kconfig: add built-in function support (e298f3b4) · Commits · 戴 / test

scripts/kconfig/preprocess.c

+130 −12

Original line number	Diff line number	Diff line
		@@ -10,6 +10,10 @@

		#include "list.h"

		#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))

		static char expand_string_with_args(const char in, int argc, char *argv[]);

		static void __attribute__((noreturn)) pperror(const char *format, ...)
		{
		va_list ap;
		@@ -92,20 +96,123 @@ void env_write_dep(FILE f, const char autoconfig_name)
		}
		}

		static char eval_clause(const char str, size_t len)
		/*
		* Built-in functions
		*/
		struct function {
		const char *name;
		unsigned int min_args;
		unsigned int max_args;
		char (func)(int argc, char *argv[]);
		};

		static const struct function function_table[] = {
		/* Name MIN MAX Function */
		};

		#define FUNCTION_MAX_ARGS 16

		static char function_expand(const char name, int argc, char *argv[])
		{
		const struct function *f;
		int i;

		for (i = 0; i < ARRAY_SIZE(function_table); i++) {
		f = &function_table[i];
		if (strcmp(f->name, name))
		continue;

		if (argc < f->min_args)
		pperror("too few function arguments passed to '%s'",
		name);

		if (argc > f->max_args)
		pperror("too many function arguments passed to '%s'",
		name);

		return f->func(argc, argv);
		}

		return NULL;
		}

		/*
		* Evaluate a clause with arguments. argc/argv are arguments from the upper
		* function call.
		*
		* Returned string must be freed when done
		*/
		static char eval_clause(const char str, size_t len, int argc, char *argv[])
		{
		char tmp, name, *res;
		char tmp, name, res, prev, *p;
		int new_argc = 0;
		char *new_argv[FUNCTION_MAX_ARGS];
		int nest = 0;
		int i;

		tmp = xstrndup(str, len);

		name = expand_string(tmp);
		prev = p = tmp;

		/*
		* Split into tokens
		* The function name and arguments are separated by a comma.
		* For example, if the function call is like this:
		* $(foo,$(x),$(y))
		*
		* The input string for this helper should be:
		* foo,$(x),$(y)
		*
		* and split into:
		* new_argv[0] = 'foo'
		* new_argv[1] = '$(x)'
		* new_argv[2] = '$(y)'
		*/
		while (*p) {
		if (nest == 0 && *p == ',') {
		*p = 0;
		if (new_argc >= FUNCTION_MAX_ARGS)
		pperror("too many function arguments");
		new_argv[new_argc++] = prev;
		prev = p + 1;
		} else if (*p == '(') {
		nest++;
		} else if (*p == ')') {
		nest--;
		}

		p++;
		}
		new_argv[new_argc++] = prev;

		/*
		* Shift arguments
		* new_argv[0] represents a function name or a variable name. Put it
		* into 'name', then shift the rest of the arguments. This simplifies
		* 'const' handling.
		*/
		name = expand_string_with_args(new_argv[0], argc, argv);
		new_argc--;
		for (i = 0; i < new_argc; i++)
		new_argv[i] = expand_string_with_args(new_argv[i + 1],
		argc, argv);

		/* Look for built-in functions */
		res = function_expand(name, new_argc, new_argv);
		if (res)
		goto free;

		/* Last, try environment variable */
		if (new_argc == 0) {
		res = env_expand(name);
		if (res)
		goto free;
		}

		res = xstrdup("");
		free:
		for (i = 0; i < new_argc; i++)
		free(new_argv[i]);
		free(name);
		free(tmp);

		@@ -124,14 +231,14 @@ free:
		* after the corresponding closing parenthesis, in this case, *str will be
		* $(BAR)
		*/
		char expand_dollar(const char *str)
		static char expand_dollar_with_args(const char str, int argc, char argv[])
		{
		const char p = str;
		const char *q;
		int nest = 0;

		/*
		* In Kconfig, variable references always start with "$(".
		* In Kconfig, variable/function references always start with "$(".
		* Neither single-letter variables as in $A nor curly braces as in ${CC}
		* are supported. '$' not followed by '(' loses its special meaning.
		*/
		@@ -158,10 +265,16 @@ char expand_dollar(const char *str)
		/* Advance 'str' to after the expanded initial portion of the string */
		*str = q + 1;

		return eval_clause(p, q - p);
		return eval_clause(p, q - p, argc, argv);
		}

		char expand_dollar(const char *str)
		{
		return expand_dollar_with_args(str, 0, NULL);
		}

		static char __expand_string(const char str, bool (is_end)(char c))
		static char __expand_string(const char str, bool (is_end)(char c),
		int argc, char *argv[])
		{
		const char in, p;
		char expansion, out;
		@@ -177,7 +290,7 @@ static char __expand_string(const char str, bool (is_end)(char c))
		if (*p == '$') {
		in_len = p - in;
		p++;
		expansion = expand_dollar(&p);
		expansion = expand_dollar_with_args(&p, argc, argv);
		out_len += in_len + strlen(expansion);
		out = xrealloc(out, out_len);
		strncat(out, in, in_len);
		@@ -210,13 +323,18 @@ static bool is_end_of_str(char c)
		}

		/*
		* Expand variables in the given string. Undefined variables
		* Expand variables and functions in the given string. Undefined variables
		* expand to an empty string.
		* The returned string must be freed when done.
		*/
		static char expand_string_with_args(const char in, int argc, char *argv[])
		{
		return __expand_string(&in, is_end_of_str, argc, argv);
		}

		char expand_string(const char in)
		{
		return __expand_string(&in, is_end_of_str);
		return expand_string_with_args(in, 0, NULL);
		}

		static bool is_end_of_token(char c)
		@@ -234,5 +352,5 @@ static bool is_end_of_token(char c)
		*/
		char expand_one_token(const char *str)
		{
		return __expand_string(str, is_end_of_token);
		return __expand_string(str, is_end_of_token, 0, NULL);
		}

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