diff mbox series

[v2,2/2] lib/tst_kconfig: Make use of boolean expression eval

Message ID 20201027110446.20416-3-chrubis@suse.cz
State Superseded
Headers show
Series Add support for kconfig constraints | expand

Commit Message

Cyril Hrubis Oct. 27, 2020, 11:04 a.m. UTC
Now each string in the kconfig[] array in tst_test structure is an
boolean expression which is evaluated. All expressions has to be true in
order for the test to continue.

This also makes the parser for the kernel config a bit more robust as it
was pointed out that there may have been cases where it could be mislead
by hand edited config files.

+ Update the docs.

Signed-off-by: Cyril Hrubis <chrubis@suse.cz>
CC: Pengfei Xu <pengfei.xu@intel.com>
---

v2:
   - squashed the two patches since we are doing more extensive changes
   - made the parser a bit more robust
   - renamed a few fucntions and identifiers to make the code easier to
     understand
   - sprinkled the code with consts

 doc/test-writing-guidelines.txt |  21 +-
 include/tst_kconfig.h           |  34 +--
 lib/newlib_tests/config06       |   1 +
 lib/newlib_tests/test_kconfig.c |   1 +
 lib/tst_kconfig.c               | 362 +++++++++++++++++++++-----------
 5 files changed, 270 insertions(+), 149 deletions(-)
 create mode 100644 lib/newlib_tests/config06

