Patent Application
20150293771
1. Field of the Invention
The present invention relates to a method, system, and article of manufacture for specifying user defined or translator definitions to use to interpret mnemonics in a computer program.
2. Description of the Related Art
Programmers write computer programs in computer languages referred to as the source code which includes data declarations and instructions that operate on data. The programmer writes keywords and commands in a language to instruct the language translator to perform certain actions. Such keywords and commands typically have meanings relevant to the context of their use, and may be abbreviated in a mnemonic form. A “mnemonic” as that term is used and defined herein may comprise a string of one or more characters, keyword, etc. having a defined meaning in a computer language. Before the program can be executed, the source code must be transformed to machine readable executable code.
Every programming language has a number of reserved names, language keywords, or mnemonics necessary for the language translator (a compiler, assembler, interpreter, etc.) to understand the structure and content of programs written in that language. The presence of reserved mnemonics may preclude the programmer from using such mnemonics in unexpected or ambiguous ways. If a programmer uses a mnemonic that matches a reserved mnemonic, also known as a built-in translator defined mnemonic, then the match may result in a misinterpretation of the meaning or structure of the program or an error message that may not indicate the actual cause of the problem.
Language keyword redefinition is especially problematic for assembler languages, where mnemonics can be used for referencing objects not defined in the program currently being assembled, and for instruction mnemonics. Most assemblers support a capability to allow the programmer to use mnemonics with the standard statement syntax to refer to both built-in or pre-defined mnemonics (such as assembler directives and machine instructions) and to user-defined mnemonics (such as macro-instructions). If the same statement syntax is used, the programmer may consequently write a statement in which such a mnemonic refers either to a built-in instruction known to the assembler or to a previously coded user-defined macro-instruction.
Prior art assembler implementations avoid possible conflicts between built-in and user defined mnemonic definitions by allowing only one definition of a given mnemonic to be used, to the exclusion of the other. That is, only one allowed form of any language keyword in the form of a mnemonic is supported, either as a built-in instruction or a macro-instruction, but not both.
As machine architectures and assembler facilities evolve, it is possible that the introduction of new built-in machine instruction mnemonics or assembler instruction mnemonics will conflict with existing user-defined macro-instruction mnemonics or the creation of new user-defined or vendor-supplied macro-instruction mnemonics will conflict with existing built-in mnemonics. In such cases, the programmer must either change the coding of his user-defined mnemonics to avoid using the unwanted new definition of the built-in machine instruction mnemonic, or must change the name of his user-defined macro-instruction to avoid conflicts when using the new built-in mnemonic.
For example, in the IBM® zSeries® z/Architecture® computers from International Business Machines Corporation, a new machine instruction with mnemonic MSG was introduced. The mnemonic MSG had been widely used in many programs for user-defined message-generating macro-instructions as a convenient abbreviation for “MESSAGE”. The built-in machine instruction stands for MULTIPLY SINGLE (the G of MSG indicates the 64-bit version). Programs using such user-defined MSG macro-instructions that had the same name as the MULTIPLY SINGLE built-in instruction were faced with the problem of either avoiding the use of the new MSG machine instruction or of rewriting the MSG macro-instruction with a new name and then revising all programs that previously used the MSG mnemonic for the MSG macro-instruction to use the new name instead. For large volumes of code, such changes can impose an expensive updating burden, and require extensive retesting of many programs. (IBM, zSeries, and z/Architecture are registered trademarks of International Business Machines Corporation in the United States, other countries, or both).
To avoid this problem, programmers may devise complex programming techniques that tell the assembler to use one or the other definition of a mnemonic alternately. However, such advanced programming techniques may be error-prone and likely to confuse later readers or maintainers of the program who do not understand such techniques which may not be documented or widely known.
Thus, there is a need for techniques to provide flexibility to users of programming languages in specifying a user defined or translator defined definition for a mnemonic.
Provided are a method, system, and article of manufacture for specifying user defined or translator definitions to use to interpret mnemonics in a computer program. A mnemonic is processed in the computer program having a user defined definition and a translator definition. The mnemonic is interpreted according to the user defined definition in response to previously processing a mnemonic command specifying the mnemonic and the user defined definition. The mnemonic is interpreted according to the translator definition in response to previously processing a mnemonic command specifying the mnemonic and the translator definition.
