Merge topic 'qt4-autolink-qtmain'

e3b5eb6 Automatically link to the qtmain library when linking to QtCore.
6c8d8af Add the $<TARGET_POLICY> expression

6 files changed, 135 insertions, 0 deletions

diff --git a/Source/cmDocumentGeneratorExpressions.h b/Source/cmDocumentGeneratorExpressions.h
index fa21907..c2bf423 100644
--- a/Source/cmDocumentGeneratorExpressions.h
+++ b/Source/cmDocumentGeneratorExpressions.h
@@ -50,6 +50,10 @@
   "  $<TARGET_PROPERTY:tgt,prop>   = The value of the property prop\n"  \
   "on the target tgt. Note that tgt is not added as a dependency of\n"  \
   "the target this expression is evaluated on.\n"                       \
+  "  $<TARGET_POLICY:pol>          = '1' if the policy was NEW when "   \
+  "the 'head' target was created, else '0'.  If the policy was not "    \
+  "set, the warning message for the policy will be emitted.  This "     \
+  "generator expression only works for a subset of policies.\n"         \
   "Boolean expressions:\n"                                              \
   "  $<AND:?[,?]...>           = '1' if all '?' are '1', else '0'\n"    \
   "  $<OR:?[,?]...>            = '0' if all '?' are '0', else '1'\n"    \
diff --git a/Source/cmGeneratorExpressionEvaluator.cxx b/Source/cmGeneratorExpressionEvaluator.cxx
index e842880..c468c39 100644
--- a/Source/cmGeneratorExpressionEvaluator.cxx
+++ b/Source/cmGeneratorExpressionEvaluator.cxx
@@ -509,6 +509,105 @@ static const struct TargetNameNode : public cmGeneratorExpressionNode
 } targetNameNode;
 
 //----------------------------------------------------------------------------
+static const char* targetPolicyWhitelist[] = {
+    "CMP0003"
+  , "CMP0004"
+  , "CMP0008"
+  , "CMP0020"
+};
+
+cmPolicies::PolicyStatus statusForTarget(cmTarget *tgt, const char *policy)
+{
+#define RETURN_POLICY(POLICY) \
+  if (strcmp(policy, #POLICY) == 0) \
+  { \
+    return tgt->GetPolicyStatus ## POLICY (); \
+  } \
+
+  RETURN_POLICY(CMP0003)
+  RETURN_POLICY(CMP0004)
+  RETURN_POLICY(CMP0008)
+  RETURN_POLICY(CMP0020)
+
+#undef RETURN_POLICY
+
+  assert("!Unreachable code. Not a valid policy");
+  return cmPolicies::WARN;
+}
+
+cmPolicies::PolicyID policyForString(const char *policy_id)
+{
+#define RETURN_POLICY_ID(POLICY_ID) \
+  if (strcmp(policy_id, #POLICY_ID) == 0) \
+  { \
+    return cmPolicies:: POLICY_ID; \
+  } \
+
+  RETURN_POLICY_ID(CMP0003)
+  RETURN_POLICY_ID(CMP0004)
+  RETURN_POLICY_ID(CMP0008)
+  RETURN_POLICY_ID(CMP0020)
+
+#undef RETURN_POLICY_ID
+
+  assert("!Unreachable code. Not a valid policy");
+  return cmPolicies::CMP0002;
+}
+
+//----------------------------------------------------------------------------
+static const struct TargetPolicyNode : public cmGeneratorExpressionNode
+{
+  TargetPolicyNode() {}
+
+  virtual int NumExpectedParameters() const { return 1; }
+
+  std::string Evaluate(const std::vector<std::string> &parameters,
+                       cmGeneratorExpressionContext *context ,
+                       const GeneratorExpressionContent *content,
+                       cmGeneratorExpressionDAGChecker *) const
+  {
+    if (!context->HeadTarget)
+      {
+      reportError(context, content->GetOriginalExpression(),
+          "$<TARGET_POLICY:prop> may only be used with targets.  It may not "
+          "be used with add_custom_command.");
+      return std::string();
+      }
+    for (size_t i = 0;
+         i < (sizeof(targetPolicyWhitelist) /
+              sizeof(*targetPolicyWhitelist));
+         ++i)
+      {
+      const char *policy = targetPolicyWhitelist[i];
+      if (parameters.front() == policy)
+        {
+        cmMakefile *mf = context->HeadTarget->GetMakefile();
+        switch(statusForTarget(context->HeadTarget, policy))
+          {
+          case cmPolicies::WARN:
+            mf->IssueMessage(cmake::AUTHOR_WARNING,
+                             mf->GetPolicies()->
+                             GetPolicyWarning(policyForString(policy)));
+          case cmPolicies::REQUIRED_IF_USED:
+          case cmPolicies::REQUIRED_ALWAYS:
+          case cmPolicies::OLD:
+            return "0";
+          case cmPolicies::NEW:
+            return "1";
+          }
+        }
+      }
+    reportError(context, content->GetOriginalExpression(),
+      "$<TARGET_POLICY:prop> may only be used with a limited number of "
+      "policies.  Currently it may be used with policies CMP0003, CMP0004, "
+      "CMP0008 and CMP0020."
+      );
+    return std::string();
+  }
+
+} targetPolicyNode;
+
+//----------------------------------------------------------------------------
 template<bool linker, bool soname>
 struct TargetFilesystemArtifactResultCreator
 {
@@ -735,6 +834,8 @@ cmGeneratorExpressionNode* GetNode(const std::string &identifier)
     return &targetPropertyNode;
   else if (identifier == "TARGET_NAME")
     return &targetNameNode;
+  else if (identifier == "TARGET_POLICY")
+    return &targetPolicyNode;
   else if (identifier == "BUILD_INTERFACE")
     return &buildInterfaceNode;
   else if (identifier == "INSTALL_INTERFACE")
diff --git a/Source/cmPolicies.cxx b/Source/cmPolicies.cxx
index eb7d666..831e92e 100644
--- a/Source/cmPolicies.cxx
+++ b/Source/cmPolicies.cxx
@@ -508,6 +508,27 @@ cmPolicies::cmPolicies()
     "for strict compatibility.  "
     "The NEW behavior for this policy is to leave the values untouched.",
     2,8,11,0, cmPolicies::WARN);
+
+  this->DefinePolicy(
+    CMP0020, "CMP0020",
+    "Automatically link Qt executables to qtmain target on Windows.",
+    "CMake 2.8.10 and lower required users of Qt to always specify a link "
+    "dependency to the qtmain.lib static library manually on Windows.  CMake "
+    "2.8.11 gained the ability to evaluate generator expressions while "
+    "determining the link dependencies from IMPORTED targets.  This allows "
+    "CMake itself to automatically link executables which link to Qt to the "
+    "qtmain.lib library when using IMPORTED Qt targets.  For applications "
+    "already linking to qtmain.lib, this should have little impact.  For "
+    "applications which supply their own alternative WinMain implementation "
+    "and for applications which use the QAxServer library, this automatic "
+    "linking will need to be disabled as per the documentation."
+    "\n"
+    "The OLD behavior for this policy is not to link executables to "
+    "qtmain.lib automatically when they link to the QtCore IMPORTED"
+    "target.  "
+    "The NEW behavior for this policy is to link executables to "
+    "qtmain.lib automatically when they link to QtCore IMPORTED target.",
+    2,8,11,0, cmPolicies::WARN);
 }
 
