[prev in list] [next in list] [prev in thread] [next in thread]
List: gdb-patches
Subject: [committed][gdb/build] Fix Wmaybe-uninitialized in gdb/ui-style.h
From: Tom de Vries <tdevries () suse ! de>
Date: 2020-07-30 7:23:39
Message-ID: 20200730072338.GA19062 () delia
[Download RAW message or body]
Hi,
When building CFLAGS/CXXFLAGS="-O2 -g -Wall" and gcc 4.8.5, we run into:
...
src/gdb/cli/cli-style.c:154:42: warning: '*((void*)&<anonymous> +8)' \
may be used uninitialized in this function [-Wmaybe-uninitialized]
src/gdb/cli/cli-style.c:154:42: warning: '*((void*)&<anonymous> +9)' \
may be used uninitialized in this function [-Wmaybe-uninitialized]
src/gdb/cli/cli-style.c:154:42: warning: '*((void*)&<anonymous> +10)' \
may be used uninitialized in this function [-Wmaybe-uninitialized]
...
The root cause is that the data members of class color, nested in struct
ui_file_style in gdb/ui-style.h:
...
bool m_simple;
int m_value;
uint8_t m_red, m_green, m_blue;
...
are only partially initialized by this constructor:
...
color (int c)
: m_simple (true),
m_value (c)
{
gdb_assert (c >= -1 && c <= 255);
}
...
but the default copy constructor will copy all the fields.
The member m_simple acts as a discriminant, to indicate which other members
are valid:
- m_value (with m_simple == true)
- m_red, m_green, m_blue (with m_simple == false)
So, we don't need storage for both m_value and m_red/m_green/m_blue at the
same time.
Fix this by wrapping the respective members in a union:
...
bool m_simple;
union
{
int m_value;
struct
{
uint8_t m_red, m_green, m_blue;
};
};
...
which also fixes the warning.
Build and reg-tested on x86_64-linux.
Committed to trunk.
Thanks,
- Tom
[gdb/build] Fix Wmaybe-uninitialized in gdb/ui-style.h
gdb/ChangeLog:
2020-07-30 Tom de Vries <tdevries@suse.de>
PR build/26320
* ui-style.h (struct ui_file_style::color): Wrap m_value and
m_red/m_green/m_blue in a union.
---
gdb/ui-style.h | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/gdb/ui-style.h b/gdb/ui-style.h
index 48ab52d5ea..9cb6dda5fc 100644
--- a/gdb/ui-style.h
+++ b/gdb/ui-style.h
@@ -126,8 +126,14 @@ struct ui_file_style
private:
bool m_simple;
- int m_value;
- uint8_t m_red, m_green, m_blue;
+ union
+ {
+ int m_value;
+ struct
+ {
+ uint8_t m_red, m_green, m_blue;
+ };
+ };
};
/* Intensity settings that are available. */
[prev in list] [next in list] [prev in thread] [next in thread]
Configure |
About |
News |
Add a list |
Sponsored by KoreLogic