From 58ba4c3b4c12e9bf6b8731fd26e0c9cac527122f Mon Sep 17 00:00:00 2001
From: Damien George <damien.p.george@gmail.com>
Date: Thu, 10 Apr 2014 14:27:31 +0000
Subject: [PATCH] py: Check explicitly for memory allocation failure in parser.
Previously, a failed malloc/realloc would throw an exception, which was
not caught. I think it's better to keep the parser free from NLR
(exception throwing), hence this patch.
---
py/malloc.c | 20 +++++++++++++++
py/misc.h | 3 +++
py/objexcept.c | 4 +--
py/parse.c | 66 ++++++++++++++++++++++++++++++++++++++----------
py/parse.h | 1 +
py/parsehelper.c | 8 ++++++
6 files changed, 86 insertions(+), 16 deletions(-)
diff --git a/py/malloc.c b/py/malloc.c
index 1d18a9a64..db2578d9a 100644
--- a/py/malloc.c
+++ b/py/malloc.c
@@ -118,6 +118,26 @@ void *m_realloc(void *ptr, int old_num_bytes, int new_num_bytes) {
return new_ptr;
}
+void *m_realloc_maybe(void *ptr, int old_num_bytes, int new_num_bytes) {
+ void *new_ptr = realloc(ptr, new_num_bytes);
+ if (new_ptr == NULL) {
+ return NULL;
+ }
+#if MICROPY_MEM_STATS
+ // At first thought, "Total bytes allocated" should only grow,
+ // after all, it's *total*. But consider for example 2K block
+ // shrunk to 1K and then grown to 2K again. It's still 2K
+ // allocated total. If we process only positive increments,
+ // we'll count 3K.
+ int diff = new_num_bytes - old_num_bytes;
+ total_bytes_allocated += diff;
+ current_bytes_allocated += diff;
+ UPDATE_PEAK();
+#endif
+ DEBUG_printf("realloc %p, %d, %d : %p\n", ptr, old_num_bytes, new_num_bytes, new_ptr);
+ return new_ptr;
+}
+
void m_free(void *ptr, int num_bytes) {
if (ptr != NULL) {
free(ptr);
diff --git a/py/misc.h b/py/misc.h
index 3f538b98e..002a97ffe 100644
--- a/py/misc.h
+++ b/py/misc.h
@@ -27,12 +27,14 @@ typedef unsigned int uint;
#define m_new0(type, num) ((type*)(m_malloc0(sizeof(type) * (num))))
#define m_new_obj(type) (m_new(type, 1))
#define m_new_obj_var(obj_type, var_type, var_num) ((obj_type*)m_malloc(sizeof(obj_type) + sizeof(var_type) * (var_num)))
+#define m_new_obj_var_maybe(obj_type, var_type, var_num) ((obj_type*)m_malloc_maybe(sizeof(obj_type) + sizeof(var_type) * (var_num)))
#if MICROPY_ENABLE_FINALISER
#define m_new_obj_with_finaliser(type) ((type*)(m_malloc_with_finaliser(sizeof(type))))
#else
#define m_new_obj_with_finaliser(type) m_new_obj(type)
#endif
#define m_renew(type, ptr, old_num, new_num) ((type*)(m_realloc((ptr), sizeof(type) * (old_num), sizeof(type) * (new_num))))
+#define m_renew_maybe(type, ptr, old_num, new_num) ((type*)(m_realloc_maybe((ptr), sizeof(type) * (old_num), sizeof(type) * (new_num))))
#define m_del(type, ptr, num) m_free(ptr, sizeof(type) * (num))
#define m_del_obj(type, ptr) (m_del(type, ptr, 1))
#define m_del_var(obj_type, var_type, var_num, ptr) (m_free(ptr, sizeof(obj_type) + sizeof(var_type) * (var_num)))
@@ -42,6 +44,7 @@ void *m_malloc_maybe(int num_bytes);
void *m_malloc_with_finaliser(int num_bytes);
void *m_malloc0(int num_bytes);
void *m_realloc(void *ptr, int old_num_bytes, int new_num_bytes);
+void *m_realloc_maybe(void *ptr, int old_num_bytes, int new_num_bytes);
void m_free(void *ptr, int num_bytes);
void *m_malloc_fail(int num_bytes);
diff --git a/py/objexcept.c b/py/objexcept.c
index 1ef3e31dc..781a00405 100644
--- a/py/objexcept.c
+++ b/py/objexcept.c
@@ -54,7 +54,7 @@ STATIC mp_obj_t mp_obj_exception_make_new(mp_obj_t type_in, uint n_args, uint n_
nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_TypeError, "%s does not take keyword arguments", mp_obj_get_type_str(type_in)));
}
- mp_obj_exception_t *o = m_malloc_maybe(sizeof(mp_obj_exception_t) + n_args * sizeof(mp_obj_t));
+ mp_obj_exception_t *o = m_new_obj_var_maybe(mp_obj_exception_t, mp_obj_t, n_args);
if (o == NULL) {
// Couldn't allocate heap memory; use local data instead.
o = &mp_emergency_exception_obj;
@@ -205,7 +205,7 @@ mp_obj_t mp_obj_new_exception_msg_varg(const mp_obj_type_t *exc_type, const char
assert(exc_type->make_new == mp_obj_exception_make_new);
// make exception object
- mp_obj_exception_t *o = m_malloc_maybe(sizeof(mp_obj_exception_t) + 1 * sizeof(mp_obj_t));
+ mp_obj_exception_t *o = m_new_obj_var_maybe(mp_obj_exception_t, mp_obj_t, 1);
if (o == NULL) {
// Couldn't allocate heap memory; use local data instead.
