edify/expr.c - android_bootable_recovery - Gitiles

 /*
  * Copyright (C) 2009 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

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

 #include "expr.h"

 // Functions should:
 //
 //    - return a malloc()'d string
 //    - if Evaluate() on any argument returns NULL, return NULL.

 int BooleanString(const char* s) {
     return s[0] != '\0';
 }

 char* Evaluate(State* state, Expr* expr) {
     return expr->fn(expr->name, state, expr->argc, expr->argv);
 }

 char* ConcatFn(const char* name, State* state, int argc, Expr* argv[]) {
     if (argc == 0) {
         return strdup("");
     }
     char** strings = malloc(argc * sizeof(char*));
     int i;
     for (i = 0; i < argc; ++i) {
         strings[i] = NULL;
     }
     char* result = NULL;
     int length = 0;
     for (i = 0; i < argc; ++i) {
         strings[i] = Evaluate(state, argv[i]);
         if (strings[i] == NULL) {
             goto done;
         }
         length += strlen(strings[i]);
     }

     result = malloc(length+1);
     int p = 0;
     for (i = 0; i < argc; ++i) {
         strcpy(result+p, strings[i]);
         p += strlen(strings[i]);
     }
     result[p] = '\0';

   done:
     for (i = 0; i < argc; ++i) {
         free(strings[i]);
     }
     return result;
 }

 char* IfElseFn(const char* name, State* state, int argc, Expr* argv[]) {
     if (argc != 2 && argc != 3) {
         free(state->errmsg);
         state->errmsg = strdup("ifelse expects 2 or 3 arguments");
         return NULL;
     }
     char* cond = Evaluate(state, argv[0]);
     if (cond == NULL) {
         return NULL;
     }

     if (BooleanString(cond) == true) {
         free(cond);
         return Evaluate(state, argv[1]);
     } else {
         if (argc == 3) {
             free(cond);
             return Evaluate(state, argv[2]);
         } else {
             return cond;
         }
     }
 }

 char* AbortFn(const char* name, State* state, int argc, Expr* argv[]) {
     char* msg = NULL;
     if (argc > 0) {
         msg = Evaluate(state, argv[0]);
     }
     free(state->errmsg);
     if (msg) {
         state->errmsg = msg;
     } else {
         state->errmsg = strdup("called abort()");
     }
     return NULL;
 }

 char* AssertFn(const char* name, State* state, int argc, Expr* argv[]) {
     int i;
     for (i = 0; i < argc; ++i) {
         char* v = Evaluate(state, argv[i]);
         if (v == NULL) {
             return NULL;
         }
         int b = BooleanString(v);
         free(v);
         if (!b) {
             int prefix_len;
             int len = argv[i]->end - argv[i]->start;
             char* err_src = malloc(len + 20);
             strcpy(err_src, "assert failed: ");
             prefix_len = strlen(err_src);
             memcpy(err_src + prefix_len, state->script + argv[i]->start, len);
             err_src[prefix_len + len] = '\0';
             free(state->errmsg);
             state->errmsg = err_src;
             return NULL;
         }
     }
     return strdup("");
 }

 char* SleepFn(const char* name, State* state, int argc, Expr* argv[]) {
     char* val = Evaluate(state, argv[0]);
     if (val == NULL) {
         return NULL;
     }
     int v = strtol(val, NULL, 10);
     sleep(v);
     return val;
 }

 char* StdoutFn(const char* name, State* state, int argc, Expr* argv[]) {
     int i;
     for (i = 0; i < argc; ++i) {
         char* v = Evaluate(state, argv[i]);
         if (v == NULL) {
             return NULL;
         }
         fputs(v, stdout);
         free(v);
     }
     return strdup("");
 }

 char* LogicalAndFn(const char* name, State* state,
                    int argc, Expr* argv[]) {
     char* left = Evaluate(state, argv[0]);
     if (left == NULL) return NULL;
     if (BooleanString(left) == true) {
         free(left);
         return Evaluate(state, argv[1]);
     } else {
         return left;
     }
 }

