It allows the programmer to write a shorthand version of a program. If form is a macro call, then macroexpand1 will expand the macro call once and return two values. When the macro is called in the program, the sequence of instructions corresponding to that macro name gets replaced in the expanded source. The c preprocessor, often known as cpp, is a macro processor that is used automatically by the c compiler to transform your program before compilation. A macro consists of a name, a set of formal parameters and a body of code. We present the methodology and give an illustration of how to write a macro easily. Cnc manual cnc programming fanuc macro programming manual.
Bca 602 system programming 100 marks 2014 and onwards 90 marks prior to 2014 time. Macros are commonly used in c to define small snippets of code. All of your canned cycles in a control are nothing but a macro. Explain with a flowchart pass 2 of a macroprocessor. Mli macro processor to implement a systems programming language called sal.
Using sas system options to debug macro programming 278 using macro language statements to debug macro programming 279 using macro functions to debug macro. Each macro expansion happens in a distinct syntax context, and each variable is tagged with the syntax context where it was introduced. The module m imports variables and syntax from l using require. There are basically two preprocessor macro expansion directives. How to differentiate between the original statements of a program. 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. Stage2 was a macro processor dating back to 1969, by w. Assembly language macros an assembly language macro is a template whose format represents a pattern of 0 or more assembly language statements that might be common to multiple programs. If the macro has parameters, they are substituted into the macro body during expansion. In nasm, macros are defined with %macro and %endmacro directives.
A macro is a unit of specification for program generation through expansion. Macro programming becomes no more complex than regular programming. Oct 23, 2008 macro programming is a useful tool for most any cnc machine shop, whether a one man garage or an international conglomerate. This lecture will focus on some of the advanced features of the macro language as implemented by the ibmsystem 360 assembler. For the love of physics walter lewin may 16, 2011 duration. How a macro program is compiled 114 how a macro program executes 120. Linux system programming kernel modules, device drivers, proc file system etc. Macro consist of name, a set of formal parameters and a body of code. Its as though the variable state inside main is painted a different color from the variable state inside the macro, and therefore they dont conflict. Introduction, macro definition and call, macro expansion, nested macro calls, advanced macro. Macro programming provides a means of shortening code and doing repetitive tasks easily and quickly. The macro begins with the %macro directive and ends with the %endmacro directive. This handson workshop presents numerous tips and tricks related to the construction of effective macros through the demonstration.
Macro expansion is always just a textual transform of the input source code. Both user and system header files are included using the preprocessing directive. The use of a macro name with a set of actual parameters is replaced by some code generated. Some of the features to be covered by this lecture include. A program that is to be run on sic system could invoke. Both the name of the macro definition and other variable parameter attributes are included. Multiple choice questions on systems programming topic system programming basics. Applications for custom macro programming probing and in process gauging communication with external devices automation printers metrology devices machine status check if machine is in proper position safe start macro check that offset data and work shifts are within range check other conditions. Net drivers are used the value indicates the number of modules. The use of concatenation to generate typespecific instructions. However, macro processors can also be used with highlevel programming languages, operating system command languages, etc. The use of macro name with a set of actual parameters is replaced by some code generated.
For this purpose, a macro language is used to provide a syntax for defining macros. Macro processors usually work in one pass and not directly related to the machine architecture. Macro expansion is a tricky operation, fraught with nasty corner cases and situations that render what you thought was a nifty way to optimize the preprocessors expansion algorithm wrong in quite subtle ways. It is an extension of an earlier macro processor m3, written by ritchie for an unknown ap3 minicomputer. When used, a macro expands from its compressed form into its actual instruction details. A macro is a sequence of instructions, assigned by a name and could be used anywhere in the program. Sep 22, 2014 for the love of physics walter lewin may 16, 2011 duration.