Comments

Xiao Yang Oct. 28, 2020, 3:45 a.m. UTC | #1
On 2020/10/27 19:04, Cyril Hrubis wrote:
> Now each string in the kconfig[] array in tst_test structure is an
> boolean expression which is evaluated. All expressions has to be true in
> order for the test to continue.
>
> This also makes the parser for the kernel config a bit more robust as it
> was pointed out that there may have been cases where it could be mislead
> by hand edited config files.
>
> + Update the docs.
>
> Signed-off-by: Cyril Hrubis<chrubis@suse.cz>
> CC: Pengfei Xu<pengfei.xu@intel.com>
> ---
>
> v2:
>     - squashed the two patches since we are doing more extensive changes
>     - made the parser a bit more robust
>     - renamed a few fucntions and identifiers to make the code easier to
>       understand
>     - sprinkled the code with consts
>
>   doc/test-writing-guidelines.txt |  21 +-
>   include/tst_kconfig.h           |  34 +--
>   lib/newlib_tests/config06       |   1 +
>   lib/newlib_tests/test_kconfig.c |   1 +
>   lib/tst_kconfig.c               | 362 +++++++++++++++++++++-----------
>   5 files changed, 270 insertions(+), 149 deletions(-)
>   create mode 100644 lib/newlib_tests/config06
>
> diff --git a/doc/test-writing-guidelines.txt b/doc/test-writing-guidelines.txt
> index 1a51ef7c7..3c2ab7166 100644
> --- a/doc/test-writing-guidelines.txt
> +++ b/doc/test-writing-guidelines.txt
> @@ -1643,21 +1643,26 @@ on the system, disabled syscalls can be detected by checking for 'ENOSYS'
>   errno etc.
>
>   However in rare cases core kernel features couldn't be detected based on the
> -kernel userspace API and we have to resort to kernel .config parsing.
> +kernel userspace API and we have to resort to parse the kernel .config.
>
> -For this cases the test should set the 'NULL' terminated '.needs_kconfigs' array
> -of kernel config options required for the test. The config option can be
> -specified either as plain "CONFIG_FOO" in which case it's sufficient for the
> -test continue if it's set to any value (typically =y or =m). Or with a value
> -as "CONFIG_FOO=bar" in which case the value has to match as well. The test is
> -aborted with 'TCONF' if any of the required options were not set.
> +For this cases the test should set the 'NULL' terminated '.needs_kconfigs'
> +array of boolean expressions with constraints on the kconfig variables. The
> +boolean expression consits of variables, two binary operations '&' and '|',
> +negation '!' and correct sequence of parentesis '()'. Variables are expected
> +to be in a form of "CONFIG_FOO[=bar]".
> +
> +The test will continue to run if all expressions are evaluated to 'True'.
> +Missing variable is mapped to 'False' as well as variable with different than
> +specified value, e.g. 'CONFIG_FOO=bar' will evaluate to 'False' if the value
> +is anything else but 'bar'. If config variable is specified as plain
> +'CONFIG_FOO' it's evaluated to true it's set to any value (typically =y or =m).
>
>   [source,c]
>   -------------------------------------------------------------------------------
>   #include "tst_test.h"
>
>   static const char *kconfigs[] = {
> -	"CONFIG_X86_INTEL_UMIP",
> +	"CONFIG_X86_INTEL_UMIP | CONFIG_X86_UMIP",
>   	NULL
>   };
>
> diff --git a/include/tst_kconfig.h b/include/tst_kconfig.h
> index 2d2cfd782..1bb21fea8 100644
> --- a/include/tst_kconfig.h
> +++ b/include/tst_kconfig.h
> @@ -6,27 +6,27 @@
>   #ifndef TST_KCONFIG_H__
>   #define TST_KCONFIG_H__
>
> -struct tst_kconfig_res {
> -	char match;
> -	char *value;
> +struct tst_kconfig_var {
> +	char id[64];
> +	unsigned int id_len;
> +	char choice;
> +	char *val;
>   };
>
>   /**
> - * Reads a kernel config and parses it for values defined in kconfigs array.
> + *
> + * Reads a kernel config, parses it and writes results into an array of
> + * tst_kconfig_var structures.
>    *
>    * The path to the kernel config should be autodetected in most of the cases as
>    * the code looks for know locations. It can be explicitely set/overrided with
>    * the KCONFIG_PATH environment variable as well.
>    *
> - * The kcofings array is expected to contain strings in a format "CONFIG_FOO"
> - * or "CONFIG_FOO=bar". The result array has to be suitably sized to fit the
> - * results.
> - *
> - * @param kconfigs array of config strings to look for
> - * @param results array to store results to
> - * @param cnt size of the arrays
> + * The caller has to initialize the tst_kconfig_var structure. The id has to be
> + * filled with config variable name such as 'CONFIG_FOO', the id_len should
> + * hold the id string length and the choice and val has to be zeroed.
>    *
> - * The match in the tst_kconfig_res structure is set as follows:
> + * After a call to this function each choice be set as follows:
>    *
>    *  'm' - config option set to m
>    *  'y' - config option set to y
> @@ -34,11 +34,13 @@ struct tst_kconfig_res {
>    *  'n' - config option is not set
>    *   0  - config option not found
>    *
> - * In the case that match is set to 'v' the value points to a newly allocated
> - * string that holds the value.
> + * In the case that match is set to 'v' the val pointer points to a newly
> + * allocated string that holds the value.
> + *
> + * @param vars An array of caller initalized tst_kconfig_var structures.
> + * @param vars_len Length of the vars array.
>    */
> -void tst_kconfig_read(const char *const kconfigs[],
> -		      struct tst_kconfig_res results[], size_t cnt);
> +void tst_kconfig_read(struct tst_kconfig_var vars[], size_t vars_len);
>
>   /**
>    * Checks if required kernel configuration options are set in the kernel
> diff --git a/lib/newlib_tests/config06 b/lib/newlib_tests/config06
> new file mode 100644
> index 000000000..b7db25411
> --- /dev/null
> +++ b/lib/newlib_tests/config06
> @@ -0,0 +1 @@
> +# Empty
> diff --git a/lib/newlib_tests/test_kconfig.c b/lib/newlib_tests/test_kconfig.c
> index d9c662fc5..183d55611 100644
> --- a/lib/newlib_tests/test_kconfig.c
> +++ b/lib/newlib_tests/test_kconfig.c
> @@ -14,6 +14,7 @@ static const char *kconfigs[] = {
>   	"CONFIG_MMU",
>   	"CONFIG_EXT4_FS=m",
>   	"CONFIG_PGTABLE_LEVELS=4",
> +	"CONFIG_MMU&  CONFIG_EXT4_FS=m",
>   	NULL
>   };
>
> diff --git a/lib/tst_kconfig.c b/lib/tst_kconfig.c
> index d49187b6f..f3159b981 100644
> --- a/lib/tst_kconfig.c
> +++ b/lib/tst_kconfig.c
> @@ -12,6 +12,7 @@
>   #define TST_NO_DEFAULT_MAIN
>   #include "tst_test.h"
>   #include "tst_kconfig.h"
> +#include "tst_bool_expr.h"
>
>   static const char *kconfig_path(char *path_buf, size_t path_buf_len)
>   {
> @@ -84,126 +85,108 @@ static void close_kconfig(FILE *fp)
>   		fclose(fp);
>   }
>
> -struct match {
> -	/* match len, string length up to \0 or = */
> -	size_t len;
> -	/* if set part of conf string after = */
> -	const char *val;
> -	/* if set the config option was matched already */
> -	int match;
> -};
> -
> -static int is_set(const char *str, const char *val)
> +static inline int kconfig_parse_line(const char *line,
> +                                     struct tst_kconfig_var *vars,
> +                                     unsigned int vars_len)
>   {
> -	size_t vlen = strlen(val);
> +	unsigned int i, var_len = 0;
> +	const char *var;
> +	int is_not_set = 0;
>
> -	while (isspace(*str))
> -		str++;
> +	while (isspace(*line))
> +		line++;
>
> -	if (strncmp(str, val, vlen))
> -		return 0;
> +	if (*line == '#') {
> +		if (!strstr(line, "is not set"))
> +			return 0;
>
> -	switch (str[vlen]) {
> -	case ' ':
> -	case '\n':
> -	case '\0':
> -		return 1;
> -	break;
> -	default:
> -		return 0;
> +		is_not_set = 1;
>   	}
> -}
> -
> -static inline int match(struct match *match, const char *conf,
> -                        struct tst_kconfig_res *result, const char *line)
> -{
> -	if (match->match)
> -		return 0;
>
> -	const char *cfg = strstr(line, "CONFIG_");
> +	var = strstr(line, "CONFIG_");
>
> -	if (!cfg)
> +	if (!var)
>   		return 0;
>
> -	if (strncmp(cfg, conf, match->len))
> -		return 0;
> -
> -	const char *val =&cfg[match->len];
> -
> -	switch (cfg[match->len]) {
> -	case '=':
> +	for (;;) {
> +		switch (var[var_len]) {
> +		case 'A' ... 'Z':
> +		case '0' ... '9':
> +		case '_':
> +			var_len++;
> +		break;
> +		default:
> +			goto out;
>   		break;
> -	case ' ':
> -		if (is_set(val, "is not set")) {
> -			result->match = 'n';
> -			goto match;
>   		}
> -	/* fall through */
> -	default:
> -		return 0;
>   	}
>
> -	if (is_set(val, "=y")) {
> -		result->match = 'y';
> -		goto match;
> -	}
> +out:
>
> -	if (is_set(val, "=m")) {
> -		result->match = 'm';
> -		goto match;
> -	}
> +	for (i = 0; i<  vars_len; i++) {
> +		const char *val;
> +		unsigned int val_len = 0;
>
> -	result->match = 'v';
> -	result->value = strndup(val+1, strlen(val)-2);
> +		if (vars[i].id_len != var_len)
> +			continue;
>
> -match:
> -	match->match = 1;
> -	return 1;
> -}
> +		if (strncmp(vars[i].id, var, var_len))
> +			continue;
>
> -void tst_kconfig_read(const char *const *kconfigs,
> -                      struct tst_kconfig_res results[], size_t cnt)
Hi Cyril,

New tst_kconfig_read() breaks the compilation of acct02 so we also need 
to update acct02. :-)

