* [PATCH v2] gdb, include: replace pragmas with DIAGNOSTIC macros, fix build with g++ 4.8
@ 2021-12-02 2:43 Simon Marchi
2021-12-02 13:00 ` Nick Clifton
2021-12-02 13:18 ` Tom de Vries
0 siblings, 2 replies; 5+ messages in thread
From: Simon Marchi @ 2021-12-02 2:43 UTC (permalink / raw)
To: gdb-patches, binutils; +Cc: Simon Marchi
New in v2:
- Patches 1 and 2 merged together
- Add the default case for when DIAGNOSTIC_ERROR_SWITCH is not defined
- Control whether DIAGNOSTIC_ERROR_SWITCH is defined based on gcc
version in diagnostic.h
When introducing this code, I forgot that we had some macros for this.
Replace some "manual" pragma diagnostic with some DIAGNOSTIC_* macros,
provided by include/diagnostics.h.
In diagnostics.h:
- Add DIAGNOSTIC_ERROR, to enable a diagnostic at error level.
- Add DIAGNOSTIC_ERROR_SWITCH, to enable -Wswitch at error level, for
both gcc and clang.
Additionally, using DIAGNOSTIC_PUSH, DIAGNOSTIC_ERROR_SWITCH and
DIAGNOSTIC_POP seems to misbehave with g++ 4.8, where we see these
errors:
CXX ada-tasks.o
/home/smarchi/src/binutils-gdb/gdb/ada-tasks.c: In function ‘void read_known_tasks()’:
/home/smarchi/src/binutils-gdb/gdb/ada-tasks.c:998:10: error: enumeration value ‘ADA_TASKS_UNKNOWN’ not handled in switch [-Werror=switch]
switch (data->known_tasks_kind)
^
Because of the POP, the diagnostic should go back to being disabled,
since it was disabled in the beginning, but that's now what we see
here. Versions of GCC >= 5 compile correctly.
Work around this by making DIAGNOSTIC_ERROR_SWITCH a no-op for GCC < 5.
Note that this code (already as it exists in master today) enables
-Wswitch at the error level even if --disable-werror is passed. It
shouldn't be a problem, as it's not like a new enumerator will appear
out of nowhere and cause a build error if building with future
compilers. Still, for correctness, we would ideally want to ask the
compiler to enable -Wswitch at its default level (as if the user had
passed -Wswitch on the command-line). There doesn't seem to be a way to
do this.
Change-Id: Id33ebec3de39bd449409ea0bab59831289ffe82d
---
gdb/target/waitstatus.c | 6 +++---
gdb/target/waitstatus.h | 7 ++++---
include/diagnostics.h | 16 ++++++++++++++++
3 files changed, 23 insertions(+), 6 deletions(-)
diff --git a/gdb/target/waitstatus.c b/gdb/target/waitstatus.c
index a7209e3f2b7..0fbcec5b7c8 100644
--- a/gdb/target/waitstatus.c
+++ b/gdb/target/waitstatus.c
@@ -30,8 +30,8 @@ target_waitstatus::to_string () const
/* Make sure the compiler warns if a new TARGET_WAITKIND enumerator is added
but not handled here. */
-#pragma GCC diagnostic push
-#pragma GCC diagnostic error "-Wswitch"
+DIAGNOSTIC_PUSH
+DIAGNOSTIC_ERROR_SWITCH
switch (this->kind ())
{
case TARGET_WAITKIND_EXITED:
@@ -63,7 +63,7 @@ target_waitstatus::to_string () const
case TARGET_WAITKIND_THREAD_CREATED:
return str;
}
-#pragma GCC diagnostic pop
+DIAGNOSTIC_POP
gdb_assert_not_reached ("invalid target_waitkind value: %d",
(int) this->kind ());
diff --git a/gdb/target/waitstatus.h b/gdb/target/waitstatus.h
index 48405d222f4..5b537354184 100644
--- a/gdb/target/waitstatus.h
+++ b/gdb/target/waitstatus.h
@@ -20,6 +20,7 @@
#ifndef TARGET_WAITSTATUS_H
#define TARGET_WAITSTATUS_H
+#include "diagnostics.h"
#include "gdbsupport/gdb_signals.h"
/* Stuff for target_wait. */
