implement PR5654: add -fassume-sane-operator-new, which is enabled by default, and adds the malloc attribute to the global function new() and to the overloaded new operators.

feel free to chage the name to this lengthy argument

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@91543 91177308-0d34-0410-b5e6-96231b3b80d8

5 files changed, 23 insertions, 4 deletions

diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp
index 70597ab913..8d82318127 100644
--- a/lib/Driver/Tools.cpp
+++ b/lib/Driver/Tools.cpp
@@ -945,6 +945,10 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
   if (!Args.hasFlag(options::OPT_fbuiltin, options::OPT_fno_builtin))
     CmdArgs.push_back("-fno-builtin");
 
+  if (!Args.hasFlag(options::OPT_fassume_sane_operator_new,
+                    options::OPT_fno_assume_sane_operator_new))
+    CmdArgs.push_back("-fno-assume-sane-operator-new");
+
   // -fblocks=0 is default.
   if (Args.hasFlag(options::OPT_fblocks, options::OPT_fno_blocks,
                    getToolChain().IsBlocksDefault())) {
diff --git a/lib/Frontend/CompilerInvocation.cpp b/lib/Frontend/CompilerInvocation.cpp
index 7a3388ffbb..025f5ddf94 100644
--- a/lib/Frontend/CompilerInvocation.cpp
+++ b/lib/Frontend/CompilerInvocation.cpp
@@ -466,6 +466,8 @@ static void LangOptsToArgs(const LangOptions &Opts,
     Res.push_back("-ffreestanding");
   if (Opts.NoBuiltin)
     Res.push_back("-fno-builtin");
+  if (!Opts.AssumeSaneOperatorNew)
+    Res.push_back("-fno-assume-sane-operator-new");
   if (Opts.ThreadsafeStatics)
     llvm::llvm_report_error("FIXME: Not yet implemented!");
   if (Opts.POSIXThreads)
@@ -1140,6 +1142,7 @@ static void ParseLangArgs(LangOptions &Opts, ArgList &Args,
   Opts.ShortWChar = Args.hasArg(OPT_fshort_wchar);
   Opts.Freestanding = Args.hasArg(OPT_ffreestanding);
   Opts.NoBuiltin = Args.hasArg(OPT_fno_builtin) || Opts.Freestanding;
+  Opts.AssumeSaneOperatorNew = !Args.hasArg(OPT_fno_assume_sane_operator_new);
   Opts.HeinousExtensions = Args.hasArg(OPT_fheinous_gnu_extensions);
   Opts.AccessControl = Args.hasArg(OPT_faccess_control);
   Opts.ElideConstructors = !Args.hasArg(OPT_fno_elide_constructors);
diff --git a/lib/Sema/Sema.h b/lib/Sema/Sema.h
index 473f2c2820..bca9ae9e5b 100644
--- a/lib/Sema/Sema.h
+++ b/lib/Sema/Sema.h
@@ -1976,7 +1976,8 @@ public:
                               bool AllowMissing, FunctionDecl *&Operator);
   void DeclareGlobalNewDelete();
   void DeclareGlobalAllocationFunction(DeclarationName Name, QualType Return,
-                                       QualType Argument);
+                                       QualType Argument,
+                                       bool addMallocAttr = false);
 
   bool FindDeallocationFunction(SourceLocation StartLoc, CXXRecordDecl *RD, 
                                 DeclarationName Name, FunctionDecl* &Operator);
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index 7a27e1185e..bf5b350da0 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -2799,6 +2799,11 @@ Sema::ActOnFunctionDeclarator(Scope* S, Declarator& D, DeclContext* DC,
                                   D.getIdentifierLoc(), Name, R, TInfo,
                                   isStatic, isInline);
 
+    if ((Name.getCXXOverloadedOperator() == OO_New ||
+	 Name.getCXXOverloadedOperator() == OO_Array_New) &&
+	getLangOptions().AssumeSaneOperatorNew)
+      NewFD->addAttr(::new (Context) MallocAttr());
+
     isVirtualOkay = !isStatic;
   } else {
     // Determine whether the function was written with a
diff --git a/lib/Sema/SemaExprCXX.cpp b/lib/Sema/SemaExprCXX.cpp
index 8870a59d13..9108137a00 100644
--- a/lib/Sema/SemaExprCXX.cpp
+++ b/lib/Sema/SemaExprCXX.cpp
@@ -715,13 +715,14 @@ void Sema::DeclareGlobalNewDelete() {
 
   QualType VoidPtr = Context.getPointerType(Context.VoidTy);
   QualType SizeT = Context.getSizeType();
+  bool AssumeSaneOperatorNew = getLangOptions().AssumeSaneOperatorNew;
 
   DeclareGlobalAllocationFunction(
       Context.DeclarationNames.getCXXOperatorName(OO_New),
-      VoidPtr, SizeT);
+      VoidPtr, SizeT, AssumeSaneOperatorNew);
   DeclareGlobalAllocationFunction(
       Context.DeclarationNames.getCXXOperatorName(OO_Array_New),
-      VoidPtr, SizeT);
+      VoidPtr, SizeT, AssumeSaneOperatorNew);
   DeclareGlobalAllocationFunction(
       Context.DeclarationNames.getCXXOperatorName(OO_Delete),
       Context.VoidTy, VoidPtr);
@@ -733,7 +734,8 @@ void Sema::DeclareGlobalNewDelete() {
 /// DeclareGlobalAllocationFunction - Declares a single implicit global
 /// allocation function if it doesn't already exist.
 void Sema::DeclareGlobalAllocationFunction(DeclarationName Name,
-                                           QualType Return, QualType Argument) {
+                                           QualType Return, QualType Argument,
+                                           bool AddMallocAttr) {
   DeclContext *GlobalCtx = Context.getTranslationUnitDecl();
 
   // Check if this function is already declared.
@@ -766,6 +768,10 @@ void Sema::DeclareGlobalAllocationFunction(DeclarationName Name,
     FunctionDecl::Create(Context, GlobalCtx, SourceLocation(), Name,
                          FnType, /*TInfo=*/0, FunctionDecl::None, false, true);
   Alloc->setImplicit();
+  
+  if (AddMallocAttr)
+    Alloc->addAttr(::new (Context) MallocAttr());
+  
   ParmVarDecl *Param = ParmVarDecl::Create(Context, Alloc, SourceLocation(),
                                            0, Argument, /*TInfo=*/0,
                                            VarDecl::None, 0);