Best Regards,
Xiao Yang
> -{
> -	struct match matches[cnt];
> -	FILE *fp;
> -	unsigned int i, j;
> -	char buf[1024];
> +		if (is_not_set) {
> +			vars[i].choice = 'n';
> +			return 1;
> +		}
>
> -	for (i = 0; i<  cnt; i++) {
> -		const char *val = strchr(kconfigs[i], '=');
> +		val = var + var_len;
>
> -		if (strncmp("CONFIG_", kconfigs[i], 7))
> -			tst_brk(TBROK, "Invalid config string '%s'", kconfigs[i]);
> +		while (isspace(*val))
> +			val++;
> +
> +		if (*val != '=')
> +			return 0;
> +
> +		val++;
>
> -		matches[i].match = 0;
> -		matches[i].len = strlen(kconfigs[i]);
> +		while (isspace(*val))
> +			val++;
>
> -		if (val) {
> -			matches[i].val = val + 1;
> -			matches[i].len -= strlen(val);
> +		while (!isspace(val[val_len]))
> +			val_len++;
> +
> +		if (val_len == 1) {
> +			switch (val[0]) {
> +			case 'y':
> +				vars[i].choice = 'y';
> +				return 1;
> +			case 'm':
> +				vars[i].choice = 'm';
> +				return 1;
> +			}
>   		}
>
> -		results[i].match = 0;
> -		results[i].value = NULL;
> +		vars[i].choice = 'v';
> +		vars[i].val = strndup(val, val_len);
>   	}
>
> -	fp = open_kconfig();
> +	return 0;
> +}
> +
> +void tst_kconfig_read(struct tst_kconfig_var vars[], size_t vars_len)
> +{
> +	char line[128];
> +	unsigned int vars_found = 0;
> +
> +	FILE *fp = open_kconfig();
>   	if (!fp)
>   		tst_brk(TBROK, "Cannot parse kernel .config");
>
> -	while (fgets(buf, sizeof(buf), fp)) {
> -		for (i = 0; i<  cnt; i++) {
> -			if (match(&matches[i], kconfigs[i],&results[i], buf)) {
> -				for (j = 0; j<  cnt; j++) {
> -					if (matches[j].match)
> -						break;
> -				}
> -
> -				if (j == cnt)
> -					goto exit;
> -			}
> -		}
> +	while (fgets(line, sizeof(line), fp)) {
> +		if (kconfig_parse_line(line, vars, vars_len))
> +			vars_found++;
>
> +		if (vars_found == vars_len)
> +			goto exit;
>   	}
>
>   exit:
> @@ -219,65 +202,194 @@ static size_t array_len(const char *const kconfigs[])
>   	return i;
>   }
>
> -static int compare_res(struct tst_kconfig_res *res, const char *kconfig,
> -                       char match, const char *val)
> +static const char *strnchr(const char *s, int c, unsigned int len)
>   {
> -	if (res->match != match) {
> -		tst_res(TINFO, "Needs kernel %s, have %c", kconfig, res->match);
> -		return 1;
> +	unsigned int i;
> +
> +	for (i = 0; i<  len; i++) {
> +		if (s[i] == c)
> +			return s + i;
>   	}
>
> -	if (match != 'v')
> -		return 0;
> +	return NULL;
> +}
> +
> +static inline unsigned int get_len(const char* kconfig, unsigned int len)
> +{
> +	const char *sep = strnchr(kconfig, '=', len);
> +
> +	if (!sep)
> +		return len;
> +
> +	return sep - kconfig;
> +}
> +
> +static inline unsigned int get_var_cnt(struct tst_expr *const exprs[],
> +                                       unsigned int expr_cnt)
> +{
> +	unsigned int i;
> +	const struct tst_expr *j;
> +	unsigned int cnt = 0;
>
> -	if (strcmp(res->value, val)) {
> -		tst_res(TINFO, "Needs kernel %s, have %s", kconfig, res->value);
> -		return 1;
> +	for (i = 0; i<  expr_cnt; i++) {
> +		for (j = exprs[i]; j; j = j->next) {
> +			if (j->op == TST_OP_VAR)
> +				cnt++;
> +		}
>   	}
>
> -	return 0;
> +	return cnt;
>   }
>
> -void tst_kconfig_check(const char *const kconfigs[])
> +static const struct tst_kconfig_var *find_var(const struct tst_kconfig_var vars[],
> +                                        unsigned int var_cnt,
> +                                        const char *var)
>   {
> -	size_t cnt = array_len(kconfigs);
> -	struct tst_kconfig_res results[cnt];
>   	unsigned int i;
> -	int abort_test = 0;
>
> -	tst_kconfig_read(kconfigs, results, cnt);
> +	for (i = 0; i<  var_cnt; i++) {
> +		if (!strcmp(vars[i].id, var))
> +			return&vars[i];
> +	}
>
> -	for (i = 0; i<  cnt; i++) {
> -		if (results[i].match == 0) {
> -			tst_res(TINFO, "Missing kernel %s", kconfigs[i]);
> -			abort_test = 1;
> +	return NULL;
> +}
> +
> +/*
> + * Fill in the kconfig variables array from the expressions. Also makes sure