During initialization and when processing the source code 12, the translator 10 may update a mnemonic table 16 including information on mnemonics that are referenced in the source code 12. As mentioned a mnemonic comprises a keyword, instruction or string of one or more characters that performs an operation associated with that mnemonic. The translator 10 may have a translator definition for a mnemonic, such as a definition included within the translator 10 code. Additionally, there may be a user defined definition for the same mnemonic. Thus, mnemonics may be provided with both a translator definition and a user defined definition. The definitions specify the operations invoked when the mnemonic is processed. The translator 10 may further update a shared work area 18 having definitions of qualification characters used to modify a mnemonic to indicate whether the user defined or translator definition is used to interpret the mnemonic. A qualified mnemonic comprises a mnemonic that is modified with one or more qualification characters, where the qualification characters may comprise a prefix, suffix, quotation or other notation with respect to the mnemonic.
The user interface 20 may comprise an input device (e.g., keyboard, mouse, etc.) and output device (e.g., display monitor, etc.) to allow the user to control and observe translation operations.
The term “qualification character” may refer to one or more alpha-numeric or special characters that are combined with a mnemonic to specify the interpretation (user defined or translator) for the mnemonic. Further, the qualification character definitions 80-90 may also indicate NULL, if no qualification character is provided for a particular definition and scope.
In further embodiments, there may be separate global, local and macro qualification characters 80-90 prefix, suffix, or quotation qualification characters.
A mnemonic command controls the interpretation of the mnemonic and how the mnemonic is defined and used. A global mnemonic command may be specified externally when the translator 10 is first invoked, by some default convention or at the start of the program 12 to be translated. The global mnemonic command specification may apply throughout the program 12 in the absence of any subsequent local or macro mnemonic controls providing statement-specific or definition-specific controls. Global mnemonic control commands may designate individual mnemonics to be interpreted with the user defined 54 or translator 56 definitions. Global qualifier commands associate a qualification character that when combined with the mnemonic specifies a user defined or translator definition for the modified mnemonic.
Global control of the interpretation of individual mnemonics is specified by providing the translator 10 with the name or names of mnemonics to be interpreted in a designated way. For example, the global command (1) may specify that the mnemonic1, mnemonic 2 . . . will be interpreted globally with the user definition 54, where “UDMNEMNONIC” is an abbreviation for user-defined mnemonic, and global command (2) specifies that the mnemonic3, mnemonic4 . . . will be interpreted globally with the translator definition 56, where “BIMNEMONIC” is an abbreviation for built-in mnemonic.
UDMNEMONIC=(mnemonic1,mnemonic2, . . . ) (1)
BIMNEMONIC=(mnemonic3,mnemonic4, . . . ) (2)
Global declaration of the notation used to control the interpretation of mnemonics in individual statements is specified by providing the translator 10 with information allowing qualified mnemonics to be interpreted in a specific way. For instance, the qualifier command (3) below specifies qualification characters, e.g., “< >”, that when providing quotes for the mnemonic “XYZ”, e.g., “<XYZ>”, indicates that the user defined definition 54 is to be used; the qualifier command (4) below specifies qualification characters that when prefixed to the mnemonic, e.g., “U.XYZ”, indicates that the user defined definition is to be used; qualifier command (5) below specifies qualification characters that when appended to the mnemonic, e.g., “XYZ.U”, indicates that the user defined definition is to be used; the qualifier command (6) specifies qualification characters, e.g., “[ ]”, that when providing quotes for the mnemonic, e.g., “[XYZ]” indicate that the translator definition 56 is to be used; qualifier command (7) specifies qualification characters that when prefixed to the mnemonic, e.g., “B.XYZ”, indicate that the translator definition is to be used; and qualifier command (8) specifies qualification characters that when appended to the mnemonic, e.g., “XYZ.B”, indicate that the translator definition is to be used.
UDMQC=‘<’,‘>’ (3)
UDPREFIX=‘U.’ (4)
UDSUFFIX=‘.U’ (5)
BIMQC=‘[’,‘]’ (6)
BIPREFIX=‘B.’ (7)
BISUFFIX=‘.B’ (8)
A local mnemonic command specifying the interpretation of a mnemonic to have local scope, i.e., to override the global or previous local interpretation, may be designated by use of a local statement, such as ACONTROL, with the mnemonic command, e.g., UDMNEMONIC, BIMNEMONIC. Use of the local statement, e.g., ACONTROL, ensures that the local interpretation flag 60 is updated with the interpretation to use for the specified mnemonic. For example, the local mnemonic command (9) may specify that the mnemonic1, mnemonic 2 . . . will be interpreted locally with the user definition 54 and the local mnemonic command (10) specifies that the mnemonic3, mnemonic4 . . . will be interpreted locally with the translator definition 56.