This gives the macro some of the power of a function. You should be able to see the code after the preprocessor the part of the compilation that does the macro expansion is done. A macro instruction is a group of programming instructions that have been compressed into a simpler form and appear as a single instruction. Using a macro, programmer can define a single instruction to represent block of code. Page 2 are also defined and statement in the body makes use of these arguments in place of data. A notable distinction between it and m4 is that stage2 supported multiline and nested constructs. Cps macros with lambdaabstractions lead to a general practical methodology of building macros systematically. Basic macro processor functions macro definition and expansion macro. To correct for this problem, two additional types of macro system variables are provided. In other words, type checking is computed as part of macro expansion. While statement pointed by mec is not a mend statement.
The macroexpand function is the conventional means for expanding a macro call. System software an introduction to systems programming, 3rd ed. It is called a macro processor because it allows you to definemacros, which are brief abbreviations for longer constructs. Cps macros with lambdaabstractions lead to a general practical methodology of building macros system atically.
Once macroexpand1 has determined that a symbol names a macro, it obtains the expansion function for that macro. We show that macros and other headfirst normalorder rewriting systems generally lack functional composition. 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. Macro function for accessing operatingsystem parameters macro functions for names of stored results. In the first macro call incr data1, data1 is the argument and the second macro call data2 is the argument that is passed. Sep 06, 2017 flow of control during macro expansion the flow of control during macro expansion is implemented using a macro expansion counter mec algorithm of macro expansion. Writing a macro is another way of ensuring modular programming in assembly language. Applications for custom macro programming probing and in process gauging communication with external devices automation printers metrology devices machine status check if machine is in proper position safe start macro check that offset data and work.
The macro begins with the % macro directive and ends with the %endmacro directive. A parameterized macro is a macro that is able to insert given objects into its expansion. Generally it doesnt come as a separate program but as a bundle to either assembler or compiler. Choose correct or the best alternative in the following. Flow of control during macro expansion the flow of control during macro expansion is implemented using a macro expansion counter mec algorithm of macro expansion.
Elements of assembly language programming, a simple assembly scheme, pass structure of assemblers, a single pass assembler for ibm pc. This works because rust has a hygienic macro system. In nasm, macros are defined with % macro and %endmacro directives. Macro instructions are single line abbreviations for group of instructions. Systems programming multiple choice questions and answers.
The language was designed by brian kernighan and dennis ritchie for the original versions of unix. The value of the variable macroexpandhook is then called as a function of three arguments. During macro expansion, the macro call statement is replaced by a sequence of assembly statements. Using macro instructions programmer can leave the mechanical details to be handled by the macro processor. 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 hook is provided for a user function to gain control during the expansion process. Each macro invocation statement has been expanded into the. Macro definition and call, macro expansion, nested macro calls, advanced macro facilities, design of macro processors. As a simple example, in the c programming language, this is a typical macro that is not a parameterized macro. Macro is also extremely useful for families of parts. Multiple choice questions on systems programming topic macro processor. Servoworks cnc macro programming manual soft servo. Where a sequence of assembly language statements can be. It does not concern the meaning of the involved statements during macro expansion.
A directory of objective type questions covering all the computer science subjects. Explain macro definition with arguments with an example. Macro programming fundamentals practical machinist. Figure 1 illustrates module and macro programming in mzscheme. Macro programming is a useful tool for most any cnc machine shop, whether a one man garage or an international conglomerate. Practice these mcq questions and answers for preparation of various competitive and entrance exams. A macro instruction abbreviated to macro is sil i l i f himply a notational convenience for the programmer. Net drivers are used the value indicates the number of modules 0 rc. A macro represents a commonly used group of statements in the source programming language expanding a macros repppglace each macro instruction with the corres ponding group of source language statements 2. Macro processor replace each macro instruction with the corresponding group of source language statements.
Vcs macro expansion debug ask your ae or, expand the macros to make a new file similar to gcc e vppreproc, part of verilogperl is a full 2009 preprocessor, fll dfully open sourced output can be fed back into any simulator al li t ll d fi talso can list all defines, etc. The present paper aims to make macro programming more like a. Allow the programmer to write a shorthand version of a program. Moreover, the macro system enforces a separation between different phases, i. Servoworks cnc macro programming manual warning important notice warning the product described herein has the potential through misuse, inattention, or lack of understanding to create conditions that could result in personal injury, damage to equipment, or damage to the products described herein.
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