cosmopolitan/libc/fmt/pflink.h

71 lines
2.9 KiB
C

#ifndef COSMOPOLITAN_LIBC_FMT_PFLINK_H_
#define COSMOPOLITAN_LIBC_FMT_PFLINK_H_
#if !(__ASSEMBLER__ + __LINKER__ + 0)
#ifndef __STRICT_ANSI__
#include "libc/dce.h"
/**
* @fileoverview builtin+preprocessor+linker tricks for printf/scanf.
*
* Your printf() function only requires that you pay for what you use.
* These macros ensure that its code size starts at under 4kb, growing
* to about 40kb for a fully-loaded implementation. This works best when
* format strings are constexprs that only contain directives.
*/
#define PFLINK(FMT) \
({ \
if (___PFLINK(FMT, strpbrk, "bxdinupo")) STATIC_YOINK("ntoa"); \
if (___PFLINK(FMT, strpbrk, "fFgGaA")) STATIC_YOINK("ftoa"); \
if (___PFLINK(FMT, strpbrk, "cmrqs")) { \
STATIC_YOINK("stoa"); \
if (___PFLINK(FMT, strchr, '#')) STATIC_YOINK("kCp437"); \
if (___PFLINK(FMT, strstr, "%m")) STATIC_YOINK("strerror"); \
if (!IsTiny() && (___PFLINK(FMT, strstr, "%*") || \
___PFLINK(FMT, strpbrk, "0123456789"))) { \
STATIC_YOINK("strnwidth"); \
STATIC_YOINK("strnwidth16"); \
STATIC_YOINK("wcsnwidth"); \
} \
} \
FMT; \
})
#define SFLINK(FMT) \
({ \
if (___PFLINK(FMT, strchr, 'm')) { \
STATIC_YOINK("malloc"); \
STATIC_YOINK("calloc"); \
STATIC_YOINK("free_s"); \
STATIC_YOINK("grow"); \
} \
FMT; \
})
#if __GNUC__ + 0 < 4 || defined(__llvm__)
#define ___PFLINK(FMT, FN, C) 1
#else
#define ___PFLINK(FMT, FN, C) \
!isconstant(FMT) || ((FMT) && __builtin_##FN(FMT, C) != NULL)
#endif
#if defined(__GNUC__) && __GNUC__ < 6
/*
* Compilers don't understand the features we've added to the format
* string DSL, such as c string escaping, therefore we can't use it.
* Ideally compilers should grant us more flexibility to define DSLs
*
* The recommended approach to turning this back on is `CFLAGS=-std=c11`
* which puts the compiler in __STRICT_ANSI__ mode, which Cosmopolitan
* respects by disabling all the esoteric tuning in headers like this.
*/
#pragma GCC diagnostic ignored "-Wformat-security"
#endif /* __GNUC__ + 0 < 6 */
#else
#define PFLINK(FMT) FMT
#define SFLINK(FMT) FMT
#endif /* __STRICT_ANSI__ */
#endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
#endif /* COSMOPOLITAN_LIBC_FMT_PFLINK_H_ */