aboutsummaryrefslogtreecommitdiffstats
path: root/src/pdclib/platform/example/include
diff options
context:
space:
mode:
authortcsullivan <tullivan99@gmail.com>2018-11-17 13:02:57 -0500
committertcsullivan <tullivan99@gmail.com>2018-11-17 13:02:57 -0500
commitc6ef89664b8c0d7aa85bddd5c7014aa6df82cbe7 (patch)
treed1f9d09412a46bdf4344fe30392455070a72993d /src/pdclib/platform/example/include
parentdb38c4b9dac461de0ed75bf6d079dacba1b31bc9 (diff)
added pdclib, removed sash
Diffstat (limited to 'src/pdclib/platform/example/include')
-rw-r--r--src/pdclib/platform/example/include/float.h75
-rw-r--r--src/pdclib/platform/example/include/pdclib/_PDCLIB_config.h426
-rw-r--r--src/pdclib/platform/example/include/signal.h84
3 files changed, 585 insertions, 0 deletions
diff --git a/src/pdclib/platform/example/include/float.h b/src/pdclib/platform/example/include/float.h
new file mode 100644
index 0000000..538d69e
--- /dev/null
+++ b/src/pdclib/platform/example/include/float.h
@@ -0,0 +1,75 @@
+/* Characteristics of floating types <float.h>
+
+ This file is part of the Public Domain C Library (PDCLib).
+ Permission is granted to use, modify, and / or redistribute at will.
+*/
+
+#ifndef _PDCLIB_FLOAT_H
+#define _PDCLIB_FLOAT_H _PDCLIB_FLOAT_H
+
+#include "pdclib/_PDCLIB_config.h"
+
+#define FLT_ROUNDS _PDCLIB_FLT_ROUNDS
+#define FLT_EVAL_METHOD _PDCLIB_FLT_EVAL_METHOD
+#define DECIMAL_DIG _PDCLIB_DECIMAL_DIG
+
+ /* Radix of exponent representation */
+#define FLT_RADIX __FLT_RADIX__
+ /* Number of base-FLT_RADIX digits in the significand of a float */
+#define FLT_MANT_DIG __FLT_MANT_DIG__
+ /* Number of decimal digits of precision in a float */
+#define FLT_DIG __FLT_DIG__
+ /* Difference between 1.0 and the minimum float greater than 1.0 */
+#define FLT_EPSILON __FLT_EPSILON__
+ /* Minimum int x such that FLT_RADIX**(x-1) is a normalised float */
+#define FLT_MIN_EXP __FLT_MIN_EXP__
+ /* Minimum normalised float */
+#define FLT_MIN __FLT_MIN__
+ /* Minimum int x such that 10**x is a normalised float */
+#define FLT_MIN_10_EXP __FLT_MIN_10_EXP__
+ /* Maximum int x such that FLT_RADIX**(x-1) is a representable float */
+#define FLT_MAX_EXP __FLT_MAX_EXP__
+ /* Maximum float */
+#define FLT_MAX __FLT_MAX__
+ /* Maximum int x such that 10**x is a representable float */
+#define FLT_MAX_10_EXP __FLT_MAX_10_EXP__
+
+ /* Number of base-FLT_RADIX digits in the significand of a double */
+#define DBL_MANT_DIG __DBL_MANT_DIG__
+ /* Number of decimal digits of precision in a double */
+#define DBL_DIG __DBL_DIG__
+ /* Difference between 1.0 and the minimum double greater than 1.0 */
+#define DBL_EPSILON __DBL_EPSILON__
+ /* Minimum int x such that FLT_RADIX**(x-1) is a normalised double */
+#define DBL_MIN_EXP __DBL_MIN_EXP__
+ /* Minimum normalised double */
+#define DBL_MIN __DBL_MIN__
+ /* Minimum int x such that 10**x is a normalised double */
+#define DBL_MIN_10_EXP __DBL_MIN_10_EXP__
+ /* Maximum int x such that FLT_RADIX**(x-1) is a representable double */
+#define DBL_MAX_EXP __DBL_MAX_EXP__
+ /* Maximum double */
+#define DBL_MAX __DBL_MAX__
+ /* Maximum int x such that 10**x is a representable double */
+#define DBL_MAX_10_EXP __DBL_MAX_10_EXP__
+
+ /* Number of base-FLT_RADIX digits in the significand of a long double */
+#define LDBL_MANT_DIG __LDBL_MANT_DIG__
+ /* Number of decimal digits of precision in a long double */
+#define LDBL_DIG __LDBL_DIG__
+ /* Difference between 1.0 and the minimum long double greater than 1.0 */
