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config: move documentation to config.h 

Move the documentation from Documentation/technical/api-config.txt into
config.h as it's easier for the developers to find the usage information
beside the code instead of looking for it in another doc file, also
documentation/technical/api-config.txt is removed because the information
it has is now redundant and it'll be hard to keep it up to date and
syncronized with the documentation in config.h

Signed-off-by: Heba Waly <heba.waly@gmail.com>
Reviewed-by: Emily Shaffer <emilyshaffer@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Heba Waly 2019-10-23 05:30:52 +00:00 committed by Junio C Hamano
parent d81542e6f3
commit 6c96630cb0
2 changed files with 335 additions and 319 deletions
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319
Documentation/technical/api-config.txt
View File

@ -1,319 +0,0 @@
config API
==========
The config API gives callers a way to access Git configuration files
(and files which have the same syntax). See linkgit:git-config[1] for a
discussion of the config file syntax.
General Usage
-------------
Config files are parsed linearly, and each variable found is passed to a
caller-provided callback function. The callback function is responsible
for any actions to be taken on the config option, and is free to ignore
some options. It is not uncommon for the configuration to be parsed
several times during the run of a Git program, with different callbacks
picking out different variables useful to themselves.
A config callback function takes three parameters:
- the name of the parsed variable. This is in canonical "flat" form: the
section, subsection, and variable segments will be separated by dots,
and the section and variable segments will be all lowercase. E.g.,
`core.ignorecase`, `diff.SomeType.textconv`.
- the value of the found variable, as a string. If the variable had no
value specified, the value will be NULL (typically this means it
should be interpreted as boolean true).
- a void pointer passed in by the caller of the config API; this can
contain callback-specific data
A config callback should return 0 for success, or -1 if the variable
could not be parsed properly.
Basic Config Querying
---------------------
Most programs will simply want to look up variables in all config files
that Git knows about, using the normal precedence rules. To do this,
call `git_config` with a callback function and void data pointer.
`git_config` will read all config sources in order of increasing
priority. Thus a callback should typically overwrite previously-seen
entries with new ones (e.g., if both the user-wide `~/.gitconfig` and
repo-specific `.git/config` contain `color.ui`, the config machinery
will first feed the user-wide one to the callback, and then the
repo-specific one; by overwriting, the higher-priority repo-specific
value is left at the end).
The `config_with_options` function lets the caller examine config
while adjusting some of the default behavior of `git_config`. It should
almost never be used by "regular" Git code that is looking up
configuration variables. It is intended for advanced callers like
`git-config`, which are intentionally tweaking the normal config-lookup
process. It takes two extra parameters:
`config_source`::
If this parameter is non-NULL, it specifies the source to parse for
configuration, rather than looking in the usual files. See `struct
git_config_source` in `config.h` for details. Regular `git_config` defaults
to `NULL`.
`opts`::
Specify options to adjust the behavior of parsing config files. See `struct
config_options` in `config.h` for details. As an example: regular `git_config`
sets `opts.respect_includes` to `1` by default.
Reading Specific Files
----------------------
To read a specific file in git-config format, use
`git_config_from_file`. This takes the same callback and data parameters
as `git_config`.
Querying For Specific Variables
-------------------------------
For programs wanting to query for specific variables in a non-callback
manner, the config API provides two functions `git_config_get_value`
and `git_config_get_value_multi`. They both read values from an internal
cache generated previously from reading the config files.
`int git_config_get_value(const char *key, const char **value)`::
Finds the highest-priority value for the configuration variable `key`,
stores the pointer to it in `value` and returns 0. When the
configuration variable `key` is not found, returns 1 without touching
`value`. The caller should not free or modify `value`, as it is owned
by the cache.
`const struct string_list *git_config_get_value_multi(const char *key)`::
Finds and returns the value list, sorted in order of increasing priority
for the configuration variable `key`. When the configuration variable
`key` is not found, returns NULL. The caller should not free or modify
the returned pointer, as it is owned by the cache.
`void git_config_clear(void)`::
Resets and invalidates the config cache.
The config API also provides type specific API functions which do conversion
as well as retrieval for the queried variable, including:
`int git_config_get_int(const char *key, int *dest)`::
Finds and parses the value to an integer for the configuration variable
`key`. Dies on error; otherwise, stores the value of the parsed integer in
`dest` and returns 0. When the configuration variable `key` is not found,
returns 1 without touching `dest`.
