(ping on this)
On Mon, May 10, 2021 at 8:37 AM David Blaikie <dblai...@gmail.com> wrote:
> Christopher - had a chance to look into this any further?
>
> Roman - I'm OK either way on that. I don't think it's the most costly
> false positive - not too much code is probably freeing via a reference
> (rather than a pointer) to allocated memory.
>
>
> On Fri, Apr 30, 2021 at 10:08 AM Roman Lebedev <lebedev...@gmail.com>
> wrote:
> >
> > Should the diagnostic be backed out until then?
> >
> > Roman
> >
> > On Fri, Apr 30, 2021 at 7:52 PM Christopher Di Bella via cfe-commits
> > <cfe-commits@lists.llvm.org> wrote:
> > >
> > > Sorry, not yet. I'll talk with my TL to see if I can get some time
> allotted for this in the next few weeks.
> > >
> > > On Thu, 29 Apr 2021 at 16:13, David Blaikie <dblai...@gmail.com>
> wrote:
> > >>
> > >> Ping on this - have you had a chance to look at this false positive?
> > >>
> > >> On Sat, Apr 3, 2021 at 4:29 PM David Blaikie <dblai...@gmail.com>
> wrote:
> > >> >
> > >> > Looks like this has a false positive (that's firing on some mlir
> code,
> > >> > committed a workaround in 499571ea835daf786626a0db1e12f890b6cd8f8d
> )
> > >> > like this:
> > >> >
> > >> > $ cat test.cpp
> > >> > #include <stdlib.h>
> > >> > void f1(int & x) { free(&x); }
> > >> > int main() { f1(*(int*)malloc(sizeof(int))); }
> > >> >
> > >> > Could you fix that? (& then revert the workaround)
> > >> >
> > >> > On Fri, Jan 15, 2021 at 1:44 PM Christopher Di Bella via cfe-commits
> > >> > <cfe-commits@lists.llvm.org> wrote:
> > >> > >
> > >> > >
> > >> > > Author: Christopher Di Bella
> > >> > > Date: 2021-01-15T21:38:47Z
> > >> > > New Revision: 4a47da2cf440c2f2006d9b04acfef4292de1e263
> > >> > >
> > >> > > URL:
> https://github.com/llvm/llvm-project/commit/4a47da2cf440c2f2006d9b04acfef4292de1e263
> > >> > > DIFF:
> https://github.com/llvm/llvm-project/commit/4a47da2cf440c2f2006d9b04acfef4292de1e263.diff
> > >> > >
> > >> > > LOG: [Sema] turns -Wfree-nonheap-object on by default
> > >> > >
> > >> > > We'd discussed adding the warning to -Wall in D89988. This patch
> honours that.
> > >> > >
> > >> > > Added:
> > >> > >
> > >> > >
> > >> > > Modified:
> > >> > > clang/include/clang/Basic/DiagnosticGroups.td
> > >> > > clang/include/clang/Basic/DiagnosticSemaKinds.td
> > >> > > clang/test/Analysis/NewDelete-intersections.mm
> > >> > > clang/test/Analysis/free.c
> > >> > >
> > >> > > Removed:
> > >> > >
> > >> > >
> > >> > >
> > >> > >
> ################################################################################
> > >> > > diff --git a/clang/include/clang/Basic/DiagnosticGroups.td
> b/clang/include/clang/Basic/DiagnosticGroups.td
> > >> > > index d500ab321058..04ba89aa457e 100644
> > >> > > --- a/clang/include/clang/Basic/DiagnosticGroups.td
> > >> > > +++ b/clang/include/clang/Basic/DiagnosticGroups.td
> > >> > > @@ -110,6 +110,7 @@ def FloatConversion :
> > >> > > FloatZeroConversion]>;
> > >> > >
> > >> > > def FrameAddress : DiagGroup<"frame-address">;
> > >> > > +def FreeNonHeapObject : DiagGroup<"free-nonheap-object">;
> > >> > > def DoublePromotion : DiagGroup<"double-promotion">;
> > >> > > def EnumTooLarge : DiagGroup<"enum-too-large">;
> > >> > > def UnsupportedNan : DiagGroup<"unsupported-nan">;
> > >> > >
> > >> > > diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td
> b/clang/include/clang/Basic/DiagnosticSemaKinds.td
> > >> > > index 7d36397a7993..e93657898f58 100644
> > >> > > --- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
> > >> > > +++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
> > >> > > @@ -7609,7 +7609,7 @@ def err_no_typeid_with_fno_rtti : Error<
> > >> > > def err_no_dynamic_cast_with_fno_rtti : Error<
> > >> > > "use of dynamic_cast requires -frtti">;
> > >> > > def warn_no_dynamic_cast_with_rtti_disabled: Warning<
> > >> > > - "dynamic_cast will not work since RTTI data is disabled by "
> > >> > > + "dynamic_cast will not work since RTTI data is disabled by "
> > >> > > "%select{-fno-rtti-data|/GR-}0">, InGroup<RTTI>;
> > >> > > def warn_no_typeid_with_rtti_disabled: Warning<
> > >> > > "typeid will not work since RTTI data is disabled by "
> > >> > > @@ -7625,8 +7625,7 @@ def warn_condition_is_assignment :
> Warning<"using the result of an "
> > >> > > InGroup<Parentheses>;
> > >> > > def warn_free_nonheap_object
> > >> > > : Warning<"attempt to call %0 on non-heap object %1">,
> > >> > > - InGroup<DiagGroup<"free-nonheap-object">>,
> > >> > > - DefaultIgnore; // FIXME: add to -Wall after sufficient
> testing
> > >> > > + InGroup<FreeNonHeapObject>;
> > >> > >
> > >> > > // Completely identical except off by default.