+#define LDBL_EPSILON __LDBL_EPSILON__
+ /* Minimum int x such that FLT_RADIX**(x-1) is a normalised long double */
+#define LDBL_MIN_EXP __LDBL_MIN_EXP__
+ /* Minimum normalised long double */
+#define LDBL_MIN __LDBL_MIN__
+ /* Minimum int x such that 10**x is a normalised long double */
+#define LDBL_MIN_10_EXP __LDBL_MIN_10_EXP__
+ /* Maximum int x such that FLT_RADIX**(x-1) is a representable long double */
+#define LDBL_MAX_EXP __LDBL_MAX_EXP__
+ /* Maximum long double */
+#define LDBL_MAX __LDBL_MAX__
+ /* Maximum int x such that 10**x is a representable long double */
+#define LDBL_MAX_10_EXP __LDBL_MAX_10_EXP__
+
+#endif
diff --git a/src/pdclib/platform/example/include/pdclib/_PDCLIB_config.h b/src/pdclib/platform/example/include/pdclib/_PDCLIB_config.h
new file mode 100644
index 0000000..9731f86
--- /dev/null
+++ b/src/pdclib/platform/example/include/pdclib/_PDCLIB_config.h
@@ -0,0 +1,426 @@
+/* Internal PDCLib configuration <_PDCLIB_config.h>
+ (Generic Template)
+
+ This file is part of the Public Domain C Library (PDCLib).
+ Permission is granted to use, modify, and / or redistribute at will.
+*/
+
+#ifndef _PDCLIB_CONFIG_H
+#define _PDCLIB_CONFIG_H _PDCLIB_CONFIG_H
+
+/* -------------------------------------------------------------------------- */
+/* Misc */
+/* -------------------------------------------------------------------------- */
+
+/* The character (sequence) your platform uses as newline. */
+#define _PDCLIB_endl "\n"
+
+/* exit() can signal success to the host environment by the value of zero or */
+/* the constant EXIT_SUCCESS. Failure is signaled by EXIT_FAILURE. Note that */
+/* any other return value is "implementation-defined", i.e. your environment */
+/* is not required to handle it gracefully. Set your definitions here. */
+#define _PDCLIB_SUCCESS 0
+#define _PDCLIB_FAILURE -1
+
+/* qsort() in <stdlib.h> requires a function that swaps two memory areas. */
+/* Below is a naive implementation that can be improved significantly for */
+/* specific platforms, e.g. by swapping int instead of char. */
+#define _PDCLIB_memswp( i, j, size ) char tmp; do { tmp = *i; *i++ = *j; *j++ = tmp; } while ( --size );
+
+/* Define this to some compiler directive that can be written after the */
+/* parameter list of a function declaration to indicate the function does */
+/* never return. If your compiler does not support such a directive, define */
+/* to nothing. (This is to avoid warnings with the exit functions under GCC.) */
+#define _PDCLIB_NORETURN __attribute__(( noreturn ))
+
+/* -------------------------------------------------------------------------- */
+/* Integers */
+/* -------------------------------------------------------------------------- */
+/* Assuming 8-bit char, two's-complement architecture here. 'short' being */
+/* 16 bit, 'int' being either 16, 32 or 64 bit, 'long' being either 32 or 64 */
+/* bit (but 64 bit only if 'int' is 32 bit), and 'long long' being 64 bit if */
+/* 'long' is not, 64 or 128 bit otherwise. */
+/* Author is quite willing to support other systems but would like to hear of */
+/* interest in such support and details on the to-be-supported architecture */
+/* first, before going to lengths about it. */
+/* -------------------------------------------------------------------------- */
+
+/* Set to 0 if your 'char' type is unsigned. */
+#ifdef __CHAR_UNSIGNED__
+#define _PDCLIB_CHAR_SIGNED 0
