message: Add new CMAKE_MESSAGE_LOG_LEVEL variable

Help/command/message.rst

@@ -59,6 +59,9 @@ The :manual:`curses interface <ccmake(1)>` shows ``STATUS`` to ``TRACE``
 messages one at a time on a status line and other messages in an
 interactive pop-up box.  The ``--log-level`` command-line option to each of
 these tools can be used to control which messages will be shown.
+To make a log level persist between CMake runs, the
+:variable:`CMAKE_MESSAGE_LOG_LEVEL` variable can be set instead.
+Note that the command line option takes precedence over the cache variable.
 
 Messages of log levels ``NOTICE`` and below will also have each line preceded
 by the content of the :variable:`CMAKE_MESSAGE_INDENT` variable (converted to

Help/manual/cmake-variables.7.rst

@@ -205,6 +205,7 @@ Variables that Change Behavior
    /variable/CMAKE_MFC_FLAG
    /variable/CMAKE_MAXIMUM_RECURSION_DEPTH
    /variable/CMAKE_MESSAGE_INDENT
+   /variable/CMAKE_MESSAGE_LOG_LEVEL
    /variable/CMAKE_MODULE_PATH
    /variable/CMAKE_POLICY_DEFAULT_CMPNNNN
    /variable/CMAKE_POLICY_WARNING_CMPNNNN

Help/manual/cmake.1.rst

@@ -206,6 +206,11 @@ Options
  The :command:`message` command will only output messages of the specified
  log level or higher.  The default log level is ``STATUS``.
 
+ To make a log level persist between CMake runs, set
+ :variable:`CMAKE_MESSAGE_LOG_LEVEL` as a cache variable instead.
+ If both the command line option and the variable are given, the command line
+ option takes precedence.
+
  For backward compatibility reasons, ``--loglevel`` is also accepted as a
  synonym for this option.
 

Help/release/dev/feature-CMAKE_MESSAGE_CONTEXT

@@ -0,0 +1,6 @@
+feature-CMAKE_MESSAGE_CONTEXT
+-----------------------------
+
+* The :variable:`CMAKE_MESSAGE_LOG_LEVEL` variable can now be used
+  to persist a log level between CMake runs, unlike the ``--log-level``
+  command line option which only applies to that particular run.

Help/variable/CMAKE_MESSAGE_LOG_LEVEL.rst

@@ -0,0 +1,15 @@
+CMAKE_MESSAGE_LOG_LEVEL
+-----------------------
+
+When set, this variable specifies the logging level used by the
+:command:`message` command.  Valid values are the same as those for the
+``--log-level`` command line option of the :manual:`cmake(1)` program.
+If this variable is set and the ``--log-level`` command line option is
+given, the command line option takes precedence.
+
+The main advantage to using this variable is to make a log level persist
+between CMake runs.  Setting it as a cache variable will ensure that
+subsequent CMake runs will continue to use the chosen log level.
+
+Projects should not set this variable, it is intended for users so that
+they may control the log level according to their own needs.

Source/cmMessageCommand.cxx

@@ -95,6 +95,15 @@ bool cmMessageCommand(std::vector<std::string> const& args,
   assert("Expected a valid log level here" &&
          desiredLevel != cmake::LogLevel::LOG_UNDEFINED);
 
+  // Command line option takes precedence over the cache variable
+  if (!mf.GetCMakeInstance()->WasLogLevelSetViaCLI()) {
+    const auto desiredLevelFromCache =
+      cmake::StringToLogLevel(mf.GetSafeDefinition("CMAKE_MESSAGE_LOG_LEVEL"));
+    if (desiredLevelFromCache != cmake::LogLevel::LOG_UNDEFINED) {
+      desiredLevel = desiredLevelFromCache;
+    }
+  }
+
   if (desiredLevel < level) {
     // Suppress the message
     return true;

Source/cmake.cxx

@@ -733,6 +733,7 @@ void cmake::SetArgs(const std::vector<std::string>& args)
         return;
       }
       this->SetLogLevel(logLevel);
+      this->LogLevelWasSetViaCLI = true;
     } else if (arg.find("--loglevel=", 0) == 0) {
       // This is supported for backward compatibility. This option only
       // appeared in the 3.15.x release series and was renamed to
@@ -744,6 +745,7 @@ void cmake::SetArgs(const std::vector<std::string>& args)
         return;
       }
       this->SetLogLevel(logLevel);
+      this->LogLevelWasSetViaCLI = true;
     } else if (arg.find("--trace-expand", 0) == 0) {
       std::cout << "Running with expanded trace output on.\n";
       this->SetTrace(true);

Source/cmake.h

@@ -380,6 +380,8 @@ public:
    */
   cmFileTimeCache* GetFileTimeCache() { return this->FileTimeCache.get(); }
 
+  bool WasLogLevelSetViaCLI() const { return this->LogLevelWasSetViaCLI; }
+
   //! Get the selected log level for `message()` commands during the cmake run.
   LogLevel GetLogLevel() const { return this->MessageLogLevel; }
   void SetLogLevel(LogLevel level) { this->MessageLogLevel = level; }
@@ -587,6 +589,7 @@ private:
   std::vector<std::string> TraceOnlyThisSources;
 
   LogLevel MessageLogLevel = LogLevel::LOG_STATUS;
+  bool LogLevelWasSetViaCLI = false;
 
   void UpdateConversionPathTable();
 

Tests/RunCMake/message/RunCMakeTest.cmake

@@ -55,6 +55,11 @@ foreach(opt IN ITEMS loglevel log-level)
     )
 endforeach()
 
+run_cmake_command(
+    message-log-level-override
+    ${CMAKE_COMMAND} --log-level=debug -DCMAKE_MESSAGE_LOG_LEVEL=TRACE -P ${RunCMake_SOURCE_DIR}/message-all-loglevels.cmake
+  )
+
 run_cmake_command(
     message-indent
     ${CMAKE_COMMAND} -P ${RunCMake_SOURCE_DIR}/message-indent.cmake

Tests/RunCMake/message/message-log-level-override-stderr.txt

@@ -0,0 +1,12 @@
+^CMake Deprecation Warning at.*/Tests/RunCMake/message/message-all-loglevels\.cmake:2 \(message\):
+  Deprecation warning
++
+CMake Warning \(dev\) at.*/Tests/RunCMake/message/message-all-loglevels\.cmake:3 \(message\):
+  Author warning message
+This warning is for project developers\.  Use -Wno-dev to suppress it\.
++
+CMake Warning at.*/Tests/RunCMake/message/message-all-loglevels\.cmake:4 \(message\):
+  Warning message
++
+Default NOTICE message
+NOTICE message$

Tests/RunCMake/message/message-log-level-override-stdout.txt

@@ -0,0 +1,3 @@
+-- STATUS message
+-- VERBOSE message
+-- DEBUG message$