diff mbox

ldbl_hidden_weak??

Message ID CAKCAbMiKjowF-92Qwu_u9s0=WYS4Hf_qKhepzJB9QGCwn=_fxw@mail.gmail.com
State Superseded
Headers

Commit Message

Zack Weinberg Dec. 26, 2017, 10:44 p.m. UTC 
  For the not-installing-libio patches I have determined that I need to
add a macro ldbl_hidden_weak, but I can't figure out how to do that.
This is as far as I've gotten:


The problem is what to put where it says /* ??? */.  It can't be
libc_hidden_weak (name), that gives me

iovsprintf.c:50:93: error: ‘__EI_vsprintf’ aliased to undefined symbol
‘__GI_vsprintf’
 ldbl_hidden_weak (__IO_vsprintf, vsprintf)

but the logic in both math_ldbl_opt.h and libc-symbols.h is so
convoluted and undocumented that I can't figure out what it _should_
be.

zw

Comments

Andreas Schwab Dec. 27, 2017, 8:38 a.m. UTC | #1 
On Dez 26 2017, Zack Weinberg <zackw@panix.com> wrote:

> The problem is what to put where it says /* ??? */.  It can't be
> libc_hidden_weak (name), that gives me
>
> iovsprintf.c:50:93: error: ‘__EI_vsprintf’ aliased to undefined symbol
> ‘__GI_vsprintf’
>  ldbl_hidden_weak (__IO_vsprintf, vsprintf)

I think that means you are missing a preceding ldbl_hidden_proto.

Andreas.
Zack Weinberg Dec. 27, 2017, 4:22 p.m. UTC | #2 
On Wed, Dec 27, 2017 at 12:38 AM, Andreas Schwab <schwab@linux-m68k.org> wrote:
> On Dez 26 2017, Zack Weinberg <zackw@panix.com> wrote:
>
>> The problem is what to put where it says /* ??? */.  It can't be
>> libc_hidden_weak (name), that gives me
>>
>> iovsprintf.c:50:93: error: ‘__EI_vsprintf’ aliased to undefined symbol
>> ‘__GI_vsprintf’
>>  ldbl_hidden_weak (__IO_vsprintf, vsprintf)
>
> I think that means you are missing a preceding ldbl_hidden_proto.

There is no such thing as ldbl_hidden_proto.  There *is* a
libc_hidden_proto for vsprintf.

$ alpha-linux-gnu-gcc iovsprintf.c ... -save-temps

iovsprintf.c:50:93: error: ‘__EI_vsprintf’ aliased to undefined symbol
‘__GI_vsprintf’
 ldbl_hidden_weak (__IO_vsprintf, vsprintf)

$ grep vsprintf iovsprintf.i | grep -v '^#'
extern int vsprintf (char *__restrict __s, const char *__restrict __format,
extern int __vsprintf_chk (char *, int, size_t, const char *,
extern __typeof (vsprintf) vsprintf __asm__ ("" "__GI_vsprintf")
__attribute__ ((visibility ("hidden")));
extern __typeof (__vsprintf_chk) __vsprintf_chk __asm__ (""
"__GI___vsprintf_chk") __attribute__ ((visibility ("hidden")));
extern int _IO_vsprintf (char*, const char*, __gnuc_va_list)
__attribute__ ((__nothrow__ ));
extern __typeof (_IO_vsprintf) _IO_vsprintf __asm__ (""
"__GI__IO_vsprintf") __attribute__ ((visibility ("hidden")));
__IO_vsprintf (char *string, const char *format, __gnuc_va_list args)
extern __typeof (_IO_vsprintf) __EI__IO_vsprintf __asm__(""
"__GI__IO_vsprintf"); extern __typeof (_IO_vsprintf) __EI__IO_vsprintf
__attribute__((alias ("" "__IO_vsprintf")));
extern __typeof (__IO_vsprintf) __GL___IO_vsprintf__IO_vsprintf
__attribute__ ((alias ("__IO_vsprintf"))); __asm__ (".symver "
"__GL___IO_vsprintf__IO_vsprintf" "," "_IO_vsprintf" "@@"
"GLIBC_2.4");
extern __typeof (__IO_vsprintf) __GL___IO_vsprintf_vsprintf
__attribute__ ((weak, alias ("__IO_vsprintf"))); __asm__ (".symver "
"__GL___IO_vsprintf_vsprintf" "," "vsprintf" "@@" "GLIBC_2.4");
extern __typeof (vsprintf) __EI_vsprintf __asm__("" "vsprintf");
extern __typeof (vsprintf) __EI_vsprintf __attribute__((alias (""
"__GI_vsprintf"))) __attribute__((weak));

That is the expansion of

ldbl_hidden_def (__IO_vsprintf, _IO_vsprintf)
ldbl_strong_alias (__IO_vsprintf, _IO_vsprintf)
ldbl_weak_alias (__IO_vsprintf, vsprintf)
ldbl_hidden_weak (__IO_vsprintf, vsprintf)

with ldbl_hidden_weak defined as libc_hidden_weak.