 cmPolicies::~cmPolicies()
diff --git a/Source/cmPolicies.h b/Source/cmPolicies.h
index d7d945c..c11af07 100644
--- a/Source/cmPolicies.h
+++ b/Source/cmPolicies.h
@@ -69,6 +69,7 @@ public:
     /// POSITION_INDEPENDENT_CODE property and *_COMPILE_OPTIONS_PI{E,C}
     /// instead.
     CMP0019, ///< No variable re-expansion in include and link info
+    CMP0020, ///< Automatically link Qt executables to qtmain target
 
     /** \brief Always the last entry.
      *
diff --git a/Source/cmTarget.cxx b/Source/cmTarget.cxx
index 2600db5..19e59d7 100644
--- a/Source/cmTarget.cxx
+++ b/Source/cmTarget.cxx
@@ -145,6 +145,7 @@ cmTarget::cmTarget()
   this->PolicyStatusCMP0003 = cmPolicies::WARN;
   this->PolicyStatusCMP0004 = cmPolicies::WARN;
   this->PolicyStatusCMP0008 = cmPolicies::WARN;
+  this->PolicyStatusCMP0020 = cmPolicies::WARN;
   this->LinkLibrariesAnalyzed = false;
   this->HaveInstallRule = false;
   this->DLLPlatform = false;
@@ -1499,6 +1500,8 @@ void cmTarget::SetMakefile(cmMakefile* mf)
     this->Makefile->GetPolicyStatus(cmPolicies::CMP0004);
   this->PolicyStatusCMP0008 =
     this->Makefile->GetPolicyStatus(cmPolicies::CMP0008);
+  this->PolicyStatusCMP0020 =
+    this->Makefile->GetPolicyStatus(cmPolicies::CMP0020);
 }
 
 //----------------------------------------------------------------------------
diff --git a/Source/cmTarget.h b/Source/cmTarget.h
index b3e17b2..65b5bdf 100644
--- a/Source/cmTarget.h
+++ b/Source/cmTarget.h
@@ -102,6 +102,10 @@ public:
   cmPolicies::PolicyStatus GetPolicyStatusCMP0008() const
     { return this->PolicyStatusCMP0008; }
 
+  /** Get the status of policy CMP0020 when the target was created.  */
+  cmPolicies::PolicyStatus GetPolicyStatusCMP0020() const
+    { return this->PolicyStatusCMP0020; }
+
   /**
    * Get the list of the custom commands for this target
    */
@@ -658,6 +662,7 @@ private:
   cmPolicies::PolicyStatus PolicyStatusCMP0003;
   cmPolicies::PolicyStatus PolicyStatusCMP0004;
   cmPolicies::PolicyStatus PolicyStatusCMP0008;
+  cmPolicies::PolicyStatus PolicyStatusCMP0020;
 
   // Internal representation details.
   friend class cmTargetInternals;