-Rename -Wargument-larger-than -> -Wlarge-by-value-copy

-Improve the diagnostic message
-Add some comments

Suggestions by Chris.

llvm-svn: 119594

3 files changed, 12 insertions, 8 deletions

diff --git a/clang/lib/Driver/Tools.cpp b/clang/lib/Driver/Tools.cpp
index d9e3760a8d8..60d2fe37925 100644
--- a/clang/lib/Driver/Tools.cpp
+++ b/clang/lib/Driver/Tools.cpp
@@ -1199,13 +1199,13 @@ 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 (Arg *A = Args.getLastArg(options::OPT_Wlarge_by_value_copy_EQ,
+                               options::OPT_Wlarge_by_value_copy_def)) {
+    CmdArgs.push_back("-Wlarge-by-value-copy");
     if (A->getNumValues())
       CmdArgs.push_back(A->getValue(Args));
     else
-      CmdArgs.push_back("64"); // default value for -Wargument-larger-than
+      CmdArgs.push_back("64"); // default value for -Wlarge-by-value-copy.
   }
 
   if (Args.hasArg(options::OPT__relocatable_pch))
diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index 466dfbd9af4..b1d6adb94ba 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -1373,7 +1373,7 @@ static void ParseLangArgs(LangOptions &Opts, ArgList &Args, InputKind IK,
   Opts.MathErrno = Args.hasArg(OPT_fmath_errno);
   Opts.InstantiationDepth = Args.getLastArgIntValue(OPT_ftemplate_depth, 1024,
                                                Diags);
-  Opts.ArgumentLargerThan = Args.getLastArgIntValue(OPT_Wargument_larger_than,
+  Opts.NumLargeByValueCopy = Args.getLastArgIntValue(OPT_Wlarge_by_value_copy,
                                                     0, Diags);
   Opts.NeXTRuntime = !Args.hasArg(OPT_fgnu_runtime);
   Opts.ObjCConstantStringClass =
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index dc017d2ba55..d36bd178e89 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -4869,14 +4869,16 @@ void Sema::DiagnoseSizeOfParametersAndReturnValue(ParmVarDecl * const *Param,
                                                   ParmVarDecl * const *ParamEnd,
                                                   QualType ReturnTy,
                                                   NamedDecl *D) {
-  if (LangOpts.ArgumentLargerThan == 0) // No check.
+  if (LangOpts.NumLargeByValueCopy == 0) // No check.
     return;
 
+  // Warn if the return value is pass-by-value and larger than the specified
+  // threshold.
   if (ReturnTy->isPODType() &&
       Diags.getDiagnosticLevel(diag::warn_return_value_size) !=
           Diagnostic::Ignored) {
     unsigned Size = Context.getTypeSizeInChars(ReturnTy).getQuantity();
-    if (Size > LangOpts.ArgumentLargerThan)
+    if (Size > LangOpts.NumLargeByValueCopy)
       Diag(D->getLocation(), diag::warn_return_value_size)
           << D->getDeclName() << Size;
   }
@@ -4884,12 +4886,14 @@ void Sema::DiagnoseSizeOfParametersAndReturnValue(ParmVarDecl * const *Param,
   if (Diags.getDiagnosticLevel(diag::warn_parameter_size)==Diagnostic::Ignored)
     return;
 
+  // Warn if any parameter is pass-by-value and larger than the specified
+  // threshold.
   for (; Param != ParamEnd; ++Param) {
     QualType T = (*Param)->getType();
     if (!T->isPODType())
       continue;
     unsigned Size = Context.getTypeSizeInChars(T).getQuantity();
-    if (Size > LangOpts.ArgumentLargerThan)
+    if (Size > LangOpts.NumLargeByValueCopy)
       Diag((*Param)->getLocation(), diag::warn_parameter_size)
           << (*Param)->getDeclName() << Size;
   }