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Add alias support #7

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783c362
Add alias support
ej-shafran Sep 16, 2023
ddf7e7f
Fix missing `NULL` for `flag_bool`
ej-shafran Sep 16, 2023
f8b65f4
Add `flag_add_alias` macro
ej-shafran Sep 16, 2023
250d6c7
Tiny optimization
ej-shafran Sep 16, 2023
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10 changes: 7 additions & 3 deletions example.c
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Original file line number Diff line number Diff line change
Expand Up @@ -13,9 +13,13 @@ void usage(FILE *stream)

int main(int argc, char **argv)
{
bool *help = flag_bool("help", false, "Print this help to stdout and exit with 0");
char **line = flag_str("line", "Hi!", "Line to output to the file");
size_t *count = flag_size("count", 64, "Amount of lines to generate");
bool *help = flag_bool("-help", false, "Print this help to stdout and exit with 0");
char **line = flag_str("-line", "Hi!", "Line to output to the file");
size_t *count = flag_size("-count", 64, "Amount of lines to generate");

flag_add_alias(help, "h");
flag_add_alias(line, "l");
flag_add_alias(count, "c");

if (!flag_parse(argc, argv)) {
usage(stderr);
Expand Down
82 changes: 67 additions & 15 deletions flag.h
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Original file line number Diff line number Diff line change
Expand Up @@ -9,6 +9,7 @@
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <stdarg.h>
#include <stdint.h>
#include <stddef.h>
#include <inttypes.h>
Expand All @@ -24,10 +25,23 @@
// WARNING! *_var functions may break the flag_name() functionality

char *flag_name(void *val);
bool *flag_bool(const char *name, bool def, const char *desc);
uint64_t *flag_uint64(const char *name, uint64_t def, const char *desc);
size_t *flag_size(const char *name, uint64_t def, const char *desc);
char **flag_str(const char *name, const char *def, const char *desc);
void flag_add_alias(void *val, const char *alias);
bool *flag_bool_null(const char *name, bool def, const char *desc, ...);
#define flag_bool(name, def, desc) flag_bool_null(name, def, desc, NULL)
#define flag_bool_aliases(name, def, desc, ...) \
flag_bool_null(name, def, desc, __VA_ARGS__, NULL)
uint64_t *flag_uint64_null(const char *name, uint64_t def, const char *desc, ...);
#define flag_uint64(name, def, desc) flag_uint64_null(name, def, desc, NULL)
#define flag_uint64_aliases(name, def, desc, ...) \
flag_uint64_null(name, def, desc, __VA_ARGS__, NULL)
size_t *flag_size_null(const char *name, uint64_t def, const char *desc, ...);
#define flag_size(name, def, desc) flag_size_null(name, def, desc, NULL)
#define flag_size_aliases(name, def, desc, ...) \
flag_size_null(name, def, desc, __VA_ARGS__, NULL)
char **flag_str_null(const char *name, const char *def, const char *desc, ...);
#define flag_str(name, def, desc) flag_str_null(name, def, desc, NULL)
#define flag_str_aliases(name, def, desc, ...) \
flag_str_null(name, def, desc, __VA_ARGS__, NULL)
bool flag_parse(int argc, char **argv);
int flag_rest_argc(void);
char **flag_rest_argv(void);
Expand Down Expand Up @@ -66,9 +80,15 @@ typedef enum {
COUNT_FLAG_ERRORS,
} Flag_Error;

#ifndef ALIAS_CAP
#define ALIAS_CAP 12
#endif // ALIAS_CAP

typedef struct {
Flag_Type type;
char *name;
const char *aliases[ALIAS_CAP];
size_t alias_count;
char *desc;
Flag_Value val;
Flag_Value def;
Expand All @@ -91,7 +111,7 @@ typedef struct {

static Flag_Context flag_global_context;

Flag *flag_new(Flag_Type type, const char *name, const char *desc)
Flag *flag_new(Flag_Type type, const char *name, const char *desc, va_list aliases)
{
Flag_Context *c = &flag_global_context;

