JPH03212738A - Function access system - Google Patents

Abstract

PURPOSE:To speed up a function access by accessing the up-to-date definition of another compiled function from a certain compiled function without passing a function identification(ID) cell. CONSTITUTION:When a function B access instruction 211 in a function A definition compile code 2 is executed, control is immediately transferred to a function B definition compile code 4 in accordance with an address stored in a function B entry 221 without passing a function B ID cell 3. Similarly, control is immediately transferred to a function C definition compile code 6 in accordance with an address stored in a function C access instruction 212. When the definition of the function B, C or the like is changed and a new function definition compile code is loaded to a storage area, the contents of the function B entry 221 and the function C entry 222 in the literal table 22 of the code 2 are changed in accordance with the loaded new code to transfer control always to the up-to- date function definition.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for calling functions, and more particularly to a method for calling compiled functions in an interpreter-based system.

[Prior art] A language processing system that operates by interpreting and executing source programs is provided with a compiler that compiles the source programs, and can also execute objects obtained by compiling other than source programs. There is a language processing system that aims to improve execution speed by doing this. In such a language processing system, it is not possible to define a unit that forms a semantic block in programming (this is called a function), or to redefine an already defined function. This can be done dynamically, and at this time, before actually calling another function from the function, even if the definition of the function you are trying to call changes, the latest function definition can be called correctly. It is important to This has conventionally been realized with a configuration as shown in FIG.

As shown in FIG. 5, a function identification cell 100.300 having entries such as a function name entry 101.301 and a function definition entry 102.302 is assigned to each function A and B, and the function definition entry 102.300 is assigned to each function A and B. From 302,
Compiled function definition Compiled code (compiled function definition in source program format) 20
The point is 0.4OO. The function definition compiled code 200, 400 is a machine language instruction sequence 201° 401
It also has literal tables 202 and 402 for resolving addresses of other objects such as character strings, lists, and other function definitions referenced from the function definition. Generally, the storage address of objects such as strings, lists, and function definitions cannot be determined when the function is compiled, so when compiling, the corresponding entry in the literal table 202, 402 is referenced to locate the target object. Generate instructions to access the machine language instruction sequence 201, 401, and write the addresses of these objects to the corresponding entries in the literal table 202, 402 when loading the function definition compiled code 200, 400 into the storage area. That's what I do. That is, for example, a function B call instruction 2010 that calls function B from function A has an entry 20 for it.
20 to access function B, and when the function definition compiled code 200 of function A is loaded into the storage area, the instruction for function B that is applied to the function definition compiled code 400 of the called function B function identification cell 3
00 address is written into the corresponding entry 2020.

With the above configuration, for example, after loading the function definition compiled code 400 of function B into the storage area, the definition of function B can be changed, and the new function definition compiled code for it can be loaded into the storage area. In this case, by changing the contents of the function definition entry 302 of the function identification cell 300 for function B accordingly, the latest function definition can always be called from function A.

[Problem to be solved by the invention]

Although it is possible to always call the latest function definition using the conventional function calling method described above, the function is always called by referring to the function definition entry in the function identification cell, so the processing to access the function identification cell is not necessary. The problem was that the time required to call a function was slower than in other compiled languages.

The present invention has solved these conventional problems, and its purpose is to provide a function calling method that allows a function to call the latest definition of another function without going through a function identification cell. be.

[Means to solve the problem]

In order to achieve the above object, the function call method of the present invention sends a function call instruction in the function definition compiled code related to the function to the address stored in the corresponding entry in the literal table without going through the function identification cell. [Referenced function table] holds the function name of the calling function called from that function and the position information of the entry in the literal table assigned to the calling function. and a "referenced function table" that holds the function name of the calling function that calls the function, and when the function definition compiled code for the function is loaded into the storage area, the "referenced function table" for the loaded function is stored. [The function name of the loaded function is stored in the referenced function table J, and the function definition compiled code related to the calling function is stored in the referenced function table J. When the address in the storage area of the code is fixed, that address is stored in the entry corresponding to the calling function in the literal table, and also in the "referenced function table" related to the loaded function. The address in the storage area of the function definition compiled code related to the loaded function is stored in the corresponding entry in the literal table of the function definition compiled code related to the calling function of each set function name.

[Effect]

To make the function calling method of the present invention easier to understand, we will explain the case where function B is called from function A as an example. First, the instruction to call function B in the function definition compiled code for the function is This is an instruction to transfer control to the address stored in the corresponding entry in the literal table without going through the function identification cell for function B. Then, when the function definition compiled code for function A is loaded into the storage area, the function name of function B set in the "referenced function table" for function A is changed to "referenced" for function B. The loaded function table is specified, and the function name of the loaded function A is stored there. At this time, if the address in the storage area of the function definition compiled code related to the calling function B is determined, that address corresponds to function B in the literal table in the function definition compiled code of function A. stored in the entry that As a result, when an instruction to call function B in the function definition compiled code of function A is executed, the address stored in the corresponding entry in the literal table,
In other words, control is quickly transferred to the function definition compiled code of function B without passing through the function identification cell for function B.