 char* LogicalOrFn(const char* name, State* state,
                   int argc, Expr* argv[]) {
     char* left = Evaluate(state, argv[0]);
     if (left == NULL) return NULL;
     if (BooleanString(left) == false) {
         free(left);
         return Evaluate(state, argv[1]);
     } else {
         return left;
     }
 }

 char* LogicalNotFn(const char* name, State* state,
                    int argc, Expr* argv[]) {
     char* val = Evaluate(state, argv[0]);
     if (val == NULL) return NULL;
     bool bv = BooleanString(val);
     free(val);
     if (bv) {
         return strdup("");
     } else {
         return strdup("t");
     }
 }

 char* SubstringFn(const char* name, State* state,
                   int argc, Expr* argv[]) {
     char* needle = Evaluate(state, argv[0]);
     if (needle == NULL) return NULL;
     char* haystack = Evaluate(state, argv[1]);
     if (haystack == NULL) {
         free(needle);
         return NULL;
     }

     char* result = strdup(strstr(haystack, needle) ? "t" : "");
     free(needle);
     free(haystack);
     return result;
 }

 char* EqualityFn(const char* name, State* state, int argc, Expr* argv[]) {
     char* left = Evaluate(state, argv[0]);
     if (left == NULL) return NULL;
     char* right = Evaluate(state, argv[1]);
     if (right == NULL) {
         free(left);
         return NULL;
     }

     char* result = strdup(strcmp(left, right) == 0 ? "t" : "");
     free(left);
     free(right);
     return result;
 }

 char* InequalityFn(const char* name, State* state, int argc, Expr* argv[]) {
     char* left = Evaluate(state, argv[0]);
     if (left == NULL) return NULL;
     char* right = Evaluate(state, argv[1]);
     if (right == NULL) {
         free(left);
         return NULL;
     }

     char* result = strdup(strcmp(left, right) != 0 ? "t" : "");
     free(left);
     free(right);
     return result;
 }

 char* SequenceFn(const char* name, State* state, int argc, Expr* argv[]) {
     char* left = Evaluate(state, argv[0]);
     if (left == NULL) return NULL;
     free(left);
     return Evaluate(state, argv[1]);
 }

 char* LessThanIntFn(const char* name, State* state, int argc, Expr* argv[]) {
     if (argc != 2) {
         free(state->errmsg);
         state->errmsg = strdup("less_than_int expects 2 arguments");
         return NULL;
     }

     char* left;
     char* right;
     if (ReadArgs(state, argv, 2, &left, &right) < 0) return NULL;

     bool result = false;
     char* end;

     long l_int = strtol(left, &end, 10);
     if (left[0] == '\0' || *end != '\0') {
         fprintf(stderr, "[%s] is not an int\n", left);
         goto done;
     }

     long r_int = strtol(right, &end, 10);
     if (right[0] == '\0' || *end != '\0') {
         fprintf(stderr, "[%s] is not an int\n", right);
         goto done;
     }

     result = l_int < r_int;

   done:
     free(left);
     free(right);
     return strdup(result ? "t" : "");
 }

 char* GreaterThanIntFn(const char* name, State* state, int argc, Expr* argv[]) {
     if (argc != 2) {
         free(state->errmsg);
         state->errmsg = strdup("greater_than_int expects 2 arguments");
         return NULL;
     }

     Expr* temp[2];
     temp[0] = argv[1];
     temp[1] = argv[0];

     return LessThanIntFn(name, state, 2, temp);
 }

 char* Literal(const char* name, State* state, int argc, Expr* argv[]) {
     return strdup(name);
 }