ACONTROL UDMNEMONIC=(mnemonic1,mnemonic2, . . . ) (9)
ACONTROL BIMNEMONIC=(mnemonic3,mnemonic4, . . . ) (10)
A local qualifier command specifying the interpretation of a qualifying character to have local scope may also be designated by use of the local statement, such as ACONTROL, with the qualifier command, as shown below. Use of the local statement, ACONTROL, with the qualifier command, as shown below in commands (11) through (16), ensures that the local qualification character 84, 86 is updated.
ACONTROL UDMQC=‘<’,‘>’ (11)
ACONTROL UDPREFIX=‘U.’ (12)
ACONTROL UDSUFFIX=‘U.’ (13)
ACONTROL BIMQC=‘[’,‘]’ (14)
ACONTROL BIPREFIX=‘B.’ (15)
ACONTROL BISUFFIX=‘B.’ (16)
A reversion command may be used to reset the local qualification characters 84, 86 to use the default characters, which may be the global qualification characters 80 and 82, specified at the time the translator 10 is invoked. For example, the reversion commands (17) through (22) may be used to reset the local qualification characters used as a prefix, suffix, and quotes to the default global qualification characters.
ACONTROL BIMQC=DEFAULT (17)
ACONTROL BIPREFIX=DEFAULT (18)
ACONTROL BISUFFIX=DEFAULT (19)
ACONTROL UDMQC=DEFAULT (20)
ACONTROL UDPREFIX=DEFAULT (21)
ACONTROL UDSUFFIX=DEFAULT (22)
A remove command may be used to remove the local qualification characters by setting the local qualification characters to NULL. For example, the remove command (23) provides an example of how particular qualification characters may be set to NULL.
ACONTROL UDSUFFIX=NULL (23)
In one embodiment, if the local mnemonic command or local qualifier command is included in a macro, then any mnemonics called within the macro and following the expansion of the macro may be interpreted using the interpretation specified by the local mnemonic command or local qualifier command included in the expanded macro. If multiple local mnemonic or qualifier commands are included in the macro, then the most recently processed command would provide the local interpretation for the mnemonic.
Described embodiments provide statements for a programmer to use to ensure that a local mnemonic command or local qualifier command invoked in a macro provide interpretations for mnemonics and qualification characters that are only applicable within macro expansions, and not to mnemonics called outside the macro following the macro expansion.
With the operations of
With the operations of
If (at block 304) the mnemonic does have a qualification character, e.g., suffix, prefix, quotes, then the translator 10 determines (at block 312) whether the qualification character matches a macro 88, 90, local 84, 86 or global 82, 80 user defined or translator qualification character in the shared work area 18. If so, then the translator 10 interprets (at block 314) the mnemonic according to the interpretation associated first with the macro qualification character 88, 90, if provided, then the local qualification character 84, 86, if provided, and then the global qualification character 80, 82, in that order. If the qualification character used with the mnemonic is not defined in the shared work area 18, then the translator 10 provides an error condition (at block 316).
If (at block 302) the mnemonic is not invoked within a macro expansion and if (at block 318) the mnemonic does not have a qualification character, then the translator 10 determines (at block 320) whether there is a local 60 or global 58 interpretation provided for that mnemonic, in that order. If so, then the translator 10 interprets (at block 324) the mnemonic according to the interpretation indicated in the local 60 or global 58 flag, using the local interpretation 60, if provided, or the global interpretation 58 if no local interpretation 60 is provided. If no local 60 or global 58 interpretation is provided, then an error indication is returned (at block 326). If (at block 318) the mnemonic has a qualification character, i.e., is a qualified mnemonic, then the translator 10 determines (at block 328) whether the qualification character matches a local 84, 86 or global 80, 82 qualification character (user defined or translator). If so, then the translator 10 interprets (at block 330) the qualified mnemonic according to the interpretation associated with the local or global qualification character, in that order so that the local defined qualification character 84, 86 has precedence over the global defined qualification character 80, 82. Otherwise, if there is no match, then an error indication is returned (at block 332).