On the other hand, if the address of the function definition compiled code of function B is not determined when loading the function definition compiled code of function A into the storage area, the address is stored in the entry for function B at that point. Not done. This address is stored when the function definition compiled code of function B is loaded onto the storage area. That is, function B
When the function definition compiled code for function B is loaded into the storage area, it is found that function B is called by function A based on the information in the "referenced function table" for function B, and the function related to function A is The definition compiled code literal table is searched and the entry for function B is
Stores the memory address of the function definition compiled code. This makes it possible to execute an instruction that calls function B in the function definition compiled code of function A.

In this way, in the present invention, when the function definition compiled code of the called function B is moved to the storage area, its address is set to the function definition compiled code of the called function A, so that the definition of the function B is When the new function definition compiled code for function B is changed and the new function definition compiled code for function B is loaded, the latest function definition compiled code for function B is stored at the address of the entry corresponding to function B in the function definition compiled code of the calling function A. The address of function B is held, and function A can always call the latest function definition of function B.

(Example) Next, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention, and shows an example of contents loaded and created on a storage area by a compiler when functions A, B, and C are called using the method of the present invention. As shown in the figure, on the storage area, function identification cells 1. A function definition compiled code 2 and a "referenced function table" 14 are created, and a function identification cell 3 is created for function B.
, function definition compiled code 4 and "referenced function table J34" are created, and function identification cell 5.function definition compiled code 4 and "referenced function table" 54 are created as those related to function C. has been done.

The function definition compiled code 2 for a function includes a machine language instruction string 21, a literal table 22, and a "referenced function table" 23, and includes a function B call instruction 211 and a function C call instruction in the machine language instruction string 21. There are instructions 212. Further, the literal table 22 has an entry 221 for function B and an entry 222 for function C. The end IJ 221 for function B stores the address of the function definition compiled code 4 of function B, and the entry 222 for function C stores the address of the function definition compiled code 4 of function B.
2 stores the address of the function definition compiled code for the number C. "Referenced function table" 2
Although not shown in FIG. 3, an entry for storing the function name B and the position information of the entry 221 for it, and an entry for storing the function name C and the position information for the entry 222 for it are provided. It is being Function B call instruction 211
is a code that jumps to the address stored in the entry 221 for function B, and is a code that jumps to the address stored in the entry 221 for function B.
12 is a code that jumps to the address stored in the entry 222 for function C.

The identification cell l for function A is function name entry 11.function definition entry 12. It is composed of "referenced function table entries" 13 and the like, and the address of the function definition compiled code 2 to the function is stored in the function definition entry 12. Also, "Referenced function table entry J
13 stores the address of the "referenced function table" 14. If there is a function that calls function A, the "referenced function table" 14 stores the name of the function.

Identification cell for function B3. Similarly to the identification cell 1 for function A, the identification cell 5 for function C also has function name entries 31, 51.
．． Function definition entries 32, 52° are composed of referenced function table entries 33, 53, etc., and function definition compiled code 4 of function B is written in function definition entry 32, 52. The address of the function definition compiled code for function C is stored. Also, the referenced function table entry 33.53 includes the "referenced function table" 34.53 for function B. The address of the "referenced function table" 54 for function C is stored. In this case, the function names of the function A that calls the function B are stored in the referenced function tables J34 and J54, respectively.

The internal structure of the function definition compiled code 4.6 for functions B and C is not shown, but the structure is similar to the function definition compiled code 2 for function A.

With the above configuration, when the function B call instruction 211 in the function definition compiled code 2 of function A is executed, the identification cell 3 for function B is called according to the address stored in the entry 221 for function B. Control is immediately passed to the function definition compiled code 4 of function B without going through the process. Similarly, when the function C call instruction 212 is executed, control is immediately passed to the function definition compilation controller of the function C according to the address stored in the function C entry 222. As described later, when the definitions of functions B, C, etc. are changed and new function definition compiled code is loaded into the storage area, the literal of function definition compiled code 2 of function A is changed accordingly. Entry 2 for function B in table 22
21. By changing the contents of the entry 222 for function C, control is always passed to the latest function definition.

Next, we will explain the first part about the processing that the compiler performs when loading the function definition compiled code 2.4.6 into the storage area.
The second part is simplified by omitting the part related to function C from the figure.
This will be explained with reference to the figure and FIG. 3 showing the flow of an example of compiler processing.

The compiler generates function definition compiled code 2 for function A.
When loading into the storage area, in process Sl of FIG. 3, the function name 231 of the function B called by the number A and the position information ( For example, the relative position from the beginning of the literal table 22 as shown in FIG. 2) 232
"Referenced function table" 23 that has a string 230 with
Create.

Next, in process S2, if the function identification cell 1 and the "referenced function table" 14 for function A have already been created, they will be used; if they have not been created, they will be created, and then the Function definition entry 12t in function identification cell 1 stores the address of function definition compiled code 2 for the function.

