On Fri, 21 Jul 2023 at 21:05, Benjamin Priour via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> Hi,
>
> Upon David's request I've joined the in progress patch to the below email.
> I hope it makes more sense now.
>
> Best,
> Benjamin.
>
> ---------- Forwarded message ---------
> From: Benjamin Priour <priour...@gmail.com>
> Date: Tue, Jul 18, 2023 at 3:30 PM
> Subject: [RFC] analyzer: Add optional trim of the analyzer diagnostics
> going too deep [PR110543]
> To: <gcc-patches@gcc.gnu.org>, David Malcolm <dmalc...@redhat.com>
>
>
> Hi,
>
> I'd like to request comments on a patch I am writing for PR110543.
> The goal of this patch is to reduce the noise of the analyzer emitted
> diagnostics when dealing with
> system headers, or simply diagnostic paths that are too long. The new
> option only affects the display
> of the diagnostics, but doesn't hinder the actual analysis.
>
> I've defaulted the new option to "system", thus preventing the diagnostic
> paths from showing system headers.
> "never" corresponds to the pre-patch behavior, whereas you can also specify
> an unsigned value <maxdepth>
> that prevents paths to go deeper than <maxdepth> frames.
>
> fanalyzer-trim-diagnostics=
> > Common Joined RejectNegative ToLower Var(flag_analyzer_trim_diagnostics)
> > Init("system")
> > -fanalyzer-trim-diagnostics=[never|system|<maxdepth>] Trim diagnostics
> > path that are too long before emission.
> >
>
> Does it sounds reasonable and user-friendly ?
>
> Regstrapping was a success against trunk, although one of the newly added
> test case fails for c++14.
> Note that the test case below was done with "never", thus behaves exactly
> as the pre-patch analyzer
> on x86_64-linux-gnu.
>
> /* { dg-additional-options "-fdiagnostics-plain-output
> > -fdiagnostics-path-format=inline-events -fanalyzer-trim-diagnostics=never"
> > } */
> > /* { dg-skip-if "" { c++98_only } } */
> >
> > #include <memory>
> > struct A {int x; int y;};
> >
> > int main () {
> > std::shared_ptr<A> a;
> > a->x = 4; /* { dg-line deref_a } */
> > /* { dg-warning "dereference of NULL" "" { target *-*-* } deref_a } */
> >
> > return 0;
> > }
> >
> > /* { dg-begin-multiline-output "" }
> > 'int main()': events 1-2
> > |
> > |
> > +--> 'std::__shared_ptr_access<_Tp, _Lp, <anonymous>, <anonymous>
> > >::element_type* std::__shared_ptr_access<_Tp, _Lp, <anonymous>,
> > <anonymous> >::operator->() const [with _Tp = A; __gnu_cxx::_Lock_policy
> > _Lp = __gnu_cxx::_S_atomic; bool <anonymous> = false; bool <anonymous> =
> > false]': events 3-4
> > |
> > |
> > +--> 'std::__shared_ptr_access<_Tp, _Lp, <anonymous>,
> > <anonymous> >::element_type* std::__shared_ptr_access<_Tp, _Lp,
> > <anonymous>, <anonymous> >::_M_get() const [with _Tp = A;
> > __gnu_cxx::_Lock_policy _Lp = __gnu_cxx::_S_atomic; bool <anonymous> =
> > false; bool <anonymous> = false]': events 5-6
> > |
> > |
> > +--> 'std::__shared_ptr<_Tp, _Lp>::element_type*
> > std::__shared_ptr<_Tp, _Lp>::get() const [with _Tp = A;
> > __gnu_cxx::_Lock_policy _Lp = __gnu_cxx::_S_atomic]': events 7-8
> > |
> > |
> > <------+
> > |
> > 'std::__shared_ptr_access<_Tp, _Lp, <anonymous>,
> > <anonymous> >::element_type* std::__shared_ptr_access<_Tp, _Lp,
> > <anonymous>, <anonymous> >::_M_get() const [with _Tp = A;
> > __gnu_cxx::_Lock_policy _Lp = __gnu_cxx::_S_atomic; bool <anonymous> =
> > false; bool <anonymous> = false]': event 9
> > |
> > |
> > <------+
> > |
> > 'std::__shared_ptr_access<_Tp, _Lp, <anonymous>, <anonymous>
> > >::element_type* std::__shared_ptr_access<_Tp, _Lp, <anonymous>,
> > <anonymous> >::operator->() const [with _Tp = A; __gnu_cxx::_Lock_policy
> > _Lp = __gnu_cxx::_S_atomic; bool <anonymous> = false; bool <anonymous> =
> > false]': event 10
> > |
> > |
> > <------+
> > |
> > 'int main()': events 11-12
> > |
> > |
> > { dg-end-multiline-output "" } */
> >
>
>
> The first events "'int main()': events 1-2" vary in c++14 (get events 1-3).
