Allow __ssp_inline to be overriden

PR/57689: RVP: getcwd() not overridable with -D_FORTIFY_SOURCE

PR/57288: Mingye Wang: <ssp/ssp.h>: Use __builtin_dynamic_object_size
for LLVM > 9 and GCC > 12, introducing _SSP_FORTIFY_LEVEL == 3

correct __ssp_overlap() to not trigger for adjacent areas

Allow SSP enabled functions to conditionally skip the object size check.
Use this is fix the getcwd(NULL, lmit) case, which breaks in lang/parrot.

add a macro to check overlapping pointers

SSP mostly works with Clang, even if optimisation is disabled.
Explicitly disable it for Lint though.

branches: 1.9.4;
Redo the SSP wrappers to be transparent on the resulting object files.
This works by having the inline wrapper calling a second function which
uses renaming to output the correct function name.

provide a way to override the weak name.

proved an __ssp_check macro.

Use the _sys alias instead of the _ alias as the way to access the baseline
syscall.

branches: 1.5.2;
Re-do ssp hijacking by defining inline functions and using the weak libc
symbols to do the indirection for unistd.h instead of #define tricks.
Fixes compilation for things that define struct { ssize_t read(int fd, ...); }.

Use __dead instead of __attribute__((__noreturn__)) directly.

branches: 1.3.10;
Remove clause 3 and 4 from TNF licenses

branches: 1.2.2; 1.2.8; 1.2.14;
- Misc cleanups to make the code more readable.
- Detect if we are compiling in libc and provide the appropriate name.

Move FORTIFY_SOURCE implementation from the somewhat ill-named "libssp"
(what other systems keep in libssp, we already have in libc) into libc
to match what other systems with FORTIFY_SOURCE do. Goodbye, libssp
dependency in libraries and executables. Discussed with christos and
mrg; Christos will merge the headers to get us the rest of the way to a
FORTIFY_SOURCE implementation that works as others' code expects.

Retire varargs.h support. Move machine/stdarg.h logic into MI
sys/stdarg.h and expect compiler to provide proper builtins, defaulting
to the GCC interface. lint still has a special fallback.
Reduce abuse of _BSD_VA_LIST_ by defining __va_list by default and
derive va_list as required by standards.

Consistently use __printflike and __scanflike.

branches: 1.3.10; 1.3.18;
Remove clause 3 and 4 from TNF licenses

branches: 1.2.2; 1.2.8; 1.2.14;
Match usage of FORTIFY_SOURCE on other platforms by not requiring special
include path: the normal header files now include the "SSP" ones (which one
should note are not really named right: SSP and FORTIFY_SOURCE are independent
features).

Disable USE_SSP on targets where the compiler doesn't support it at all
(mips, alpha) or it's known broken (sh3). But enable FORTIFY_SOURCE,
without SSP, on those platforms -- tested on mipsel.

Move FORTIFY_SOURCE implementation from the somewhat ill-named "libssp"
(what other systems keep in libssp, we already have in libc) into libc
to match what other systems with FORTIFY_SOURCE do. Goodbye, libssp
dependency in libraries and executables. Discussed with christos and
mrg; Christos will merge the headers to get us the rest of the way to a
FORTIFY_SOURCE implementation that works as others' code expects.

make the 2nd argument to __memmove_chk() const

Create the stpncpy() inline only when GCC>=4.8 || clang

Mirrors the stpncpy() wrapper macro and avoids the following:
warning: implicit declaration of function ‘__builtin___stpncpy_chk’

Apparently clang pretends to be gcc 4.2 but is secretly much awesomer
than gcc 4.2, so enable the stpncpy() wrapper also for clang.

Wrap stpncpy() iff GNUC_PREREQ(4,8). Fixes USE_SSP=yes builds
with gcc 4.5.

add stpncpy()

branches: 1.9.2;
gcc-4.8.1 is has a builtin stpncpy, but is missing the __builtin_ ssp
equivalent. go figure.

Revert my last change. I'm not convinced it is correct and while it seems
to fix some build problems it might cause others.

Add missing declarations for SSP versions of stpcpy(3) and stpncpy(3).

add stp{,n}cpy

branches: 1.5.2;
Always provide *_chk prototypes. Fixes DBG=-g build of libc.

branches: 1.4.8;
add some prototypes for checked string functions

branches: 1.3.10;
Remove clause 3 and 4 from TNF licenses

branches: 1.2.2; 1.2.8; 1.2.14;
Match usage of FORTIFY_SOURCE on other platforms by not requiring special
include path: the normal header files now include the "SSP" ones (which one
should note are not really named right: SSP and FORTIFY_SOURCE are independent
features).

Disable USE_SSP on targets where the compiler doesn't support it at all
(mips, alpha) or it's known broken (sh3). But enable FORTIFY_SOURCE,
without SSP, on those platforms -- tested on mipsel.

Move FORTIFY_SOURCE implementation from the somewhat ill-named "libssp"
(what other systems keep in libssp, we already have in libc) into libc
to match what other systems with FORTIFY_SOURCE do. Goodbye, libssp
dependency in libraries and executables. Discussed with christos and
mrg; Christos will merge the headers to get us the rest of the way to a
FORTIFY_SOURCE implementation that works as others' code expects.

branches: 1.3.10;
Remove clause 3 and 4 from TNF licenses

branches: 1.2.2; 1.2.8; 1.2.14;
Match usage of FORTIFY_SOURCE on other platforms by not requiring special
include path: the normal header files now include the "SSP" ones (which one
should note are not really named right: SSP and FORTIFY_SOURCE are independent
features).

Disable USE_SSP on targets where the compiler doesn't support it at all
(mips, alpha) or it's known broken (sh3). But enable FORTIFY_SOURCE,
without SSP, on those platforms -- tested on mipsel.

Move FORTIFY_SOURCE implementation from the somewhat ill-named "libssp"
(what other systems keep in libssp, we already have in libc) into libc
to match what other systems with FORTIFY_SOURCE do. Goodbye, libssp
dependency in libraries and executables. Discussed with christos and
mrg; Christos will merge the headers to get us the rest of the way to a
FORTIFY_SOURCE implementation that works as others' code expects.

Allow SSP enabled functions to conditionally skip the object size check.
Use this is fix the getcwd(NULL, lmit) case, which breaks in lang/parrot.

fix readlink prototype.

branches: 1.5.2;
Re-do ssp hijacking by defining inline functions and using the weak libc
symbols to do the indirection for unistd.h instead of #define tricks.
Fixes compilation for things that define struct { ssize_t read(int fd, ...); }.

branches: 1.4.10;
Remove clause 3 and 4 from TNF licenses

branches: 1.3.2; 1.3.8; 1.3.14;
- Misc cleanups to make the code more readable.
- Detect if we are compiling in libc and provide the appropriate name.

Match usage of FORTIFY_SOURCE on other platforms by not requiring special
include path: the normal header files now include the "SSP" ones (which one
should note are not really named right: SSP and FORTIFY_SOURCE are independent
features).

Disable USE_SSP on targets where the compiler doesn't support it at all
(mips, alpha) or it's known broken (sh3). But enable FORTIFY_SOURCE,
without SSP, on those platforms -- tested on mipsel.

Move FORTIFY_SOURCE implementation from the somewhat ill-named "libssp"
(what other systems keep in libssp, we already have in libc) into libc
to match what other systems with FORTIFY_SOURCE do. Goodbye, libssp
dependency in libraries and executables. Discussed with christos and
mrg; Christos will merge the headers to get us the rest of the way to a
FORTIFY_SOURCE implementation that works as others' code expects.