 Expr* Build(Function fn, YYLTYPE loc, int count, ...) {
     va_list v;
     va_start(v, count);
     Expr* e = malloc(sizeof(Expr));
     e->fn = fn;
     e->name = "(operator)";
     e->argc = count;
     e->argv = malloc(count * sizeof(Expr*));
     int i;
     for (i = 0; i < count; ++i) {
         e->argv[i] = va_arg(v, Expr*);
     }
     va_end(v);
     e->start = loc.start;
     e->end = loc.end;
     return e;
 }

 // -----------------------------------------------------------------
 //   the function table
 // -----------------------------------------------------------------

 static int fn_entries = 0;
 static int fn_size = 0;
 NamedFunction* fn_table = NULL;

 void RegisterFunction(const char* name, Function fn) {
     if (fn_entries >= fn_size) {
         fn_size = fn_size*2 + 1;
         fn_table = realloc(fn_table, fn_size * sizeof(NamedFunction));
     }
     fn_table[fn_entries].name = name;
     fn_table[fn_entries].fn = fn;
     ++fn_entries;
 }

 static int fn_entry_compare(const void* a, const void* b) {
     const char* na = ((const NamedFunction*)a)->name;
     const char* nb = ((const NamedFunction*)b)->name;
     return strcmp(na, nb);
 }

 void FinishRegistration() {
     qsort(fn_table, fn_entries, sizeof(NamedFunction), fn_entry_compare);
 }

 Function FindFunction(const char* name) {
     NamedFunction key;
     key.name = name;
     NamedFunction* nf = bsearch(&key, fn_table, fn_entries,
                                 sizeof(NamedFunction), fn_entry_compare);
     if (nf == NULL) {
         return NULL;
     }
     return nf->fn;
 }

 void RegisterBuiltins() {
     RegisterFunction("ifelse", IfElseFn);
     RegisterFunction("abort", AbortFn);
     RegisterFunction("assert", AssertFn);
     RegisterFunction("concat", ConcatFn);
     RegisterFunction("is_substring", SubstringFn);
     RegisterFunction("stdout", StdoutFn);
     RegisterFunction("sleep", SleepFn);

     RegisterFunction("less_than_int", LessThanIntFn);
     RegisterFunction("greater_than_int", GreaterThanIntFn);
 }


 // -----------------------------------------------------------------
 //   convenience methods for functions
 // -----------------------------------------------------------------

 // Evaluate the expressions in argv, giving 'count' char* (the ... is
 // zero or more char** to put them in).  If any expression evaluates
 // to NULL, free the rest and return -1.  Return 0 on success.
 int ReadArgs(State* state, Expr* argv[], int count, ...) {
     char** args = malloc(count * sizeof(char*));
     va_list v;
     va_start(v, count);
     int i;
     for (i = 0; i < count; ++i) {
         args[i] = Evaluate(state, argv[i]);
         if (args[i] == NULL) {
             va_end(v);
             int j;
             for (j = 0; j < i; ++j) {
                 free(args[j]);
             }
             return -1;
         }
         *(va_arg(v, char**)) = args[i];
     }
     va_end(v);
     return 0;
 }

 // Evaluate the expressions in argv, returning an array of char*
 // results.  If any evaluate to NULL, free the rest and return NULL.
 // The caller is responsible for freeing the returned array and the
 // strings it contains.
 char** ReadVarArgs(State* state, int argc, Expr* argv[]) {
     char** args = (char**)malloc(argc * sizeof(char*));
     int i = 0;
     for (i = 0; i < argc; ++i) {
         args[i] = Evaluate(state, argv[i]);
         if (args[i] == NULL) {
             int j;
             for (j = 0; j < i; ++j) {
                 free(args[j]);
             }
             free(args);
             return NULL;
         }
     }
     return args;
 }

 // Use printf-style arguments to compose an error message to put into
 // *state.  Returns NULL.
 char* ErrorAbort(State* state, char* format, ...) {
     char* buffer = malloc(4096);
     va_list v;
     va_start(v, format);
     vsnprintf(buffer, 4096, format, v);
     va_end(v);
     free(state->errmsg);
     state->errmsg = buffer;
     return NULL;
 }
	/*
	* Copyright (C) 2009 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