>
> >
> > // c++14 with fully detailed output
> > ‘int main()’: events 1-3
> > |
> > | 8 | int main () {
> > | | ^~~~
> > | | |
> > | | (1) entry to ‘main’
> > | 9 | std::shared_ptr<A> a;
> > | | ~
> > | | |
> > | | (2)
> > ‘a.std::shared_ptr<A>::<anonymous>.std::__shared_ptr<A,
> > __gnu_cxx::_S_atomic>::_M_ptr’ is NULL
> > | 10 | a->x = 4; /* { dg-line deref_a } */
> > | | ~~
> > | | |
> > | | (3) calling ‘std::__shared_ptr_access<A,
> > __gnu_cxx::_S_atomic, false, false>::operator->’ from ‘main’
> >
>
> whereas c++17 and posterior give
>
> > // c++17 with fully detailed output
> >
> // ./xg++ -fanalyzer
> > ../../gcc/gcc/testsuite/g++.dg/analyzer/fanalyzer-trim-diagnostics-never.C
> > -B. -shared-libgcc -fanalyzer-trim-diagnostics=never -std=c++17
> >
> ‘int main()’: events 1-2
> > |
> > | 8 | int main () {
> > | | ^~~~
> > | | |
> > | | (1) entry to ‘main’
> > | 9 | std::shared_ptr<A> a;
> > | 10 | a->x = 4; /* { dg-line deref_a } */
> > | | ~~
> > | | |
> > | | (2) calling ‘std::__shared_ptr_access<A,
> > __gnu_cxx::_S_atomic, false, false>::operator->’ from ‘main’
> >
>
> Is there a way to make dg-multiline-output check for a regex ? Or would
> checking the multiline-output only for c++17 and c++20 be acceptable ?
> This divergence results from two slightly different IPA:
>
> // c++14 -fdump-ipa-analyzer
> > // std::shared_ptr<A> a; becomes
> > a.D.29392._M_ptr = 0B;
> > a.D.29392._M_refcount._M_pi = 0B;
> >
>
> whereas in c++17
>
> > // c++17 -fdump-ipa-analyzer
> > // std::shared_ptr<A> a; becomes
> > a = {};
> >
>
> I know shared_ptr limited support is a coincidence more than a feature, but
> maybe there is still a way to make the above test case work ?
> Otherwise, I'd fallback to a supported system function. If you have any
> that you fancy, do tell me.
>
> Thanks,
> Benjamin.
>
> ---
> gcc/analyzer/analyzer.cc | 2 +-
> gcc/analyzer/analyzer.h | 1 +
> gcc/analyzer/analyzer.opt | 4 +
> gcc/analyzer/diagnostic-manager.cc | 132 ++++++++++++++++++
> gcc/analyzer/diagnostic-manager.h | 7 +
> .../analyzer/fanalyzer-trim-diagnostics-0.C | 19 +++
> .../analyzer/fanalyzer-trim-diagnostics-1.C | 28 ++++
> .../analyzer/fanalyzer-trim-diagnostics-2.C | 44 ++++++
> .../fanalyzer-trim-diagnostics-default.C | 21 +++
> .../fanalyzer-trim-diagnostics-never.C | 44 ++++++
> .../fanalyzer-trim-diagnostics-system.C | 19 +++
> 11 files changed, 320 insertions(+), 1 deletion(-)
> create mode 100644
> gcc/testsuite/g++.dg/analyzer/fanalyzer-trim-diagnostics-0.C
> create mode 100644
> gcc/testsuite/g++.dg/analyzer/fanalyzer-trim-diagnostics-1.C
> create mode 100644
> gcc/testsuite/g++.dg/analyzer/fanalyzer-trim-diagnostics-2.C
> create mode 100644
> gcc/testsuite/g++.dg/analyzer/fanalyzer-trim-diagnostics-default.C
> create mode 100644
> gcc/testsuite/g++.dg/analyzer/fanalyzer-trim-diagnostics-never.C
> create mode 100644
> gcc/testsuite/g++.dg/analyzer/fanalyzer-trim-diagnostics-system.C
>
> diff --git a/gcc/analyzer/analyzer.cc b/gcc/analyzer/analyzer.cc
> index 5091fb7a583..b27d8e359db 100644
> --- a/gcc/analyzer/analyzer.cc
> +++ b/gcc/analyzer/analyzer.cc
> @@ -274,7 +274,7 @@ is_named_call_p (const_tree fndecl, const char
> *funcname)
> Compare with cp/typeck.cc: decl_in_std_namespace_p, but this doesn't
> rely on being the C++ FE (or handle inline namespaces inside of std).