> + * that each variable is copied to the array exaclty once.
> + */
> +static inline unsigned int populate_vars(struct tst_expr *exprs[],
> +                                         unsigned int expr_cnt,
> +                                    struct tst_kconfig_var vars[])
> +{
> +	unsigned int i;
> +	struct tst_expr *j;
> +	unsigned int cnt = 0;
> +
> +	for (i = 0; i<  expr_cnt; i++) {
> +		for (j = exprs[i]; j; j = j->next) {
> +			const struct tst_kconfig_var *var;
> +
> +			if (j->op != TST_OP_VAR)
> +				continue;
> +
> +			vars[cnt].id_len = get_len(j->tok, j->tok_len);
> +
> +			if (vars[cnt].id_len + 1>= sizeof(vars[cnt].id))
> +				tst_brk(TBROK, "kconfig var id too long!");
> +
> +			strncpy(vars[cnt].id, j->tok, vars[cnt].id_len);
> +			vars[cnt].id[vars[cnt].id_len] = 0;
> +			vars[cnt].choice = 0;
> +
> +			var = find_var(vars, cnt, vars[cnt].id);
> +
> +			if (var)
> +				j->priv = var;
> +			else
> +				j->priv =&vars[cnt++];
> +		}
> +	}
> +
> +	return cnt;
> +}
> +
> +static int map(struct tst_expr *expr)
> +{
> +	const struct tst_kconfig_var *var = expr->priv;
> +
> +	if (var->choice == 0)
> +		return 0;
> +
> +	const char *val = strnchr(expr->tok, '=', expr->tok_len);
> +
> +	/* CONFIG_FOO evaluates to true if y or m */
> +	if (!val)
> +		return var->choice == 'y' || var->choice == 'm';
> +
> +	unsigned int len = expr->tok_len - (val - expr->tok);
> +	char choice = 'v';
> +	val++;
> +
> +	if (!strncmp(val, "n", len))
> +		choice = 'n';
> +
> +	if (!strncmp(val, "y", len))
> +		choice = 'y';
> +
> +	if (!strncmp(val, "m", len))
> +		choice = 'm';
> +
> +	if (choice != 'v')
> +		return var->choice == choice;
> +
> +	return !strncmp(val, var->val, len);
> +}
> +
> +static void dump_vars(const struct tst_expr *expr)
> +{
> +	const struct tst_expr *i;
> +	const struct tst_kconfig_var *var;
> +
> +	tst_res(TINFO, "Variables:");
> +
> +	for (i = expr; i; i = i->next) {
> +		if (i->op != TST_OP_VAR)
> +			continue;
> +
> +		var = i->priv;
> +
> +		if (!var->choice) {
> +			tst_res(TINFO, " %s Undefined", var->id);
>   			continue;
>   		}
>
> -		if (results[i].match == 'n') {
> -			tst_res(TINFO, "Kernel %s is not set", kconfigs[i]);
> -			abort_test = 1;
> +		if (var->choice == 'v') {
> +			tst_res(TINFO, " %s=%s", var->id, var->val);
>   			continue;
>   		}
>
> -		const char *val = strchr(kconfigs[i], '=');
> +		tst_res(TINFO, " %s=%c", var->id, var->choice);
> +	}
> +}
>
> -		if (val) {
> -			char match = 'v';
> -			val++;
> +void tst_kconfig_check(const char *const kconfigs[])
> +{
> +	size_t expr_cnt = array_len(kconfigs);
> +	struct tst_expr *exprs[expr_cnt];
> +	unsigned int i, var_cnt;
> +	int abort_test = 0;
>
> -			if (!strcmp(val, "y"))
> -				match = 'y';
> +	for (i = 0; i<  expr_cnt; i++) {
> +		exprs[i] = tst_bool_expr_parse(kconfigs[i]);
>
> -			if (!strcmp(val, "m"))
> -				match = 'm';
> +		if (!exprs[i])
> +			tst_brk(TBROK, "Invalid kconfig expression!");
> +	}
>
> -			if (compare_res(&results[i], kconfigs[i], match, val))
> -				abort_test = 1;
> +	var_cnt = get_var_cnt(exprs, expr_cnt);
> +	struct tst_kconfig_var vars[var_cnt];
>
> +	var_cnt = populate_vars(exprs, expr_cnt, vars);
> +
> +	tst_kconfig_read(vars, var_cnt);
> +
> +	for (i = 0; i<  expr_cnt; i++) {
> +		int val = tst_bool_expr_eval(exprs[i], map);
> +
> +		if (val != 1) {
> +			abort_test = 1;
> +			tst_res(TINFO, "Expression '%s' not satisfied!", kconfigs[i]);
> +			dump_vars(exprs[i]);
>   		}
>
> -		free(results[i].value);
> +		tst_bool_expr_free(exprs[i]);
> +	}
> +
> +	for (i = 0; i<  var_cnt; i++) {
> +		if (vars[i].choice == 'v')
> +			free(vars[i].val);
>   	}
>
>   	if (abort_test)
Cyril Hrubis Oct. 29, 2020, 10:39 a.m. UTC | #2
Hi!
> > -void tst_kconfig_read(const char *const *kconfigs,
> > -                      struct tst_kconfig_res results[], size_t cnt)
> Hi Cyril,
> 
> New tst_kconfig_read() breaks the compilation of acct02 so we also need 
> to update acct02. :-)

