Basic macro processor functions macro invocation oft f d toften referred to as a macro call need the name of the macro instruction begin invoked and the arguments to be used in expanding the macro expanded program figure 4. Thus, the macro language serves as a dynamic editor for sas programs. Macro variables defined by the macro processor sas. The macro processor replaces each macro instruction with the. Macro languages often include programming controls if then, goto, while, etc. It does not concern the meaning of the involved statements during macro expansion. Using macros in an assembly program involves two steps. A macro file macro set that contains macro tools is called a tool set. A macro processor is a program that copies a stream of text from one place to another, making a systematic set of replacements as it does so. An integrated macro processor can support macro instructions that. Macros and macro processors macro computer science. Macros support commands that allow a variety of advanced functions, such as making decisions for example, if.
The object is to customize a postprocessor in order to accommodate a special tape header. The macro processor replaces each macro instruction with the corresponding group of source language statements expanding normally, it performs no analysis of the text it handles. The macro processor pulls tokens from the input stack and compiles until the %mend statement terminates the macro definition macro app in the input stack. Macros are similar to pascal procedures, except the procedure keyword is replaced by macro and the procedure heading is a text string that becomes a command in the special menu when the macro is loaded. The use of a macro name with a set of actual parameters is replaced by some code generated. Create a generic post processor for a 3axes mill with a fanuc 6m, using the control. Codewarrior development studio macroprocessor language.
Many programming language provide built in facilities for writing macros. Macro represents a group of commonly used statements in the source programming language. For the sake of illustration, the compiled app macro looks like the. The fhdl macro processor provides many of the features of a high level language, including variables, loops, conditionals, recursive functions, and data structures. Layzell, the history of macro processors in programming language extensibility, the computer journal, volume 28, issue 1, 1985, pages 2933. When sas is going to compile a sas program it first sends the program to a word scanner which intercepts the macro syntax before it can reach the compiler. Macro instructions are single line abbreviations for group of instructions. During macro compilation, the macro processor does the following. There are two special macro functions, %sysfunc and %qsysfunc, that provide access to sas language functions or. Codewarrior development studio macroprocessor language reference manual, rev. It provides a name to the sequence of statements called macro name that are repeated and ever needed it make use of the name in the main program. String this exercise allows a better familiarization with string variables available in the post processor macro language.
The object is to customize a post processor in order to accommodate a special tape header. All macro invocation statements are expanded during the second pass. Ritchie bell laboratories murray hill, new jersey 07974 introduction a macro processor is a useful way to enhance a programming language, to make it more palatable or more readable, or to tailor it to a particular application. The macro definition consists of the following parts. Higher version of processor family also provide such facility. An example of a simple macro is one that types your address. It is an extension of an earlier macro processor m3, written by ritchie for an unknown ap3 minicomputer the macro preprocessor operates as a textreplacement tool. The language was designed by brian kernighan and dennis ritchie for the original versions of unix. The m4 macro processor is an extension of a macro processor called m3 which was written by d. M3 was in turn based on a macro processor implemented for 1. Scribd is the worlds largest social reading and publishing site.
A special category of macro functions, the macro quoting functions, mask special characters so they are not misinterpreted by the macro processor. The macroprocessor transforms a mod le with macrocommands into a mod le without macrocommands doing text expansionsinclusions and then feeds it to the dynare parser the key point to understand is that the macroprocessor only does text substitution like. Macro processor is a program that lets you define the code that is reused many times giving it a specific macro name and reuse the code by just writing the macro name only. Create a generic postprocessor for a 3axes mill with a fanuc 6m, using the control. Macro languages often include programming controls if then, goto.
When you invoke sas, the macro processor creates automatic macro variables that supply. When you invoke sas, the macro processor creates automatic macro variables that supply information related to the sas session. Macro language article about macro language by the free. Imagej macro language programmers reference guide v1. Hence, the macro facility is a preprocessor, which interprets all macro calls into assembly code prior to passing the expanded code.
It provides a convenient way to generate a sequence of assembler language statements many times in one or more programs. Generalpurpose macropurpose macro processors macro processors have been developed for some highlevel programming languages these specialthese specialpurpose macro processors arepurpose macro processors are similar in general function and approach. During the preprocessing stage, the c preprocessor a part of the c compiler simply substitutes the body of the macro wherever its name appears. To study the design and implementation of macro processors.
The design of a macro processor generally is machine independent. A macro is a unit of specification for program generation through expansion. A generalpurpose macro processor or general purpose preprocessor is a macro processor that is not tied to or integrated with a particular language or piece of software a macro processor is a program that copies a stream of text from one place to another, making a systematic set of replacements as it does so. The macro processor executes the compiled %do instructin and recognizes that the next item is text. Macro processor article about macro processor by the free.
Macro are used to provide a program generation facility through macro expansion. Macro quoting functions mask special characters and mnemonic operators so the macro processor interprets them as text instead of elements of the macro language. The macro processor places the text on top of the input stack and waits for the word scanner to begin tokenization. The term macro refers to a word that stands for an entire group of instructions. When it is called, the assembler processes and normally generates assembler language statements from the definition into the source module. The generated statements are then processed as any other assembler language statement. Introduction images builtin macro programming language can be used to automate complex or repetitive tasks. The macro language a macro is a saved sequence of commands or keystrokes that are stored for later use. It is an extension of an earlier macro processor m3, written by ritchie for an unknown ap3 minicomputer. Assembly language macros most assemblers include support for macros.