> */
>
> -static inline bool
> +bool
> is_std_function_p (const_tree fndecl)
> {
> tree name_decl = DECL_NAME (fndecl);
> diff --git a/gcc/analyzer/analyzer.h b/gcc/analyzer/analyzer.h
> index 579517c23e6..31597079153 100644
> --- a/gcc/analyzer/analyzer.h
> +++ b/gcc/analyzer/analyzer.h
> @@ -386,6 +386,7 @@ extern bool is_special_named_call_p (const gcall *call,
> const char *funcname,
> extern bool is_named_call_p (const_tree fndecl, const char *funcname);
> extern bool is_named_call_p (const_tree fndecl, const char *funcname,
> const gcall *call, unsigned int num_args);
> +extern bool is_std_function_p (const_tree fndecl);
> extern bool is_std_named_call_p (const_tree fndecl, const char *funcname);
> extern bool is_std_named_call_p (const_tree fndecl, const char *funcname,
> const gcall *call, unsigned int num_args);
> diff --git a/gcc/analyzer/analyzer.opt b/gcc/analyzer/analyzer.opt
> index 2760aaa8151..78ff2c07483 100644
> --- a/gcc/analyzer/analyzer.opt
> +++ b/gcc/analyzer/analyzer.opt
> @@ -362,4 +362,8 @@ fdump-analyzer-untracked
> Common RejectNegative Var(flag_dump_analyzer_untracked)
> Emit custom warnings with internal details intended for analyzer
> developers.
>
> +fanalyzer-trim-diagnostics=
> +Common Joined RejectNegative ToLower Var(flag_analyzer_trim_diagnostics)
> Init("system")
> +-fanalyzer-trim-diagnostics=[never|system|<maxdepth>] Trim diagnostics
> path that are too long before emission.
> +
> ; This comment is to ensure we retain the blank line above.
> diff --git a/gcc/analyzer/diagnostic-manager.cc
> b/gcc/analyzer/diagnostic-manager.cc
> index cfca305d552..d946ad5bac7 100644
> --- a/gcc/analyzer/diagnostic-manager.cc
> +++ b/gcc/analyzer/diagnostic-manager.cc
> @@ -20,9 +20,11 @@ along with GCC; see the file COPYING3. If not see
>
> #include "config.h"
> #define INCLUDE_MEMORY
> +#define INCLUDE_VECTOR
> #include "system.h"
> #include "coretypes.h"
> #include "tree.h"
> +#include "input.h"
> #include "pretty-print.h"
> #include "gcc-rich-location.h"
> #include "gimple-pretty-print.h"
> @@ -60,6 +62,37 @@ along with GCC; see the file COPYING3. If not see
>
> #if ENABLE_ANALYZER
>
> +/* Return positive value of fanalyzer-trim-diagnostics if a depth was given
> + or a negative value otherwise. */
> +
> +long trim_diagnostics_depth ()
> +{
> + if (trim_diagnostics_system_p () || trim_diagnostics_never_p ())
> + return -1;
> +
> + char *end = NULL;
> + long depth = strtol (flag_analyzer_trim_diagnostics, &end, 10);
> + gcc_assert (end == NULL || *end == '\0');
> + gcc_assert (!(end == flag_analyzer_trim_diagnostics && depth == 0));
> + return depth;
> +}
> +
> +/* Return true if fanalyzer-trim-diagnostics is set to "system". */
> +
> +bool trim_diagnostics_system_p ()
> +{
> + int len = strlen (flag_analyzer_trim_diagnostics);
> + return len == 6 && strcmp (flag_analyzer_trim_diagnostics, "system") ==
> 0;
> +}
> +
> +/* Return true if fanalyzer-trim-diagnostics is set to "never". */
> +
> +bool trim_diagnostics_never_p ()
> +{
> + int len = strlen (flag_analyzer_trim_diagnostics);
> + return len == 5 && strcmp (flag_analyzer_trim_diagnostics, "never") == 0;
> +}
Hi Benjamin,
Just wondering if the len check is necessary here ?
