tools/nolibc/stdlib: add a simple getenv() implementation

This implementation relies on an extern definition of the environ
variable, that the caller must declare and initialize from envp.

Signed-o

tools/nolibc/stdlib: add a simple getenv() implementation

This implementation relies on an extern definition of the environ
variable, that the caller must declare and initialize from envp.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

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tools/nolibc/stdlib: implement abort()

libgcc uses it for certain divide functions, so it must be exported. Like
for memset() we do that in its own section so that the linker can strip
it when not n

tools/nolibc/stdlib: implement abort()

libgcc uses it for certain divide functions, so it must be exported. Like
for memset() we do that in its own section so that the linker can strip
it when not needed.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

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tools/nolibc/signal: move raise() to signal.h

This function is normally found in signal.h, and providing the file
eases porting of existing programs. Let's move it there.

Signed-off-by: Willy Tarre

tools/nolibc/signal: move raise() to signal.h

This function is normally found in signal.h, and providing the file
eases porting of existing programs. Let's move it there.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

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tools/nolibc/unistd: extract msleep(), sleep(), tcsetpgrp() to unistd.h

These functions are normally provided by unistd.h. For ease of porting,
let's create the file and move them there.

Signed-off

tools/nolibc/unistd: extract msleep(), sleep(), tcsetpgrp() to unistd.h

These functions are normally provided by unistd.h. For ease of porting,
let's create the file and move them there.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

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tools/nolibc: move exported functions to their own section

Some functions like raise() and memcpy() are permanently exported because
they're needed by libgcc on certain platforms. However most of th

tools/nolibc: move exported functions to their own section

Some functions like raise() and memcpy() are permanently exported because
they're needed by libgcc on certain platforms. However most of the time
they are not needed and needlessly take space.

Let's move them to their own sub-section, called .text.nolibc_<function>.
This allows ld to get rid of them if unused when passed --gc-sections.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

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tools/nolibc/stdlib: make raise() use the lower level syscalls only

raise() doesn't set errno, so there's no point calling kill(), better
call sys_kill(), which also reduces the function's size.

Si

tools/nolibc/stdlib: make raise() use the lower level syscalls only

raise() doesn't set errno, so there's no point calling kill(), better
call sys_kill(), which also reduces the function's size.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

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tools/nolibc/stdlib: avoid a 64-bit shift in u64toh_r()

The build of printf() on mips requires libgcc for functions __ashldi3 and
__lshrdi3 due to 64-bit shifts when scanning the input number. These

tools/nolibc/stdlib: avoid a 64-bit shift in u64toh_r()

The build of printf() on mips requires libgcc for functions __ashldi3 and
__lshrdi3 due to 64-bit shifts when scanning the input number. These are
not really needed in fact since we scan the number 4 bits at a time. Let's
arrange the loop to perform two 32-bit shifts instead on 32-bit platforms.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

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tools/nolibc/stdlib: add utoh() and u64toh()

This adds a pair of functions to emit hex values.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

tools/nolibc/stdlib: add i64toa() and u64toa()

These are 64-bit variants of the itoa() and utoa() functions. They also
support reentrant ones, and use the same itoa_buffer. The functions are
a bit l

tools/nolibc/stdlib: add i64toa() and u64toa()

These are 64-bit variants of the itoa() and utoa() functions. They also
support reentrant ones, and use the same itoa_buffer. The functions are
a bit larger than the previous ones in 32-bit mode (86 and 98 bytes on
x86_64 and armv7 respectively), which is why we continue to provide them
as separate functions.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

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tools/nolibc/stdlib: replace the ltoa() function with more efficient ones

The original ltoa() function and the reentrant one ltoa_r() present a
number of drawbacks. The divide by 10 generates calls

tools/nolibc/stdlib: replace the ltoa() function with more efficient ones

The original ltoa() function and the reentrant one ltoa_r() present a
number of drawbacks. The divide by 10 generates calls to external code
from libgcc_s, and the number does not necessarily start at the beginning
of the buffer.

Let's rewrite these functions so that they do not involve a divide and
only use loops on powers of 10, and implement both signed and unsigned
variants, always starting from the buffer's first character. Instead of
using a static buffer for each function, we're now using a common one.

In order to avoid confusion with the ltoa() name, the new functions are
called itoa_r() and utoa_r() to distinguish the signed and unsigned
versions, and for convenience for their callers, these functions now
reutrn the number of characters emitted. The ltoa_r() function is just
an inline mapping to the signed one and which returns the buffer.

The functions are quite small (86 bytes on x86_64, 68 on armv7) and
do not depend anymore on external code.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

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tools/nolibc/stdlib: move ltoa() to stdlib.h

This function is not standard and performs the opposite of atol(). Let's
move it with atol(). It's been split between a reentrant function and one
using

tools/nolibc/stdlib: move ltoa() to stdlib.h

This function is not standard and performs the opposite of atol(). Let's
move it with atol(). It's been split between a reentrant function and one
using a static buffer.

There's no more definition in nolibc.h anymore now.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

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tools/nolibc/stdlib: extract the stdlib-specific functions to their own file

The new file stdlib.h contains the definitions of functions that
are usually found in stdlib.h. Many more could certainly

tools/nolibc/stdlib: extract the stdlib-specific functions to their own file

The new file stdlib.h contains the definitions of functions that
are usually found in stdlib.h. Many more could certainly be added.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

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