Add script-generator

This commit is contained in:
fosslinux 2023-11-04 10:38:35 +11:00
parent d13320dbfa
commit 0907cfd073
1 changed files with 627 additions and 0 deletions

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sysa/script-generator.c Normal file
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/*
* SPDX-FileCopyrightText: 2023 fosslinux <fosslinux@aussies.space>
*
* SPDX-License-Idnetifier: GPL-3.0-or-later
*/
#define MAX_TOKEN 64
#define MAX_STRING 2048
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <bootstrappable.h>
struct Token {
char *val;
struct Token *next;
};
typedef struct Token Token;
#define TYPE_BUILD 1
#define TYPE_IMPROVE 2
#define TYPE_DEFINE 3
#define TYPE_JUMP 4
#define TYPE_MAINT 5
struct Directive {
Token *tok;
struct Directive *next;
int type;
char *arg; /* The primary argument */
};
typedef struct Directive Directive;
/* Tokenizer. */
/* Skip over a comment. */
char consume_comment(FILE *in) {
/* Discard the rest of the line. */
char c = fgetc(in);
while (c != -1 && c != '\n')
c = fgetc(in);
return c;
}
char consume_line(FILE *in, Directive *directive) {
char c = fgetc(in);
/* Short-circuit if whole line is comment or blank line. */
if (c == '#') {
c = consume_comment(in);
return c;
} else if (c == '\n' || c == -1) {
return c;
}
/* Ok, we will have something to put here. */
directive->next = calloc(1, sizeof(Directive));
directive = directive->next;
Token *head = calloc(1, sizeof(Token));
Token *cur = head;
char *out;
int i = 0;
while (c != -1 && c != '\n') {
/* Initialize next token. */
cur->next = calloc(1, sizeof(Token));
cur = cur->next;
cur->val = calloc(MAX_TOKEN, sizeof(char));
out = cur->val;
/* Copy line to token until a space (or EOL/EOF) or comment is found. */
while (c != -1 && c != '\n' && c != ' ' && c != '#') {
out[0] = c;
out += 1;
c = fgetc(in);
}
/* Go to start of next token. */
if (c == ' ') {
c = fgetc(in);
}
/* Handle comment. */
if (c == '#') {
c = consume_comment(in);
}
}
/* Add information to directive. */
directive->tok = head->next;
return c;
}
Directive *tokenizer(FILE *in) {
Directive *head = calloc(1, sizeof(Directive));
Directive *cur = head;
char c;
while (c != -1) {
/*
* Note that consume_line fills cur->next, not cur.
* This avoids having an empty last Directive.
*/
c = consume_line(in, cur);
if (cur->next != NULL) {
cur = cur->next;
}
}
return head->next;
}
/* Config variables. */
struct Variable {
char *name;
char *val;
struct Variable *next;
};
typedef struct Variable Variable;
Variable *variables;
Variable *load_config() {
FILE *config = fopen("/steps/bootstrap.cfg", "r");
/* File does not exist check. */
if (config == NULL) {
return NULL;
}
char *line = calloc(MAX_STRING, sizeof(char));
Variable *head = calloc(1, sizeof(Variable));
Variable *cur = head;
/* For each line... */
char *equals;
while (fgets(line, MAX_STRING, config) != 0) {
/* Weird M2-Planet behaviour. */
if (*line == 0) {
break;
}
cur->next = calloc(1, sizeof(Variable));
cur = cur->next;
/* Split on the equals. First half is name, second half is value. */
equals = strchr(line, '=');
if (equals == 0) {
fputs("bootstrap.cfg should have the format var=val on each line.", stderr);
exit(1);
}
cur->name = calloc(equals - line + 1, sizeof(char));
strncpy(cur->name, line, equals - line);
equals += 1;
cur->val = calloc(strlen(equals), sizeof(char));
strncpy(cur->val, equals, strlen(equals) - 1);
line = calloc(MAX_STRING, sizeof(char));
}
variables = head->next;
fclose(config);
}
void output_config(FILE *out) {
Variable *variable;
for (variable = variables; variable != NULL; variable = variable->next) {