IIUC, strcmp should handle the case correctly when the strings are of
different lengths ?
Also, I suppose it'd be better to merge above two functions, taking
the string to match against ("system" / "never") as argument.
Thanks,
Prathamesh
> +
> namespace ana {
>
> class feasible_worklist;
> @@ -2281,6 +2314,8 @@ diagnostic_manager::prune_path (checker_path *path,
> path->maybe_log (get_logger (), "path");
> prune_for_sm_diagnostic (path, sm, sval, state);
> prune_interproc_events (path);
> + if (! trim_diagnostics_never_p ())
> + trim_diagnostic_path (path);
> consolidate_conditions (path);
> finish_pruning (path);
> path->maybe_log (get_logger (), "pruned");
> @@ -2667,6 +2702,103 @@ diagnostic_manager::prune_interproc_events
> (checker_path *path) const
> while (changed);
> }
>
> +void
> +diagnostic_manager::trim_diagnostic_path (checker_path *path) const
> +{
> + if (trim_diagnostics_system_p ())
> + prune_system_headers (path);
> + else
> + prune_events_too_deep (path);
> +}
> +
> +/* Remove everything within ]callsite, IDX]. */
> +static void
> +prune_within_frame (checker_path *path, int &idx)
> +{
> + int nesting = 1;
> + while (idx >= 0 && nesting != 0)
> + {
> + if (path->get_checker_event (idx)->is_call_p ())
> + nesting--;
> + else if (path->get_checker_event (idx)->is_return_p ())
> + nesting++;
> +
> + path->delete_event (idx--);
> + }
> +}
> +
> +void
> +diagnostic_manager::prune_system_headers (checker_path *path) const
> +{
> + int idx = (signed)path->num_events () - 1;
> + while (idx >= 0)
> + {
> + const checker_event *event = path->get_checker_event (idx);
> + /* Prune everything between [..., system call, (...), system return,
> ...]. */
> + if (event->is_return_p ()
> + && in_system_header_at (event->get_location ()))
> + {
> + int ret_idx = idx;
> + prune_within_frame (path, idx);
> +
> + if (get_logger ())
> + {
> + label_text desc
> + (path->get_checker_event (idx)->get_desc (false));
> + log ("filtering event %i-%i:"
> + " system header event: %s",
> + idx, ret_idx, desc.get ());
> + }
> + // delete callsite
> + if (idx >= 0)
> + path->delete_event (idx);
> + }
> +
> + idx--;
> + }
> +}
> +
> +void
> +diagnostic_manager::prune_events_too_deep (checker_path *path) const
> +{
> + long depth = 0;
> + long maxdepth = trim_diagnostics_depth ();
> + gcc_assert (maxdepth >= 0);
> + int idx = (signed)path->num_events () - 1;
> + if (idx >= 0)
> + {
> + depth = path->get_checker_event (0)->get_stack_depth ();
> + maxdepth += depth;
> + }
> +
> + while (idx >= 0)
> + {
> + const checker_event *event = path->get_checker_event (idx);
> + /* Prune everything between [..., call too deep, (...), return too
> deep, ...]. */
> + if (event->is_return_p ()
> + && event->get_stack_depth () > maxdepth)
> + {
> + int ret_idx = idx;
> + prune_within_frame (path, idx);
> +
> + if (get_logger ())
> + {
> + label_text desc
> + (path->get_checker_event (idx)->get_desc (false));
> + log ("filtering event %i-%i:"
> + " event too deep: %s",
> + idx, ret_idx, desc.get ());
> + }
> + // delete callsite
> + if (idx >= 0)
> + path->delete_event (idx);
> + }
> +
> + idx--;
> + }
> +
> +}
> +
> /* Return true iff event IDX within PATH is on the same line as
> REF_EXP_LOC. */
>
> static bool
> diff --git a/gcc/analyzer/diagnostic-manager.h