Good catch, will fix that.
Li Wang Nov. 2, 2020, 10:17 a.m. UTC | #3
On Tue, Oct 27, 2020 at 7:04 PM Cyril Hrubis <chrubis@suse.cz> wrote:

> Now each string in the kconfig[] array in tst_test structure is an
> boolean expression which is evaluated. All expressions has to be true in
> order for the test to continue.
>
> This also makes the parser for the kernel config a bit more robust as it
> was pointed out that there may have been cases where it could be mislead
> by hand edited config files.
>
> + Update the docs.
>
> Signed-off-by: Cyril Hrubis <chrubis@suse.cz>
> CC: Pengfei Xu <pengfei.xu@intel.com>
> ---
>
> v2:
>    - squashed the two patches since we are doing more extensive changes
>    - made the parser a bit more robust
>    - renamed a few fucntions and identifiers to make the code easier to
>      understand
>    - sprinkled the code with consts
>
>  doc/test-writing-guidelines.txt |  21 +-
>  include/tst_kconfig.h           |  34 +--
>  lib/newlib_tests/config06       |   1 +
>  lib/newlib_tests/test_kconfig.c |   1 +
>  lib/tst_kconfig.c               | 362 +++++++++++++++++++++-----------
>  5 files changed, 270 insertions(+), 149 deletions(-)
>  create mode 100644 lib/newlib_tests/config06
>
> diff --git a/doc/test-writing-guidelines.txt
> b/doc/test-writing-guidelines.txt
> index 1a51ef7c7..3c2ab7166 100644
> --- a/doc/test-writing-guidelines.txt
> +++ b/doc/test-writing-guidelines.txt
> @@ -1643,21 +1643,26 @@ on the system, disabled syscalls can be detected
> by checking for 'ENOSYS'
>  errno etc.
>
>  However in rare cases core kernel features couldn't be detected based on
> the
> -kernel userspace API and we have to resort to kernel .config parsing.
> +kernel userspace API and we have to resort to parse the kernel .config.
>
> -For this cases the test should set the 'NULL' terminated
> '.needs_kconfigs' array
> -of kernel config options required for the test. The config option can be
> -specified either as plain "CONFIG_FOO" in which case it's sufficient for
> the
> -test continue if it's set to any value (typically =y or =m). Or with a
> value
> -as "CONFIG_FOO=bar" in which case the value has to match as well. The
> test is
> -aborted with 'TCONF' if any of the required options were not set.
> +For this cases the test should set the 'NULL' terminated '.needs_kconfigs'
> +array of boolean expressions with constraints on the kconfig variables.
> The
> +boolean expression consits of variables, two binary operations '&' and
> '|',
> +negation '!' and correct sequence of parentesis '()'. Variables are
> expected
> +to be in a form of "CONFIG_FOO[=bar]".
> +
> +The test will continue to run if all expressions are evaluated to 'True'.
> +Missing variable is mapped to 'False' as well as variable with different
> than
> +specified value, e.g. 'CONFIG_FOO=bar' will evaluate to 'False' if the
> value
> +is anything else but 'bar'. If config variable is specified as plain
> +'CONFIG_FOO' it's evaluated to true it's set to any value (typically =y
> or =m).
>
>  [source,c]
>
>  -------------------------------------------------------------------------------
>  #include "tst_test.h"
>
>  static const char *kconfigs[] = {
> -       "CONFIG_X86_INTEL_UMIP",
> +       "CONFIG_X86_INTEL_UMIP | CONFIG_X86_UMIP",
>         NULL
>  };
>
> diff --git a/include/tst_kconfig.h b/include/tst_kconfig.h
> index 2d2cfd782..1bb21fea8 100644
> --- a/include/tst_kconfig.h
> +++ b/include/tst_kconfig.h
> @@ -6,27 +6,27 @@
>  #ifndef TST_KCONFIG_H__
>  #define TST_KCONFIG_H__
>
> -struct tst_kconfig_res {
> -       char match;
> -       char *value;
> +struct tst_kconfig_var {
> +       char id[64];
> +       unsigned int id_len;
> +       char choice;
> +       char *val;
>  };
>
>  /**
> - * Reads a kernel config and parses it for values defined in kconfigs
> array.
> + *
> + * Reads a kernel config, parses it and writes results into an array of
> + * tst_kconfig_var structures.
>   *
>   * The path to the kernel config should be autodetected in most of the
> cases as
>   * the code looks for know locations. It can be explicitely set/overrided
> with
>   * the KCONFIG_PATH environment variable as well.
>   *
> - * The kcofings array is expected to contain strings in a format
> "CONFIG_FOO"
> - * or "CONFIG_FOO=bar". The result array has to be suitably sized to fit
> the
> - * results.
> - *
> - * @param kconfigs array of config strings to look for
> - * @param results array to store results to
> - * @param cnt size of the arrays
> + * The caller has to initialize the tst_kconfig_var structure. The id has
> to be
> + * filled with config variable name such as 'CONFIG_FOO', the id_len
> should
> + * hold the id string length and the choice and val has to be zeroed.
>   *
> - * The match in the tst_kconfig_res structure is set as follows:
> + * After a call to this function each choice be set as follows:
>   *
>   *  'm' - config option set to m
>   *  'y' - config option set to y
> @@ -34,11 +34,13 @@ struct tst_kconfig_res {
>   *  'n' - config option is not set
>   *   0  - config option not found
>   *
> - * In the case that match is set to 'v' the value points to a newly
> allocated
> - * string that holds the value.
> + * In the case that match is set to 'v' the val pointer points to a newly
> + * allocated string that holds the value.
> + *
> + * @param vars An array of caller initalized tst_kconfig_var structures.
> + * @param vars_len Length of the vars array.
>   */
> -void tst_kconfig_read(const char *const kconfigs[],
> -                     struct tst_kconfig_res results[], size_t cnt);
> +void tst_kconfig_read(struct tst_kconfig_var vars[], size_t vars_len);
>
>  /**
>   * Checks if required kernel configuration options are set in the kernel
> diff --git a/lib/newlib_tests/config06 b/lib/newlib_tests/config06
> new file mode 100644
> index 000000000..b7db25411
> --- /dev/null
> +++ b/lib/newlib_tests/config06
> @@ -0,0 +1 @@
> +# Empty
> diff --git a/lib/newlib_tests/test_kconfig.c
> b/lib/newlib_tests/test_kconfig.c
> index d9c662fc5..183d55611 100644
> --- a/lib/newlib_tests/test_kconfig.c
> +++ b/lib/newlib_tests/test_kconfig.c
> @@ -14,6 +14,7 @@ static const char *kconfigs[] = {
>         "CONFIG_MMU",
>         "CONFIG_EXT4_FS=m",
>         "CONFIG_PGTABLE_LEVELS=4",
> +       "CONFIG_MMU & CONFIG_EXT4_FS=m",
>

The patchset looks awesome.

But a tiny issue was found from my test, the tst_kconfig_check() would be
failed to parse expression if reverse the sequence of the above string.

i.e.
-       "CONFIG_MMU & CONFIG_EXT4_FS=m",
+       "CONFIG_EXT4_FS=m & CONFIG_MMU",
(Core dumped here)

But trying with =Num, it gets different errors:

"CONFIG_MMU & CONFIG_PGTABLE_LEVELS=4",
(works well)

"CONFIG_PGTABLE_LEVELS=4 & CONFIG_MMU",
(print Expression not satisfied!)
Cyril Hrubis Nov. 2, 2020, 10:38 a.m. UTC | #4
Hi!
> But a tiny issue was found from my test, the tst_kconfig_check() would be
> failed to parse expression if reverse the sequence of the above string.
> 
> i.e.
> -       "CONFIG_MMU & CONFIG_EXT4_FS=m",
> +       "CONFIG_EXT4_FS=m & CONFIG_MMU",
> (Core dumped here)
> 
> But trying with =Num, it gets different errors:
> 
> "CONFIG_MMU & CONFIG_PGTABLE_LEVELS=4",
> (works well)
> 
> "CONFIG_PGTABLE_LEVELS=4 & CONFIG_MMU",
> (print Expression not satisfied!)

