[PATCH] D105225: [clang] Add support for optional flag -fnew-infallible to restrict exception propagation

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This revision was landed with ongoing or failed builds.
This revision was automatically updated to reflect the committed changes.
Closed by commit rGb40a2a533a9d: [clang] Add support for optional flag -fnew-infallible to restrict exception… (authored by modimo).
Herald added a project: clang.
Herald added a subscriber: cfe-commits.

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D105225/new/

https://reviews.llvm.org/D105225

Files:
  clang/docs/ClangCommandLineReference.rst
  clang/include/clang/Basic/LangOptions.def
  clang/include/clang/Driver/Options.td
  clang/lib/Driver/ToolChains/Clang.cpp
  clang/lib/Sema/SemaExprCXX.cpp
  clang/test/CodeGenCXX/new-infallible.cpp


Index: clang/test/CodeGenCXX/new-infallible.cpp
===================================================================
--- /dev/null
+++ clang/test/CodeGenCXX/new-infallible.cpp
@@ -0,0 +1,7 @@
+// RUN: %clang_cc1 -emit-llvm -triple x86_64-linux-gnu -fnew-infallible -o - %s | FileCheck %s
+
+// CHECK: call noalias nonnull i8* @_Znwm(i64 4)
+
+// CHECK: ; Function Attrs: nobuiltin nounwind allocsize(0)
+// CHECK-NEXT: declare nonnull i8* @_Znwm(i64)
+int *new_infallible = new int;
Index: clang/lib/Sema/SemaExprCXX.cpp
===================================================================
--- clang/lib/Sema/SemaExprCXX.cpp
+++ clang/lib/Sema/SemaExprCXX.cpp
@@ -3049,6 +3049,9 @@
       EPI.ExceptionSpec.Type = EST_Dynamic;
       EPI.ExceptionSpec.Exceptions = llvm::makeArrayRef(BadAllocType);
     }
+    if (getLangOpts().NewInfallible) {
+      EPI.ExceptionSpec.Type = EST_DynamicNone;
+    }
   } else {
     EPI.ExceptionSpec =
         getLangOpts().CPlusPlus11 ? EST_BasicNoexcept : EST_DynamicNone;
@@ -3064,6 +3067,10 @@
     // Global allocation functions should always be visible.
     Alloc->setVisibleDespiteOwningModule();
 
+    if (HasBadAllocExceptionSpec && getLangOpts().NewInfallible)
+      Alloc->addAttr(
+          ReturnsNonNullAttr::CreateImplicit(Context, Alloc->getLocation()));
+
     Alloc->addAttr(VisibilityAttr::CreateImplicit(
         Context, LangOpts.GlobalAllocationFunctionVisibilityHidden
                      ? VisibilityAttr::Hidden
Index: clang/lib/Driver/ToolChains/Clang.cpp
===================================================================
--- clang/lib/Driver/ToolChains/Clang.cpp
+++ clang/lib/Driver/ToolChains/Clang.cpp
@@ -5711,7 +5711,7 @@
   Args.AddLastArg(CmdArgs, options::OPT_fvisibility_inlines_hidden_static_local_var,
                            options::OPT_fno_visibility_inlines_hidden_static_local_var);
   Args.AddLastArg(CmdArgs, options::OPT_fvisibility_global_new_delete_hidden);
-
+  Args.AddLastArg(CmdArgs, options::OPT_fnew_infallible);
   Args.AddLastArg(CmdArgs, options::OPT_ftlsmodel_EQ);
 
   if (Args.hasFlag(options::OPT_fno_operator_names,
Index: clang/include/clang/Driver/Options.td
===================================================================
--- clang/include/clang/Driver/Options.td
+++ clang/include/clang/Driver/Options.td
@@ -2730,6 +2730,10 @@
 def fvisibility_global_new_delete_hidden : Flag<["-"], "fvisibility-global-new-delete-hidden">, Group<f_Group>,
   HelpText<"Give global C++ operator new and delete declarations hidden visibility">, Flags<[CC1Option]>,
   MarshallingInfoFlag<LangOpts<"GlobalAllocationFunctionVisibilityHidden">>;
+def fnew_infallible : Flag<["-"], "fnew-infallible">, Group<f_Group>,
+  HelpText<"Treats throwing global C++ operator new as always returning valid memory "
+  "(annotates with __attribute__((returns_nonnull)) and throw()). This is detectable in source.">,
+  Flags<[CC1Option]>, MarshallingInfoFlag<LangOpts<"NewInfallible">>;
 defm whole_program_vtables : BoolFOption<"whole-program-vtables",
   CodeGenOpts<"WholeProgramVTables">, DefaultFalse,
   PosFlag<SetTrue, [CC1Option], "Enables whole-program vtable optimization. Requires -flto">,
Index: clang/include/clang/Basic/LangOptions.def
===================================================================
--- clang/include/clang/Basic/LangOptions.def
+++ clang/include/clang/Basic/LangOptions.def
@@ -280,6 +280,7 @@
                "hidden visibility for static local variables in inline C++ "
                "methods when -fvisibility-inlines hidden is enabled")
 LANGOPT(GlobalAllocationFunctionVisibilityHidden , 1, 0, "hidden visibility for global operator new and delete declaration")
+LANGOPT(NewInfallible , 1, 0, "Treats throwing global C++ operator new as always returning valid memory (annotates with __attribute__((returns_nonnull)) and throw()). This is detectable in source.")
 BENIGN_LANGOPT(ParseUnknownAnytype, 1, 0, "__unknown_anytype")
 BENIGN_LANGOPT(DebuggerSupport , 1, 0, "debugger support")
 BENIGN_LANGOPT(DebuggerCastResultToId, 1, 0, "for 'po' in the debugger, cast the result to id if it is of unknown type")
Index: clang/docs/ClangCommandLineReference.rst
===================================================================
--- clang/docs/ClangCommandLineReference.rst
+++ clang/docs/ClangCommandLineReference.rst
@@ -1941,6 +1941,10 @@
 
 Specifies the largest alignment guaranteed by '::operator new(size\_t)'
 
+.. option:: -fnew-infallible
+
+Treats throwing global C++ operator new as always returning valid memory (annotates with \_\_attribute\_\_((returns\_nonnull)) and throw()). This is detectable in source.
+
 .. option:: -fnext-runtime
 
 .. option:: -fno-builtin-<arg>


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