The described embodiments provide programming statements to enable a programmer to set and then change in the source code the mnemonic interpretation as user defined or translator and the association of the qualification characters with user defined or translator definitions. The programmer may further specify the scope of interpretation as global, local, and macro, and use statements to provide for statement specific definitions.
The described operations may be implemented as a method, apparatus or article of manufacture using standard programming and/or engineering techniques to produce software, firmware, hardware, or any combination thereof. The described operations may be implemented as code maintained in a “computer readable medium”, where a processor may read and execute the code from the computer readable medium. A computer readable medium may comprise media such as magnetic storage medium (e.g., hard disk drives, floppy disks, tape, etc.), optical storage (CD-ROMs, DVDs, optical disks, etc.), volatile and non-volatile memory devices (e.g., EEPROMs, ROMs, PROMs, RAMs, DRAMs, SRAMs, Flash Memory, firmware, programmable logic, etc.), etc. The code implementing the described operations may further be implemented in hardware logic (e.g., an integrated circuit chip, Programmable Gate Array (PGA), Application Specific Integrated Circuit (ASIC), etc.). Still further, the code implementing the described operations may be implemented in “transmission signals”, where transmission signals may propagate through space or through a transmission medium, such as an optical fiber, copper wire, etc. The transmission signals in which the code or logic is encoded may further comprise a wireless signal, satellite transmission, radio waves, infrared signals, Bluetooth, etc. The transmission signals in which the code or logic is encoded is capable of being transmitted by a transmitting station and received by a receiving station, where the code or logic encoded in the transmission signal may be decoded and stored in hardware or a computer readable medium at the receiving and transmitting stations or devices. An “article of manufacture” comprises computer readable medium, hardware logic, and/or transmission signals in which code may be implemented. A device in which the code implementing the described embodiments of operations is encoded may comprise a computer readable medium or hardware logic. Of course, those skilled in the art will recognize that many modifications may be made to this configuration without departing from the scope of the present invention, and that the article of manufacture may comprise suitable information bearing medium known in the art.
The terms “an embodiment”, “embodiment”, “embodiments”, “the embodiment”, “the embodiments”, “one or more embodiments”, “some embodiments”, and “one embodiment” mean “one or more (but not all) embodiments of the present invention(s)” unless expressly specified otherwise.
The terms “including”, “comprising”, “having” and variations thereof mean “including but not limited to”, unless expressly specified otherwise.
The enumerated listing of items does not imply that any or all of the items are mutually exclusive, unless expressly specified otherwise.
The terms “a”, “an” and “the” mean “one or more”, unless expressly specified otherwise.
Devices that are in communication with each other need not be in continuous communication with each other, unless expressly specified otherwise. In addition, devices that are in communication with each other may communicate directly or indirectly through one or more intermediaries.
A description of an embodiment with several components in communication with each other does not imply that all such components are required. On the contrary a variety of optional components are described to illustrate the wide variety of possible embodiments of the present invention.
Further, although process steps, method steps, algorithms or the like may be described in a sequential order, such processes, methods and algorithms may be configured to work in alternate orders. In other words, any sequence or order of steps that may be described does not necessarily indicate a requirement that the steps be performed in that order. The steps of processes described herein may be performed in any order practical. Further, some steps may be performed simultaneously.
When a single device or article is described herein, it will be readily apparent that more than one device/article (whether or not they cooperate) may be used in place of a single device/article. Similarly, where more than one device or article is described herein (whether or not they cooperate), it will be readily apparent that a single device/article may be used in place of the more than one device or article or a different number of devices/articles may be used instead of the shown number of devices or programs. The functionality and/or the features of a device may be alternatively embodied by one or more other devices which are not explicitly described as having such functionality/features. Thus, other embodiments of the present invention need not include the device itself.
The illustrated operations of
The foregoing description of various embodiments of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. It is intended that the scope of the invention be limited not by this detailed description, but rather by the claims appended hereto. The above specification, examples and data provide a complete description of the manufacture and use of the composition of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.
This application is a continuation of U.S. patent application Ser. No. 11/614,935, filed Dec. 21, 2006, which application is incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 11614935 | Dec 2006 | US |
| Child | 14749600 | US |