+#else
+#define _PDCLIB_CHAR_SIGNED 1
+#endif
+
+/* Width of the integer types short, int, long, and long long, in bytes. */
+/* SHRT == 2, INT >= SHRT, LONG >= INT >= 4, LLONG >= LONG - check your */
+/* compiler manuals. */
+#define _PDCLIB_SHRT_BYTES 2
+#define _PDCLIB_INT_BYTES 4
+#ifdef __LP64__
+#define _PDCLIB_LONG_BYTES 8
+#else
+#define _PDCLIB_LONG_BYTES 4
+#endif
+#define _PDCLIB_LLONG_BYTES 8
+
+/* <stdlib.h> defines the div() function family that allows taking quotient */
+/* and remainder of an integer division in one operation. Many platforms */
+/* support this in hardware / opcode, and the standard permits ordering of */
+/* the return structure in any way to fit the hardware. That is why those */
+/* structs can be configured here. */
+
+struct _PDCLIB_div_t
+{
+ int quot;
+ int rem;
+};
+
+struct _PDCLIB_ldiv_t
+{
+ long int quot;
+ long int rem;
+};
+
+struct _PDCLIB_lldiv_t
+{
+ long long int quot;
+ long long int rem;
+};
+
+/* -------------------------------------------------------------------------- */
+/* <stdint.h> defines a set of integer types that are of a minimum width, and */
+/* "usually fastest" on the system. (If, for example, accessing a single char */
+/* requires the CPU to access a complete int and then mask out the char, the */
+/* "usually fastest" type of at least 8 bits would be int, not char.) */
+/* If you do not have information on the relative performance of the types, */
+/* the standard allows you to define any type that meets minimum width and */
+/* signedness requirements. */
+/* The defines below are just configuration for the real typedefs and limit */
+/* definitions done in <_PDCLIB_int.h>. The uppercase define shall be either */
+/* SHRT, INT, LONG, or LLONG (telling which values to use for the *_MIN and */
+/* *_MAX limits); the lowercase define either short, int, long, or long long */
+/* (telling the actual type to use). */
+/* The third define is the length modifier used for the type in printf() and */
+/* scanf() functions (used in <inttypes.h>). */
+/* If you require a non-standard datatype to define the "usually fastest" */
+/* types, PDCLib as-is doesn't support that. Please contact the author with */
+/* details on your platform in that case, so support can be added. */
+/* -------------------------------------------------------------------------- */
+
+#define _PDCLIB_FAST8 INT
+#define _PDCLIB_fast8 int
+#define _PDCLIB_FAST8_CONV
+
+#define _PDCLIB_FAST16 INT
+#define _PDCLIB_fast16 int
+#define _PDCLIB_FAST16_CONV
+
+#define _PDCLIB_FAST32 INT
+#define _PDCLIB_fast32 int
+#define _PDCLIB_FAST32_CONV
+
+#define _PDCLIB_FAST64 LONG
+#define _PDCLIB_fast64 long
+#define _PDCLIB_FAST64_CONV l
+
+/* -------------------------------------------------------------------------- */
+/* What follows are a couple of "special" typedefs and their limits. Again, */
+/* the actual definition of the limits is done in <_PDCLIB_int.h>, and the */
+/* defines here are merely "configuration". See above for details. */
+/* -------------------------------------------------------------------------- */
+
+/* The result type of substracting two pointers */
+#define _PDCLIB_ptrdiff long
+#define _PDCLIB_PTRDIFF LONG
+#define _PDCLIB_PTR_CONV l
+
+/* An integer type that can be accessed as atomic entity (think asynchronous
+ interrupts). The type itself is not defined in a freestanding environment,
+ but its limits are. (Don't ask.)
