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Cleanup code around JERRY_UNREACHABLEs (#2342)

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`JERRY_UNREACHABLE`s often signal code structure that could be
improved: they can usually either be rewritten to `JERRY_ASSERT`s
or eliminated by restructuring loops, `if`s or `#if`s. Roughly,
the only valid occurences are in default cases of `switch`es. And
even they can often be merged into non-default cases.

Moreover, it is dangerous to write meaningful code after
`JERRY_UNREACHABLE` because it pretends as if there was a way to
recover from an impossible situation.

This patch rewrites/eliminates `JERRY_UNREACHABLE`s where possible
and removes misleading code from after them.

JerryScript-DCO-1.0-Signed-off-by: Akos Kiss akiss@inf.u-szeged.hu
This commit is contained in:
Akos Kiss
2018-05-25 07:27:30 +02:00
committed by GitHub
parent acb3e71436
commit 4779451284
24 changed files with 168 additions and 256 deletions
Download Patch File Download Diff File Expand all files Collapse all files
jerry-core/api/jerry-snapshot.c
+8 -8
View File
@@ -154,9 +154,9 @@ snapshot_add_compiled_code (ecma_compiled_code_t *compiled_code_p, /**< compiled
uint8_t *copied_code_start_p = snapshot_buffer_p + globals_p->snapshot_buffer_write_offset;
ecma_compiled_code_t *copied_code_p = (ecma_compiled_code_t *) copied_code_start_p;
#ifndef CONFIG_DISABLE_REGEXP_BUILTIN
if (!(compiled_code_p->status_flags & CBC_CODE_FLAGS_FUNCTION))
{
#ifndef CONFIG_DISABLE_REGEXP_BUILTIN
/* Regular expression. */
if (globals_p->snapshot_buffer_write_offset + sizeof (ecma_compiled_code_t) > snapshot_buffer_size)
{
@@ -204,11 +204,11 @@ snapshot_add_compiled_code (ecma_compiled_code_t *compiled_code_p, /**< compiled
copied_code_p->status_flags = compiled_code_p->status_flags;
#else /* CONFIG_DISABLE_REGEXP_BUILTIN */
JERRY_UNREACHABLE (); /* RegExp is not supported in the selected profile. */
#endif /* !CONFIG_DISABLE_REGEXP_BUILTIN */
return start_offset;
}
#endif /* !CONFIG_DISABLE_REGEXP_BUILTIN */
JERRY_ASSERT (compiled_code_p->status_flags & CBC_CODE_FLAGS_FUNCTION);
if (!snapshot_write_to_buffer_by_offset (snapshot_buffer_p,
snapshot_buffer_size,
@@ -536,9 +536,9 @@ snapshot_load_compiled_code (const uint8_t *base_addr_p, /**< base address of th
ecma_compiled_code_t *bytecode_p = (ecma_compiled_code_t *) base_addr_p;
uint32_t code_size = ((uint32_t) bytecode_p->size) << JMEM_ALIGNMENT_LOG;
#ifndef CONFIG_DISABLE_REGEXP_BUILTIN
if (!(bytecode_p->status_flags & CBC_CODE_FLAGS_FUNCTION))
{
#ifndef CONFIG_DISABLE_REGEXP_BUILTIN
const re_compiled_code_t *re_bytecode_p = NULL;
const uint8_t *regex_start_p = ((const uint8_t *) bytecode_p) + sizeof (ecma_compiled_code_t);
@@ -554,10 +554,10 @@ snapshot_load_compiled_code (const uint8_t *base_addr_p, /**< base address of th
ecma_deref_ecma_string (pattern_str_p);
return (ecma_compiled_code_t *) re_bytecode_p;
#else /* CONFIG_DISABLE_REGEXP_BUILTIN */
JERRY_UNREACHABLE (); /* RegExp is not supported in the selected profile. */
#endif /* !CONFIG_DISABLE_REGEXP_BUILTIN */
}
#endif /* !CONFIG_DISABLE_REGEXP_BUILTIN */
JERRY_ASSERT (bytecode_p->status_flags & CBC_CODE_FLAGS_FUNCTION);
size_t header_size;
uint32_t argument_end = 0;
jerry-core/api/jerry.c
+6 -18
View File
@@ -100,11 +100,7 @@ static const char * const wrong_args_msg_p = "wrong type of argument";
static inline void JERRY_ATTR_ALWAYS_INLINE
jerry_assert_api_available (void)
{
if (JERRY_UNLIKELY (!(JERRY_CONTEXT (status_flags) & ECMA_STATUS_API_AVAILABLE)))
{
/* Terminates the execution. */
JERRY_UNREACHABLE ();
}
JERRY_ASSERT (JERRY_CONTEXT (status_flags) & ECMA_STATUS_API_AVAILABLE);
} /* jerry_assert_api_available */
/**
@@ -178,11 +174,8 @@ jerry_throw (jerry_value_t value) /**< return value */
void
jerry_init (jerry_init_flag_t flags) /**< combination of Jerry flags */
{
if (JERRY_UNLIKELY (JERRY_CONTEXT (status_flags) & ECMA_STATUS_API_AVAILABLE))
{
/* This function cannot be called twice unless jerry_cleanup is called. */
JERRY_UNREACHABLE ();
}
/* This function cannot be called twice unless jerry_cleanup is called. */
JERRY_ASSERT (!(JERRY_CONTEXT (status_flags) & ECMA_STATUS_API_AVAILABLE));
/* Zero out all members. */
memset (&JERRY_CONTEXT (JERRY_CONTEXT_FIRST_MEMBER), 0, sizeof (jerry_context_t));
@@ -834,21 +827,16 @@ jerry_value_get_type (const jerry_value_t value) /**< input value to check */
{
return JERRY_TYPE_FUNCTION;
}
case LIT_MAGIC_STRING_OBJECT:
default:
{
JERRY_ASSERT (lit_id == LIT_MAGIC_STRING_OBJECT);
/* Based on the ECMA 262 5.1 standard the 'null' value is an object.
* Thus we'll do an extra check for 'null' here.
*/
return ecma_is_value_null (argument) ? JERRY_TYPE_NULL : JERRY_TYPE_OBJECT;
}
default:
{
JERRY_UNREACHABLE ();
break;
}
}
return JERRY_TYPE_NONE;
} /* jerry_value_get_type */
/**