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authorPřemysl Janouch <p.janouch@gmail.com>2017-05-18 20:45:46 +0200
committerPřemysl Janouch <p.janouch@gmail.com>2017-05-21 13:19:45 +0200
commit365d6e69e17e44f972934fd9582a01cc03754fe1 (patch)
treeb72d0a3a35ef2dcd392601b1382cc7dee4f8efe9
parent5963b99c3eba2c217e8ff86ab04501c89be3ccb0 (diff)
downloadell-365d6e69e17e44f972934fd9582a01cc03754fe1.tar.gz
ell-365d6e69e17e44f972934fd9582a01cc03754fe1.tar.xz
ell-365d6e69e17e44f972934fd9582a01cc03754fe1.zip
Various mostly safety fixes
-rw-r--r--README.adoc2
-rwxr-xr-xell.c58
2 files changed, 35 insertions, 25 deletions
diff --git a/README.adoc b/README.adoc
index 3ac6f15..376edfc 100644
--- a/README.adoc
+++ b/README.adoc
@@ -47,7 +47,7 @@ Runtime
-------
All variables are put in a single global namespace with no further scoping.
When calling a command (which is a list of lists), all arguments are
-automatically stored in variables named 1, 2, 3, ... n. They are however
+automatically stored in variables named 0, 1, 2, 3, ... n. They are however
effectively inaccessible and you must rename them first using the `arg` special
form.
diff --git a/ell.c b/ell.c
index 9572711..7fd4c53 100755
--- a/ell.c
+++ b/ell.c
@@ -270,8 +270,10 @@ lexer_free (struct lexer *self) {
free (self->string.s);
}
-// FIXME: other isspace() stuff is missing
-static bool lexer_is_word_char (int c) { return !strchr ("()[]{}\n@#' ", c); }
+static bool lexer_is_ignored (int c) { return c == ' ' || c == '\t'; }
+static bool lexer_is_word_char (int c) {
+ return !lexer_is_ignored (c) && !strchr ("()[]{}\n@#' ", c);
+}
static int
lexer_advance (struct lexer *self) {
@@ -286,11 +288,10 @@ lexer_advance (struct lexer *self) {
return c;
}
-static void lexer_error (struct lexer *self, char **e, const char *fmt, ...)
+static bool lexer_error (struct lexer *self, char **e, const char *fmt, ...)
ATTRIBUTE_PRINTF (3, 4);
-// TODO: see "script", we can just use error constants to avoid allocation
-static void
+static bool
lexer_error (struct lexer *self, char **e, const char *fmt, ...) {
va_list ap;
va_start (ap, fmt);
@@ -300,11 +301,12 @@ lexer_error (struct lexer *self, char **e, const char *fmt, ...) {
*e = format ("near line %u, column %u: %s",
self->line + 1, self->column + 1, description);
- // TODO: see above, we should be able to indicate error without allocation
+ // TODO: see "script", we can just use error constants to avoid allocation
if (!*e)
abort ();
free (description);
+ return false;
}
static bool
@@ -333,10 +335,8 @@ lexer_hexa_escape (struct lexer *self, struct buffer *output) {
static bool
lexer_escape_sequence (struct lexer *self, struct buffer *output, char **e) {
- if (!self->len) {
- lexer_error (self, e, "premature end of escape sequence");
- return false;
- }
+ if (!self->len)
+ return lexer_error (self, e, "premature end of escape sequence");
unsigned char c = *self->p;
switch (c) {
@@ -356,12 +356,10 @@ lexer_escape_sequence (struct lexer *self, struct buffer *output, char **e) {
if (lexer_hexa_escape (self, output))
return true;
- lexer_error (self, e, "invalid hexadecimal escape");
- return false;
+ return lexer_error (self, e, "invalid hexadecimal escape");
default:
- lexer_error (self, e, "unknown escape sequence");
- return false;
+ return lexer_error (self, e, "unknown escape sequence");
}
buffer_append_c (output, c);
@@ -380,14 +378,13 @@ lexer_string (struct lexer *self, struct buffer *output, char **e) {
else if (!lexer_escape_sequence (self, output, e))
return false;
}
- lexer_error (self, e, "premature end of string");
- return false;
+ return lexer_error (self, e, "premature end of string");
}
static enum token
lexer_next (struct lexer *self, char **e) {
// Skip over any whitespace between tokens
- while (self->len && isspace (*self->p) && *self->p != '\n')
+ while (self->len && lexer_is_ignored (*self->p))
lexer_advance (self);
if (!self->len)
return T_ABORT;
@@ -428,6 +425,8 @@ lexer_next (struct lexer *self, char **e) {
// --- Parsing -----------------------------------------------------------------
+// FIXME: the parser generally ignores memory allocation errors
+
static void
print_string (const char *s) {
putc ('\'', stdout);
@@ -675,6 +674,9 @@ register_native (const char *name, handler_fn handler) {
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+// TODO: fill in "error_is_fatal"
+// TODO: probably add new_*() methods that set "memory_failure"
+
struct context {
struct item *variables; ///< List of variables
@@ -704,7 +706,6 @@ get (struct context *ctx, const char *name) {
return NULL;
}
-// FIXME: cloning and removing
static bool
set (struct context *ctx, const char *name, struct item *value) {
struct item *iter, *key = NULL, *pair = NULL;
@@ -713,12 +714,19 @@ set (struct context *ctx, const char *name, struct item *value) {
break;
if (iter) {
item_free (iter->head->next);
- iter->head->next = value;
+ if (!(iter->head->next = new_clone (value))) {
+ ctx->memory_failure = true;
+ return false;
+ }
return true;
}
if ((key = new_string (name, strlen (name)))
&& (pair = new_list (NULL))) {
- (pair->head = key)->next = value;
+ if (!((pair->head = key)->next = new_clone (value))) {
+ item_free (pair);
+ ctx->memory_failure = true;
+ return false;
+ }
pair->next = ctx->variables;
ctx->variables = pair;
return true;
@@ -756,10 +764,12 @@ rename_arguments (struct context *ctx, struct item *names) {
if (names->type != ITEM_STRING)
continue;
- if (value)
- set (ctx, names->value, new_clone (value));
- else
- set (ctx, names->value, NULL);
+ if (value && !(value = new_clone (value))) {
+ ctx->memory_failure = true;
+ return false;
+ }
+ if (!set (ctx, names->value, value))
+ return false;
}
return true;
}