Next, perform the following processing for all function names stored in the "referenced function table" 23 (53~
S9).

First, extract one function name from the "referenced function table" 23, and if the function name is the end, go to steps 33 to S9.
After completing the processing, the process proceeds to processing SIO.

If it is not the end, determine whether a function with the retrieved function name already exists (S5), and if it does exist, process S5).
Proceed to step 7, and if it does not exist, create the function identification cell of the function name and the "referenced function teful j" and process s7
Proceed to. Next, in process s7, the function name of the rotated function A is stored in the "referenced function table" for that function name. Then, in step S8, it is determined whether an address is stored in the function definition end J in the function identification cell of the function name, and if it is not stored, the process returns to step S3, and if it is stored, the address is It is stored in the entry corresponding to the function name in the literal file 221 of the function definition compiled code 2 of the loaded function A (S9). Then, the process returns to process S3.

By performing the above processes from 53 to S9 on the function name of function B, the function name of function A is registered in the "referenced function title" 34 linked to the function identification cell 3 for function B. and if function B already exists, that is, if the function definition compiled code 4 of function B has been loaded into the storage area, then the address stored in the function definition entry 32 is the function of function A. Each time it is stored in the entry 221 for function B in the literal table 22 of the definition compilation code 12.

Next, in processes SlO to S12, the following processing is performed for all function names stored in the ``referenced function table j14L''. If the function name is registered,
Search the "referenced function table" of the function definition compiled code for that function name using the called function name (function name of the function loaded this time), and point to the location information corresponding to the same function name found. The address of the function definition compiled code 2 of the loaded function A is stored in the entry in the literal table 22.

The above processing is also performed when the function definition compiled code 4 of function B is moved to the memory area. As a result,
If function B does not exist yet when function A's function definition compile code 2 is loaded, process 5IO executed when function B's function definition compiler build code 40 is loaded.
In the process of -312, the function name of the function A in the "referenced function table" 34 is processed, and the literal character 22 of the function definition compiled code 2 for that function is searched for by the function name B, and the same function Literal full 2 indicated by the place 1 corresponding to the given name (231) 91 (232)
The address of the [IB function definition compiled code 4] is stored in the entry 221 of [IB].

Furthermore, when the definition of function iB is changed, the process shown in FIG. 3 is also executed when the function definition compilation code +"4 of function B after the change is moved to the storage area. Therefore,
The contents of the end IJ 221 for function B in the function definition compiled code 2 for the calling function can be matched with the address of the latest function definition compiled code 4 of function B.

Note that if the function definition is not compiled and is in a list format as a source program such as in the LISP language, the list format of the definition must be passed to the interpreter of the interpreter for execution. Therefore, in this case, the compiler controls so that the calling method via the function identification cell is performed as in the conventional case. That is, the fourth
As shown in the figure, when the number A calls a function in the source program format, the function identification self for the function that holds the address of the function definition 8 in the source program format related to the function in the function definition entry 72 is The function entry 223 holds the function call instruction 213.
is a code that transfers control to the escalator 9 of the system.

〔Effect of the invention〕

As explained above, according to the function calling method of the present invention, it is possible to call the latest definition of another compiled function from a compiled function without going through the function identification cell, and the function calling method is fast. can be realized.

[Brief explanation of drawings]

Figure 1 is a configuration diagram of an embodiment of the present invention, Figure 2 is a simplified diagram of Figure 1, Figure 3 is a flowchart of an example of compiler processing, and Figure 4 calls a function definition in source program format. FIG. 5 is an explanatory diagram of a conventional system. In the figure, 1.3, 5.7...Function identification cell 2.4.6...Function definition compiled code 8...
Function definition in source program format 9...System evaluator 11.31.51...Function name entry 12.32,5
2.72...Function definition entry 13.33.53...
-Referenced function table entry 14.34.54...Referenced function table 2
1... Machine language instruction sequence 22... Literal table 23... Referenced function table 211... Function B call instruction 212... Function C call instruction 221... Entry for function B 222... ...Entry for function C

Claims (1)

[Scope of Claims] A function call instruction in a function definition compiled code related to a function is changed to an instruction for transferring control to an address stored in a corresponding entry in a literal table without going through a function identification cell, A "referenced function table" that holds the function name of the called function called from that function and the position information of the entry in the literal table assigned to the called function, and the calling function that calls that function. A "referenced function table" that holds function names is set up, and when the function definition compiled code for a function is loaded into the storage area, it is set in the "referenced function table" for the loaded function. The function name of the loaded function is stored in the "referenced function table" of the called function of each function name, and the memory address of the function definition compiled code for the called function is determined. If it is, store its address in the entry corresponding to the called function in the literal table, and also check the caller of each function name set in the "referenced function table" related to the loaded function. A function calling method characterized in that an address in a storage area of a function definition compiled code related to the loaded function is stored in a corresponding entry in a literal table of a function definition compiled code related to the function.