@@ -108,8 +109,8 @@ target_waitkind_str (target_waitkind kind)
{
/* Make sure the compiler warns if a new TARGET_WAITKIND enumerator is added
but not handled here. */
-#pragma GCC diagnostic push
-#pragma GCC diagnostic error "-Wswitch"
+DIAGNOSTIC_PUSH
+DIAGNOSTIC_ERROR_SWITCH
switch (kind)
{
case TARGET_WAITKIND_EXITED:
@@ -145,7 +146,7 @@ target_waitkind_str (target_waitkind kind)
case TARGET_WAITKIND_THREAD_EXITED:
return "THREAD_EXITED";
};
-#pragma GCC diagnostic pop
+DIAGNOSTIC_POP
gdb_assert_not_reached ("invalid target_waitkind value: %d\n", (int) kind);
}
diff --git a/include/diagnostics.h b/include/diagnostics.h
index f6fd30e26df..7b3f6db9ff3 100644
--- a/include/diagnostics.h
+++ b/include/diagnostics.h
@@ -40,6 +40,8 @@
# define DIAGNOSTIC_IGNORE(option) \
_Pragma (DIAGNOSTIC_STRINGIFY (GCC diagnostic ignored option))
+# define DIAGNOSTIC_ERROR(option) \
+ _Pragma (DIAGNOSTIC_STRINGIFY (GCC diagnostic error option))
#else
# define DIAGNOSTIC_PUSH
# define DIAGNOSTIC_POP
@@ -61,6 +63,9 @@
# define DIAGNOSTIC_IGNORE_FORMAT_NONLITERAL \
DIAGNOSTIC_IGNORE ("-Wformat-nonliteral")
+# define DIAGNOSTIC_ERROR_SWITCH \
+ DIAGNOSTIC_ERROR ("-Wswitch")
+
#elif defined (__GNUC__) /* GCC */
# if __GNUC__ >= 7
@@ -74,6 +79,13 @@
# define DIAGNOSTIC_IGNORE_FORMAT_NONLITERAL \
DIAGNOSTIC_IGNORE ("-Wformat-nonliteral")
+/* GCC 4.8's "diagnostic push/pop" seems broken when using this, -Wswitch
+ remains enabled at the error level even after a pop. Therefore, don't
+ use it for GCC < 5. */
+# if __GNUC__ >= 5
+# define DIAGNOSTIC_ERROR_SWITCH DIAGNOSTIC_ERROR ("-Wswitch")
+# endif
+
#endif
#ifndef DIAGNOSTIC_IGNORE_SELF_MOVE
@@ -100,4 +112,8 @@
# define DIAGNOSTIC_IGNORE_FORMAT_NONLITERAL
#endif
+#ifndef DIAGNOSTIC_ERROR_SWITCH
+# define DIAGNOSTIC_ERROR_SWITCH
+#endif
+
#endif /* DIAGNOSTICS_H */
--
2.34.1
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v2] gdb, include: replace pragmas with DIAGNOSTIC macros, fix build with g++ 4.8
2021-12-02 2:43 [PATCH v2] gdb, include: replace pragmas with DIAGNOSTIC macros, fix build with g++ 4.8 Simon Marchi
@ 2021-12-02 13:00 ` Nick Clifton
2021-12-02 13:24 ` Simon Marchi
2021-12-02 13:18 ` Tom de Vries
1 sibling, 1 reply; 5+ messages in thread
From: Nick Clifton @ 2021-12-02 13:00 UTC (permalink / raw)
To: Simon Marchi, gdb-patches, binutils
Hi Simon,
> include/diagnostics.h | 16 ++++++++++++++++
I have no objections to these changes from a binutils point of view.
Cheers
Nick
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v2] gdb, include: replace pragmas with DIAGNOSTIC macros, fix build with g++ 4.8
2021-12-02 2:43 [PATCH v2] gdb, include: replace pragmas with DIAGNOSTIC macros, fix build with g++ 4.8 Simon Marchi
2021-12-02 13:00 ` Nick Clifton
@ 2021-12-02 13:18 ` Tom de Vries
2021-12-02 13:23 ` Simon Marchi
1 sibling, 1 reply; 5+ messages in thread
From: Tom de Vries @ 2021-12-02 13:18 UTC (permalink / raw)
To: Simon Marchi, gdb-patches, binutils
On 12/2/21 3:43 AM, Simon Marchi via Gdb-patches wrote:
> New in v2:
>
> - Patches 1 and 2 merged together
> - Add the default case for when DIAGNOSTIC_ERROR_SWITCH is not defined
> - Control whether DIAGNOSTIC_ERROR_SWITCH is defined based on gcc
> version in diagnostic.h
>
> When introducing this code, I forgot that we had some macros for this.