fputs(variable->name, out);
fputs("=", out);
fputs(variable->val, out);
fputs("\n", out);
}
}
char *get_var(char *name) {
/* Search through existing variables. */
Variable *var;
Variable *last;
for (var = variables; var != NULL; var = var->next) {
if (strcmp(name, var->name) == 0) {
return var->val;
}
last = var;
}
/* If the variable is unset, prompt the user. */
if (variables == NULL) {
variables = calloc(1, sizeof(Variable));
var = variables;
} else {
last->next = calloc(1, sizeof(Variable));
var = last->next;
}
var->name = calloc(strlen(name) + 1, sizeof(char));
strcpy(var->name, name);
var->val = calloc(MAX_STRING, sizeof(char));
fputs("You have not set a value for ", stdout);
fputs(name, stdout);
fputs(" in bootstrap.cfg. Please set it now:\n", stdout);
while (fgets(var->val, MAX_STRING, stdin) == 0 || var->val[0] == '\n') {
fputs("Error inputting, try again:\n", stdout);
}
if (var->val[0] == 0) {
fputs("You put in an EOF!\n", stderr);
exit(1);
}
/* Trim the newline. */
var->val[strlen(var->val)] = 0;
return var->val;
}
/* Recursive descent interpreter. */
Token *fill(Token *tok, Directive *directive, int type) {
directive->type = type;
directive->arg = tok->val;
return tok->next;
}
Token *logic(Token *tok, char **val) {
/* logic = "("
* (name |
* (name "==" value) |
* (logic "||" logic) |
* (logic "&&" logic))
* ")"
*/
char *lhs = tok->val;
char *rhs;
tok = tok->next;
if (strcmp(tok->val, ")") == 0) {
/* Case where it's just a constant. */
*val = lhs;
return tok;
} else if (strcmp(tok->val, "==") == 0) {
/* Case for equality. */
rhs = tok->next->val;
tok = tok->next->next;
if (strcmp(get_var(lhs), rhs) == 0) {
lhs = "True";
} else {
lhs = "False";
}
} else {
fputs("Expected == after ", stderr);
fputs(lhs, stderr);
fputs(" in logic\n", stderr);
exit(1);
}
if (strcmp(tok->val, ")") == 0) {
*val = lhs;
return tok;
} else if (strcmp(tok->val, "||") == 0) {
/* OR */
tok = logic(tok->next, &rhs);
if (strcmp(lhs, "True") == 0 || strcmp(rhs, "True") == 0) {
lhs = "True";
} else {
lhs = "False";
}
} else if (strcmp(tok->val, "&&") == 0) {
/* AND */
tok = logic(tok->next, &rhs);
if (strcmp(lhs, "True") == 0 && strcmp(rhs, "True") == 0) {
lhs = "True";
} else {
lhs = "False";
}
} else {
fputs("Expected || or && in logic\n", stderr);
exit(1);
}
*val = lhs;
return tok;
}
Token *primary_logic(Token *tok, char **val) {
/* Starting ( */
if (strcmp(tok->val, "(") != 0) {
fputs("Expected logic to begin with (\n", stderr);
exit(1);
}
tok = tok->next;
tok = logic(tok, val);
if (strcmp(tok->val, ")") != 0) {
fputs("Expected logic to end with )\n", stderr);
exit(1);
}
return tok;
}
int eval_predicate(Token *tok) {
char *result;
tok = primary_logic(tok, &result);
return strcmp(result, "True") == 0;
}
Token *define(Token *tok, Directive *directive) {
/* define = name "=" (logic | constant) */
char *name = tok->val;
tok = tok->next;
if (strcmp(tok->val, "=") != 0) {
fputs("define of ", stderr);
fputs(name, stderr);
fputs(" has a missing equals\n", stderr);
exit(1);
}
tok = tok->next;
char *val = calloc(MAX_STRING, sizeof(char));
if (strcmp(tok->val, "(") == 0) {
/* It is a logic. */
tok = primary_logic(tok, &val);
} else {
/* It is a constant. */
strcpy(val, tok->val);
}
/* Check for predicate. */
tok = tok->next;
if (tok != NULL) {
if (!eval_predicate(tok)) {
/* Nothing more to do. */
return tok;
}
}
/* Update existing variable, or else, add to the end of variables. */
/* Special case: empty variables. */
if (variables == NULL) {
variables = calloc(1, sizeof(Variable));
variables->name = name;
variables->val = val;
}
Variable *var;
