cmake: Add an option to control what files needs to be traced

Even in relatively small projects using `--trace` (and `--trace-expand`)
may produce a lot of output.  When developing a custom module usually
one is interested in output of only a few particular modules.

Add a `--trace-source=<file>` option to enable tracing only a subset of
source files.  The final output would be only from requested modules,
ignoring anything else not matched to given filename(s).

1 files changed, 5 insertions, 0 deletions

diff --git a/Source/cmake.cxx b/Source/cmake.cxx
index db0072a..654100b 100644
--- a/Source/cmake.cxx
+++ b/Source/cmake.cxx
@@ -589,6 +589,11 @@ void cmake::SetArgs(const std::vector<std::string>& args,
       std::cout << "Running with expanded trace output on.\n";
       this->SetTrace(true);
       this->SetTraceExpand(true);
+    } else if (arg.find("--trace-source=", 0) == 0) {
+      std::string file = arg.substr(strlen("--trace-source="));
+      cmSystemTools::ConvertToUnixSlashes(file);
+      this->AddTraceSource(file);
+      this->SetTrace(true);
     } else if (arg.find("--trace", 0) == 0) {
       std::cout << "Running with trace output on.\n";
       this->SetTrace(true);