> > >> > > def warn_condition_is_idiomatic_assignment : Warning<"using the
> result "
> > >> > >
> > >> > > diff --git a/clang/test/Analysis/NewDelete-intersections.mm
> b/clang/test/Analysis/NewDelete-intersections.mm
> > >> > > index f01d62f8d365..6f81034ee349 100644
> > >> > > --- a/clang/test/Analysis/NewDelete-intersections.mm
> > >> > > +++ b/clang/test/Analysis/NewDelete-intersections.mm
> > >> > > @@ -24,9 +24,6 @@
> > >> > > extern "C" void free(void *);
> > >> > >
> > >> > > void testMallocFreeNoWarn() {
> > >> > > - int i;
> > >> > > - free(&i); // no warn
> > >> > > -
> > >> > > int *p1 = (int *)malloc(sizeof(int));
> > >> > > free(++p1); // no warn
> > >> > >
> > >> > > @@ -51,7 +48,7 @@ void testDeleteMalloced() {
> > >> > >
> > >> > > int *p2 = (int *)__builtin_alloca(sizeof(int));
> > >> > > delete p2; // no warn
> > >> > > -}
> > >> > > +}
> > >> > >
> > >> > > void testUseZeroAllocatedMalloced() {
> > >> > > int *p1 = (int *)malloc(0);
> > >> > > @@ -79,13 +76,13 @@ void testObjcFreeNewed() {
> > >> > > }
> > >> > >
> > >> > > void testFreeAfterDelete() {
> > >> > > - int *p = new int;
> > >> > > + int *p = new int;
> > >> > > delete p;
> > >> > > free(p); // newdelete-warning{{Use of memory after it is
> freed}}
> > >> > > }
> > >> > >
> > >> > > void testStandardPlacementNewAfterDelete() {
> > >> > > - int *p = new int;
> > >> > > + int *p = new int;
> > >> > > delete p;
> > >> > > p = new (p) int; // newdelete-warning{{Use of memory after it
> is freed}}
> > >> > > }
> > >> > >
> > >> > > diff --git a/clang/test/Analysis/free.c
> b/clang/test/Analysis/free.c
> > >> > > index 0d29bacf274c..b50145713924 100644
> > >> > > --- a/clang/test/Analysis/free.c
> > >> > > +++ b/clang/test/Analysis/free.c
> > >> > > @@ -12,17 +12,23 @@ void *alloca(size_t);
> > >> > >
> > >> > > void t1 () {
> > >> > > int a[] = { 1 };
> > >> > > - free(a); // expected-warning {{Argument to free() is the
> address of the local variable 'a', which is not memory allocated by
> malloc()}}
> > >> > > + free(a);
> > >> > > + // expected-warning@-1{{Argument to free() is the address of
> the local variable 'a', which is not memory allocated by malloc()}}
> > >> > > + // expected-warning@-2{{attempt to call free on non-heap
> object 'a'}}
> > >> > > }
> > >> > >
> > >> > > void t2 () {
> > >> > > int a = 1;
> > >> > > - free(&a); // expected-warning {{Argument to free() is the
> address of the local variable 'a', which is not memory allocated by
> malloc()}}
> > >> > > + free(&a);
> > >> > > + // expected-warning@-1{{Argument to free() is the address of
> the local variable 'a', which is not memory allocated by malloc()}}
> > >> > > + // expected-warning@-2{{attempt to call free on non-heap
> object 'a'}}
> > >> > > }
> > >> > >
> > >> > > void t3 () {
> > >> > > static int a[] = { 1 };
> > >> > > - free(a); // expected-warning {{Argument to free() is the
> address of the static variable 'a', which is not memory allocated by
> malloc()}}
> > >> > > + free(a);
> > >> > > + // expected-warning@-1{{Argument to free() is the address of
> the static variable 'a', which is not memory allocated by malloc()}}
> > >> > > + // expected-warning@-2{{attempt to call free on non-heap
> object 'a'}}
> > >> > > }
> > >> > >
> > >> > > void t4 (char *x) {
> > >> > > @@ -71,12 +77,16 @@ void t13 () {
> > >> > > }
> > >> > >
> > >> > > void t14 (char a) {
> > >> > > - free(&a); // expected-warning {{Argument to free() is the
> address of the parameter 'a', which is not memory allocated by malloc()}}
> > >> > > + free(&a);
> > >> > > + // expected-warning@-1{{Argument to free() is the address of
> the parameter 'a', which is not memory allocated by malloc()}}
> > >> > > + // expected-warning@-2{{attempt to call free on non-heap
> object 'a'}}
> > >> > > }
> > >> > >
> > >> > > static int someGlobal[2];
> > >> > > void t15 () {
> > >> > > - free(someGlobal); // expected-warning {{Argument to free() is
> the address of the global variable 'someGlobal', which is not memory
> allocated by malloc()}}
> > >> > > + free(someGlobal);
> > >> > > + // expected-warning@-1{{Argument to free() is the address of
> the global variable 'someGlobal', which is not memory allocated by
> malloc()}}
> > >> > > + // expected-warning@-2{{attempt to call free on non-heap
> object 'someGlobal'}}
> > >> > > }
> > >> > >
> > >> > > void t16 (char **x, int offset) {
> > >> > >
> > >> > >
> > >> > >
> > >> > > _______________________________________________
> > >> > > cfe-commits mailing list
> > >> > > cfe-commits@lists.llvm.org
> > >> > > https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
> > >
> > >
> > >
> > > --
> > > Kind regards,
> > >
> > > Christopher Di Bella (he/him/his)
> > > _______________________________________________
> > > cfe-commits mailing list
> > > cfe-commits@lists.llvm.org
> > > https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
>
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