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

	#include "expr.h"

	// Functions should:
	//
	// - return a malloc()'d string
	// - if Evaluate() on any argument returns NULL, return NULL.

	int BooleanString(const char* s) {
	return s[0] != '\0';
	}

	char* Evaluate(State* state, Expr* expr) {
	return expr->fn(expr->name, state, expr->argc, expr->argv);
	}

	char* ConcatFn(const char* name, State* state, int argc, Expr* argv[]) {
	if (argc == 0) {
	return strdup("");
	}
	char** strings = malloc(argc * sizeof(char*));
	int i;
	for (i = 0; i < argc; ++i) {
	strings[i] = NULL;
	}
	char* result = NULL;
	int length = 0;
	for (i = 0; i < argc; ++i) {
	strings[i] = Evaluate(state, argv[i]);
	if (strings[i] == NULL) {
	goto done;
	}
	length += strlen(strings[i]);
	}

	result = malloc(length+1);
	int p = 0;
	for (i = 0; i < argc; ++i) {
	strcpy(result+p, strings[i]);
	p += strlen(strings[i]);
	}
	result[p] = '\0';

	done:
	for (i = 0; i < argc; ++i) {
	free(strings[i]);
	}
	return result;
	}

	char* IfElseFn(const char* name, State* state, int argc, Expr* argv[]) {
	if (argc != 2 && argc != 3) {
	free(state->errmsg);
	state->errmsg = strdup("ifelse expects 2 or 3 arguments");
	return NULL;
	}
	char* cond = Evaluate(state, argv[0]);
	if (cond == NULL) {
	return NULL;
	}

	if (BooleanString(cond) == true) {
	free(cond);
	return Evaluate(state, argv[1]);
	} else {
	if (argc == 3) {
	free(cond);
	return Evaluate(state, argv[2]);
	} else {
	return cond;
	}
	}
	}

	char* AbortFn(const char* name, State* state, int argc, Expr* argv[]) {
	char* msg = NULL;
	if (argc > 0) {
	msg = Evaluate(state, argv[0]);
	}
	free(state->errmsg);
	if (msg) {
	state->errmsg = msg;
	} else {
	state->errmsg = strdup("called abort()");
	}
	return NULL;
	}

	char* AssertFn(const char* name, State* state, int argc, Expr* argv[]) {
	int i;
	for (i = 0; i < argc; ++i) {
	char* v = Evaluate(state, argv[i]);
	if (v == NULL) {
	return NULL;
	}
	int b = BooleanString(v);
	free(v);
	if (!b) {
	int prefix_len;
	int len = argv[i]->end - argv[i]->start;
	char* err_src = malloc(len + 20);
	strcpy(err_src, "assert failed: ");
	prefix_len = strlen(err_src);
	memcpy(err_src + prefix_len, state->script + argv[i]->start, len);
	err_src[prefix_len + len] = '\0';
	free(state->errmsg);
	state->errmsg = err_src;
	return NULL;
	}
	}
	return strdup("");
	}

	char* SleepFn(const char* name, State* state, int argc, Expr* argv[]) {
	char* val = Evaluate(state, argv[0]);
	if (val == NULL) {
	return NULL;
	}
	int v = strtol(val, NULL, 10);
	sleep(v);
	return val;
	}

	char* StdoutFn(const char* name, State* state, int argc, Expr* argv[]) {
	int i;
	for (i = 0; i < argc; ++i) {
	char* v = Evaluate(state, argv[i]);
	if (v == NULL) {
	return NULL;
	}
	fputs(v, stdout);
	free(v);
	}
	return strdup("");
	}

	char* LogicalAndFn(const char* name, State* state,
	int argc, Expr* argv[]) {
	char* left = Evaluate(state, argv[0]);
	if (left == NULL) return NULL;
	if (BooleanString(left) == true) {
	free(left);
	return Evaluate(state, argv[1]);
	} else {
	return left;
	}
	}