`int git_config_get_ulong(const char *key, unsigned long *dest)`::
Similar to `git_config_get_int` but for unsigned longs.
`int git_config_get_bool(const char *key, int *dest)`::
Finds and parses the value into a boolean value, for the configuration
variable `key` respecting keywords like "true" and "false". Integer
values are converted into true/false values (when they are non-zero or
zero, respectively). Other values cause a die(). If parsing is successful,
stores the value of the parsed result in `dest` and returns 0. When the
configuration variable `key` is not found, returns 1 without touching
`dest`.
`int git_config_get_bool_or_int(const char *key, int *is_bool, int *dest)`::
Similar to `git_config_get_bool`, except that integers are copied as-is,
and `is_bool` flag is unset.
`int git_config_get_maybe_bool(const char *key, int *dest)`::
Similar to `git_config_get_bool`, except that it returns -1 on error
rather than dying.
`int git_config_get_string_const(const char *key, const char **dest)`::
Allocates and copies the retrieved string into the `dest` parameter for
the configuration variable `key`; if NULL string is given, prints an
error message and returns -1. When the configuration variable `key` is
not found, returns 1 without touching `dest`.
`int git_config_get_string(const char *key, char **dest)`::
Similar to `git_config_get_string_const`, except that retrieved value
copied into the `dest` parameter is a mutable string.
`int git_config_get_pathname(const char *key, const char **dest)`::
Similar to `git_config_get_string`, but expands `~` or `~user` into
the user's home directory when found at the beginning of the path.
`git_die_config(const char *key, const char *err, ...)`::
First prints the error message specified by the caller in `err` and then
dies printing the line number and the file name of the highest priority
value for the configuration variable `key`.
`void git_die_config_linenr(const char *key, const char *filename, int linenr)`::
Helper function which formats the die error message according to the
parameters entered. Used by `git_die_config()`. It can be used by callers
handling `git_config_get_value_multi()` to print the correct error message
for the desired value.
See test-config.c for usage examples.
Value Parsing Helpers
---------------------
To aid in parsing string values, the config API provides callbacks with
a number of helper functions, including:
`git_config_int`::
Parse the string to an integer, including unit factors. Dies on error;
otherwise, returns the parsed result.
`git_config_ulong`::
Identical to `git_config_int`, but for unsigned longs.
`git_config_bool`::
Parse a string into a boolean value, respecting keywords like "true" and
"false". Integer values are converted into true/false values (when they
are non-zero or zero, respectively). Other values cause a die(). If
parsing is successful, the return value is the result.
`git_config_bool_or_int`::
Same as `git_config_bool`, except that integers are returned as-is, and
an `is_bool` flag is unset.
`git_parse_maybe_bool`::
Same as `git_config_bool`, except that it returns -1 on error rather
than dying.
`git_config_string`::
Allocates and copies the value string into the `dest` parameter; if no
string is given, prints an error message and returns -1.
`git_config_pathname`::
Similar to `git_config_string`, but expands `~` or `~user` into the
user's home directory when found at the beginning of the path.
Include Directives
------------------
By default, the config parser does not respect include directives.
However, a caller can use the special `git_config_include` wrapper
callback to support them. To do so, you simply wrap your "real" callback
function and data pointer in a `struct config_include_data`, and pass
the wrapper to the regular config-reading functions. For example:
-------------------------------------------
int read_file_with_include(const char *file, config_fn_t fn, void *data)
{
struct config_include_data inc = CONFIG_INCLUDE_INIT;
inc.fn = fn;
inc.data = data;
return git_config_from_file(git_config_include, file, &inc);
}
-------------------------------------------
`git_config` respects includes automatically. The lower-level
`git_config_from_file` does not.
Custom Configsets
-----------------
A `config_set` can be used to construct an in-memory cache for
config-like files that the caller specifies (i.e., files like `.gitmodules`,
`~/.gitconfig` etc.). For example,
----------------------------------------
struct config_set gm_config;
git_configset_init(&gm_config);
int b;
/* we add config files to the config_set */
git_configset_add_file(&gm_config, ".gitmodules");
git_configset_add_file(&gm_config, ".gitmodules_alt");
if (!git_configset_get_bool(gm_config, "submodule.frotz.ignore", &b)) {
/* hack hack hack */
}
/* when we are done with the configset */
git_configset_clear(&gm_config);
----------------------------------------
Configset API provides functions for the above mentioned work flow, including:
`void git_configset_init(struct config_set *cs)`::
Initializes the config_set `cs`.
