Merge topic 'pch-reuse-from-without-pch-warning' into release-4.2

cb6423703a PrecompileHeaders: downgrade `REUSE_FROM` without a PCH to a warning

Acked-by: Kitware Robot <[email protected]>
Tested-by: buildbot <[email protected]>
Merge-request: !11318

Source/cmGeneratorTarget.cxx

@@ -2906,10 +2906,10 @@ cmGeneratorTarget const* cmGeneratorTarget::GetPchReuseTarget() const
   if (generatorTarget) {
     if (generatorTarget->GetPropertyAsBool("DISABLE_PRECOMPILE_HEADERS")) {
       this->Makefile->IssueMessage(
-        MessageType::FATAL_ERROR,
+        MessageType::WARNING,
         cmStrCat(
           "Target \"", *pchReuseFrom, "\" for the \"", this->GetName(),
-          R"(" target's "PRECOMPILE_HEADERS_REUSE_FROM" property has set "DISABLE_PRECOMPILE_HEADERS".)"));
+          R"(" target's "PRECOMPILE_HEADERS_REUSE_FROM" property has set "DISABLE_PRECOMPILE_HEADERS"; ignoring.)"));
       return nullptr;
     }
 
@@ -2959,10 +2959,10 @@ cmGeneratorTarget* cmGeneratorTarget::GetPchReuseTarget()
   if (generatorTarget) {
     if (generatorTarget->GetPropertyAsBool("DISABLE_PRECOMPILE_HEADERS")) {
       this->Makefile->IssueMessage(
-        MessageType::FATAL_ERROR,
+        MessageType::WARNING,
         cmStrCat(
           "Target \"", *pchReuseFrom, "\" for the \"", this->GetName(),
-          R"(" target's "PRECOMPILE_HEADERS_REUSE_FROM" property has set "DISABLE_PRECOMPILE_HEADERS".)"));
+          R"(" target's "PRECOMPILE_HEADERS_REUSE_FROM" property has set "DISABLE_PRECOMPILE_HEADERS"; ignoring.)"));
       return nullptr;
     }
 

Tests/RunCMake/PrecompileHeaders/PchReuseWithoutPch-result.txt

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

Tests/RunCMake/PrecompileHeaders/PchReuseWithoutPch-stderr.txt

@@ -1,4 +1,4 @@
-CMake Error in CMakeLists\.txt:
+CMake Warning in CMakeLists\.txt:
   Target "pch-generator" for the "reuse_from_nopch" target's
   "PRECOMPILE_HEADERS_REUSE_FROM" property has set
-  "DISABLE_PRECOMPILE_HEADERS".
+  "DISABLE_PRECOMPILE_HEADERS"; ignoring.