> b/gcc/analyzer/diagnostic-manager.h
> index 9b3e903fc5d..9afef0975be 100644
> --- a/gcc/analyzer/diagnostic-manager.h
> +++ b/gcc/analyzer/diagnostic-manager.h
> @@ -21,6 +21,10 @@ along with GCC; see the file COPYING3. If not see
> #ifndef GCC_ANALYZER_DIAGNOSTIC_MANAGER_H
> #define GCC_ANALYZER_DIAGNOSTIC_MANAGER_H
>
> +long trim_diagnostics_depth ();
> +bool trim_diagnostics_system_p ();
> +bool trim_diagnostics_never_p ();
> +
> namespace ana {
>
> class epath_finder;
> @@ -180,6 +184,9 @@ private:
> state_machine::state_t state) const;
> void update_for_unsuitable_sm_exprs (tree *expr) const;
> void prune_interproc_events (checker_path *path) const;
> + void trim_diagnostic_path (checker_path *path) const;
> + void prune_system_headers (checker_path *path) const;
> + void prune_events_too_deep (checker_path *path) const;
> void consolidate_conditions (checker_path *path) const;
> void finish_pruning (checker_path *path) const;
>
> diff --git a/gcc/testsuite/g++.dg/analyzer/fanalyzer-trim-diagnostics-0.C
> b/gcc/testsuite/g++.dg/analyzer/fanalyzer-trim-diagnostics-0.C
> new file mode 100644
> index 00000000000..ddf39ed1690
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/analyzer/fanalyzer-trim-diagnostics-0.C
> @@ -0,0 +1,19 @@
> +/* { dg-additional-options "-fdiagnostics-plain-output
> -fdiagnostics-path-format=inline-events -fanalyzer-trim-diagnostics=0" } */
> +/* { dg-skip-if "" { c++98_only } } */
> +
> +#include <memory>
> +
> +struct A {int x; int y;};
> +
> +int main () {
> + std::shared_ptr<A> a;
> + a->x = 4; /* { dg-line deref_a } */
> + /* { dg-warning "dereference of NULL" "" { target *-*-* } deref_a } */
> +
> + return 0;
> +}
> +/* { dg-begin-multiline-output "" }
> + 'int main()': events 1-2
> + |
> + |
> + { dg-end-multiline-output "" } */
> \ No newline at end of file
> diff --git a/gcc/testsuite/g++.dg/analyzer/fanalyzer-trim-diagnostics-1.C
> b/gcc/testsuite/g++.dg/analyzer/fanalyzer-trim-diagnostics-1.C
> new file mode 100644
> index 00000000000..83a132078a1
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/analyzer/fanalyzer-trim-diagnostics-1.C
> @@ -0,0 +1,28 @@
> +/* { dg-additional-options "-fdiagnostics-plain-output
> -fdiagnostics-path-format=inline-events -fanalyzer-trim-diagnostics=1" } */
> +/* { dg-skip-if "" { c++98_only } } */
> +
> +#include <memory>
> +
> +struct A {int x; int y;};
> +
> +int main () {
> + std::shared_ptr<A> a;
> + a->x = 4; /* { dg-line deref_a } */
> + /* { dg-warning "dereference of NULL" "" { target *-*-* } deref_a } */
> +
> + return 0;
> +}
> +
> +/* { dg-begin-multiline-output "" }
> + 'int main()': events 1-2
> + |
> + |
> + +--> 'std::__shared_ptr_access<_Tp, _Lp, <anonymous>, <anonymous>
> >::element_type* std::__shared_ptr_access<_Tp, _Lp, <anonymous>,
> <anonymous> >::operator->() const [with _Tp = A; __gnu_cxx::_Lock_policy
> _Lp = __gnu_cxx::_S_atomic; bool <anonymous> = false; bool <anonymous> =
> false]': event 3
> + |
> + |
> + <------+
> + |
> + 'int main()': events 4-5
> + |
> + |
> + { dg-end-multiline-output "" } */
> \ No newline at end of file
> diff --git a/gcc/testsuite/g++.dg/analyzer/fanalyzer-trim-diagnostics-2.C
> b/gcc/testsuite/g++.dg/analyzer/fanalyzer-trim-diagnostics-2.C
> new file mode 100644
> index 00000000000..cf065929ec9
