tests: test CMP0053 in WARN mode when watching variables

When CMP0053 is in WARN mode, variables get expanded twice, leaking the
fact that the string was expanded twice and changing behavior. Instead,
suppress variable watches when running the expansion to trigger the
CMP0053 warning.

11 files changed, 46 insertions, 1 deletions

diff --git a/Source/cmMakefile.cxx b/Source/cmMakefile.cxx
index 9f33b92..3510dcb 100644
--- a/Source/cmMakefile.cxx
+++ b/Source/cmMakefile.cxx
@@ -103,6 +103,7 @@ cmMakefile::cmMakefile(): Internal(new Internals)
   this->GeneratingBuildSystem = false;
 
   this->NumLastMatches = 0;
+  this->SuppressWatches = false;
 }
 
 cmMakefile::cmMakefile(const cmMakefile& mf): Internal(new Internals)
@@ -153,6 +154,7 @@ cmMakefile::cmMakefile(const cmMakefile& mf): Internal(new Internals)
   this->OutputToSource = mf.OutputToSource;
 
   this->NumLastMatches = mf.NumLastMatches;
+  this->SuppressWatches = mf.SuppressWatches;
 }
 
 //----------------------------------------------------------------------------
@@ -2463,7 +2465,7 @@ const char* cmMakefile::GetDefinition(const std::string& name) const
     }
 #ifdef CMAKE_BUILD_WITH_CMAKE
   cmVariableWatch* vv = this->GetVariableWatch();
-  if ( vv )
+  if ( vv && !this->SuppressWatches )
     {
     if ( def )
       {
@@ -2570,10 +2572,14 @@ const char *cmMakefile::ExpandVariablesInString(std::string& source,
       original = source;
       newResult = source;
       compareResults = true;
+      // Suppress variable watches to avoid calling hooks twice. Suppress new
+      // dereferences since the OLD behavior is still what is actually used.
+      this->SuppressWatches = true;
       newError =
         ExpandVariablesInStringNew(newErrorstr, newResult, escapeQuotes,
                                    noEscapes, atOnly, filename, line,
                                    removeEmpty, replaceAt);
+      this->SuppressWatches = false;
       }
     case cmPolicies::OLD:
       mtype = ExpandVariablesInStringOld(errorstr, source, escapeQuotes,
diff --git a/Source/cmMakefile.h b/Source/cmMakefile.h
index 11904a6..9a4b9c7 100644
--- a/Source/cmMakefile.h
+++ b/Source/cmMakefile.h
@@ -1127,6 +1127,8 @@ private:
                              const std::string& feature) const;
   bool HaveCxxFeatureAvailable(cmTarget const* target,
                                const std::string& feature) const;
+
+  mutable bool SuppressWatches;
 };
 
 //----------------------------------------------------------------------------
diff --git a/Tests/RunCMake/CMP0053/CMP0053-NEW-stderr.txt b/Tests/RunCMake/CMP0053/CMP0053-NEW-stderr.txt
new file mode 100644
index 0000000..836b0ff
--- /dev/null
+++ b/Tests/RunCMake/CMP0053/CMP0053-NEW-stderr.txt
@@ -0,0 +1,2 @@
+^called
+--><--$
diff --git a/Tests/RunCMake/CMP0053/CMP0053-NEW.cmake b/Tests/RunCMake/CMP0053/CMP0053-NEW.cmake
new file mode 100644
index 0000000..6ffedc6
--- /dev/null
+++ b/Tests/RunCMake/CMP0053/CMP0053-NEW.cmake
@@ -0,0 +1,8 @@
+cmake_policy(SET CMP0053 NEW)
+
+function (watch_callback)
+  message("called")
+endfunction ()
+
+variable_watch(test watch_callback)
+message("-->${test}<--")
diff --git a/Tests/RunCMake/CMP0053/CMP0053-OLD-stderr.txt b/Tests/RunCMake/CMP0053/CMP0053-OLD-stderr.txt
new file mode 100644
index 0000000..836b0ff
--- /dev/null
+++ b/Tests/RunCMake/CMP0053/CMP0053-OLD-stderr.txt
@@ -0,0 +1,2 @@
+^called
+--><--$
diff --git a/Tests/RunCMake/CMP0053/CMP0053-OLD.cmake b/Tests/RunCMake/CMP0053/CMP0053-OLD.cmake
new file mode 100644
index 0000000..41f5347
--- /dev/null
+++ b/Tests/RunCMake/CMP0053/CMP0053-OLD.cmake
@@ -0,0 +1,8 @@
+cmake_policy(SET CMP0053 OLD)
+
+function (watch_callback)
+  message("called")
+endfunction ()
+
+variable_watch(test watch_callback)
+message("-->${test}<--")
diff --git a/Tests/RunCMake/CMP0053/CMP0053-WARN-stderr.txt b/Tests/RunCMake/CMP0053/CMP0053-WARN-stderr.txt
new file mode 100644
index 0000000..836b0ff
--- /dev/null
+++ b/Tests/RunCMake/CMP0053/CMP0053-WARN-stderr.txt
@@ -0,0 +1,2 @@
+^called
+--><--$
diff --git a/Tests/RunCMake/CMP0053/CMP0053-WARN.cmake b/Tests/RunCMake/CMP0053/CMP0053-WARN.cmake
new file mode 100644
index 0000000..b010d13
--- /dev/null
+++ b/Tests/RunCMake/CMP0053/CMP0053-WARN.cmake
@@ -0,0 +1,6 @@
+function (watch_callback)
+  message("called")
+endfunction ()
+
+variable_watch(test watch_callback)
+message("-->${test}<--")
diff --git a/Tests/RunCMake/CMP0053/CMakeLists.txt b/Tests/RunCMake/CMP0053/CMakeLists.txt
new file mode 100644
index 0000000..3482e6b
--- /dev/null
+++ b/Tests/RunCMake/CMP0053/CMakeLists.txt
@@ -0,0 +1,3 @@
+cmake_minimum_required(VERSION 3.0)
+project(${RunCMake_TEST} CXX)
+include(${RunCMake_TEST}.cmake)
diff --git a/Tests/RunCMake/CMP0053/RunCMakeTest.cmake b/Tests/RunCMake/CMP0053/RunCMakeTest.cmake
new file mode 100644
index 0000000..6521ac0
--- /dev/null
+++ b/Tests/RunCMake/CMP0053/RunCMakeTest.cmake
@@ -0,0 +1,5 @@
+include(RunCMake)
+
+run_cmake(CMP0053-OLD)
+run_cmake(CMP0053-NEW)
+run_cmake(CMP0053-WARN)
diff --git a/Tests/RunCMake/CMakeLists.txt b/Tests/RunCMake/CMakeLists.txt
index 4efc73a..165f027 100644
--- a/Tests/RunCMake/CMakeLists.txt
+++ b/Tests/RunCMake/CMakeLists.txt
@@ -35,6 +35,7 @@ add_RunCMake_test(CMP0046)
 add_RunCMake_test(CMP0049)
 add_RunCMake_test(CMP0050)
 add_RunCMake_test(CMP0051)
+add_RunCMake_test(CMP0053)
 add_RunCMake_test(CTest)
 if(UNIX AND "${CMAKE_GENERATOR}" MATCHES "Unix Makefiles")
   add_RunCMake_test(CompilerChange)