Looks like off by one in the strncmp() in the map() function, I will fix
that as well and send v3.

Thanks a lot for testing.
diff mbox series

Patch

diff --git a/doc/test-writing-guidelines.txt b/doc/test-writing-guidelines.txt
index 1a51ef7c7..3c2ab7166 100644
--- a/doc/test-writing-guidelines.txt
+++ b/doc/test-writing-guidelines.txt
@@ -1643,21 +1643,26 @@  on the system, disabled syscalls can be detected by checking for 'ENOSYS'
 errno etc.
 
 However in rare cases core kernel features couldn't be detected based on the
-kernel userspace API and we have to resort to kernel .config parsing.
+kernel userspace API and we have to resort to parse the kernel .config.
 
-For this cases the test should set the 'NULL' terminated '.needs_kconfigs' array
-of kernel config options required for the test. The config option can be
-specified either as plain "CONFIG_FOO" in which case it's sufficient for the
-test continue if it's set to any value (typically =y or =m). Or with a value
-as "CONFIG_FOO=bar" in which case the value has to match as well. The test is
-aborted with 'TCONF' if any of the required options were not set.
+For this cases the test should set the 'NULL' terminated '.needs_kconfigs'
+array of boolean expressions with constraints on the kconfig variables. The
+boolean expression consits of variables, two binary operations '&' and '|',
+negation '!' and correct sequence of parentesis '()'. Variables are expected
+to be in a form of "CONFIG_FOO[=bar]".
+
+The test will continue to run if all expressions are evaluated to 'True'.
+Missing variable is mapped to 'False' as well as variable with different than
+specified value, e.g. 'CONFIG_FOO=bar' will evaluate to 'False' if the value
+is anything else but 'bar'. If config variable is specified as plain
+'CONFIG_FOO' it's evaluated to true it's set to any value (typically =y or =m).
 
 [source,c]
 -------------------------------------------------------------------------------
 #include "tst_test.h"
 
 static const char *kconfigs[] = {
-	"CONFIG_X86_INTEL_UMIP",
+	"CONFIG_X86_INTEL_UMIP | CONFIG_X86_UMIP",
 	NULL
 };
 
diff --git a/include/tst_kconfig.h b/include/tst_kconfig.h
index 2d2cfd782..1bb21fea8 100644
--- a/include/tst_kconfig.h
+++ b/include/tst_kconfig.h
@@ -6,27 +6,27 @@ 
 #ifndef TST_KCONFIG_H__
 #define TST_KCONFIG_H__
 
-struct tst_kconfig_res {
-	char match;
-	char *value;
+struct tst_kconfig_var {
+	char id[64];
+	unsigned int id_len;
+	char choice;
+	char *val;
 };
 
 /**
- * Reads a kernel config and parses it for values defined in kconfigs array.
+ *
+ * Reads a kernel config, parses it and writes results into an array of
+ * tst_kconfig_var structures.
  *
  * The path to the kernel config should be autodetected in most of the cases as
  * the code looks for know locations. It can be explicitely set/overrided with
  * the KCONFIG_PATH environment variable as well.
  *
- * The kcofings array is expected to contain strings in a format "CONFIG_FOO"
- * or "CONFIG_FOO=bar". The result array has to be suitably sized to fit the
- * results.
- *
- * @param kconfigs array of config strings to look for
- * @param results array to store results to
- * @param cnt size of the arrays
+ * The caller has to initialize the tst_kconfig_var structure. The id has to be
+ * filled with config variable name such as 'CONFIG_FOO', the id_len should
+ * hold the id string length and the choice and val has to be zeroed.
  *
- * The match in the tst_kconfig_res structure is set as follows:
+ * After a call to this function each choice be set as follows:
  *
  *  'm' - config option set to m
  *  'y' - config option set to y
@@ -34,11 +34,13 @@  struct tst_kconfig_res {
  *  'n' - config option is not set
  *   0  - config option not found
  *
- * In the case that match is set to 'v' the value points to a newly allocated
- * string that holds the value.
+ * In the case that match is set to 'v' the val pointer points to a newly
+ * allocated string that holds the value.
+ *
+ * @param vars An array of caller initalized tst_kconfig_var structures.
+ * @param vars_len Length of the vars array.
  */
-void tst_kconfig_read(const char *const kconfigs[],
-		      struct tst_kconfig_res results[], size_t cnt);
+void tst_kconfig_read(struct tst_kconfig_var vars[], size_t vars_len);
 
 /**
  * Checks if required kernel configuration options are set in the kernel
diff --git a/lib/newlib_tests/config06 b/lib/newlib_tests/config06
new file mode 100644
index 000000000..b7db25411
--- /dev/null
+++ b/lib/newlib_tests/config06
@@ -0,0 +1 @@ 
+# Empty
diff --git a/lib/newlib_tests/test_kconfig.c b/lib/newlib_tests/test_kconfig.c
index d9c662fc5..183d55611 100644
--- a/lib/newlib_tests/test_kconfig.c
+++ b/lib/newlib_tests/test_kconfig.c
@@ -14,6 +14,7 @@  static const char *kconfigs[] = {
 	"CONFIG_MMU",
 	"CONFIG_EXT4_FS=m",
 	"CONFIG_PGTABLE_LEVELS=4",
+	"CONFIG_MMU & CONFIG_EXT4_FS=m",
 	NULL
 };
 
diff --git a/lib/tst_kconfig.c b/lib/tst_kconfig.c
index d49187b6f..f3159b981 100644
--- a/lib/tst_kconfig.c
+++ b/lib/tst_kconfig.c
@@ -12,6 +12,7 @@ 
 #define TST_NO_DEFAULT_MAIN
 #include "tst_test.h"
 #include "tst_kconfig.h"
+#include "tst_bool_expr.h"
 
 static const char *kconfig_path(char *path_buf, size_t path_buf_len)
 {
@@ -84,126 +85,108 @@  static void close_kconfig(FILE *fp)
 		fclose(fp);
 }
 