+*/
+#define _PDCLIB_sig_atomic int
+#define _PDCLIB_SIG_ATOMIC INT
+
+/* Result type of the 'sizeof' operator (must be unsigned) */
+#define _PDCLIB_size unsigned long
+#define _PDCLIB_SIZE ULONG
+
+/* Large enough an integer to hold all character codes of the largest supported
+ locale.
+*/
+#define _PDCLIB_wchar unsigned int
+#define _PDCLIB_WCHAR UINT
+
+/* Large enough an integer to hold all character codes of the largest supported
+ locale plus WEOF (which needs not to be equal to EOF, nor needs to be of
+ negative value).
+*/
+#define _PDCLIB_wint unsigned int
+#define _PDCLIB_WINT UINT
+
+/* (Signed) integer type capable of taking the (cast) value of a void *, and
+ having the value cast back to void *, comparing equal to the original.
+*/
+#define _PDCLIB_intptr long
+#define _PDCLIB_INTPTR LONG
+
+/* Largest supported integer type. Implementation note: see _PDCLIB_atomax(). */
+#define _PDCLIB_intmax long long int
+#define _PDCLIB_INTMAX LLONG
+#define _PDCLIB_MAX_CONV ll
+/* You are also required to state the literal suffix for the intmax type */
+#define _PDCLIB_INTMAX_LITERAL ll
+
+/* <inttypes.h> defines imaxdiv(), which is equivalent to the div() function */
+/* family (see further above) with intmax_t as basis. */
+
+struct _PDCLIB_imaxdiv_t
+{
+ _PDCLIB_intmax quot;
+ _PDCLIB_intmax rem;
+};
+
+/* -------------------------------------------------------------------------- */
+/* Time types */
+/* -------------------------------------------------------------------------- */
+
+/* See <time.h> for a couple of comments on these types and their semantics. */
+
+#define _PDCLIB_time long
+
+#define _PDCLIB_clock long
+#define _PDCLIB_CLOCKS_PER_SEC 1000000
+
+#define _PDCLIB_TIME_UTC 1
+
+/* -------------------------------------------------------------------------- */
+/* Floating Point */
+/* -------------------------------------------------------------------------- */
+
+/* Whether the implementation rounds toward zero (0), to nearest (1), toward
+ positive infinity (2), or toward negative infinity (3). (-1) signifies
+ indeterminable rounding, any other value implementation-specific rounding.
+*/
+#define _PDCLIB_FLT_ROUNDS -1
+
+/* Whether the implementation uses exact-width precision (0), promotes float
+ to double (1), or promotes float and double to long double (2). (-1)
+ signifies indeterminable behaviour, any other value implementation-specific
+ behaviour.
+*/
+#define _PDCLIB_FLT_EVAL_METHOD -1
+
+/* "Number of the decimal digits (n), such that any floating-point number in the
+ widest supported floating type with p(max) radix (b) digits can be rounded to
+ a floating-point number with (n) decimal digits and back again without change
+ to the value p(max) log(10)b if (b) is a power of 10, [1 + p(max) log(10)b]
+ otherwise."
+ 64bit IEC 60559 double format (53bit mantissa) is DECIMAL_DIG 17.
+ 80bit IEC 60559 double-extended format (64bit mantissa) is DECIMAL_DIG 21.
+*/
+#define _PDCLIB_DECIMAL_DIG 17
+
+/* -------------------------------------------------------------------------- */
+/* Platform-dependent macros defined by the standard headers. */
+/* -------------------------------------------------------------------------- */
+
+/* The offsetof macro
+ Contract: Expand to an integer constant expression of type size_t, which
+ represents the offset in bytes to the structure member from the beginning
+ of the structure. If the specified member is a bitfield, behaviour is
+ undefined.
+ There is no standard-compliant way to do this.
+ This implementation casts an integer zero to 'pointer to type', and then
+ takes the address of member. This is undefined behaviour but should work on
+ most compilers.
+*/
+#define _PDCLIB_offsetof( type, member ) ( (size_t) &( ( (type *) 0 )->member ) )
+
+/* Variable Length Parameter List Handling (<stdarg.h>)
+ The macros defined by <stdarg.h> are highly dependent on the calling
+ conventions used, and you probably have to replace them with builtins of
+ your compiler.