`int git_configset_add_file(struct config_set *cs, const char *filename)`::
Parses the file and adds the variable-value pairs to the `config_set`,
dies if there is an error in parsing the file. Returns 0 on success, or
-1 if the file does not exist or is inaccessible. The user has to decide
if he wants to free the incomplete configset or continue using it when
the function returns -1.
`int git_configset_get_value(struct config_set *cs, const char *key, const char **value)`::
Finds the highest-priority value for the configuration variable `key`
and config set `cs`, stores the pointer to it in `value` and returns 0.
When the configuration variable `key` is not found, returns 1 without
touching `value`. The caller should not free or modify `value`, as it
is owned by the cache.
`const struct string_list *git_configset_get_value_multi(struct config_set *cs, const char *key)`::
Finds and returns the value list, sorted in order of increasing priority
for the configuration variable `key` and config set `cs`. When the
configuration variable `key` is not found, returns NULL. The caller
should not free or modify the returned pointer, as it is owned by the cache.
`void git_configset_clear(struct config_set *cs)`::
Clears `config_set` structure, removes all saved variable-value pairs.
In addition to above functions, the `config_set` API provides type specific
functions in the vein of `git_config_get_int` and family but with an extra
parameter, pointer to struct `config_set`.
They all behave similarly to the `git_config_get*()` family described in
"Querying For Specific Variables" above.
Writing Config Files
--------------------
Git gives multiple entry points in the Config API to write config values to
files namely `git_config_set_in_file` and `git_config_set`, which write to
a specific config file or to `.git/config` respectively. They both take a
key/value pair as parameter.
In the end they both call `git_config_set_multivar_in_file` which takes four
parameters:
- the name of the file, as a string, to which key/value pairs will be written.
- the name of key, as a string. This is in canonical "flat" form: the section,
subsection, and variable segments will be separated by dots, and the section
and variable segments will be all lowercase.
E.g., `core.ignorecase`, `diff.SomeType.textconv`.
- the value of the variable, as a string. If value is equal to NULL, it will
remove the matching key from the config file.
- the value regex, as a string. It will disregard key/value pairs where value
does not match.
- a multi_replace value, as an int. If value is equal to zero, nothing or only
one matching key/value is replaced, else all matching key/values (regardless
how many) are removed, before the new pair is written.
It returns 0 on success.
Also, there are functions `git_config_rename_section` and
`git_config_rename_section_in_file` with parameters `old_name` and `new_name`
for renaming or removing sections in the config files. If NULL is passed
through `new_name` parameter, the section will be removed from the config file.

335
config.h
View File

@ -4,6 +4,22 @@
#include "hashmap.h"
#include "string-list.h"
/**
* The config API gives callers a way to access Git configuration files
* (and files which have the same syntax).
*
* General Usage
* -------------
*
* Config files are parsed linearly, and each variable found is passed to a
* caller-provided callback function. The callback function is responsible
* for any actions to be taken on the config option, and is free to ignore
* some options. It is not uncommon for the configuration to be parsed
* several times during the run of a Git program, with different callbacks
* picking out different variables useful to themselves.
*/
struct object_id;
/* git_config_parse_key() returns these negated: */
@ -71,9 +87,34 @@ struct config_options {
} error_action;
};
/**
* A config callback function takes three parameters:
*
* - the name of the parsed variable. This is in canonical "flat" form: the
* section, subsection, and variable segments will be separated by dots,
* and the section and variable segments will be all lowercase. E.g.,
* `core.ignorecase`, `diff.SomeType.textconv`.
*
* - the value of the found variable, as a string. If the variable had no
* value specified, the value will be NULL (typically this means it
* should be interpreted as boolean true).
*
* - a void pointer passed in by the caller of the config API; this can
* contain callback-specific data
*
* A config callback should return 0 for success, or -1 if the variable
* could not be parsed properly.
*/
typedef int (*config_fn_t)(const char *, const char *, void *);
int git_default_config(const char *, const char *, void *);
/**
* Read a specific file in git-config format.
* This function takes the same callback and data parameters as `git_config`.
