forked from Imagelibrary/binutils-gdb
5a99adb860
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.
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.
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