+*/
+
+#if defined( __i386 )
+
+/* The following generic implementation works only for pure
+ stack-based architectures, and only if arguments are aligned to pointer
+ type. Credits to Michael Moody, who contributed this to the Public Domain.
+*/
+
+/* Internal helper macro. va_round is not part of <stdarg.h>. */
+#define _PDCLIB_va_round( type ) ( (sizeof(type) + sizeof(void *) - 1) & ~(sizeof(void *) - 1) )
+
+typedef char * _PDCLIB_va_list;
+#define _PDCLIB_va_arg( ap, type ) ( (ap) += (_PDCLIB_va_round(type)), ( *(type*) ( (ap) - (_PDCLIB_va_round(type)) ) ) )
+#define _PDCLIB_va_copy( dest, src ) ( (dest) = (src), (void)0 )
+#define _PDCLIB_va_end( ap ) ( (ap) = (void *)0, (void)0 )
+#define _PDCLIB_va_start( ap, parmN ) ( (ap) = (char *) &parmN + ( _PDCLIB_va_round(parmN) ), (void)0 )
+
+#elif defined( __x86_64 ) || defined( __arm__ )
+
+/* No way to cover x86_64 or arm with a generic implementation, as it uses
+ register-based parameter passing. Using compiler builtins here.
+*/
+typedef __builtin_va_list _PDCLIB_va_list;
+#define _PDCLIB_va_arg( ap, type ) ( __builtin_va_arg( ap, type ) )
+#define _PDCLIB_va_copy( dest, src ) ( __builtin_va_copy( dest, src ) )
+#define _PDCLIB_va_end( ap ) ( __builtin_va_end( ap ) )
+#define _PDCLIB_va_start( ap, parmN ) ( __builtin_va_start( ap, parmN ) )
+
+#else
+
+#error Please create your own _PDCLIB_config.h. Using the existing one as-is will not work.
+
+#endif
+
+/* -------------------------------------------------------------------------- */
+/* OS "glue", part 1 */
+/* These are values and data type definitions that you would have to adapt to */
+/* the capabilities and requirements of your OS. */
+/* The actual *functions* of the OS interface are declared in _PDCLIB_glue.h. */
+/* -------------------------------------------------------------------------- */
+
+/* Memory management -------------------------------------------------------- */
+
+/* Set this to the page size of your OS. If your OS does not support paging, set
+ to an appropriate value. (Too small, and malloc() will call the kernel too
+ often. Too large, and you will waste memory.)
+*/
+#define _PDCLIB_PAGESIZE 4096
+
+/* Set this to the minimum memory node size. Any malloc() for a smaller size
+ will be satisfied by a malloc() of this size instead (to avoid excessive
+ fragmentation).
+*/
+#define _PDCLIB_MINALLOC 8
+
+/* I/O ---------------------------------------------------------------------- */
+
+/* The type of the file descriptor returned by _PDCLIB_open(). */
+typedef int _PDCLIB_fd_t;
+
+/* The value (of type _PDCLIB_fd_t) returned by _PDCLIB_open() if the operation
+ failed.
+*/
+#define _PDCLIB_NOHANDLE ( (_PDCLIB_fd_t) -1 )
+
+/* The default size for file buffers. Must be at least 256. */
+#define _PDCLIB_BUFSIZ 1024
+
+/* The minimum number of files the implementation can open simultaneously. Must
+ be at least 8. Depends largely on how the bookkeeping is done by fopen() /
+ freopen() / fclose(). The example implementation limits the number of open
+ files only by available memory.
+*/
+#define _PDCLIB_FOPEN_MAX 8
+
+/* Length of the longest filename the implementation guarantees to support. */
+#define _PDCLIB_FILENAME_MAX 128
+
+/* Maximum length of filenames generated by tmpnam(). (See tmpfile.c.) */
+#define _PDCLIB_L_tmpnam 46
+
+/* Number of distinct file names that can be generated by tmpnam(). */
+#define _PDCLIB_TMP_MAX 50
+
+/* The values of SEEK_SET, SEEK_CUR and SEEK_END, used by fseek().