*/
int git_config_from_file(config_fn_t fn, const char *, void *);
int git_config_from_file_with_options(config_fn_t fn, const char *,
void *,
const struct config_options *);
@ -88,34 +129,157 @@ void git_config_push_parameter(const char *text);
int git_config_from_parameters(config_fn_t fn, void *data);
void read_early_config(config_fn_t cb, void *data);
void read_very_early_config(config_fn_t cb, void *data);
/**
* Most programs will simply want to look up variables in all config files
* that Git knows about, using the normal precedence rules. To do this,
* call `git_config` with a callback function and void data pointer.
*
* `git_config` will read all config sources in order of increasing
* priority. Thus a callback should typically overwrite previously-seen
* entries with new ones (e.g., if both the user-wide `~/.gitconfig` and
* repo-specific `.git/config` contain `color.ui`, the config machinery
* will first feed the user-wide one to the callback, and then the
* repo-specific one; by overwriting, the higher-priority repo-specific
* value is left at the end).
*/
void git_config(config_fn_t fn, void *);
/**
* Lets the caller examine config while adjusting some of the default
* behavior of `git_config`. It should almost never be used by "regular"
* Git code that is looking up configuration variables.
* It is intended for advanced callers like `git-config`, which are
* intentionally tweaking the normal config-lookup process.
* It takes two extra parameters:
*
* - `config_source`
* If this parameter is non-NULL, it specifies the source to parse for
* configuration, rather than looking in the usual files. See `struct
* git_config_source` in `config.h` for details. Regular `git_config` defaults
* to `NULL`.
*
* - `opts`
* Specify options to adjust the behavior of parsing config files. See `struct
* config_options` in `config.h` for details. As an example: regular `git_config`
* sets `opts.respect_includes` to `1` by default.
*/
int config_with_options(config_fn_t fn, void *,
struct git_config_source *config_source,
const struct config_options *opts);
/**
* Value Parsing Helpers
* ---------------------
*
* The following helper functions aid in parsing string values
*/
int git_parse_ssize_t(const char *, ssize_t *);
int git_parse_ulong(const char *, unsigned long *);
/**
* Same as `git_config_bool`, except that it returns -1 on error rather
* than dying.
*/
int git_parse_maybe_bool(const char *);
/**
* Parse the string to an integer, including unit factors. Dies on error;
* otherwise, returns the parsed result.
*/
int git_config_int(const char *, const char *);
int64_t git_config_int64(const char *, const char *);
/**
* Identical to `git_config_int`, but for unsigned longs.
*/
unsigned long git_config_ulong(const char *, const char *);
ssize_t git_config_ssize_t(const char *, const char *);
/**
* Same as `git_config_bool`, except that integers are returned as-is, and
* an `is_bool` flag is unset.
*/
int git_config_bool_or_int(const char *, const char *, int *);
/**
* Parse a string into a boolean value, respecting keywords like "true" and
* "false". Integer values are converted into true/false values (when they
* are non-zero or zero, respectively). Other values cause a die(). If
* parsing is successful, the return value is the result.
*/
int git_config_bool(const char *, const char *);
/**
* Allocates and copies the value string into the `dest` parameter; if no
* string is given, prints an error message and returns -1.
*/
int git_config_string(const char **, const char *, const char *);
/**
* Similar to `git_config_string`, but expands `~` or `~user` into the
* user's home directory when found at the beginning of the path.
*/
int git_config_pathname(const char **, const char *, const char *);
int git_config_expiry_date(timestamp_t *, const char *, const char *);
int git_config_color(char *, const char *, const char *);
int git_config_set_in_file_gently(const char *, const char *, const char *);
/**
* write config values to a specific config file, takes a key/value pair as
* parameter.
*/
void git_config_set_in_file(const char *, const char *, const char *);
int git_config_set_gently(const char *, const char *);
/**
* write config values to `.git/config`, takes a key/value pair as parameter.
*/
void git_config_set(const char *, const char *);
int git_config_parse_key(const char *, char **, int *);
int git_config_key_is_valid(const char *key);
int git_config_set_multivar_gently(const char *, const char *, const char *, int);
void git_config_set_multivar(const char *, const char *, const char *, int);
int git_config_set_multivar_in_file_gently(const char *, const char *, const char *, const char *, int);
/**
* takes four parameters:
*
* - the name of the file, as a string, to which key/value pairs will be written.
