LINK_WHAT_YOU_USE feature: externalize configuration

Currently, this feature is only supported on ELF platforms. So, the property
LINK_WHAT_YOU_USE will be ignored for other plateforms.
Moreover, flags and commands are now controled by CMake variables.

Fixes: #20174

1 files changed, 4 insertions, 7 deletions

diff --git a/Source/cmcmd.cxx b/Source/cmcmd.cxx
index 1f4c0b8..1e0f497 100644
--- a/Source/cmcmd.cxx
+++ b/Source/cmcmd.cxx
@@ -385,18 +385,15 @@ int HandleTidy(const std::string& runCmd, const std::string& sourceFile,
   return ret;
 }
 
-int HandleLWYU(const std::string& runCmd, const std::string& /* sourceFile */,
+int HandleLWYU(const std::string& runCmd, const std::string& sourceFile,
                const std::vector<std::string>&)
 {
   // Construct the ldd -r -u (link what you use lwyu) command line
   // ldd -u -r lwuy target
-  std::vector<std::string> lwyu_cmd;
-  lwyu_cmd.emplace_back("ldd");
-  lwyu_cmd.emplace_back("-u");
-  lwyu_cmd.emplace_back("-r");
-  lwyu_cmd.push_back(runCmd);
+  std::vector<std::string> lwyu_cmd = cmExpandedList(runCmd, true);
+  lwyu_cmd.push_back(sourceFile);
 
-  // Run the ldd -u -r command line.
+  // Run the lwyu check command line,  currently ldd is expected.
   // Capture its stdout and hide its stderr.
   // Ignore its return code because the tool always returns non-zero
   // if there are any warnings, but we just want to warn.