	char* LogicalOrFn(const char* name, State* state,
	int argc, Expr* argv[]) {
	char* left = Evaluate(state, argv[0]);
	if (left == NULL) return NULL;
	if (BooleanString(left) == false) {
	free(left);
	return Evaluate(state, argv[1]);
	} else {
	return left;
	}
	}

	char* LogicalNotFn(const char* name, State* state,
	int argc, Expr* argv[]) {
	char* val = Evaluate(state, argv[0]);
	if (val == NULL) return NULL;
	bool bv = BooleanString(val);
	free(val);
	if (bv) {
	return strdup("");
	} else {
	return strdup("t");
	}
	}

	char* SubstringFn(const char* name, State* state,
	int argc, Expr* argv[]) {
	char* needle = Evaluate(state, argv[0]);
	if (needle == NULL) return NULL;
	char* haystack = Evaluate(state, argv[1]);
	if (haystack == NULL) {
	free(needle);
	return NULL;
	}

	char* result = strdup(strstr(haystack, needle) ? "t" : "");
	free(needle);
	free(haystack);
	return result;
	}

	char* EqualityFn(const char* name, State* state, int argc, Expr* argv[]) {
	char* left = Evaluate(state, argv[0]);
	if (left == NULL) return NULL;
	char* right = Evaluate(state, argv[1]);
	if (right == NULL) {
	free(left);
	return NULL;
	}

	char* result = strdup(strcmp(left, right) == 0 ? "t" : "");
	free(left);
	free(right);
	return result;
	}

	char* InequalityFn(const char* name, State* state, int argc, Expr* argv[]) {
	char* left = Evaluate(state, argv[0]);
	if (left == NULL) return NULL;
	char* right = Evaluate(state, argv[1]);
	if (right == NULL) {
	free(left);
	return NULL;
	}

	char* result = strdup(strcmp(left, right) != 0 ? "t" : "");
	free(left);
	free(right);
	return result;
	}

	char* SequenceFn(const char* name, State* state, int argc, Expr* argv[]) {
	char* left = Evaluate(state, argv[0]);
	if (left == NULL) return NULL;
	free(left);
	return Evaluate(state, argv[1]);
	}

	char* LessThanIntFn(const char* name, State* state, int argc, Expr* argv[]) {
	if (argc != 2) {
	free(state->errmsg);
	state->errmsg = strdup("less_than_int expects 2 arguments");
	return NULL;
	}

	char* left;
	char* right;
	if (ReadArgs(state, argv, 2, &left, &right) < 0) return NULL;

	bool result = false;
	char* end;

	long l_int = strtol(left, &end, 10);
	if (left[0] == '\0' \|\| *end != '\0') {
	fprintf(stderr, "[%s] is not an int\n", left);
	goto done;
	}

	long r_int = strtol(right, &end, 10);
	if (right[0] == '\0' \|\| *end != '\0') {
	fprintf(stderr, "[%s] is not an int\n", right);
	goto done;
	}

	result = l_int < r_int;

	done:
	free(left);
	free(right);
	return strdup(result ? "t" : "");
	}

	char* GreaterThanIntFn(const char* name, State* state, int argc, Expr* argv[]) {
	if (argc != 2) {
	free(state->errmsg);
	state->errmsg = strdup("greater_than_int expects 2 arguments");
	return NULL;
	}

	Expr* temp[2];
	temp[0] = argv[1];
	temp[1] = argv[0];

	return LessThanIntFn(name, state, 2, temp);
	}

	char* Literal(const char* name, State* state, int argc, Expr* argv[]) {
	return strdup(name);
	}