*
* - the name of key, as a string. This is in canonical "flat" form: the section,
* subsection, and variable segments will be separated by dots, and the section
* and variable segments will be all lowercase.
* E.g., `core.ignorecase`, `diff.SomeType.textconv`.
*
* - the value of the variable, as a string. If value is equal to NULL, it will
* remove the matching key from the config file.
*
* - the value regex, as a string. It will disregard key/value pairs where value
* does not match.
*
* - a multi_replace value, as an int. If value is equal to zero, nothing or only
* one matching key/value is replaced, else all matching key/values (regardless
* how many) are removed, before the new pair is written.
*
* It returns 0 on success.
*/
void git_config_set_multivar_in_file(const char *, const char *, const char *, const char *, int);
/**
* rename or remove sections in the config file
* parameters `old_name` and `new_name`
* If NULL is passed through `new_name` parameter,
* the section will be removed from the config file.
*/
int git_config_rename_section(const char *, const char *);
int git_config_rename_section_in_file(const char *, const char *, const char *);
int git_config_copy_section(const char *, const char *);
int git_config_copy_section_in_file(const char *, const char *, const char *);
@ -142,6 +306,30 @@ enum config_scope current_config_scope(void);
const char *current_config_origin_type(void);
const char *current_config_name(void);
/**
* Include Directives
* ------------------
*
* By default, the config parser does not respect include directives.
* However, a caller can use the special `git_config_include` wrapper
* callback to support them. To do so, you simply wrap your "real" callback
* function and data pointer in a `struct config_include_data`, and pass
* the wrapper to the regular config-reading functions. For example:
*
* -------------------------------------------
* int read_file_with_include(const char *file, config_fn_t fn, void *data)
* {
* struct config_include_data inc = CONFIG_INCLUDE_INIT;
* inc.fn = fn;
* inc.data = data;
* return git_config_from_file(git_config_include, file, &inc);
* }
* -------------------------------------------
*
* `git_config` respects includes automatically. The lower-level
* `git_config_from_file` does not.
*
*/
struct config_include_data {
int depth;
config_fn_t fn;
@ -169,6 +357,33 @@ int parse_config_key(const char *var,
const char **subsection, int *subsection_len,
const char **key);
/**
* Custom Configsets
* -----------------
*
* A `config_set` can be used to construct an in-memory cache for
* config-like files that the caller specifies (i.e., files like `.gitmodules`,
* `~/.gitconfig` etc.). For example,
*
* ----------------------------------------
* struct config_set gm_config;
* git_configset_init(&gm_config);
* int b;
* //we add config files to the config_set
* git_configset_add_file(&gm_config, ".gitmodules");
* git_configset_add_file(&gm_config, ".gitmodules_alt");
*
* if (!git_configset_get_bool(gm_config, "submodule.frotz.ignore", &b)) {
* //hack hack hack
* }
*
* when we are done with the configset:
* git_configset_clear(&gm_config);
* ----------------------------------------
*
* Configset API provides functions for the above mentioned work flow
*/
struct config_set_element {
struct hashmap_entry ent;
char *key;
@ -197,16 +412,47 @@ struct config_set {
struct configset_list list;
};
/**
* Initializes the config_set `cs`.
*/
void git_configset_init(struct config_set *cs);
/**
* Parses the file and adds the variable-value pairs to the `config_set`,
* dies if there is an error in parsing the file. Returns 0 on success, or
* -1 if the file does not exist or is inaccessible. The user has to decide
* if he wants to free the incomplete configset or continue using it when
* the function returns -1.
*/
int git_configset_add_file(struct config_set *cs, const char *filename);
/**
* Finds and returns the value list, sorted in order of increasing priority
* for the configuration variable `key` and config set `cs`. When the
* configuration variable `key` is not found, returns NULL. The caller
* should not free or modify the returned pointer, as it is owned by the cache.
*/
const struct string_list *git_configset_get_value_multi(struct config_set *cs, const char *key);
/**
* Clears `config_set` structure, removes all saved variable-value pairs.
*/
void git_configset_clear(struct config_set *cs);
/*
* These functions return 1 if not found, and 0 if found, leaving the found
* value in the 'dest' pointer.
*/
/*
* Finds the highest-priority value for the configuration variable `key`
* and config set `cs`, stores the pointer to it in `value` and returns 0.
