[cfe-commits] [PATCH] Print warning instead of error if optional ASan features are listed w/o -fsanitize=address

[David Blaikie]

On Mon, Jan 21, 2013 at 12:35 PM, Alexey Samsonov <samsonov at google.com> wrote:
>
> On Mon, Jan 21, 2013 at 9:56 PM, David Blaikie <dblaikie at gmail.com> wrote:
>>
>> On Mon, Jan 21, 2013 at 8:28 AM, Alexey Samsonov <samsonov at google.com>
>> wrote:
>> > Hi rsmith, kcc,
>> >
>> > This patch changes the behavior of Clang driver for command line like
>> > "clang++ -fsanitize=init-order a.cc": now it ignores
>> > -fsanitize=init-order argument and
>> > warns that it's unused w/o "-fsanitize=address" (instead of reporting an
>> > error).
>>
>> So if I understand correctly, the same warning is produced for all
>> these variants:
>> -fsanitize=init-order
>> -fno-sanitize=address -fsanitize=init-order
>> -fsanitize=address,init-order -fno-sanitize=address
>
>
> Yes.
>
>>
>>
>> Could we specifically special case for situations like the last one?
>> (or at least the last two) & make those silent (no warning) while
>> possibly still producing an error for the first? Maybe that's
>> difficult with our options parsing & not worth the hassle but I
>> figured I'd check/ask.
>
>
> Hm, interesting. We can somehow hack sanitizer option parsing to
> deal with this and clearly distinguish the first and the last case, but
> we deviation from current behavior ("-fsanitize" enables some set of
> sanitizers,
> "-fno-sanitize'" disables some set) may make things less clear.
> E.g. if "-fsanitize=address,init-order -fno-sanitize=address" is "no
> sanitizing",

(excuse the delay - dropped this draft somewhere along the way)

Sorry, I didn't mean to suggest a change in behavior - perhaps I
misunderstood your warning/error.

What I was assuming was that -fsanitize=init-order requires
-fsanitize=address, right? In that case, -fsanitize=address,init-order
-fno-sanitize=address would be good if it was silent (essentially:
disabling -fsanitize-address would disable any
subfeatures/dependencies of it)

> then what should "-fsanitize=address,init-order -fno-sanitize=address
> -fsanitize=address"
> expand into?

Fair question - I suppose it'd still be best to have that turn on both
address and init-order.

(but my points here are fairly hypothetical, I assume it's not worth
going to this level of detail for this issue - but I don't know the
use cases well enough to judge that)

