cregit-Linux how code gets into the kernel

Release 4.18 scripts/kconfig/preprocess.c

Directory: scripts/kconfig
// SPDX-License-Identifier: GPL-2.0
//
// Copyright (C) 2018 Masahiro Yamada <yamada.masahiro@socionext.com>

#include <stdarg.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#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;

	fprintf(stderr, "%s:%d: ", current_file->name, yylineno);
	va_start(ap, format);
	vfprintf(stderr, format, ap);
	va_end(ap);
	fprintf(stderr, "\n");

	exit(1);
}

/*
 * Environment variables
 */
static LIST_HEAD(env_list);


struct env {
	
char *name;
	
char *value;
	
struct list_head node;
};


static void env_add(const char *name, const char *value) { struct env *e; e = xmalloc(sizeof(*e)); e->name = xstrdup(name); e->value = xstrdup(value); list_add_tail(&e->node, &env_list); }

Contributors

PersonTokensPropCommitsCommitProp
Masahiro Yamada61100.00%1100.00%
Total61100.00%1100.00%


static void env_del(struct env *e) { list_del(&e->node); free(e->name); free(e->value); free(e); }

Contributors

PersonTokensPropCommitsCommitProp
Masahiro Yamada38100.00%1100.00%
Total38100.00%1100.00%

/* The returned pointer must be freed when done */
static char *env_expand(const char *name) { struct env *e; const char *value; if (!*name) return NULL; list_for_each_entry(e, &env_list, node) { if (!strcmp(name, e->name)) return xstrdup(e->value); } value = getenv(name); if (!value) return NULL; /* * We need to remember all referenced environment variables. * They will be written out to include/config/auto.conf.cmd */ env_add(name, value); return xstrdup(value); }

Contributors

PersonTokensPropCommitsCommitProp
Masahiro Yamada90100.00%1100.00%
Total90100.00%1100.00%


void env_write_dep(FILE *f, const char *autoconfig_name) { struct env *e, *tmp; list_for_each_entry_safe(e, tmp, &env_list, node) { fprintf(f, "ifneq \"$(%s)\" \"%s\"\n", e->name, e->value); fprintf(f, "%s: FORCE\n", autoconfig_name); fprintf(f, "endif\n"); env_del(e); } }

Contributors

PersonTokensPropCommitsCommitProp
Masahiro Yamada70100.00%1100.00%
Total70100.00%1100.00%

/* * Built-in functions */ struct function { const char *name; unsigned int min_args; unsigned int max_args; char *(*func)(int argc, char *argv[]); };
static char *do_error_if(int argc, char *argv[]) { if (!strcmp(argv[0], "y")) pperror("%s", argv[1]); return NULL; }

Contributors

PersonTokensPropCommitsCommitProp
Masahiro Yamada41100.00%1100.00%
Total41100.00%1100.00%


static char *do_filename(int argc, char *argv[]) { return xstrdup(current_file->name); }

Contributors

PersonTokensPropCommitsCommitProp
Masahiro Yamada23100.00%1100.00%
Total23100.00%1100.00%


static char *do_info(int argc, char *argv[]) { printf("%s\n", argv[0]); return xstrdup(""); }

Contributors

PersonTokensPropCommitsCommitProp
Masahiro Yamada31100.00%1100.00%
Total31100.00%1100.00%


static char *do_lineno(int argc, char *argv[]) { char buf[16]; sprintf(buf, "%d", yylineno); return xstrdup(buf); }

Contributors

PersonTokensPropCommitsCommitProp
Masahiro Yamada36100.00%1100.00%
Total36100.00%1100.00%


static char *do_shell(int argc, char *argv[]) { FILE *p; char buf[256]; char *cmd; size_t nread; int i; cmd = argv[0]; p = popen(cmd, "r"); if (!p) { perror(cmd); exit(1); } nread = fread(buf, 1, sizeof(buf), p); if (nread == sizeof(buf)) nread--; /* remove trailing new lines */ while (nread > 0 && buf[nread - 1] == '\n') nread--; buf[nread] = 0; /* replace a new line with a space */ for (i = 0; i < nread; i++) { if (buf[i] == '\n') buf[i] = ' '; } if (pclose(p) == -1) { perror(cmd); exit(1); } return xstrdup(buf); }