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/analyzer/fanalyzer-trim-diagnostics-2.C
> @@ -0,0 +1,44 @@
> +/* { dg-additional-options "-fdiagnostics-plain-output
> -fdiagnostics-path-format=inline-events -fanalyzer-trim-diagnostics=2" } */
> +/* { dg-skip-if "" { c++98_only } } */
> +
> +#include <memory>
> +
> +struct A {int x; int y;};
> +
> +int main () {
> + std::shared_ptr<A> a;
> + a->x = 4; /* { dg-line deref_a } */
> + /* { dg-warning "dereference of NULL" "" { target *-*-* } deref_a } */
> +
> + return 0;
> +}
> +
> +/* { dg-begin-multiline-output "" }
> + 'int main()': events 1-2
> + |
> + |
> + +--> 'std::__shared_ptr_access<_Tp, _Lp, <anonymous>, <anonymous>
> >::element_type* std::__shared_ptr_access<_Tp, _Lp, <anonymous>,
> <anonymous> >::operator->() const [with _Tp = A; __gnu_cxx::_Lock_policy
> _Lp = __gnu_cxx::_S_atomic; bool <anonymous> = false; bool <anonymous> =
> false]': events 3-4
> + |
> + |
> + +--> 'std::__shared_ptr_access<_Tp, _Lp, <anonymous>,
> <anonymous> >::element_type* std::__shared_ptr_access<_Tp, _Lp,
> <anonymous>, <anonymous> >::_M_get() const [with _Tp = A;
> __gnu_cxx::_Lock_policy _Lp = __gnu_cxx::_S_atomic; bool <anonymous> =
> false; bool <anonymous> = false]': events 5-6
> + |
> + |
> + +--> 'std::__shared_ptr<_Tp, _Lp>::element_type*
> std::__shared_ptr<_Tp, _Lp>::get() const [with _Tp = A;
> __gnu_cxx::_Lock_policy _Lp = __gnu_cxx::_S_atomic]': events 7-8
> + |
> + |
> + <------+
> + |
> + 'std::__shared_ptr_access<_Tp, _Lp, <anonymous>,
> <anonymous> >::element_type* std::__shared_ptr_access<_Tp, _Lp,
> <anonymous>, <anonymous> >::_M_get() const [with _Tp = A;
> __gnu_cxx::_Lock_policy _Lp = __gnu_cxx::_S_atomic; bool <anonymous> =
> false; bool <anonymous> = false]': event 9
> + |
> + |
> + <------+
> + |
> + 'std::__shared_ptr_access<_Tp, _Lp, <anonymous>, <anonymous>
> >::element_type* std::__shared_ptr_access<_Tp, _Lp, <anonymous>,
> <anonymous> >::operator->() const [with _Tp = A; __gnu_cxx::_Lock_policy
> _Lp = __gnu_cxx::_S_atomic; bool <anonymous> = false; bool <anonymous> =
> false]': event 10
> + |
> + |
> + <------+
> + |
> + 'int main()': events 11-12
> + |
> + |
> + { dg-end-multiline-output "" } */
> \ No newline at end of file
> diff --git
> a/gcc/testsuite/g++.dg/analyzer/fanalyzer-trim-diagnostics-default.C
> b/gcc/testsuite/g++.dg/analyzer/fanalyzer-trim-diagnostics-default.C
> new file mode 100644
> index 00000000000..fc271309d4e
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/analyzer/fanalyzer-trim-diagnostics-default.C
> @@ -0,0 +1,21 @@
> +/* { dg-additional-options "-O0 -fdiagnostics-plain-output
> -fdiagnostics-path-format=inline-events" } */
> +/* { dg-skip-if "" { c++98_only } } */
> +
> +// Must behave like -fanalyzer-trim-diagnostics=system
> +
> +#include <memory>
> +
> +struct A {int x; int y;};
> +
> +int main () {
> + std::shared_ptr<A> a;
> + a->x = 4; /* { dg-line deref_a } */
> + /* { dg-warning "dereference of NULL" "" { target *-*-* } deref_a } */
> +
> + return 0;
> +}
> +/* { dg-begin-multiline-output "" }
> + 'int main()': events 1-2
> + |
> + |
> + { dg-end-multiline-output "" } */
> \ No newline at end of file
> diff --git
> a/gcc/testsuite/g++.dg/analyzer/fanalyzer-trim-diagnostics-never.C
