Commit 843a9778 authored by Jeremy Stenglein's avatar Jeremy Stenglein Committed by Erich Keane
Browse files

Add a warning for builtin_return_address/frame_address with > 0 argument 

Clang is missing a warning for
builtin_return_address/builtin_frame_address called with > 0 argument.
Gcc provides a warning for this via -Wframe-address:

https://gcc.gnu.org/onlinedocs/gcc/Return-Address.html

As calling these functions with argument > 0 has caused several crashes
for us, we would like to have the same warning as gcc here. This diff
adds the warning and makes it part of -Wmost.

Differential Revision: https://reviews.llvm.org/D75768
parent eb682b80

clang/include/clang/Basic/DiagnosticGroups.td

+2 −0
Original line number Diff line number Diff line
@@ -99,6 +99,7 @@ def FloatConversion : 
  DiagGroup<"float-conversion", [FloatOverflowConversion,

                                 FloatZeroConversion]>;



def FrameAddress : DiagGroup<"frame-address">;

def DoublePromotion : DiagGroup<"double-promotion">;

def EnumTooLarge : DiagGroup<"enum-too-large">;

def UnsupportedNan : DiagGroup<"unsupported-nan">;
@@ -872,6 +873,7 @@ def Most : DiagGroup<"most", [ 
    DeleteNonVirtualDtor,

    Format,

    ForLoopAnalysis,

    FrameAddress,

    Implicit,

    InfiniteRecursion,

    IntInBoolContext,

clang/include/clang/Basic/DiagnosticSemaKinds.td

+5 −0
Original line number Diff line number Diff line
@@ -1780,6 +1780,11 @@ def note_due_to_dllexported_class : Note< 
def err_illegal_union_or_anon_struct_member : Error<

  "%select{anonymous struct|union}0 member %1 has a non-trivial "

  "%sub{select_special_member_kind}2">;













def warn_frame_address : Warning<













  "calling '%0' with a nonzero argument is unsafe">,













  InGroup<FrameAddress>, DefaultIgnore;



























def warn_cxx98_compat_nontrivial_union_or_anon_struct_member : Warning<















  "%select{anonymous struct|union}0 member %1 with a non-trivial "















  "%sub{select_special_member_kind}2 is incompatible with C++98">,

































clang/lib/Sema/SemaChecking.cpp



+11
−0






























Original line number
Diff line number
Diff line








@@ -1853,6 +1853,17 @@ Sema::CheckBuiltinFunctionCall(FunctionDecl *FDecl, unsigned BuiltinID,













  case Builtin::BI__builtin_return_address:















    if (SemaBuiltinConstantArgRange(TheCall, 0, 0, 0xFFFF))















      return ExprError();

























    // -Wframe-address warning if non-zero passed to builtin













    // return/frame address.













    Expr::EvalResult Result;













    if (TheCall->getArg(0)->EvaluateAsInt(Result, getASTContext()) &&













        Result.Val.getInt() != 0)













      Diag(TheCall->getBeginLoc(), diag::warn_frame_address)













          << ((BuiltinID == Builtin::BI__builtin_return_address)













                  ? "__builtin_return_address"













                  : "__builtin_frame_address")













          << TheCall->getSourceRange();















    break;















  }















































clang/test/Misc/warning-wall.c



+1
−0






























Original line number
Diff line number
Diff line








@@ -16,6 +16,7 @@ CHECK-NEXT:      -Wformat-security













CHECK-NEXT:      -Wformat-y2k















CHECK-NEXT:      -Wformat-invalid-specifier















CHECK-NEXT:    -Wfor-loop-analysis













CHECK-NEXT:    -Wframe-address















CHECK-NEXT:    -Wimplicit















CHECK-NEXT:      -Wimplicit-function-declaration















CHECK-NEXT:      -Wimplicit-int