zw
Andreas Schwab Dec. 27, 2017, 9:46 p.m. UTC | #3 
On Dez 27 2017, Zack Weinberg <zackw@panix.com> wrote:

> On Wed, Dec 27, 2017 at 12:38 AM, Andreas Schwab <schwab@linux-m68k.org> wrote:
>> On Dez 26 2017, Zack Weinberg <zackw@panix.com> wrote:
>>
>>> The problem is what to put where it says /* ??? */.  It can't be
>>> libc_hidden_weak (name), that gives me
>>>
>>> iovsprintf.c:50:93: error: ‘__EI_vsprintf’ aliased to undefined symbol
>>> ‘__GI_vsprintf’
>>>  ldbl_hidden_weak (__IO_vsprintf, vsprintf)
>>
>> I think that means you are missing a preceding ldbl_hidden_proto.
>
> There is no such thing as ldbl_hidden_proto.

Then you need to implement it.

Andreas.
Zack Weinberg Dec. 27, 2017, 10:10 p.m. UTC | #4 
On Wed, Dec 27, 2017 at 1:46 PM, Andreas Schwab <schwab@linux-m68k.org> wrote:
> On Dez 27 2017, Zack Weinberg <zackw@panix.com> wrote:
>
>> On Wed, Dec 27, 2017 at 12:38 AM, Andreas Schwab <schwab@linux-m68k.org> wrote:
>>> On Dez 26 2017, Zack Weinberg <zackw@panix.com> wrote:
>>>
>>>> The problem is what to put where it says /* ??? */.  It can't be
>>>> libc_hidden_weak (name), that gives me
>>>>
>>>> iovsprintf.c:50:93: error: ‘__EI_vsprintf’ aliased to undefined symbol
>>>> ‘__GI_vsprintf’
>>>>  ldbl_hidden_weak (__IO_vsprintf, vsprintf)
>>>
>>> I think that means you are missing a preceding ldbl_hidden_proto.
>>
>> There is no such thing as ldbl_hidden_proto.
>
> Then you need to implement it.

In fact, no, the key piece that turns out to be missing is libc_hidden_weak_ver.

zw
diff mbox

Patch

diff --git a/libio/iovsprintf.c b/libio/iovsprintf.c
index 63290fb365..871d8db072 100644
--- a/libio/iovsprintf.c
+++ b/libio/iovsprintf.c
@@ -47,4 +47,4 @@  ldbl_hidden_def (__IO_vsprintf, _IO_vsprintf)

 ldbl_strong_alias (__IO_vsprintf, _IO_vsprintf)
 ldbl_weak_alias (__IO_vsprintf, vsprintf)
-libc_hidden_weak (vsprintf)
+ldbl_hidden_weak (__IO_vsprintf, vsprintf)
diff --git a/sysdeps/generic/math_ldbl_opt.h b/sysdeps/generic/math_ldbl_opt.h
index 8a5d8ba107..a4b3806a10 100644
--- a/sysdeps/generic/math_ldbl_opt.h
+++ b/sysdeps/generic/math_ldbl_opt.h
@@ -9,6 +9,7 @@ 
 #define LONG_DOUBLE_COMPAT(lib, introduced) 0
 #define long_double_symbol(lib, local, symbol)
 #define ldbl_hidden_def(local, name) libc_hidden_def (name)
+#define ldbl_hidden_weak(local, name) libc_hidden_weak (name)
 #define ldbl_strong_alias(name, aliasname) strong_alias (name, aliasname)
 #define ldbl_weak_alias(name, aliasname) weak_alias (name, aliasname)
 #define __ldbl_is_dbl 0
diff --git a/sysdeps/ieee754/ldbl-opt/math_ldbl_opt.h
b/sysdeps/ieee754/ldbl-opt/math_ldbl_opt.h
index af861c11ea..88bf5e49a9 100644
--- a/sysdeps/ieee754/ldbl-opt/math_ldbl_opt.h
+++ b/sysdeps/ieee754/ldbl-opt/math_ldbl_opt.h
@@ -12,6 +12,7 @@ 
   long_double_symbol_1 (lib, local, symbol, LONG_DOUBLE_COMPAT_VERSION)
 #ifdef SHARED
 # define ldbl_hidden_def(local, name) libc_hidden_ver (local, name)
+# define ldbl_hidden_weak(local, name) /* ??? */
 # define ldbl_strong_alias(name, aliasname) \
   strong_alias (name, __GL_##name##_##aliasname) \
   long_double_symbol (libc, __GL_##name##_##aliasname, aliasname);
@@ -22,6 +23,7 @@ 
   versioned_symbol (lib, local, symbol, version)
 #else
 # define ldbl_hidden_def(local, name) libc_hidden_def (name)
+# define ldbl_hidden_weak(local, name) libc_hidden_weak (name)
 # define ldbl_strong_alias(name, aliasname) strong_alias (name, aliasname)
 # define ldbl_weak_alias(name, aliasname) weak_alias (name, aliasname)
 # ifndef __ASSEMBLER__