>
>>
>>
>> > As a rationale, consider the case when one wants to optionally build a
>> > large project
>> > with ASan, but disable instrumentation for specific files. Previously,
>> > adding
>> > "-fno-sanitize=address" to a file-specific compile options would produce
>> > an error when building the whole project with
>> > "-fsanitize=address,init-order",
>> > so we'd have to go and fix all "-fno-sanitize=..." occurences to contain
>> > all possible features of ASan.
>> >
>> > http://llvm-reviews.chandlerc.com/D315
>> >
>> > Files:
>> >   lib/Driver/Tools.cpp
>> >   lib/Driver/SanitizerArgs.h
>> >   test/Driver/fsanitize.c
>> >   include/clang/Basic/DiagnosticGroups.td
>> >   include/clang/Basic/DiagnosticDriverKinds.td
>> >
>> > Index: lib/Driver/Tools.cpp
>> > ===================================================================
>> > --- lib/Driver/Tools.cpp
>> > +++ lib/Driver/Tools.cpp
>> > @@ -1475,10 +1475,10 @@
>> >
>> >    // If -fsanitize contains extra features of ASan, it should also
>> >    // explicitly contain -fsanitize=address.
>> > -  if (NeedsAsan && ((Kind & Address) == 0))
>> > -    D.Diag(diag::err_drv_argument_only_allowed_with)
>> > -      << lastArgumentForKind(D, Args, NeedsAsanRt)
>> > -      << "-fsanitize=address";
>> > +  if (((Kind & Address) == 0) && ((Kind & AddressFull) != 0))
>> > +    D.Diag(diag::warn_drv_unused_sanitizer)
>> > +     << lastArgumentForKind(D, Args, AddressFull)
>> > +     << "-fsanitize=address";
>> >
>> >    // Parse -f(no-)sanitize-blacklist options.
>> >    if (Arg *BLArg = Args.getLastArg(options::OPT_fsanitize_blacklist,
>> > Index: lib/Driver/SanitizerArgs.h
>> > ===================================================================
>> > --- lib/Driver/SanitizerArgs.h
>> > +++ lib/Driver/SanitizerArgs.h
>> > @@ -33,7 +33,7 @@
>> >  #define SANITIZER(NAME, ID) ID = 1 << SO_##ID,
>> >  #define SANITIZER_GROUP(NAME, ID, ALIAS) ID = ALIAS,
>> >  #include "clang/Basic/Sanitizers.def"
>> > -    NeedsAsanRt = AddressFull,
>> > +    NeedsAsanRt = Address,
>> >      NeedsTsanRt = Thread,
>> >      NeedsMsanRt = Memory,
>> >      NeedsUbsanRt = (Undefined & ~Bounds) | Integer
>> > Index: test/Driver/fsanitize.c
>> > ===================================================================
>> > --- test/Driver/fsanitize.c
>> > +++ test/Driver/fsanitize.c
>> > @@ -31,7 +31,10 @@
>> >  // CHECK-ASAN-TSAN: '-faddress-sanitizer' not allowed with
>> > '-fthread-sanitizer'
>> >
>> >  // RUN: %clang -target x86_64-linux-gnu -fsanitize=init-order %s -###
>> > 2>&1 | FileCheck %s --check-prefix=CHECK-ONLY-EXTRA-ASAN
>> > -// CHECK-ONLY-EXTRA-ASAN: argument '-fsanitize=init-order' only allowed
>> > with '-fsanitize=address'
>> > +// CHECK-ONLY-EXTRA-ASAN: '-fsanitize=init-order' is ignored in absence
>> > of '-fsanitize=address'
>> > +
>> > +// RUN: %clang -target x86_64-linux-gnu -Wno-unused-sanitize-argument
>> > -fsanitize=init-order %s -### 2>&1 | FileCheck %s
>> > --check-prefix=CHECK-WNO-UNUSED-SANITIZE-ARGUMENT
>> > +// CHECK-WNO-UNUSED-SANITIZE-ARGUMENT-NOT: '-fsanitize=init-order' is
>> > ignored in absence of '-fsanitize=address'
>> >
>> >  // RUN: %clang -target x86_64-linux-gnu -fsanitize-memory-track-origins
>> > -pie %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-ONLY-TRACK-ORIGINS
>> >  // CHECK-ONLY-TRACK-ORIGINS: warning: argument unused during
>> > compilation: '-fsanitize-memory-track-origins'
>> > Index: include/clang/Basic/DiagnosticGroups.td
>> > ===================================================================
>> > --- include/clang/Basic/DiagnosticGroups.td
>> > +++ include/clang/Basic/DiagnosticGroups.td
>> > @@ -270,7 +270,9 @@
>> >  def UnnamedTypeTemplateArgs : DiagGroup<"unnamed-type-template-args",
>> >
>> > [CXX98CompatUnnamedTypeTemplateArgs]>;
>> >  def UnusedArgument : DiagGroup<"unused-argument">;
>> > -def UnusedCommandLineArgument :
>> > DiagGroup<"unused-command-line-argument">;
>> > +def UnusedSanitizeArgument : DiagGroup<"unused-sanitize-argument">;
>> > +def UnusedCommandLineArgument :
>> > DiagGroup<"unused-command-line-argument",
>> > +                                          [UnusedSanitizeArgument]>;
>> >  def UnusedComparison : DiagGroup<"unused-comparison">;
>> >  def UnusedExceptionParameter : DiagGroup<"unused-exception-parameter">;
>> >  def UnneededInternalDecl : DiagGroup<"unneeded-internal-declaration">;
>> > Index: include/clang/Basic/DiagnosticDriverKinds.td
>> > ===================================================================
>> > --- include/clang/Basic/DiagnosticDriverKinds.td
>> > +++ include/clang/Basic/DiagnosticDriverKinds.td
>> > @@ -123,6 +123,8 @@
>> >  def warn_drv_empty_joined_argument : Warning<
>> >    "joined argument expects additional value: '%0'">,
>> >    InGroup<UnusedCommandLineArgument>;
>> > +def warn_drv_unused_sanitizer : Warning<"'%0' is ignored in absence of
>> > '%1'">,
>> > +  InGroup<UnusedSanitizeArgument>;
>> >  def warn_drv_clang_unsupported : Warning<
>> >    "the clang compiler does not support '%0'">;
>> >  def warn_drv_deprecated_arg : Warning<
>> >
>> > _______________________________________________
>> > cfe-commits mailing list
>> > cfe-commits at cs.uiuc.edu
>> > http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits
>> >
>
>
>
>
> --
> Alexey Samsonov, MSK