+ Since at least one platform (POSIX) uses the same symbols for its own "seek"
+ function, we use whatever the host defines (if it does define them).
+*/
+#define _PDCLIB_SEEK_SET 0
+#define _PDCLIB_SEEK_CUR 1
+#define _PDCLIB_SEEK_END 2
+
+/* The number of characters that can be buffered with ungetc(). The standard
+ guarantees only one (1); anything larger would make applications relying on
+ this capability dependent on implementation-defined behaviour (not good).
+*/
+#define _PDCLIB_UNGETCBUFSIZE 1
+
+/* errno -------------------------------------------------------------------- */
+
+/* These are the values that _PDCLIB_errno can be set to by the library.
+
+ By keeping PDCLib's errno in the _PDCLIB_* namespace, the library is capable
+ to "translate" between errno values used by the hosting operating system and
+ those used and passed out by the library.
+
+ Example: In the example platform, the remove() function uses the unlink()
+ system call as backend. Linux sets its errno to EISDIR if you try to unlink()
+ a directory, but POSIX demands EPERM. Within the remove() function, you can
+ catch the 'errno == EISDIR', and set '_PDCLIB_errno = _PDCLIB_EPERM'. Anyone
+ using PDCLib's <errno.h> will "see" EPERM instead of EISDIR (the _PDCLIB_*
+ prefix removed by <errno.h> mechanics).
+
+ If you do not want that kind of translation, you might want to "match" the
+ values used by PDCLib with those used by the host OS, as to avoid confusion.
+
+ The standard only defines three distinct errno values: ERANGE, EDOM, and
+ EILSEQ. The standard leaves it up to "the implementation" whether there are
+ any more beyond those three. There is some controversy as to whether errno is
+ such a good idea at all, so you might want to come up with a different error
+ reporting facility for your platform. Since errno values beyond the three
+ defined by the standard are not portable anyway (unless you look at POSIX),
+ having your own error reporting facility would not hurt anybody either.
+*/
+#define _PDCLIB_ERANGE 1
+#define _PDCLIB_EDOM 2
+#define _PDCLIB_EILSEQ 3
+
+/* The following is not strictly "configuration", but there is no better place
+ to explain it than here.
+
+ PDCLib strives to be as generic as possible, so by default it does NOT define
+ any values beyond the three standard ones above, even where it would have
+ been prudent and convenient to do so. Any errno "caught" from the host OS,
+ and some internal error conditions as well, are all lumped together into the
+ value of '_PDCLIB_ERROR'.
+
+ '_PDCLIB_ERROR' is STRICLY meant as a PLACEHOLDER only.
+
+ You should NEVER ship an adaption of PDCLib still using that particular
+ value. You should NEVER write code that *tests* for that value. Indeed it is
+ not even conforming, since errno values should be defined as beginning with
+ an uppercase 'E', and there is no mechanics in <errno.h> to unmask that
+ particular value (for exactly that reason).
+
+ There also is no error message available for this value through either the
+ strerror() or perror() functions. It is being reported as "unknown" error.
+
+ The idea is that you scan the source of PDCLib for occurrences of this macro
+ and replace _PDCLIB_ERROR with whatever additional errno value you came up
+ with for your platform.
+
+ If you cannot find it within you to do that, tell your clients to check for
+ an errno value larger than zero. That, at least, would be standard compliant
+ (and fully portable).
