add_library/CMP0073-stdout.txt
@@ -0,0 +1,3 @@
+-- warn_LIB_DEPENDS='general;bar;'
+-- old_LIB_DEPENDS='general;bar;'
+-- new_LIB_DEPENDS=''
diff --git a/Tests/RunCMake/add_library/CMP0073.cmake b/Tests/RunCMake/add_library/CMP0073.cmake
new file mode 100644
index 0000000..b34f5dc
--- /dev/null
+++ b/Tests/RunCMake/add_library/CMP0073.cmake
@@ -0,0 +1,18 @@
+enable_language(C)
+
+add_library(warn empty.c)
+target_link_libraries(warn bar)
+message(STATUS "warn_LIB_DEPENDS='${warn_LIB_DEPENDS}'")
+
+cmake_policy(SET CMP0073 OLD)
+add_library(old empty.c)
+target_link_libraries(old bar)
+message(STATUS "old_LIB_DEPENDS='${old_LIB_DEPENDS}'")
+
+cmake_policy(SET CMP0073 NEW)
+add_library(new empty.c)
+target_link_libraries(new bar)
+message(STATUS "new_LIB_DEPENDS='${new_LIB_DEPENDS}'")
+if(DEFINED new_LIB_DEPENDS)
+  message(FATAL_ERROR "new_LIB_DEPENDS set but should not be")
+endif()
diff --git a/Tests/RunCMake/add_library/RunCMakeTest.cmake b/Tests/RunCMake/add_library/RunCMakeTest.cmake
index 0ba6216..dfadb8f 100644
--- a/Tests/RunCMake/add_library/RunCMakeTest.cmake
+++ b/Tests/RunCMake/add_library/RunCMakeTest.cmake
@@ -1,5 +1,7 @@
 include(RunCMake)
 
+run_cmake(CMP0073)
+
 run_cmake(INTERFACEwithNoSources)
 run_cmake(OBJECTwithNoSources)
 run_cmake(STATICwithNoSources)
diff --git a/Tests/RunCMake/add_library/empty.c b/Tests/RunCMake/add_library/empty.c
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/Tests/RunCMake/add_library/empty.c