-struct match {
-	/* match len, string length up to \0 or = */
-	size_t len;
-	/* if set part of conf string after = */
-	const char *val;
-	/* if set the config option was matched already */
-	int match;
-};
-
-static int is_set(const char *str, const char *val)
+static inline int kconfig_parse_line(const char *line,
+                                     struct tst_kconfig_var *vars,
+                                     unsigned int vars_len)
 {
-	size_t vlen = strlen(val);
+	unsigned int i, var_len = 0;
+	const char *var;
+	int is_not_set = 0;
 
-	while (isspace(*str))
-		str++;
+	while (isspace(*line))
+		line++;
 
-	if (strncmp(str, val, vlen))
-		return 0;
+	if (*line == '#') {
+		if (!strstr(line, "is not set"))
+			return 0;
 
-	switch (str[vlen]) {
-	case ' ':
-	case '\n':
-	case '\0':
-		return 1;
-	break;
-	default:
-		return 0;
+		is_not_set = 1;
 	}
-}
-
-static inline int match(struct match *match, const char *conf,
-                        struct tst_kconfig_res *result, const char *line)
-{
-	if (match->match)
-		return 0;
 
-	const char *cfg = strstr(line, "CONFIG_");
+	var = strstr(line, "CONFIG_");
 
-	if (!cfg)
+	if (!var)
 		return 0;
 
-	if (strncmp(cfg, conf, match->len))
-		return 0;
-
-	const char *val = &cfg[match->len];
-
-	switch (cfg[match->len]) {
-	case '=':
+	for (;;) {
+		switch (var[var_len]) {
+		case 'A' ... 'Z':
+		case '0' ... '9':
+		case '_':
+			var_len++;
+		break;
+		default:
+			goto out;
 		break;
-	case ' ':
-		if (is_set(val, "is not set")) {
-			result->match = 'n';
-			goto match;
 		}
-	/* fall through */
-	default:
-		return 0;
 	}
 
-	if (is_set(val, "=y")) {
-		result->match = 'y';
-		goto match;
-	}
+out:
 
-	if (is_set(val, "=m")) {
-		result->match = 'm';
-		goto match;
-	}
+	for (i = 0; i < vars_len; i++) {
+		const char *val;
+		unsigned int val_len = 0;
 
-	result->match = 'v';
-	result->value = strndup(val+1, strlen(val)-2);
+		if (vars[i].id_len != var_len)
+			continue;
 
-match:
-	match->match = 1;
-	return 1;
-}
+		if (strncmp(vars[i].id, var, var_len))
+			continue;
 
-void tst_kconfig_read(const char *const *kconfigs,
-                      struct tst_kconfig_res results[], size_t cnt)
-{
-	struct match matches[cnt];
-	FILE *fp;
-	unsigned int i, j;
-	char buf[1024];
+		if (is_not_set) {
+			vars[i].choice = 'n';
+			return 1;
+		}
 
-	for (i = 0; i < cnt; i++) {
-		const char *val = strchr(kconfigs[i], '=');
+		val = var + var_len;
 
-		if (strncmp("CONFIG_", kconfigs[i], 7))
-			tst_brk(TBROK, "Invalid config string '%s'", kconfigs[i]);
+		while (isspace(*val))
+			val++;
+
+		if (*val != '=')
+			return 0;
+
+		val++;
 
-		matches[i].match = 0;
-		matches[i].len = strlen(kconfigs[i]);
+		while (isspace(*val))
+			val++;
 
-		if (val) {
-			matches[i].val = val + 1;
-			matches[i].len -= strlen(val);
+		while (!isspace(val[val_len]))
+			val_len++;
+
+		if (val_len == 1) {
+			switch (val[0]) {
+			case 'y':
+				vars[i].choice = 'y';
+				return 1;
+			case 'm':
+				vars[i].choice = 'm';
+				return 1;
+			}
 		}
 
-		results[i].match = 0;
-		results[i].value = NULL;
+		vars[i].choice = 'v';
+		vars[i].val = strndup(val, val_len);
 	}
 
-	fp = open_kconfig();
+	return 0;
+}
+
+void tst_kconfig_read(struct tst_kconfig_var vars[], size_t vars_len)
+{
+	char line[128];
+	unsigned int vars_found = 0;
+
+	FILE *fp = open_kconfig();
 	if (!fp)
 		tst_brk(TBROK, "Cannot parse kernel .config");
 
-	while (fgets(buf, sizeof(buf), fp)) {
-		for (i = 0; i < cnt; i++) {
-			if (match(&matches[i], kconfigs[i], &results[i], buf)) {
-				for (j = 0; j < cnt; j++) {
-					if (matches[j].match)
-						break;
-				}
-
-				if (j == cnt)
-					goto exit;
-			}
-		}
+	while (fgets(line, sizeof(line), fp)) {
+		if (kconfig_parse_line(line, vars, vars_len))
+			vars_found++;
 
+		if (vars_found == vars_len)
+			goto exit;
 	}
 
 exit:
@@ -219,65 +202,194 @@  static size_t array_len(const char *const kconfigs[])
 	return i;
 }
 
-static int compare_res(struct tst_kconfig_res *res, const char *kconfig,
-                       char match, const char *val)
+static const char *strnchr(const char *s, int c, unsigned int len)
 {
-	if (res->match != match) {
-		tst_res(TINFO, "Needs kernel %s, have %c", kconfig, res->match);
-		return 1;
+	unsigned int i;
+
+	for (i = 0; i < len; i++) {
+		if (s[i] == c)
+			return s + i;
 	}
 
-	if (match != 'v')
-		return 0;
+	return NULL;
+}
+
+static inline unsigned int get_len(const char* kconfig, unsigned int len)
+{
+	const char *sep = strnchr(kconfig, '=', len);
+
+	if (!sep)
+		return len;
+
+	return sep - kconfig;
+}
+
+static inline unsigned int get_var_cnt(struct tst_expr *const exprs[],
+                                       unsigned int expr_cnt)
+{
+	unsigned int i;
+	const struct tst_expr *j;
+	unsigned int cnt = 0;
 
