treewide: fix issues reported by clang code analyzer

Signed-off-by: Jo-Philipp Wich <jo@mein.io>

5 files changed, 51 insertions, 31 deletions

diff --git a/compiler.c b/compiler.c
index 7c0a2a1..757ff0c 100644
--- a/compiler.c
+++ b/compiler.c
@@ -1757,7 +1757,6 @@ uc_compiler_compile_object(uc_compiler *compiler, bool assignable)
 	if (len > 0) {
 		uc_compiler_emit_insn(compiler, compiler->parser->prev.pos, I_SOBJ);
 		uc_compiler_emit_u32(compiler, 0, len);
-		len = 0;
 	}
 
 	/* set initial size hint */
@@ -2166,14 +2165,14 @@ uc_compiler_compile_for_count(uc_compiler *compiler, bool local, uc_token *var)
 
 	/* Initializer ---------------------------------------------------------- */
 
-	/* We parsed a `local x` or `local x, y` expression, so (re)declare
-	 * last label as local initializer variable */
-	if (local)
-		uc_compiler_declare_local_null(compiler, var->pos, var->val);
-
-	/* If we parsed at least on label, try continue parsing as variable
+	/* If we parsed at least one label, try continue parsing as variable
 	 * expression... */
 	if (var) {
+		/* We parsed a `local x` or `local x, y` expression, so (re)declare
+		 * last label as local initializer variable */
+		if (local)
+			uc_compiler_declare_local_null(compiler, var->pos, var->val);
+
 		uc_compiler_compile_labelexpr(compiler, true);
 		uc_compiler_emit_insn(compiler, 0, I_POP);
 
@@ -2268,10 +2267,6 @@ uc_compiler_compile_for(uc_compiler *compiler)
 
 	local = uc_compiler_parse_match(compiler, TK_LOCAL);
 
-	if (local && !uc_compiler_parse_check(compiler, TK_LABEL))
-		uc_compiler_syntax_error(compiler, compiler->parser->curr.pos,
-			"Expecting label after 'local'");
-
 	if (uc_compiler_parse_match(compiler, TK_LABEL)) {
 		keyvar = compiler->parser->prev;
 		uc_value_get(keyvar.val);
@@ -2291,6 +2286,12 @@ uc_compiler_compile_for(uc_compiler *compiler)
 			goto out;
 		}
 	}
+	else if (local) {
+		uc_compiler_syntax_error(compiler, compiler->parser->curr.pos,
+			"Expecting label after 'local'");
+
+		goto out;
+	}
 
 	/*
 	 * The previous expression ruled out a for-in loop, so continue parsing
@@ -2335,6 +2336,7 @@ uc_compiler_compile_switch(uc_compiler *compiler)
 		/* handle `default:` */
 		if (uc_compiler_parse_match(compiler, TK_DEFAULT)) {
 			if (default_off) {
+				uc_vector_clear(&cases);
 				uc_compiler_syntax_error(compiler, compiler->parser->prev.pos,
 					"more than one switch default case");
 
diff --git a/lexer.c b/lexer.c
index ada8671..1fba88f 100644
--- a/lexer.c
+++ b/lexer.c
@@ -728,7 +728,7 @@ parse_label(uc_lexer *lex, bool no_regexp)
 
 	if (!buf_remaining(lex) || (lex->bufstart[0] != '_' && !isalnum(lex->bufstart[0]))) {
 		for (i = 0, word = &reserved_words[0]; i < ARRAY_SIZE(reserved_words); i++, word = &reserved_words[i]) {
-			if (lex->lookbehindlen == word->plen && !strncmp(lex->lookbehind, word->pat, word->plen)) {
+			if (lex->lookbehind && lex->lookbehindlen == word->plen && !strncmp(lex->lookbehind, word->pat, word->plen)) {
 				lookbehind_reset(lex);
 
 				switch (word->type) {
diff --git a/lib.c b/lib.c
index a4cfdea..ea87a6b 100644
--- a/lib.c
+++ b/lib.c
@@ -508,6 +508,7 @@ uc_unshift(uc_vm *vm, size_t nargs)
 static json_object *
 uc_chr(uc_vm *vm, size_t nargs)
 {
+	json_object *rv = NULL;
 	size_t idx;
 	int64_t n;
 	char *str;
@@ -528,7 +529,10 @@ uc_chr(uc_vm *vm, size_t nargs)
 		str[idx] = (char)n;
 	}
 