Contributors

PersonTokensPropCommitsCommitProp
Masahiro Yamada17897.80%150.00%
Jerry James42.20%150.00%
Total182100.00%2100.00%


static char *do_warning_if(int argc, char *argv[]) { if (!strcmp(argv[0], "y")) fprintf(stderr, "%s:%d: %s\n", current_file->name, yylineno, argv[1]); return xstrdup(""); }

Contributors

PersonTokensPropCommitsCommitProp
Masahiro Yamada52100.00%1100.00%
Total52100.00%1100.00%

static const struct function function_table[] = { /* Name MIN MAX Function */ { "error-if", 2, 2, do_error_if }, { "filename", 0, 0, do_filename }, { "info", 1, 1, do_info }, { "lineno", 0, 0, do_lineno }, { "shell", 1, 1, do_shell }, { "warning-if", 2, 2, do_warning_if }, }; #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; }

Contributors

PersonTokensPropCommitsCommitProp
Masahiro Yamada110100.00%1100.00%
Total110100.00%1100.00%

/* * Variables (and user-defined functions) */ static LIST_HEAD(variable_list); struct variable { char *name; char *value; enum variable_flavor flavor; int exp_count; struct list_head node; };
static struct variable *variable_lookup(const char *name) { struct variable *v; list_for_each_entry(v, &variable_list, node) { if (!strcmp(name, v->name)) return v; } return NULL; }

Contributors

PersonTokensPropCommitsCommitProp
Masahiro Yamada46100.00%1100.00%
Total46100.00%1100.00%


static char *variable_expand(const char *name, int argc, char *argv[]) { struct variable *v; char *res; v = variable_lookup(name); if (!v) return NULL; if (argc == 0 && v->exp_count) pperror("Recursive variable '%s' references itself (eventually)", name); if (v->exp_count > 1000) pperror("Too deep recursive expansion"); v->exp_count++; if (v->flavor == VAR_RECURSIVE) res = expand_string_with_args(v->value, argc, argv); else res = xstrdup(v->value); v->exp_count--; return res; }

Contributors

PersonTokensPropCommitsCommitProp
Masahiro Yamada118100.00%3100.00%
Total118100.00%3100.00%


void variable_add(const char *name, const char *value, enum variable_flavor flavor) { struct variable *v; char *new_value; bool append = false; v = variable_lookup(name); if (v) { /* For defined variables, += inherits the existing flavor */ if (flavor == VAR_APPEND) { flavor = v->flavor; append = true; } else { free(v->value); } } else { /* For undefined variables, += assumes the recursive flavor */ if (flavor == VAR_APPEND) flavor = VAR_RECURSIVE; v = xmalloc(sizeof(*v)); v->name = xstrdup(name); v->exp_count = 0; list_add_tail(&v->node, &variable_list); } v->flavor = flavor; if (flavor == VAR_SIMPLE) new_value = expand_string(value); else new_value = xstrdup(value); if (append) { v->value = xrealloc(v->value, strlen(v->value) + strlen(new_value) + 2); strcat(v->value, " "); strcat(v->value, new_value); free(new_value); } else { v->value = new_value; } }

Contributors

PersonTokensPropCommitsCommitProp
Masahiro Yamada216100.00%4100.00%
Total216100.00%4100.00%


static void variable_del(struct variable *v) { list_del(&v->node); free(v->name); free(v->value); free(v); }

Contributors

PersonTokensPropCommitsCommitProp
Masahiro Yamada38100.00%1100.00%
Total38100.00%1100.00%


void variable_all_del(void) { struct variable *v, *tmp; list_for_each_entry_safe(v, tmp, &variable_list, node) variable_del(v); }

Contributors

PersonTokensPropCommitsCommitProp
Masahiro Yamada30100.00%1100.00%
Total30100.00%1100.00%