-	if (strcmp(res->value, val)) {
-		tst_res(TINFO, "Needs kernel %s, have %s", kconfig, res->value);
-		return 1;
+	for (i = 0; i < expr_cnt; i++) {
+		for (j = exprs[i]; j; j = j->next) {
+			if (j->op == TST_OP_VAR)
+				cnt++;
+		}
 	}
 
-	return 0;
+	return cnt;
 }
 
-void tst_kconfig_check(const char *const kconfigs[])
+static const struct tst_kconfig_var *find_var(const struct tst_kconfig_var vars[],
+                                        unsigned int var_cnt,
+                                        const char *var)
 {
-	size_t cnt = array_len(kconfigs);
-	struct tst_kconfig_res results[cnt];
 	unsigned int i;
-	int abort_test = 0;
 
-	tst_kconfig_read(kconfigs, results, cnt);
+	for (i = 0; i < var_cnt; i++) {
+		if (!strcmp(vars[i].id, var))
+			return &vars[i];
+	}
 
-	for (i = 0; i < cnt; i++) {
-		if (results[i].match == 0) {
-			tst_res(TINFO, "Missing kernel %s", kconfigs[i]);
-			abort_test = 1;
+	return NULL;
+}
+
+/*
+ * Fill in the kconfig variables array from the expressions. Also makes sure
+ * that each variable is copied to the array exaclty once.
+ */
+static inline unsigned int populate_vars(struct tst_expr *exprs[],
+                                         unsigned int expr_cnt,
+                                    struct tst_kconfig_var vars[])
+{
+	unsigned int i;
+	struct tst_expr *j;
+	unsigned int cnt = 0;
+
+	for (i = 0; i < expr_cnt; i++) {
+		for (j = exprs[i]; j; j = j->next) {
+			const struct tst_kconfig_var *var;
+
+			if (j->op != TST_OP_VAR)
+				continue;
+
+			vars[cnt].id_len = get_len(j->tok, j->tok_len);
+
+			if (vars[cnt].id_len + 1 >= sizeof(vars[cnt].id))
+				tst_brk(TBROK, "kconfig var id too long!");
+
+			strncpy(vars[cnt].id, j->tok, vars[cnt].id_len);
+			vars[cnt].id[vars[cnt].id_len] = 0;
+			vars[cnt].choice = 0;
+
+			var = find_var(vars, cnt, vars[cnt].id);
+
+			if (var)
+				j->priv = var;
+			else
+				j->priv = &vars[cnt++];
+		}
+	}
+
+	return cnt;
+}
+
+static int map(struct tst_expr *expr)
+{
+	const struct tst_kconfig_var *var = expr->priv;
+
+	if (var->choice == 0)
+		return 0;
+
+	const char *val = strnchr(expr->tok, '=', expr->tok_len);
+
+	/* CONFIG_FOO evaluates to true if y or m */
+	if (!val)
+		return var->choice == 'y' || var->choice == 'm';
+
+	unsigned int len = expr->tok_len - (val - expr->tok);
+	char choice = 'v';
+	val++;
+
+	if (!strncmp(val, "n", len))
+		choice = 'n';
+
+	if (!strncmp(val, "y", len))
+		choice = 'y';
+
+	if (!strncmp(val, "m", len))
+		choice = 'm';
+
+	if (choice != 'v')
+		return var->choice == choice;
+
+	return !strncmp(val, var->val, len);
+}
+
+static void dump_vars(const struct tst_expr *expr)
+{
+	const struct tst_expr *i;
+	const struct tst_kconfig_var *var;
+
+	tst_res(TINFO, "Variables:");
+
+	for (i = expr; i; i = i->next) {
+		if (i->op != TST_OP_VAR)
+			continue;
+
+		var = i->priv;
+
+		if (!var->choice) {
+			tst_res(TINFO, " %s Undefined", var->id);
 			continue;
 		}
 
-		if (results[i].match == 'n') {
-			tst_res(TINFO, "Kernel %s is not set", kconfigs[i]);
-			abort_test = 1;
+		if (var->choice == 'v') {
+			tst_res(TINFO, " %s=%s", var->id, var->val);
 			continue;
 		}
 
-		const char *val = strchr(kconfigs[i], '=');
+		tst_res(TINFO, " %s=%c", var->id, var->choice);
+	}
+}
 
-		if (val) {
-			char match = 'v';
-			val++;
+void tst_kconfig_check(const char *const kconfigs[])
+{
+	size_t expr_cnt = array_len(kconfigs);
+	struct tst_expr *exprs[expr_cnt];
+	unsigned int i, var_cnt;
+	int abort_test = 0;
 
-			if (!strcmp(val, "y"))
-				match = 'y';
+	for (i = 0; i < expr_cnt; i++) {
+		exprs[i] = tst_bool_expr_parse(kconfigs[i]);
 
-			if (!strcmp(val, "m"))
-				match = 'm';
+		if (!exprs[i])
+			tst_brk(TBROK, "Invalid kconfig expression!");
+	}
 
-			if (compare_res(&results[i], kconfigs[i], match, val))
-				abort_test = 1;
+	var_cnt = get_var_cnt(exprs, expr_cnt);
+	struct tst_kconfig_var vars[var_cnt];
 
+	var_cnt = populate_vars(exprs, expr_cnt, vars);
+
+	tst_kconfig_read(vars, var_cnt);
+
+	for (i = 0; i < expr_cnt; i++) {
+		int val = tst_bool_expr_eval(exprs[i], map);
+
+		if (val != 1) {
+			abort_test = 1;
+			tst_res(TINFO, "Expression '%s' not satisfied!", kconfigs[i]);
+			dump_vars(exprs[i]);
 		}
 
-		free(results[i].value);
+		tst_bool_expr_free(exprs[i]);
+	}
+
+	for (i = 0; i < var_cnt; i++) {
+		if (vars[i].choice == 'v')
+			free(vars[i].val);
 	}
 
 	if (abort_test)