This commit adds a new concept 'function' to do more text processing in Kconfig. A function call looks like this: $(function arg1, arg2, arg3, ...) This commit adds the basic infrastructure to expand functions. Change the text expansion helpers to take arguments. Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx> --- Changes in v3: - Split base infrastructure and 'shell' function into separate patches. Changes in v2: - Use 'shell' for getting stdout from the comment. It was 'shell-stdout' in the previous version. - Symplify the implementation since the expansion has been moved to lexer. scripts/kconfig/preprocess.c | 142 +++++++++++++++++++++++++++++++++++++++---- 1 file changed, 130 insertions(+), 12 deletions(-) diff --git a/scripts/kconfig/preprocess.c b/scripts/kconfig/preprocess.c index fa4abc8..e77cf7c 100644 --- a/scripts/kconfig/preprocess.c +++ b/scripts/kconfig/preprocess.c @@ -8,6 +8,10 @@ #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[]); + /* * Environment variables */ @@ -74,9 +78,47 @@ void env_write_dep(FILE *f, const char *autoconfig_name) } } -static char *eval_clause(const char *in) +/* + * Built-in Functions + */ +struct function { + char *name; + char *(*func)(int argc, char *argv[]); +}; + +static const struct function function_table[] = { +}; + +static char *function_call(const char *name, int argc, char *argv[]) { - char *res, *name; + const struct function *f; + int i; + + for (i = 0; i < ARRAY_SIZE(function_table); i++) { + f = &function_table[i]; + if (!strcmp(f->name, name)) + return f->func(argc, argv); + } + + return NULL; +} + +#define FUNCTION_MAX_ARGS 16 + +/* + * 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 *in, int argc, char *argv[]) +{ + char *tmp, *prev, *p, *res, *name; + char delim = ' '; + int new_argc = 0; + char *new_argv[FUNCTION_MAX_ARGS]; + int nest = 0; + int i; /* * Returns an empty string because '$()' should be evaluated @@ -85,10 +127,73 @@ static char *eval_clause(const char *in) if (!*in) return xstrdup(""); - name = expand_string(in); + tmp = xstrdup(in); + + prev = p = tmp; - res = env_expand(name); + /* + * Split into tokens + * The function name and the first argument are separated by a space. + * Arguments are separated by a comma. + * For example, if the function call is like this: + * $(foo abc,$(x),$(y)) + * + * The input string for this helper should be: + * foo abc,$(x),$(y) + * + * and split into: + * new_argv[0]: foo + * new_argv[1]: abc + * new_argv[2]: $(x) + * new_argv[3]: $(y) + */ + while (*p) { + if (nest == 0 && *p == delim) { + *p = 0; + new_argv[new_argc++] = prev; + prev = p + 1; + delim = ','; + } 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); + + free(tmp); + + /* Look for built-in functions */ + res = function_call(name, new_argc, new_argv); + if (res) + goto out; + + /* Last, try environment variable */ + if (new_argc == 0) { + res = env_expand(name); + if (res) + goto out; + } + + res = xstrdup(""); +out: free(name); + for (i = 0; i < new_argc; i++) + free(new_argv[i]); return res; } @@ -115,7 +220,7 @@ static char *eval_clause(const char *in) * This is because $ABC is equivalent to $(A)BC. (Like Make, you can omit * parentheses if the variable name consists of a single character. */ -char *expand_dollar(const char **str) +static char *expand_dollar_with_args(const char **str, int argc, char *argv[]) { const char *p = *str; const char *q; @@ -124,6 +229,9 @@ char *expand_dollar(const char **str) /* * A standalone '$' at the end of a token is treated as-is. + * For example, the '$' before the comma in $(foo $,A) and the '$' + * before the closing parenthesis in $(shell echo $) lose the special + * meaning. This is the behavior of Make 4.2 or newer. */ if (!*p) return xstrdup("$"); @@ -140,15 +248,15 @@ char *expand_dollar(const char **str) tmp[0] = *p; tmp[1] = 0; *str = p + 1; - out = eval_clause(tmp); + out = eval_clause(tmp, argc, argv); free(tmp); return out; } /* - * Variables that consist of multiple letters + * Variables that consist of multiple letters, and function calls * must be surrounded with parentheses. - * For example, $(FOO) + * For example, $(FOO), $(shell echo helloworld) */ p++; q = p; @@ -163,7 +271,7 @@ char *expand_dollar(const char **str) memcpy(tmp, p, q - p); tmp[q - p] = 0; *str = q + 1; - out = eval_clause(tmp); + out = eval_clause(tmp, argc, argv); free(tmp); return out; } @@ -179,11 +287,11 @@ char *expand_dollar(const char **str) } /* - * Expand variables in the given string. Undefined variables + * Expand variables, functions, etc. in the given string. Undefined variables * expand to an empty string. * The returned string must be freed when done. */ -char *expand_string(const char *in) +static char *expand_string_with_args(const char *in, int argc, char *argv[]) { const char *prev_in, *p; char *new, *out; @@ -195,7 +303,7 @@ char *expand_string(const char *in) while ((p = strchr(in, '$'))) { prev_in = in; in = p + 1; - new = expand_dollar(&in); + new = expand_dollar_with_args(&in, argc, argv); outlen = strlen(out) + (p - prev_in) + strlen(new) + 1; out = xrealloc(out, outlen); strncat(out, prev_in, p - prev_in); @@ -210,6 +318,16 @@ char *expand_string(const char *in) return out; } +char *expand_string(const char *in) +{ + return expand_string_with_args(in, 0, NULL); +} + +char *expand_dollar(const char **str) +{ + return expand_dollar_with_args(str, 0, NULL); +} + /* * Expand variables in a token. The parsing stops when a token separater * (in most cases, it is a whitespace) is encountered. 'str' is updated to -- 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html