	Expr* Build(Function fn, YYLTYPE loc, int count, ...) {
	va_list v;
	va_start(v, count);
	Expr* e = malloc(sizeof(Expr));
	e->fn = fn;
	e->name = "(operator)";
	e->argc = count;
	e->argv = malloc(count * sizeof(Expr*));
	int i;
	for (i = 0; i < count; ++i) {
	e->argv[i] = va_arg(v, Expr*);
	}
	va_end(v);
	e->start = loc.start;
	e->end = loc.end;
	return e;
	}

	// -----------------------------------------------------------------
	// the function table
	// -----------------------------------------------------------------

	static int fn_entries = 0;
	static int fn_size = 0;
	NamedFunction* fn_table = NULL;

	void RegisterFunction(const char* name, Function fn) {
	if (fn_entries >= fn_size) {
	fn_size = fn_size*2 + 1;
	fn_table = realloc(fn_table, fn_size * sizeof(NamedFunction));
	}
	fn_table[fn_entries].name = name;
	fn_table[fn_entries].fn = fn;
	++fn_entries;
	}

	static int fn_entry_compare(const void* a, const void* b) {
	const char* na = ((const NamedFunction*)a)->name;
	const char* nb = ((const NamedFunction*)b)->name;
	return strcmp(na, nb);
	}

	void FinishRegistration() {
	qsort(fn_table, fn_entries, sizeof(NamedFunction), fn_entry_compare);
	}

	Function FindFunction(const char* name) {
	NamedFunction key;
	key.name = name;
	NamedFunction* nf = bsearch(&key, fn_table, fn_entries,
	sizeof(NamedFunction), fn_entry_compare);
	if (nf == NULL) {
	return NULL;
	}
	return nf->fn;
	}

	void RegisterBuiltins() {
	RegisterFunction("ifelse", IfElseFn);
	RegisterFunction("abort", AbortFn);
	RegisterFunction("assert", AssertFn);
	RegisterFunction("concat", ConcatFn);
	RegisterFunction("is_substring", SubstringFn);
	RegisterFunction("stdout", StdoutFn);
	RegisterFunction("sleep", SleepFn);

	RegisterFunction("less_than_int", LessThanIntFn);
	RegisterFunction("greater_than_int", GreaterThanIntFn);
	}


	// -----------------------------------------------------------------
	// convenience methods for functions
	// -----------------------------------------------------------------

	// Evaluate the expressions in argv, giving 'count' char* (the ... is
	// zero or more char** to put them in). If any expression evaluates
	// to NULL, free the rest and return -1. Return 0 on success.
	int ReadArgs(State* state, Expr* argv[], int count, ...) {
	char** args = malloc(count * sizeof(char*));
	va_list v;
	va_start(v, count);
	int i;
	for (i = 0; i < count; ++i) {
	args[i] = Evaluate(state, argv[i]);
	if (args[i] == NULL) {
	va_end(v);
	int j;
	for (j = 0; j < i; ++j) {
	free(args[j]);
	}
	return -1;
	}
	(va_arg(v, char*)) = args[i];
	}
	va_end(v);
	return 0;
	}

	// Evaluate the expressions in argv, returning an array of char*
	// results. If any evaluate to NULL, free the rest and return NULL.
	// The caller is responsible for freeing the returned array and the
	// strings it contains.
	char** ReadVarArgs(State* state, int argc, Expr* argv[]) {
	char args = (char)malloc(argc * sizeof(char*));
	int i = 0;
	for (i = 0; i < argc; ++i) {
	args[i] = Evaluate(state, argv[i]);
	if (args[i] == NULL) {
	int j;
	for (j = 0; j < i; ++j) {
	free(args[j]);
	}
	free(args);
	return NULL;
	}
	}
	return args;
	}

	// Use printf-style arguments to compose an error message to put into
	// *state. Returns NULL.
	char* ErrorAbort(State* state, char* format, ...) {
	char* buffer = malloc(4096);
	va_list v;
	va_start(v, format);
	vsnprintf(buffer, 4096, format, v);
	va_end(v);
	free(state->errmsg);
	state->errmsg = buffer;
	return NULL;
	}