> b/gcc/testsuite/g++.dg/analyzer/fanalyzer-trim-diagnostics-never.C
> new file mode 100644
> index 00000000000..a69416608da
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/analyzer/fanalyzer-trim-diagnostics-never.C
> @@ -0,0 +1,44 @@
> +/* { dg-additional-options "-fdiagnostics-plain-output
> -fdiagnostics-path-format=inline-events -fanalyzer-trim-diagnostics=never"
> } */
> +/* { dg-skip-if "" { c++98_only } } */
> +
> +#include <memory>
> +
> +struct A {int x; int y;};
> +
> +int main () {
> + std::shared_ptr<A> a;
> + a->x = 4; /* { dg-line deref_a } */
> + /* { dg-warning "dereference of NULL" "" { target *-*-* } deref_a } */
> +
> + return 0;
> +}
> +
> +/* { dg-begin-multiline-output "" }
> + 'int main()': events 1-2
> + |
> + |
> + +--> 'std::__shared_ptr_access<_Tp, _Lp, <anonymous>, <anonymous>
> >::element_type* std::__shared_ptr_access<_Tp, _Lp, <anonymous>,
> <anonymous> >::operator->() const [with _Tp = A; __gnu_cxx::_Lock_policy
> _Lp = __gnu_cxx::_S_atomic; bool <anonymous> = false; bool <anonymous> =
> false]': events 3-4
> + |
> + |
> + +--> 'std::__shared_ptr_access<_Tp, _Lp, <anonymous>,
> <anonymous> >::element_type* std::__shared_ptr_access<_Tp, _Lp,
> <anonymous>, <anonymous> >::_M_get() const [with _Tp = A;
> __gnu_cxx::_Lock_policy _Lp = __gnu_cxx::_S_atomic; bool <anonymous> =
> false; bool <anonymous> = false]': events 5-6
> + |
> + |
> + +--> 'std::__shared_ptr<_Tp, _Lp>::element_type*
> std::__shared_ptr<_Tp, _Lp>::get() const [with _Tp = A;
> __gnu_cxx::_Lock_policy _Lp = __gnu_cxx::_S_atomic]': events 7-8
> + |
> + |
> + <------+
> + |
> + 'std::__shared_ptr_access<_Tp, _Lp, <anonymous>,
> <anonymous> >::element_type* std::__shared_ptr_access<_Tp, _Lp,
> <anonymous>, <anonymous> >::_M_get() const [with _Tp = A;
> __gnu_cxx::_Lock_policy _Lp = __gnu_cxx::_S_atomic; bool <anonymous> =
> false; bool <anonymous> = false]': event 9
> + |
> + |
> + <------+
> + |
> + 'std::__shared_ptr_access<_Tp, _Lp, <anonymous>, <anonymous>
> >::element_type* std::__shared_ptr_access<_Tp, _Lp, <anonymous>,
> <anonymous> >::operator->() const [with _Tp = A; __gnu_cxx::_Lock_policy
> _Lp = __gnu_cxx::_S_atomic; bool <anonymous> = false; bool <anonymous> =
> false]': event 10
> + |
> + |
> + <------+
> + |
> + 'int main()': events 11-12
> + |
> + |
> + { dg-end-multiline-output "" } */
> \ No newline at end of file
> diff --git
> a/gcc/testsuite/g++.dg/analyzer/fanalyzer-trim-diagnostics-system.C
> b/gcc/testsuite/g++.dg/analyzer/fanalyzer-trim-diagnostics-system.C
> new file mode 100644
> index 00000000000..22fadc84e75
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/analyzer/fanalyzer-trim-diagnostics-system.C
> @@ -0,0 +1,19 @@
> +/* { dg-additional-options "-fdiagnostics-plain-output
> -fdiagnostics-path-format=inline-events -fanalyzer-trim-diagnostics=system"
> } */
> +/* { dg-skip-if "" { c++98_only } } */
> +
> +#include <memory>
> +
> +struct A {int x; int y;};
> +
> +int main () {
> + std::shared_ptr<A> a;
> + a->x = 4; /* { dg-line deref_a } */
> + /* { dg-warning "dereference of NULL" "" { target *-*-* } deref_a } */
> +
> + return 0;
> +}
> +/* { dg-begin-multiline-output "" }
> + 'int main()': events 1-2
> + |
> + |
> + { dg-end-multiline-output "" } */
> \ No newline at end of file
> --
> 2.34.1