// Unfortunately, we won't be able to format the string...
diff --git a/py/parse.c b/py/parse.c
index 1381f1293..6c899ce56 100644
--- a/py/parse.c
+++ b/py/parse.c
@@ -86,6 +86,8 @@ typedef struct _rule_stack_t {
} rule_stack_t;
typedef struct _parser_t {
+ bool had_memory_error;
+
uint rule_stack_alloc;
uint rule_stack_top;
rule_stack_t *rule_stack;
@@ -97,9 +99,21 @@ typedef struct _parser_t {
mp_lexer_t *lexer;
} parser_t;
+STATIC inline void memory_error(parser_t *parser) {
+ parser->had_memory_error = true;
+}
+
STATIC void push_rule(parser_t *parser, int src_line, const rule_t *rule, int arg_i) {
+ if (parser->had_memory_error) {
+ return;
+ }
if (parser->rule_stack_top >= parser->rule_stack_alloc) {
- parser->rule_stack = m_renew(rule_stack_t, parser->rule_stack, parser->rule_stack_alloc, parser->rule_stack_alloc * 2);
+ rule_stack_t *rs = m_renew_maybe(rule_stack_t, parser->rule_stack, parser->rule_stack_alloc, parser->rule_stack_alloc * 2);
+ if (rs == NULL) {
+ memory_error(parser);
+ return;
+ }
+ parser->rule_stack = rs;
parser->rule_stack_alloc *= 2;
}
rule_stack_t *rs = &parser->rule_stack[parser->rule_stack_top++];
@@ -116,6 +130,7 @@ STATIC void push_rule_from_arg(parser_t *parser, uint arg) {
}
STATIC void pop_rule(parser_t *parser, const rule_t **rule, uint *arg_i, uint *src_line) {
+ assert(!parser->had_memory_error);
parser->rule_stack_top -= 1;
*rule = rules[parser->rule_stack[parser->rule_stack_top].rule_id];
*arg_i = parser->rule_stack[parser->rule_stack_top].arg_i;
@@ -129,15 +144,6 @@ mp_parse_node_t mp_parse_node_new_leaf(machine_int_t kind, machine_int_t arg) {
return (mp_parse_node_t)(kind | (arg << 5));
}
-//int num_parse_nodes_allocated = 0;
-mp_parse_node_struct_t *parse_node_new_struct(int src_line, int rule_id, int num_args) {
- mp_parse_node_struct_t *pn = m_new_obj_var(mp_parse_node_struct_t, mp_parse_node_t, num_args);
- pn->source_line = src_line;
- pn->kind_num_nodes = (rule_id & 0xff) | (num_args << 8);
- //num_parse_nodes_allocated += 1;
- return pn;
-}
-
uint mp_parse_node_free(mp_parse_node_t pn) {
uint cnt = 0;
if (MP_PARSE_NODE_IS_STRUCT(pn)) {
@@ -211,18 +217,32 @@ STATIC void result_stack_show(parser_t *parser) {
*/
STATIC mp_parse_node_t pop_result(parser_t *parser) {
+ if (parser->had_memory_error) {
+ return MP_PARSE_NODE_NULL;
+ }
assert(parser->result_stack_top > 0);
return parser->result_stack[--parser->result_stack_top];
}
STATIC mp_parse_node_t peek_result(parser_t *parser, int pos) {
+ if (parser->had_memory_error) {
+ return MP_PARSE_NODE_NULL;
+ }
assert(parser->result_stack_top > pos);
return parser->result_stack[parser->result_stack_top - 1 - pos];
}
STATIC void push_result_node(parser_t *parser, mp_parse_node_t pn) {
+ if (parser->had_memory_error) {
+ return;
+ }
if (parser->result_stack_top >= parser->result_stack_alloc) {
- parser->result_stack = m_renew(mp_parse_node_t, parser->result_stack, parser->result_stack_alloc, parser->result_stack_alloc * 2);
+ mp_parse_node_t *pn = m_renew_maybe(mp_parse_node_t, parser->result_stack, parser->result_stack_alloc, parser->result_stack_alloc * 2);
+ if (pn == NULL) {
+ memory_error(parser);
+ return;
+ }
+ parser->result_stack = pn;
parser->result_stack_alloc *= 2;
}
parser->result_stack[parser->result_stack_top++] = pn;
@@ -283,7 +303,13 @@ STATIC void push_result_token(parser_t *parser, const mp_lexer_t *lex) {
}
STATIC void push_result_rule(parser_t *parser, int src_line, const rule_t *rule, int num_args) {