* When the configuration variable `key` is not found, returns 1 without
* touching `value`. The caller should not free or modify `value`, as it
* is owned by the cache.
*/
int git_configset_get_value(struct config_set *cs, const char *key, const char **dest);
int git_configset_get_string_const(struct config_set *cs, const char *key, const char **dest);
int git_configset_get_string(struct config_set *cs, const char *key, char **dest);
int git_configset_get_int(struct config_set *cs, const char *key, int *dest);
@ -240,17 +486,94 @@ int repo_config_get_maybe_bool(struct repository *repo,
int repo_config_get_pathname(struct repository *repo,
const char *key, const char **dest);
/**
* Querying For Specific Variables
* -------------------------------
*
* For programs wanting to query for specific variables in a non-callback
* manner, the config API provides two functions `git_config_get_value`
* and `git_config_get_value_multi`. They both read values from an internal
* cache generated previously from reading the config files.
*/
/**
* Finds the highest-priority value for the configuration variable `key`,
* stores the pointer to it in `value` and returns 0. When the
* configuration variable `key` is not found, returns 1 without touching
* `value`. The caller should not free or modify `value`, as it is owned
* by the cache.
*/
int git_config_get_value(const char *key, const char **value);
/**
* Finds and returns the value list, sorted in order of increasing priority
* for the configuration variable `key`. When the configuration variable
* `key` is not found, returns NULL. The caller should not free or modify
* the returned pointer, as it is owned by the cache.
*/
const struct string_list *git_config_get_value_multi(const char *key);
/**
* Resets and invalidates the config cache.
*/
void git_config_clear(void);
/**
* Allocates and copies the retrieved string into the `dest` parameter for
* the configuration variable `key`; if NULL string is given, prints an
* error message and returns -1. When the configuration variable `key` is
* not found, returns 1 without touching `dest`.
*/
int git_config_get_string_const(const char *key, const char **dest);
/**
* Similar to `git_config_get_string_const`, except that retrieved value
* copied into the `dest` parameter is a mutable string.
*/
int git_config_get_string(const char *key, char **dest);
/**
* Finds and parses the value to an integer for the configuration variable
* `key`. Dies on error; otherwise, stores the value of the parsed integer in
* `dest` and returns 0. When the configuration variable `key` is not found,
* returns 1 without touching `dest`.
*/
int git_config_get_int(const char *key, int *dest);
/**
* Similar to `git_config_get_int` but for unsigned longs.
*/
int git_config_get_ulong(const char *key, unsigned long *dest);
/**
* Finds and parses the value into a boolean value, for the configuration
* variable `key` respecting keywords like "true" and "false". Integer
* values are converted into true/false values (when they are non-zero or
* zero, respectively). Other values cause a die(). If parsing is successful,
* stores the value of the parsed result in `dest` and returns 0. When the
* configuration variable `key` is not found, returns 1 without touching
* `dest`.
*/
int git_config_get_bool(const char *key, int *dest);
/**
* Similar to `git_config_get_bool`, except that integers are copied as-is,
* and `is_bool` flag is unset.
*/
int git_config_get_bool_or_int(const char *key, int *is_bool, int *dest);
/**
* Similar to `git_config_get_bool`, except that it returns -1 on error
* rather than dying.
*/
int git_config_get_maybe_bool(const char *key, int *dest);
/**
* Similar to `git_config_get_string`, but expands `~` or `~user` into
* the user's home directory when found at the beginning of the path.
*/
int git_config_get_pathname(const char *key, const char **dest);
int git_config_get_index_threads(int *dest);
int git_config_get_untracked_cache(void);
int git_config_get_split_index(void);
@ -270,7 +593,19 @@ struct key_value_info {
enum config_scope scope;
};
/**
* First prints the error message specified by the caller in `err` and then
* dies printing the line number and the file name of the highest priority
* value for the configuration variable `key`.
*/
NORETURN void git_die_config(const char *key, const char *err, ...) __attribute__((format(printf, 2, 3)));
/**
* Helper function which formats the die error message according to the
* parameters entered. Used by `git_die_config()`. It can be used by callers
* handling `git_config_get_value_multi()` to print the correct error message
* for the desired value.
*/
NORETURN void git_die_config_linenr(const char *key, const char *filename, int linenr);
#define LOOKUP_CONFIG(mapping, var) \