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Difference between revisions of "OT Bytecode Attributes/CallinFlags"
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===Location:=== | ===Location:=== | ||
| − | A role method or a callin wrapper. | + | A role method or a callin wrapper or a base call surrogate (for return type). |
===Content:=== | ===Content:=== | ||
| Line 11: | Line 11: | ||
===Purpose:=== | ===Purpose:=== | ||
| − | CALLIN_FLAG_OVERRIDING: | + | *Used by OTRE: |
| − | The OTRE uses this information to realize the inheritance of method bindings. | + | :CALLIN_FLAG_OVERRIDING |
| − | (OTRE internal: This flag prevents the OTRE from generating an empty base-call-surrogate which would wrongly override an inherited (non-empty) version.) | + | :CALLIN_FLAG_WRAPPER |
| + | :The OTRE uses this information to realize the inheritance of method bindings. | ||
| + | :(OTRE internal: This flag prevents the OTRE from generating an empty base-call-surrogate which would wrongly override an inherited (non-empty) version.) | ||
| + | |||
| + | *The other flags are only used by the compiler. | ||
| + | :CALLIN_FLAG_BASE_SUPER_CALL: OTRE part is handled via [[OT_Bytecode_Attributes/OTSpecialAccess|OTSpecialAccess]] attribute (kind SUPER_METHOD_ACCESS). | ||
===Format:=== | ===Format:=== | ||
| Line 24: | Line 29: | ||
The items of the CallinFlags structure are as follows: | The items of the CallinFlags structure are as follows: | ||
*attribute_name_index | *attribute_name_index | ||
| − | :The constant_pool entry at that index must be a CONSTANT_Utf8_info representing the string " | + | :The constant_pool entry at that index must be a CONSTANT_Utf8_info representing the string "CallinFlags". |
*attribute_length | *attribute_length | ||
:The value of the attribute_length item indicates the length of the attribute, excluding the initial six bytes. | :The value of the attribute_length item indicates the length of the attribute, excluding the initial six bytes. | ||
| Line 32: | Line 37: | ||
| − | {| cellpadding="5" border="1 | + | {| cellpadding="5" border="1" |
|- | |- | ||
! Flag Name !! Value !! Interpretation | ! Flag Name !! Value !! Interpretation | ||
| Line 40: | Line 45: | ||
| CALLIN_FLAG_WRAPPER || <tt>2</tt> || this method is the generated team-level callin wrapper | | CALLIN_FLAG_WRAPPER || <tt>2</tt> || this method is the generated team-level callin wrapper | ||
|- | |- | ||
| − | | CALLIN_FLAG_DEFINITELY_MISSING_BASECALL || <tt>8</tt> || | + | | CALLIN_FLAG_DEFINITELY_MISSING_BASECALL || <tt>8</tt> || for base call flow analysis including super calls |
|- | |- | ||
| − | | CALLIN_FLAG_POTENTIALLY_MISSING_BASECALL || <tt>16</tt> || | + | | CALLIN_FLAG_POTENTIALLY_MISSING_BASECALL || <tt>16</tt> || for base call flow analysis including super calls |
|- | |- | ||
| − | | CALLIN_FLAG_BASE_SUPER_CALL || <tt>32</tt> || | + | | CALLIN_FLAG_BASE_SUPER_CALL || <tt>32</tt> || is the base call targeting the base's super? |
|- | |- | ||
| − | | CALLIN_RETURN_MASK || <tt>9-12</tt> || | + | | CALLIN_RETURN_MASK || bits <tt>9-12</tt> || encoding of original non-reference return type, see <tt>IOTConstants.CALLIN_RETURN_VOID</tt> ff.. |
|} | |} | ||
[[Category:Object Teams Development]] | [[Category:Object Teams Development]] | ||
Latest revision as of 07:26, 4 July 2010
Attribute CallinFlags
Intent
The CallinFlags attribute is a fixed-length attribute used in the attributes table of method_info structures.
Location:
A role method or a callin wrapper or a base call surrogate (for return type).
Content:
An integer encoding the callin flags.
Purpose:
- Used by OTRE:
- CALLIN_FLAG_OVERRIDING
- CALLIN_FLAG_WRAPPER
- The OTRE uses this information to realize the inheritance of method bindings.
- (OTRE internal: This flag prevents the OTRE from generating an empty base-call-surrogate which would wrongly override an inherited (non-empty) version.)
- The other flags are only used by the compiler.
- CALLIN_FLAG_BASE_SUPER_CALL: OTRE part is handled via OTSpecialAccess attribute (kind SUPER_METHOD_ACCESS).
Format:
CallinFlags {
u2 attribute_name_index;
u4 attribute_length;
u2 callin_flags;
}
The items of the CallinFlags structure are as follows:
- attribute_name_index
- The constant_pool entry at that index must be a CONSTANT_Utf8_info representing the string "CallinFlags".
- attribute_length
- The value of the attribute_length item indicates the length of the attribute, excluding the initial six bytes.
- callin_flags
- The value of the callin_flags item is a mask of flags (used to denote ...). The interpretation of each flag, when set, is as shown in the following:
| Flag Name | Value | Interpretation |
|---|---|---|
| CALLIN_FLAG_OVERRIDING | 1 | this method is overriding an inherited version |
| CALLIN_FLAG_WRAPPER | 2 | this method is the generated team-level callin wrapper |
| CALLIN_FLAG_DEFINITELY_MISSING_BASECALL | 8 | for base call flow analysis including super calls |
| CALLIN_FLAG_POTENTIALLY_MISSING_BASECALL | 16 | for base call flow analysis including super calls |
| CALLIN_FLAG_BASE_SUPER_CALL | 32 | is the base call targeting the base's super? |
| CALLIN_RETURN_MASK | bits 9-12 | encoding of original non-reference return type, see IOTConstants.CALLIN_RETURN_VOID ff.. |