cmake: add --trace-expand option

The --trace option is helpful, but sometimes, what you're looking for is
deep under many layers of function calls and figuring out what instance
of the function call you're looking at is tedious to determine (usually
involving patching and message()). Instead, add a --trace-expand option
to trace while expanding commands into what CMake actually sees.

4 files changed, 26 insertions, 2 deletions

diff --git a/Source/cmMakefile.cxx b/Source/cmMakefile.cxx
index ae69b24..7c98970 100644
--- a/Source/cmMakefile.cxx
+++ b/Source/cmMakefile.cxx
@@ -307,10 +307,21 @@ void cmMakefile::PrintCommandTrace(const cmListFileFunction& lff) const
   std::ostringstream msg;
   msg << this->GetExecutionFilePath() << "(" << lff.Line << "):  ";
   msg << lff.Name << "(";
+  bool expand = this->GetCMakeInstance()->GetTraceExpand();
+  std::string temp;
   for(std::vector<cmListFileArgument>::const_iterator i =
         lff.Arguments.begin(); i != lff.Arguments.end(); ++i)
     {
-    msg << i->Value;
+    if (expand)
+      {
+      temp = i->Value;
+      this->ExpandVariablesInString(temp);
+      msg << temp;
+      }
+    else
+      {
+      msg << i->Value;
+      }
     msg << " ";
     }
   msg << ")";
@@ -4802,7 +4813,8 @@ bool cmMakefile::PolicyOptionalWarningEnabled(std::string const& var)
       return cmSystemTools::IsOn(val);
       }
     }
-  // Enable optional policy warnings with --debug-output or --trace.
+  // Enable optional policy warnings with --debug-output, --trace,
+  // or --trace-expand.
   cmake* cm = this->GetCMakeInstance();
   return cm->GetDebugOutput() || cm->GetTrace();
 }
diff --git a/Source/cmake.cxx b/Source/cmake.cxx
index 7bf3832..6abdbed 100644
--- a/Source/cmake.cxx
+++ b/Source/cmake.cxx
@@ -121,6 +121,7 @@ void cmWarnUnusedCliWarning(const std::string& variable,
 cmake::cmake()
 {
   this->Trace = false;
+  this->TraceExpand = false;
   this->WarnUninitialized = false;
   this->WarnUnused = false;
   this->WarnUnusedCli = true;
@@ -617,10 +618,17 @@ void cmake::SetArgs(const std::vector<std::string>& args,
       std::cout << "Running with debug output on.\n";
       this->SetDebugOutputOn(true);
       }
+    else if(arg.find("--trace-expand",0) == 0)
+      {
+      std::cout << "Running with expanded trace output on.\n";
+      this->SetTrace(true);
+      this->SetTraceExpand(true);
+      }
     else if(arg.find("--trace",0) == 0)
       {
       std::cout << "Running with trace output on.\n";
       this->SetTrace(true);
+      this->SetTraceExpand(false);
       }
     else if(arg.find("--warn-uninitialized",0) == 0)
       {
diff --git a/Source/cmake.h b/Source/cmake.h
index f0f9411..20e49e3 100644
--- a/Source/cmake.h
+++ b/Source/cmake.h
@@ -270,6 +270,8 @@ class cmake
   // Do we want trace output during the cmake run.
   bool GetTrace() { return this->Trace;}
   void SetTrace(bool b) {  this->Trace = b;}
+  bool GetTraceExpand() { return this->TraceExpand;}
+  void SetTraceExpand(bool b) {  this->TraceExpand = b;}
   bool GetWarnUninitialized() { return this->WarnUninitialized;}
   void SetWarnUninitialized(bool b) {  this->WarnUninitialized = b;}
   bool GetWarnUnused() { return this->WarnUnused;}
@@ -378,6 +380,7 @@ private:
   WorkingMode CurrentWorkingMode;
   bool DebugOutput;
   bool Trace;
+  bool TraceExpand;
   bool WarnUninitialized;
   bool WarnUnused;
   bool WarnUnusedCli;
diff --git a/Source/cmakemain.cxx b/Source/cmakemain.cxx
index c94ffec..a06b26f 100644
--- a/Source/cmakemain.cxx
+++ b/Source/cmakemain.cxx
@@ -83,6 +83,7 @@ static const char * cmDocumentationOptions[][2] =
    "useful on one try_compile at a time."},
   {"--debug-output", "Put cmake in a debug mode."},
   {"--trace", "Put cmake in trace mode."},
+  {"--trace-expand", "Put cmake in trace mode with variable expansion."},
   {"--warn-uninitialized", "Warn about uninitialized values."},
   {"--warn-unused-vars", "Warn about unused variables."},
   {"--no-warn-unused-cli", "Don't warn about command line options."},