A macro instruction macro i s a notational convenience for the programmer o it allows the programmer to write shorthand version of a program m odule programming. Ch4 macro processors macro computer science central. Save a tool set in the imagejmacrostoolsets folder and it will appear in menu at the right end of the toolbar. When sas compiles program text, two delimiters trigger macro processor activity. A macro instruction written in the format of the target assembly language would be processed by a macro compiler, which was a preprocessor to the assembler, to generate one or more assembly language instructions to be processed next by the assembler program that would translate the assembly language instructions into machine language instructions. Macro quoting functions lists the macro quoting functions, and also describes the special characters they mask and when they operate. Hence, the macro facility is a preprocessor, which interprets all macro calls into assembly code prior to passing the expanded. In arm code in any processor and in thumb code in processors before armv6t2, a testandbranch operation.
While many macro statements have similarities to the statements in the data step, you must. Macro variables defined by the macro processor sas 9. The macro language consists of its own set of commands, options, syntax, and compiler. Jan 01, 2018 macro, example program for macro in assembly language in urdu hindi macro in assembly in hindi, example of macro in assembly language in hindi, assembly language macro, difference between macro. A macro represents a commonly used group of statements in the source programming language. However, the macro processor does not store the macro for execution. Macro definitions are typically located at the start of a program. Generally it doesnt come as a separate program but as a bundle to either assembler or compiler.
A macro prototype statement one or more model statements macro preprocessor statements the macro prototype statement declares the name of a macro and the names and kinds of its parameters. Nonconfidential pdf versionarm dui0379h arm compiler v5. A macro prototype statement one or more model statements macro preprocessor statements the macro prototype statement declares the name of a. However, macro processors can also be used with highlevel programming languages, operating system command languages, etc. History of macro processors in programming language.
The macro processor replaces each macro instruction with the corresponding group of source language statements. The macro processor translates the macro syntax into standard sas syntax which is then compiled. Source file means a file containing source texts for the device in question. A macro instruction written in the format of the target assembly language would be processed by a macro compiler, which was a pre processor to the assembler, to generate one or more assembly language instructions to be processed next by the assembler program that would translate the assembly language instructions into machine language instructions. During macro execution, the macro processor does the following.
Node 3 of 5 node 3 of 5 how the macro processor executes a compiled macro tree level 3. Department of computing science and mathematics university of. The macro processor effectively constitutes a separate language processor with its own language. Feb 21, 2018 integrated macro processor an integrated macro processor can potentially make use of any information about the source program that is extracted by the language translator. The macro language provides the means to communicate with the macro processor. Macro processor replace each macro instruction with the corresponding group of source language statements. Macro processors are often embedded in other programs, such as assemblers and compilers. Macro language dictionary definition macro language defined.
Macro execution begins with the macro processor opening the sasmacr catalog to read the appropriate macro entry. Dec 05, 2019 macro execution begins with the macro processor opening the sasmacr catalog to read the appropriate macro entry. In code generation, this file is processed using an internal macroprocessor see processor expert macrolanguage description, which will process, in a defined manner, conditional. Using macro instructions programmer can leave the mechanical details to be handled by the macro processor. Dec 05, 2019 how the macro processor compiles a macro definition tree level 3. Select the tool set from the menu and the tools contained. Automatic variables are global except syspbuff, which is local. Macro processor a macro represents a commonly used group of statements in the source programming language.
Apart from simple macro features such as named constants and conditional expansion, m4 can be used to provide syntactic sugar for a language and to support translation between languages. How the macro processor compiles a macro definition tree level 3. Jun 06, 2011 macro processor is a program that lets you define the code that is reused many times giving it a specific macro name and reuse the code by just writing the macro name only. A macro definition is a named sequence of statements you can call with a macro instruction. Twopass macro processor would not allow the body of one macro instruction to contain definitions of other macros. A macro instruction macro is a notational convenience for the programmer it allows the programmer to write shorthand version of a program module programming the macro processor replaces each macro instruction with the corresponding group of source language statements expanding normally, it performs no analysis of the text it handles. An integrated macro processor can support macro instructions that depend upon the context in which they occur. In this example, the macro definition is compiled and stored sucessfully figure 4. String this exercise allows a better familiarization with string variables available in the postprocessor macro language. Sometimes they are standalone programs that can be used to process any kind of text. Using a macro, programmer can define a single instruction to represent block of code. A macro processor like m4 is a useful software engineering tool. Readers unfamiliar with the basic ideas of macro processing may wish to read some of the discussion there.
Jan 01, 1970 a macro file can contain up to eight macro tools, along with any number of ordinary macros. Chapter 4 macro processors z a macro represents a commonly used group of statements in the source programming language. A macro facility is used to interpret macro definitions and expand each macro call as it occurs with the requisite pattern of assembly language statements, providing expanded source code ready for the assembler. Macros and macro processors free download as powerpoint presentation. As the macro processor executes the compiled instructions in the macro entry, it performs a series of simple repetitive actions. A generalpurpose macro processor or general purpose preprocessor is a macro processor that is not tied to or integrated with a particular language or piece of software a macro processor is a program that copies a stream of text from one place to another, making a systematic set. A macro consists of a name, a set of formal parameters and a body of code. The assembler generates a sequence of assembler language statements for each occurrence of the same macro instruction. A language independent macroprocessor article pdf available in communications of the acm 107. Macro language is an extension of assembler language. A macro that the macro processor compiles but does not store is called a dummy macro.
1049 1118 1267 1183 54 1380 1161 257 985 37 876 964 370 324 926 1390 779 637 790 1399 909 1326 868 1111 496 917 1231 1010 732 750 803 737 526 1464 220 192 1450 1122 259 1340