for (var = variables; var->next != NULL; var = var->next) {
if (strcmp(var->next->name, name) == 0) {
var->next->val = val;
break;
}
}
if (var->next == NULL) {
/* We did not update an existing variable. */
var->next = calloc(1, sizeof(Variable));
var->next->name = name;
var->next->val = val;
}
return tok;
}
int interpret(Directive *directive) {
/* directive = (build | improve | define | jump | maint) predicate? */
Token *tok = directive->tok;
if (strcmp(tok->val, "build:") == 0) {
tok = fill(tok->next, directive, TYPE_BUILD);
} else if (strcmp(tok->val, "improve:") == 0) {
tok = fill(tok->next, directive, TYPE_IMPROVE);
} else if (strcmp(tok->val, "jump:") == 0) {
tok = fill(tok->next, directive, TYPE_JUMP);
} else if (strcmp(tok->val, "maint:") == 0) {
tok = fill(tok->next, directive, TYPE_MAINT);
} else if (strcmp(tok->val, "define:") == 0) {
tok = define(tok->next, directive);
return 1; /* There is no codegen for a define. */
}
if (tok != NULL) {
return !eval_predicate(tok);
}
return 0;
}
Directive *interpreter(Directive *directives) {
Directive *directive;
Directive *last;
for (directive = directives; directive != NULL; directive = directive->next) {
if (interpret(directive)) {
/* This means this directive needs to be removed from the linked list. */
if (last == NULL) {
/* First directive. */
directives = directive->next;
} else {
last->next = directive->next;
}
} else {
last = directive;
}
}
return directives;
}
void add_to_fiwix_filelist(char *filename) {
/* Add the filename to fiwix-file-list.txt */
FILE *fiwix_list = fopen("/steps/lwext4-1.0.0-lb1/files/fiwix-file-list.txt", "r");
fseek(fiwix_list, 0, SEEK_END);
long size = ftell(fiwix_list);
char *contents = calloc(size, sizeof(char));
fseek(fiwix_list, 0, SEEK_SET);
fread(contents, 1, size, fiwix_list);
fclose(fiwix_list);
fiwix_list = fopen("/steps/lwext4-1.0.0-lb1/files/fiwix-file-list.txt", "w");
fwrite(contents, 1, size, fiwix_list);
fputs(filename, fiwix_list);
fputc('\n', fiwix_list);
fclose(fiwix_list);
}
/* Script generator. */
FILE *start_script(int id, int using_bash) {
/* Create the file /steps/$id.sh */
char *filename = calloc(MAX_STRING, sizeof(char));
strcpy(filename, "/steps/");
strcat(filename, int2str(id, 10, 0));
strcat(filename, ".sh");
add_to_fiwix_filelist(filename);
FILE *out = fopen(filename, "w");
if (out == NULL) {
fputs("Error opening output file ", stderr);
fputs(filename, stderr);
fputs("\n", stderr);
exit(1);
}
if (using_bash) {
fputs("#!/bin/bash\n", out);
fputs("set -e\n", out);
fputs("cd /steps\n", out);
fputs(". ./bootstrap.cfg\n", out);
fputs(". ./env\n", out);
fputs(". ./helpers.sh\n", out);
} else {
fputs("set -ex\n", out);
fputs("cd /steps\n", out);
output_config(out);
FILE *env = fopen("/steps/env", "r");
char *line = calloc(MAX_STRING, sizeof(char));
while (fgets(line, MAX_STRING, env) != 0) {
/* Weird M2-Planet behaviour. */
if (*line == 0) {
break;
}
fputs(line, out);
line = calloc(MAX_STRING, sizeof(char));
}
fclose(env);
}
return out;
}
void output_call_script(FILE *out, char *type, char *name, int using_bash, int source) {
if (using_bash) {
if (source) {
fputs(". ", out);
} else {
fputs("bash ", out);
}
} else {
fputs("kaem --file ", out);
}
fputs("/steps/", out);
fputs(type, out);
fputs("/", out);
fputs(name, out);
fputs(".sh\n", out);
}
void output_build(FILE *out, Directive *directive, int pass_no, int using_bash) {
if (using_bash) {
fputs("build ", out);
fputs(directive->arg, out);
fputs(" pass", out);
fputs(int2str(pass_no, 10, 0), out);
fputs(".sh\n", out);
} else {
fputs("pkg=", out);
fputs(directive->arg, out);
fputs("\n", out);
fputs("cd ${pkg}\n", out);