> Replace some "manual" pragma diagnostic with some DIAGNOSTIC_* macros,
> provided by include/diagnostics.h.
>
> In diagnostics.h:
>
> - Add DIAGNOSTIC_ERROR, to enable a diagnostic at error level.
> - Add DIAGNOSTIC_ERROR_SWITCH, to enable -Wswitch at error level, for
> both gcc and clang.
>
> Additionally, using DIAGNOSTIC_PUSH, DIAGNOSTIC_ERROR_SWITCH and
> DIAGNOSTIC_POP seems to misbehave with g++ 4.8, where we see these
> errors:
>
> CXX ada-tasks.o
> /home/smarchi/src/binutils-gdb/gdb/ada-tasks.c: In function ‘void read_known_tasks()’:
> /home/smarchi/src/binutils-gdb/gdb/ada-tasks.c:998:10: error: enumeration value ‘ADA_TASKS_UNKNOWN’ not handled in switch [-Werror=switch]
> switch (data->known_tasks_kind)
> ^
>
> Because of the POP, the diagnostic should go back to being disabled,
> since it was disabled in the beginning, but that's now what we see
now -> not typo
Otherwise, LGTM.
Thanks,
- Tom
> here. Versions of GCC >= 5 compile correctly.
>
> Work around this by making DIAGNOSTIC_ERROR_SWITCH a no-op for GCC < 5.
>
> Note that this code (already as it exists in master today) enables
> -Wswitch at the error level even if --disable-werror is passed. It
> shouldn't be a problem, as it's not like a new enumerator will appear
> out of nowhere and cause a build error if building with future
> compilers. Still, for correctness, we would ideally want to ask the
> compiler to enable -Wswitch at its default level (as if the user had
> passed -Wswitch on the command-line). There doesn't seem to be a way to
> do this.
>
> Change-Id: Id33ebec3de39bd449409ea0bab59831289ffe82d
> ---
> gdb/target/waitstatus.c | 6 +++---
> gdb/target/waitstatus.h | 7 ++++---
> include/diagnostics.h | 16 ++++++++++++++++
> 3 files changed, 23 insertions(+), 6 deletions(-)
>
> diff --git a/gdb/target/waitstatus.c b/gdb/target/waitstatus.c
> index a7209e3f2b7..0fbcec5b7c8 100644
> --- a/gdb/target/waitstatus.c
> +++ b/gdb/target/waitstatus.c
> @@ -30,8 +30,8 @@ target_waitstatus::to_string () const
>
> /* Make sure the compiler warns if a new TARGET_WAITKIND enumerator is added
> but not handled here. */
> -#pragma GCC diagnostic push
> -#pragma GCC diagnostic error "-Wswitch"
> +DIAGNOSTIC_PUSH
> +DIAGNOSTIC_ERROR_SWITCH
> switch (this->kind ())
> {
> case TARGET_WAITKIND_EXITED:
> @@ -63,7 +63,7 @@ target_waitstatus::to_string () const
> case TARGET_WAITKIND_THREAD_CREATED:
> return str;
> }
> -#pragma GCC diagnostic pop
> +DIAGNOSTIC_POP
>
> gdb_assert_not_reached ("invalid target_waitkind value: %d",
> (int) this->kind ());
> diff --git a/gdb/target/waitstatus.h b/gdb/target/waitstatus.h
> index 48405d222f4..5b537354184 100644
> --- a/gdb/target/waitstatus.h
> +++ b/gdb/target/waitstatus.h
> @@ -20,6 +20,7 @@
> #ifndef TARGET_WAITSTATUS_H
> #define TARGET_WAITSTATUS_H
>
> +#include "diagnostics.h"
> #include "gdbsupport/gdb_signals.h"
>
> /* Stuff for target_wait. */
> @@ -108,8 +109,8 @@ target_waitkind_str (target_waitkind kind)
> {
> /* Make sure the compiler warns if a new TARGET_WAITKIND enumerator is added
> but not handled here. */
> -#pragma GCC diagnostic push
> -#pragma GCC diagnostic error "-Wswitch"
> +DIAGNOSTIC_PUSH
> +DIAGNOSTIC_ERROR_SWITCH
> switch (kind)
> {