- mp_parse_node_struct_t *pn = parse_node_new_struct(src_line, rule->rule_id, num_args);
+ mp_parse_node_struct_t *pn = m_new_obj_var_maybe(mp_parse_node_struct_t, mp_parse_node_t, num_args);
+ if (pn == NULL) {
+ memory_error(parser);
+ return;
+ }
+ pn->source_line = src_line;
+ pn->kind_num_nodes = (rule->rule_id & 0xff) | (num_args << 8);
for (int i = num_args; i > 0; i--) {
pn->nodes[i - 1] = pop_result(parser);
}
@@ -296,6 +322,8 @@ mp_parse_node_t mp_parse(mp_lexer_t *lex, mp_parse_input_kind_t input_kind, mp_p
parser_t *parser = m_new_obj(parser_t);
+ parser->had_memory_error = false;
+
parser->rule_stack_alloc = 64;
parser->rule_stack_top = 0;
parser->rule_stack = m_new(rule_stack_t, parser->rule_stack_alloc);
@@ -327,7 +355,7 @@ mp_parse_node_t mp_parse(mp_lexer_t *lex, mp_parse_input_kind_t input_kind, mp_p
for (;;) {
next_rule:
- if (parser->rule_stack_top == 0) {
+ if (parser->rule_stack_top == 0 || parser->had_memory_error) {
break;
}
@@ -596,6 +624,16 @@ mp_parse_node_t mp_parse(mp_lexer_t *lex, mp_parse_input_kind_t input_kind, mp_p
}
}
+ mp_parse_node_t result;
+
+ // check if we had a memory error
+ if (parser->had_memory_error) {
+ *parse_error_kind_out = MP_PARSE_ERROR_MEMORY;
+ result = MP_PARSE_NODE_NULL;
+ goto finished;
+
+ }
+
// check we are at the end of the token stream
if (!mp_lexer_is_kind(lex, MP_TOKEN_END)) {
goto syntax_error;
@@ -609,7 +647,7 @@ mp_parse_node_t mp_parse(mp_lexer_t *lex, mp_parse_input_kind_t input_kind, mp_p
// get the root parse node that we created
assert(parser->result_stack_top == 1);
- mp_parse_node_t result = parser->result_stack[0];
+ result = parser->result_stack[0];
finished:
// free the memory that we don't need anymore
diff --git a/py/parse.h b/py/parse.h
index 135de47d1..29bcf36e7 100644
--- a/py/parse.h
+++ b/py/parse.h
@@ -67,6 +67,7 @@ typedef enum {
} mp_parse_input_kind_t;
typedef enum {
+ MP_PARSE_ERROR_MEMORY,
MP_PARSE_ERROR_UNEXPECTED_INDENT,
MP_PARSE_ERROR_UNMATCHED_UNINDENT,
MP_PARSE_ERROR_INVALID_SYNTAX,
diff --git a/py/parsehelper.c b/py/parsehelper.c
index 3177e9a34..e069657b1 100644
--- a/py/parsehelper.c
+++ b/py/parsehelper.c
@@ -11,6 +11,7 @@
#include "obj.h"
#include "parsehelper.h"
+#define STR_MEMORY "parser could not allocate enough memory"
#define STR_UNEXPECTED_INDENT "unexpected indent"
#define STR_UNMATCHED_UNINDENT "unindent does not match any outer indentation level"
#define STR_INVALID_SYNTAX "invalid syntax"
@@ -18,6 +19,10 @@
void mp_parse_show_exception(mp_lexer_t *lex, mp_parse_error_kind_t parse_error_kind) {
printf(" File \"%s\", line %d, column %d\n", qstr_str(mp_lexer_source_name(lex)), mp_lexer_cur(lex)->src_line, mp_lexer_cur(lex)->src_column);
switch (parse_error_kind) {
+ case MP_PARSE_ERROR_MEMORY:
+ printf("MemoryError: %s\n", STR_MEMORY);
+ break;
+
case MP_PARSE_ERROR_UNEXPECTED_INDENT:
printf("IndentationError: %s\n", STR_UNEXPECTED_INDENT);
break;
@@ -36,6 +41,9 @@ void mp_parse_show_exception(mp_lexer_t *lex, mp_parse_error_kind_t parse_error_
mp_obj_t mp_parse_make_exception(mp_parse_error_kind_t parse_error_kind) {
// TODO add source file and line number to exception?
switch (parse_error_kind) {
+ case MP_PARSE_ERROR_MEMORY:
+ return mp_obj_new_exception_msg(&mp_type_MemoryError, STR_MEMORY);
+
case MP_PARSE_ERROR_UNEXPECTED_INDENT:
return mp_obj_new_exception_msg(&mp_type_IndentationError, STR_UNEXPECTED_INDENT);
--
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