Honor visibility properties for all target types (#15556)

The <LANG>_VISIBILITY_PRESET and VISIBILITY_INLINES_HIDDEN were first
merged in commit v2.8.12~322 (Merge topic 'VISIBILITY_PRESET-property',
2013-06-05) but worked only for shared libraries and executables with
exports.  Prior to commit v3.0.0-rc1~581^2 (GenerateExportHeader:
Deprecate add_compiler_export_flags function., 2013-09-02) the
add_compiler_export_flags function was used to add visibility flags to
all targets.

The visibility flags are useful for sources in all target types because
they may be later linked into shared libraries or executables with
exports.  Introduce policy CMP0063 to enable them for all target types
while preserving compatibility with existing projects that do not expect
this.

4 files changed, 55 insertions, 13 deletions

diff --git a/Source/cmLocalGenerator.cxx b/Source/cmLocalGenerator.cxx
index c2e996c..41dc8c5 100644
--- a/Source/cmLocalGenerator.cxx
+++ b/Source/cmLocalGenerator.cxx
@@ -2248,7 +2248,8 @@ AddCompilerRequirementFlag(std::string &flags, cmTarget const* target,
 static void AddVisibilityCompileOption(std::string &flags,
                                        cmTarget const* target,
                                        cmLocalGenerator *lg,
-                                       const std::string& lang)
+                                       const std::string& lang,
+                                       std::string* warnCMP0063)
 {
   std::string l(lang);
   std::string compileOption = "CMAKE_" + l + "_COMPILE_OPTIONS_VISIBILITY";
@@ -2264,6 +2265,11 @@ static void AddVisibilityCompileOption(std::string &flags,
     {
     return;
     }
+  if (warnCMP0063)
+    {
+    *warnCMP0063 += "  " + flagDefine + "\n";
+    return;
+    }
   if (strcmp(prop, "hidden") != 0
       && strcmp(prop, "default") != 0
       && strcmp(prop, "protected") != 0
@@ -2281,7 +2287,8 @@ static void AddVisibilityCompileOption(std::string &flags,
 
 static void AddInlineVisibilityCompileOption(std::string &flags,
                                        cmTarget const* target,
-                                       cmLocalGenerator *lg)
+                                       cmLocalGenerator *lg,
+                                       std::string* warnCMP0063)
 {
   std::string compileOption
                 = "CMAKE_CXX_COMPILE_OPTIONS_VISIBILITY_INLINES_HIDDEN";
@@ -2296,6 +2303,11 @@ static void AddInlineVisibilityCompileOption(std::string &flags,
     {
     return;
     }
+  if (warnCMP0063)
+    {
+    *warnCMP0063 += "  VISIBILITY_INLINES_HIDDEN\n";
+    return;
+    }
   lg->AppendFlags(flags, opt);
 }
 
@@ -2304,25 +2316,49 @@ void cmLocalGenerator
 ::AddVisibilityPresetFlags(std::string &flags, cmTarget const* target,
                             const std::string& lang)
 {
-  int targetType = target->GetType();
-  bool suitableTarget = ((targetType == cmTarget::SHARED_LIBRARY)
-                      || (targetType == cmTarget::MODULE_LIBRARY)
-                      || (target->IsExecutableWithExports()));
-
-  if (!suitableTarget)
+  if (lang.empty())
     {
     return;
     }
 
-  if (lang.empty())
+  std::string warnCMP0063;
+  std::string *pWarnCMP0063 = 0;
+  if (target->GetType() != cmTarget::SHARED_LIBRARY &&
+      target->GetType() != cmTarget::MODULE_LIBRARY &&
+      !target->IsExecutableWithExports())
     {
-    return;
+    switch (target->GetPolicyStatusCMP0063())
+      {
+      case cmPolicies::OLD:
+        return;
+      case cmPolicies::WARN:
+        pWarnCMP0063 = &warnCMP0063;
+        break;
+      default:
+        break;
+      }
     }
-  AddVisibilityCompileOption(flags, target, this, lang);
+
+  AddVisibilityCompileOption(flags, target, this, lang, pWarnCMP0063);
 
   if(lang == "CXX")
     {
-    AddInlineVisibilityCompileOption(flags, target, this);
+    AddInlineVisibilityCompileOption(flags, target, this, pWarnCMP0063);
+    }
+
+  if (!warnCMP0063.empty() &&
+      this->WarnCMP0063.insert(target).second)
+    {
+    std::ostringstream w;
+    w <<
+      cmPolicies::GetPolicyWarning(cmPolicies::CMP0063) << "\n"
+      "Target \"" << target->GetName() << "\" of "
+      "type \"" << cmTarget::GetTargetTypeName(target->GetType()) << "\" "
+      "has the following visibility properties set for " << lang << ":\n" <<
+      warnCMP0063 <<
+      "For compatibility CMake is not honoring them for this target.";
+    target->GetMakefile()->GetCMakeInstance()
+      ->IssueMessage(cmake::AUTHOR_WARNING, w.str(), target->GetBacktrace());
     }
 }
 
diff --git a/Source/cmLocalGenerator.h b/Source/cmLocalGenerator.h
index 3fca225..2585a2c 100644
--- a/Source/cmLocalGenerator.h
+++ b/Source/cmLocalGenerator.h
@@ -456,6 +456,8 @@ protected:
   std::string::size_type ObjectPathMax;
   std::set<std::string> ObjectMaxPathViolations;
 
+  std::set<cmTarget const*> WarnCMP0063;
+
   bool LinkScriptShell;
   bool UseRelativePaths;
   bool Configured;
diff --git a/Source/cmPolicies.h b/Source/cmPolicies.h
index eb56494..00d857a 100644
--- a/Source/cmPolicies.h
+++ b/Source/cmPolicies.h
@@ -214,6 +214,9 @@ class cmPolicy;
     3, 3, 0, cmPolicies::WARN) \
   SELECT(POLICY, CMP0062, \
     "Disallow install() of export() result.", \
+    3, 3, 0, cmPolicies::WARN) \
+  SELECT(POLICY, CMP0063, \
+    "Honor visibility properties for all target types.", \
     3, 3, 0, cmPolicies::WARN)
 
 #define CM_SELECT_ID(F, A1, A2, A3, A4, A5, A6) F(A1)
diff --git a/Source/cmTarget.h b/Source/cmTarget.h
index 1a8b75a..2150b83 100644
--- a/Source/cmTarget.h
+++ b/Source/cmTarget.h
@@ -39,7 +39,8 @@
   F(CMP0042) \
   F(CMP0046) \
   F(CMP0052) \
-  F(CMP0060)
+  F(CMP0060) \
+  F(CMP0063)
 
 class cmake;
 class cmMakefile;