Expand All @@ -102,6 +122,12 @@ Flag *flag_new(Flag_Type type, const char *name, const char *desc)
// NOTE: I won't touch them I promise Kappa
flag->name = (char*) name;
flag->desc = (char*) desc;
const char *alias = va_arg(aliases, const char *);
while (alias != NULL) {
assert(flag->alias_count <= ALIAS_CAP);
flag->aliases[flag->alias_count++] = alias;
alias = va_arg(aliases, const char *);
}
return flag;
}

Expand All @@ -111,33 +137,48 @@ char *flag_name(void *val)
return flag->name;
}

bool *flag_bool(const char *name, bool def, const char *desc)
void flag_add_alias(void *val, const char *alias)
{
Flag *flag = (Flag*) ((char*) val - offsetof(Flag, val));
assert(flag->alias_count + 1 <= ALIAS_CAP);
flag->aliases[flag->alias_count++] = alias;
}

bool *flag_bool_null(const char *name, bool def, const char *desc, ...)
{
Flag *flag = flag_new(FLAG_BOOL, name, desc);
va_list aliases;
va_start(aliases, desc);
Flag *flag = flag_new(FLAG_BOOL, name, desc, aliases);
flag->def.as_bool = def;
flag->val.as_bool = def;
return &flag->val.as_bool;
}

uint64_t *flag_uint64(const char *name, uint64_t def, const char *desc)
uint64_t *flag_uint64_null(const char *name, uint64_t def, const char *desc, ...)
{
Flag *flag = flag_new(FLAG_UINT64, name, desc);
va_list aliases;
va_start(aliases, desc);
Flag *flag = flag_new(FLAG_UINT64, name, desc, aliases);
flag->val.as_uint64 = def;
flag->def.as_uint64 = def;
return &flag->val.as_uint64;
}

size_t *flag_size(const char *name, uint64_t def, const char *desc)
size_t *flag_size_null(const char *name, uint64_t def, const char *desc, ...)
{
Flag *flag = flag_new(FLAG_SIZE, name, desc);
va_list aliases;
va_start(aliases, desc);
Flag *flag = flag_new(FLAG_SIZE, name, desc, aliases);
flag->val.as_size = def;
flag->def.as_size = def;
return &flag->val.as_size;
}

char **flag_str(const char *name, const char *def, const char *desc)
char **flag_str_null(const char *name, const char *def, const char *desc, ...)
{
Flag *flag = flag_new(FLAG_STR, name, desc);
va_list aliases;
va_start(aliases, desc);
Flag *flag = flag_new(FLAG_STR, name, desc, aliases);
flag->val.as_str = (char*) def;
flag->def.as_str = (char*) def;
return &flag->val.as_str;
Expand Down Expand Up @@ -190,7 +231,15 @@ bool flag_parse(int argc, char **argv)

bool found = false;
for (size_t i = 0; i < c->flags_count; ++i) {
if (strcmp(c->flags[i].name, flag) == 0) {
bool is_name = strcmp(c->flags[i].name, flag) == 0;
bool is_alias = false;
if (!is_name) {
for (size_t j = 0; !is_alias && j < c->flags[i].alias_count; ++j) {
if (strcmp(c->flags[i].aliases[j], flag) == 0)
is_alias = true;
}
}
if (is_name || is_alias) {
static_assert(COUNT_FLAG_TYPES == 4, "Exhaustive flag type parsing");
switch (c->flags[i].type) {
case FLAG_BOOL: {
Expand Down Expand Up @@ -311,7 +360,10 @@ void flag_print_options(FILE *stream)
for (size_t i = 0; i < c->flags_count; ++i) {
Flag *flag = &c->flags[i];

fprintf(stream, " -%s\n", flag->name);
fprintf(stream, " -%s", flag->name);
for (size_t j = 0; j < flag->alias_count; ++j)
fprintf(stream, ", -%s", flag->aliases[j]);
fprintf(stream, "\n");
fprintf(stream, " %s\n", flag->desc);
static_assert(COUNT_FLAG_TYPES == 4, "Exhaustive flag type defaults printing");
switch (c->flags[i].type) {
Expand Down