fputs("kaem --file pass", out);
fputs(int2str(pass_no, 10, 0), out);
fputs(".kaem\n", out);
fputs("cd ..\n", out);
}
}
void generate_preseed_jump(int id) {
FILE *out = fopen("/preseed-jump.kaem", "w");
fputs("set -ex\n", out);
fputs("PATH=/usr/bin\n", out);
fputs("bash /steps/", out);
fputs(int2str(id, 10, 0), out);
fputs(".sh\n", out);
fclose(out);
}
void generate(Directive *directives) {
/*
* We are separating the stages given in the mainfest into a bunch of
* smaller scripts. The following conditions call for the creation of
* a new script:
* - a jump
* - build of bash
*/
int counter = 0;
/* Initially, we use kaem, not bash. */
int using_bash = 0;
FILE *out = start_script(counter, using_bash);
counter += 1;
Directive *directive;
Directive *past;
char *filename;
int pass_no;
for (directive = directives; directive != NULL; directive = directive->next) {
if (directive->type == TYPE_BUILD) {
/* Get what pass number this is. */
pass_no = 1;
for (past = directives; past != directive; past = past->next) {
if (strcmp(past->arg, directive->arg) == 0) {
pass_no += 1;
}
}
output_build(out, directive, pass_no, using_bash);
if (strncmp(directive->arg, "bash-", 5) == 0) {
if (!using_bash) {
/*
* We are transitioning from bash to kaem, the point at which "early
* preseed" occurs. So generate the preseed jump script at this point.
*/
generate_preseed_jump(counter);
}
using_bash = 1;
/* Create call to new script. */
output_call_script(out, "", int2str(counter, 10, 0), using_bash, 0);
fclose(out);
out = start_script(counter, using_bash);
counter += 1;
}
} else if (directive->type == TYPE_IMPROVE) {
output_call_script(out, "improve", directive->arg, using_bash, 1);
} else if (directive->type == TYPE_JUMP) {
/*
* Create /init to call new script.
* We actually do this by creating /init.X for some number X, and then
* moving that to /init at the appropriate time.
*/
filename = calloc(MAX_STRING, sizeof(char));
if (using_bash) {
fputs("mv /init /init.bak\n", out);
/* Move new init to /init. */
strcpy(filename, "/init.");
strcat(filename, int2str(counter, 10, 0));
fputs("cp ", out);
fputs(filename, out);
fputs(" /init\n", out);
fputs("chmod 755 /init\n", out);
} else {
strcpy(filename, "/kaem.run.");
strcat(filename, int2str(counter, 10, 0));
fputs("cp ", out);
fputs(filename, out);
fputs(" /kaem.run\n", out);
fputs("cp /usr/bin/kaem /init\n", out);
fputs("chmod 755 /init\n", out);
}
output_call_script(out, "jump", directive->arg, using_bash, 1);
fclose(out);
/*
* This cannot go before here as builder-hex0 does not like having
* multiple files open at once!
*/
add_to_fiwix_filelist(filename);
if (using_bash) {
out = fopen(filename, "w");
if (out == NULL) {
fputs("Error opening /init\n", stderr);
exit(1);
}
fputs("#!/bin/bash\n", out);
} else {
out = fopen(filename, "w");
if (out == NULL) {
fputs("Error opening /kaem.run\n", stderr);
exit(1);
}
fputs("set -ex\n", out);
}
output_call_script(out, "", int2str(counter, 10, 0), using_bash, 0);
fclose(out);
out = start_script(counter, using_bash);
counter += 1;
} else if (directive->type == TYPE_MAINT) {
output_call_script(out, "maint", directive->arg, using_bash, 1);
}
}
fclose(out);
}
void main(int argc, char **argv) {
if (argc != 2) {
fputs("Usage: script-generator <script>\n", stderr);
exit(1);
}
FILE *in = fopen(argv[1], "r");
if (in == NULL) {
fputs("Error opening input file\n", stderr);
exit(1);
}
Directive *directives = tokenizer(in);
fclose(in);
load_config();
directives = interpreter(directives);
generate(directives);
FILE *config = fopen("/steps/bootstrap.cfg", "w");
output_config(config);
fclose(config);
}