-	return xjs_new_string_len(str, nargs);
+	rv = xjs_new_string_len(str, nargs);
+	free(str);
+
+	return rv;
 }
 
 static json_object *
@@ -1194,6 +1198,7 @@ uc_uc(uc_vm *vm, size_t nargs)
 static json_object *
 uc_uchr(uc_vm *vm, size_t nargs)
 {
+	json_object *rv = NULL;
 	size_t idx, ulen;
 	char *p, *str;
 	int64_t n;
@@ -1226,7 +1231,10 @@ uc_uchr(uc_vm *vm, size_t nargs)
 			break;
 	}
 
-	return xjs_new_string_len(str, ulen);
+	rv = xjs_new_string_len(str, ulen);
+	free(str);
+
+	return rv;
 }
 
 static json_object *
@@ -1663,11 +1671,10 @@ invalid:
 static json_object *
 uc_require(uc_vm *vm, size_t nargs)
 {
-	const char *name = json_object_get_string(uc_get_arg(0));
-
 	json_object *val = uc_get_arg(0);
 	json_object *search, *se, *res;
 	size_t arridx, arrlen;
+	const char *name;
 
 	if (!json_object_is_type(val, json_type_string))
 		return NULL;
@@ -1882,8 +1889,7 @@ uc_replace_str(uc_vm *vm, json_object *str,
                const char *subject, regmatch_t *pmatch, size_t plen,
                char **sp, size_t *sl)
 {
-	const char *r = str ? json_object_get_string(str) : "null";
-	const char *p = r;
+	const char *p, *r = str ? json_object_get_string(str) : "null";
 	bool esc = false;
 	int i;
 
@@ -2202,13 +2208,20 @@ uc_system(uc_vm *vm, size_t nargs)
 {
 	json_object *cmdline = uc_get_arg(0);
 	json_object *timeout = uc_get_arg(1);
+	const char **arglist, *fn, *s;
 	sigset_t sigmask, sigomask;
-	const char **arglist, *fn;
 	struct timespec ts;
 	int64_t tms;
+	int rc, len;
 	pid_t cld;
 	size_t i;
-	int rc;
+
+	if (timeout && (!json_object_is_type(timeout, json_type_int) || json_object_get_int64(timeout) < 0)) {
+		uc_vm_raise_exception(vm, EXCEPTION_TYPE,
+		                      "Invalid timeout specified");
+
+		return NULL;
+	}
 
 	switch (json_object_get_type(cmdline)) {
 	case json_type_string:
@@ -2220,10 +2233,21 @@ uc_system(uc_vm *vm, size_t nargs)
 		break;
 
 	case json_type_array:
-		arglist = xalloc(sizeof(*arglist) * (json_object_array_length(cmdline) + 1));
+		len = json_object_array_length(cmdline);
+
+		if (len == 0) {
+			uc_vm_raise_exception(vm, EXCEPTION_TYPE,
+			                      "Passed command array is empty");
 
-		for (i = 0; i < json_object_array_length(cmdline); i++)
-			arglist[i] = json_object_get_string(json_object_array_get_idx(cmdline, i));
+			return NULL;
+		}
+
+		arglist = xalloc(sizeof(*arglist) * (len + 1));
+
+		for (i = 0; i < len; i++) {
+			s = json_object_get_string(json_object_array_get_idx(cmdline, i));
+			arglist[i] = s ? s : "null";
+		}
 
 		arglist[i] = NULL;
 
@@ -2236,13 +2260,6 @@ uc_system(uc_vm *vm, size_t nargs)
 		return NULL;
 	}
 
-	if (timeout && (!json_object_is_type(timeout, json_type_int) || json_object_get_int64(timeout) < 0)) {
-		uc_vm_raise_exception(vm, EXCEPTION_TYPE,
-		                      "Invalid timeout specified");
-
-		return NULL;
-	}
-
 	tms = timeout ? json_object_get_int64(timeout) : 0;
 
 	if (tms > 0) {
diff --git a/lib/fs.c b/lib/fs.c
index 6ea4ec1..7a33529 100644
--- a/lib/fs.c
+++ b/lib/fs.c
@@ -629,6 +629,7 @@ uc_fs_getcwd(uc_vm *vm, size_t nargs)
 		if (errno == ERANGE)
 			continue;
 
+		free(buf);
 		err_return(errno);
 	}
 	while (true);
diff --git a/main.c b/main.c
index 55c9dd8..c185524 100644
--- a/main.c
+++ b/main.c
@@ -197,7 +197,7 @@ static json_object *
 parse_envfile(FILE *fp)
 {
 	json_object *rv = NULL;
-	enum json_tokener_error err;
+	enum json_tokener_error err = json_tokener_continue;
 	struct json_tokener *tok;
 	char buf[128];
 	size_t rlen;