Introduce option -Wargument-larger-than[=N] which warns about function definitions if they take by-value

or return by-value any POD that is larger than some threshold (default is 64 bytes).

Implements rdar://8548050.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@119583 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 9 insertions, 0 deletions

diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp
index aa1b439916..d9e3760a8d 100644
--- a/lib/Driver/Tools.cpp
+++ b/lib/Driver/Tools.cpp
@@ -1199,6 +1199,15 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
     CmdArgs.push_back(A->getValue(Args));
   }
 
+  if (Arg *A = Args.getLastArg(options::OPT_Wargument_larger_than_EQ,
+                               options::OPT_Wargument_larger_than_def)) {
+    CmdArgs.push_back("-Wargument-larger-than");
+    if (A->getNumValues())
+      CmdArgs.push_back(A->getValue(Args));
+    else
+      CmdArgs.push_back("64"); // default value for -Wargument-larger-than
+  }
+
   if (Args.hasArg(options::OPT__relocatable_pch))
     CmdArgs.push_back("-relocatable-pch");