> case TARGET_WAITKIND_EXITED:
> @@ -145,7 +146,7 @@ target_waitkind_str (target_waitkind kind)
> case TARGET_WAITKIND_THREAD_EXITED:
> return "THREAD_EXITED";
> };
> -#pragma GCC diagnostic pop
> +DIAGNOSTIC_POP
>
> gdb_assert_not_reached ("invalid target_waitkind value: %d\n", (int) kind);
> }
> diff --git a/include/diagnostics.h b/include/diagnostics.h
> index f6fd30e26df..7b3f6db9ff3 100644
> --- a/include/diagnostics.h
> +++ b/include/diagnostics.h
> @@ -40,6 +40,8 @@
>
> # define DIAGNOSTIC_IGNORE(option) \
> _Pragma (DIAGNOSTIC_STRINGIFY (GCC diagnostic ignored option))
> +# define DIAGNOSTIC_ERROR(option) \
> + _Pragma (DIAGNOSTIC_STRINGIFY (GCC diagnostic error option))
> #else
> # define DIAGNOSTIC_PUSH
> # define DIAGNOSTIC_POP
> @@ -61,6 +63,9 @@
> # define DIAGNOSTIC_IGNORE_FORMAT_NONLITERAL \
> DIAGNOSTIC_IGNORE ("-Wformat-nonliteral")
>
> +# define DIAGNOSTIC_ERROR_SWITCH \
> + DIAGNOSTIC_ERROR ("-Wswitch")
> +
> #elif defined (__GNUC__) /* GCC */
>
> # if __GNUC__ >= 7
> @@ -74,6 +79,13 @@
> # define DIAGNOSTIC_IGNORE_FORMAT_NONLITERAL \
> DIAGNOSTIC_IGNORE ("-Wformat-nonliteral")
>
> +/* GCC 4.8's "diagnostic push/pop" seems broken when using this, -Wswitch
> + remains enabled at the error level even after a pop. Therefore, don't
> + use it for GCC < 5. */
> +# if __GNUC__ >= 5
> +# define DIAGNOSTIC_ERROR_SWITCH DIAGNOSTIC_ERROR ("-Wswitch")
> +# endif
> +
> #endif
>
> #ifndef DIAGNOSTIC_IGNORE_SELF_MOVE
> @@ -100,4 +112,8 @@
> # define DIAGNOSTIC_IGNORE_FORMAT_NONLITERAL
> #endif
>
> +#ifndef DIAGNOSTIC_ERROR_SWITCH
> +# define DIAGNOSTIC_ERROR_SWITCH
> +#endif
> +
> #endif /* DIAGNOSTICS_H */
>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v2] gdb, include: replace pragmas with DIAGNOSTIC macros, fix build with g++ 4.8
2021-12-02 13:18 ` Tom de Vries
@ 2021-12-02 13:23 ` Simon Marchi
0 siblings, 0 replies; 5+ messages in thread
From: Simon Marchi @ 2021-12-02 13:23 UTC (permalink / raw)
To: Tom de Vries, Simon Marchi, gdb-patches, binutils
>> Because of the POP, the diagnostic should go back to being disabled,
>> since it was disabled in the beginning, but that's now what we see
>
> now -> not typo
>
> Otherwise, LGTM.
Fixed and pushed, thanks.
Simon
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v2] gdb, include: replace pragmas with DIAGNOSTIC macros, fix build with g++ 4.8
2021-12-02 13:00 ` Nick Clifton
@ 2021-12-02 13:24 ` Simon Marchi
0 siblings, 0 replies; 5+ messages in thread
From: Simon Marchi @ 2021-12-02 13:24 UTC (permalink / raw)
To: Nick Clifton, Simon Marchi, gdb-patches, binutils
On 2021-12-02 08:00, Nick Clifton via Gdb-patches wrote:
> Hi Simon,
>
>> include/diagnostics.h | 16 ++++++++++++++++
>
> I have no objections to these changes from a binutils point of view.
>
> Cheers
> Nick
>
Thanks, pushed.
Simon
^ permalink raw reply [flat|nested] 5+ messages in thread
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2021-12-02 2:43 [PATCH v2] gdb, include: replace pragmas with DIAGNOSTIC macros, fix build with g++ 4.8 Simon Marchi
2021-12-02 13:00 ` Nick Clifton
2021-12-02 13:24 ` Simon Marchi
2021-12-02 13:18 ` Tom de Vries
2021-12-02 13:23 ` Simon Marchi
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