/* * 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, *endptr, *prev, *p; int new_argc = 0; char *new_argv[FUNCTION_MAX_ARGS]; int nest = 0; int i; unsigned long n; tmp = xstrndup(str, len); /* * If variable name is '1', '2', etc. It is generally an argument * from a user-function call (i.e. local-scope variable). If not * available, then look-up global-scope variables. */ n = strtoul(tmp, &endptr, 10); if (!*endptr && n > 0 && n <= argc) { res = xstrdup(argv[n - 1]); goto free_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); /* Search for variables */ res = variable_expand(name, new_argc, new_argv); if (res) goto free; /* 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: free(tmp); return res; }

Contributors

PersonTokensPropCommitsCommitProp
Masahiro Yamada369100.00%3100.00%
Total369100.00%3100.00%

/* * Expand a string that follows '$' * * For example, if the input string is * ($(FOO)$($(BAR)))$(BAZ) * this helper evaluates * $($(FOO)$($(BAR))) * and returns a new string containing the expansion (note that the string is * recursively expanded), also advancing 'str' to point to the next character * after the corresponding closing parenthesis, in this case, *str will be * $(BAR) */
static char *expand_dollar_with_args(const char **str, int argc, char *argv[]) { const char *p = *str; const char *q; int nest = 0; /* * In Kconfig, variable/function references always start with "$(". * Neither single-letter variables as in $A nor curly braces as in ${CC} * are supported. '$' not followed by '(' loses its special meaning. */ if (*p != '(') { *str = p; return xstrdup("$"); } p++; q = p; while (*q) { if (*q == '(') { nest++; } else if (*q == ')') { if (nest-- == 0) break; } q++; } if (!*q) pperror("unterminated reference to '%s': missing ')'", p); /* Advance 'str' to after the expanded initial portion of the string */ *str = q + 1; return eval_clause(p, q - p, argc, argv); }

Contributors

PersonTokensPropCommitsCommitProp
Masahiro Yamada142100.00%2100.00%
Total142100.00%2100.00%


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

Contributors

PersonTokensPropCommitsCommitProp
Masahiro Yamada22100.00%2100.00%
Total22100.00%2100.00%


static char *__expand_string(const char **str, bool (*is_end)(char c), int argc, char *argv[]) { const char *in, *p; char *expansion, *out; size_t in_len, out_len; out = xmalloc(1); *out = 0; out_len = 1; p = in = *str; while (1) { if (*p == '$') { in_len = p - in; 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); strcat(out, expansion); free(expansion); in = p; continue; } if (is_end(*p)) break; p++; } in_len = p - in; out_len += in_len; out = xrealloc(out, out_len); strncat(out, in, in_len); /* Advance 'str' to the end character */ *str = p; return out; }

Contributors

PersonTokensPropCommitsCommitProp
Masahiro Yamada203100.00%2100.00%
Total203100.00%2100.00%


static bool is_end_of_str(char c) { return !c; }

Contributors

PersonTokensPropCommitsCommitProp
Masahiro Yamada13100.00%1100.00%
Total13100.00%1100.00%

/* * 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); }

Contributors

PersonTokensPropCommitsCommitProp
Masahiro Yamada33100.00%2100.00%
Total33100.00%2100.00%


char *expand_string(const char *in) { return expand_string_with_args(in, 0, NULL); }

Contributors

PersonTokensPropCommitsCommitProp
Masahiro Yamada21100.00%2100.00%
Total21100.00%2100.00%


static bool is_end_of_token(char c) { /* Why are '.' and '/' valid characters for symbols? */ return !(isalnum(c) || c == '_' || c == '-' || c == '.' || c == '/'); }

Contributors

PersonTokensPropCommitsCommitProp
Masahiro Yamada35100.00%1100.00%
Total35100.00%1100.00%

/* * 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 * point to the next character. * * The returned string must be freed when done. */
char *expand_one_token(const char **str) { return __expand_string(str, is_end_of_token, 0, NULL); }

Contributors

PersonTokensPropCommitsCommitProp
Masahiro Yamada24100.00%2100.00%
Total24100.00%2100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Masahiro Yamada232499.83%990.00%
Jerry James40.17%110.00%
Total2328100.00%10100.00%
Directory: scripts/kconfig
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