+*/
+#define _PDCLIB_ERROR 4
+
+/* The maximum value that errno can be set to. This is used to set the size */
+/* of the array in struct _PDCLIB_lc_text_t holding error messages for the */
+/* strerror() and perror() functions. (If you change this value because you */
+/* are using additional errno values, you *HAVE* to provide appropriate error */
+/* messages for *ALL* locales.) */
+/* Default is 4 (0, ERANGE, EDOM, EILSEQ). */
+#define _PDCLIB_ERRNO_MAX 4
+
+/* locale data -------------------------------------------------------------- */
+
+/* The default path where PDCLib should look for its locale data. */
+/* Must end with the appropriate separator character. */
+#define _PDCLIB_LOCALE_PATH "/usr/share/pdclib/i18n"
+
+/* The name of the environment variable that can be used to override that */
+/* path setting. */
+#define _PDCLIB_LOCALE_PATH_ENV PDCLIB_I18N
+
+#ifdef __CYGWIN__
+typedef unsigned int wint_t;
+#endif
+
+
+#endif
diff --git a/src/pdclib/platform/example/include/signal.h b/src/pdclib/platform/example/include/signal.h
new file mode 100644
index 0000000..c5f6f28
--- /dev/null
+++ b/src/pdclib/platform/example/include/signal.h
@@ -0,0 +1,84 @@
+/* Signal handling <string.h>
+
+ This file is part of the Public Domain C Library (PDCLib).
+ Permission is granted to use, modify, and / or redistribute at will.
+*/
+
+#ifndef _PDCLIB_SIGNAL_H
+#define _PDCLIB_SIGNAL_H _PDCLIB_SIGNAL_H
+
+#include "pdclib/_PDCLIB_config.h"
+
+/* Signals ------------------------------------------------------------------ */
+
+/* A word on signals, to the people using PDCLib in their OS projects.
+
+ The definitions of the C standard leave about everything that *could* be
+ useful to be "implementation defined". Without additional, non-standard
+ arrangements, it is not possible to turn them into a useful tool.
+
+ This example implementation chose to "not generate any of these signals,
+ except as a result of explicit calls to the raise function", which is
+ allowed by the standard but of course does nothing for the usefulness of
+ <signal.h>.
+
+ A useful signal handling would:
+ 1) make signal() a system call that registers the signal handler with the OS
+ 2) make raise() a system call triggering an OS signal to the running process
+ 3) make provisions that further signals of the same type are blocked until
+ the signal handler returns (optional for SIGILL)
+*/
+
+/* These are the values used by Linux. */
+
+/* Abnormal termination / abort() */
+#define SIGABRT 6
+/* Arithmetic exception / division by zero / overflow */
+#define SIGFPE 8
+/* Illegal instruction */
+#define SIGILL 4
+/* Interactive attention signal */
+#define SIGINT 2
+/* Invalid memory access */
+#define SIGSEGV 11
+/* Termination request */
+#define SIGTERM 15
+
+/* The following should be defined to pointer values that could NEVER point to
+ a valid signal handler function. (They are used as special arguments to
+ signal().) Again, these are the values used by Linux.
+*/
+#define SIG_DFL (void (*)( int ))0
+#define SIG_ERR (void (*)( int ))-1
+#define SIG_IGN (void (*)( int ))1
+
+typedef _PDCLIB_sig_atomic sig_atomic_t;
+
+/* Installs a signal handler "func" for the given signal.
+ A signal handler is a function that takes an integer as argument (the signal
+ number) and returns void.
+
+ Note that a signal handler can do very little else than:
+ 1) assign a value to a static object of type "volatile sig_atomic_t",
+ 2) call signal() with the value of sig equal to the signal received,
+ 3) call _Exit(),
+ 4) call abort().
+ Virtually everything else is undefind.
+
+ The signal() function returns the previous installed signal handler, which
+ at program start may be SIG_DFL or SIG_ILL. (This implementation uses
+ SIG_DFL for all handlers.) If the request cannot be honored, SIG_ERR is
+ returned and errno is set to an unspecified positive value.
+*/
+void (*signal( int sig, void (*func)( int ) ) )( int );
+
+/* Raises the given signal (executing the registered signal handler with the
+ given signal number as parameter).
+ This implementation does not prevent further signals of the same time from
+ occuring, but executes signal( sig, SIG_DFL ) before entering the signal
+ handler (i.e., a second signal before the signal handler re-registers itself
+ or SIG_IGN will end the program).
+ Returns zero if successful, nonzero otherwise. */
+int raise( int sig );
+
+#endif