Type Equivalence, 214 | HP SunSoft Pascal 4.0 specs

9

Type Equivalence

The Pascal compiler produces several diagnostics that generate the following message:

non-equivalent types

In general, Pascal considers types to be the same only if they derive from the same type identiﬁer. Therefore, the following two variables have different types, even though the types look the same and have the same characteristics.

x : record

a:integer;

b:char;

end;

y : record

a:integer;

b:char;

end;

The assignment:

x := y

produces the following diagnostic messages:

Mon Feb 13 14:22:46 1995 inchar.p:

E 25170 line 12 - Type clash: non-identical record types

... 25560: Type of expression clashed with type of variable in assignment

214	Pascal 4.0 User’s Guide

Image 238

HP SunSoft Pascal 4.0 manual Type Equivalence, 214

Contents

Pascal 4.0 User’s Guide Trademarks Contents Pascal Compiler Contents Pic, -Kpicand -PIC, -KPIC Contents Vii Program Construction and Management Viii Separate Compilation C++-Pascal Interface Error Diagnostics XView Toolkit Xii Contents Xiii Math Libraries Xiv Figures Pascal 4.0 User’s Guide Tables Fortran Xviii Preface InstallationOperating Environment Audience Organization Conventions Used in This Guide AaBbCc123 Related Documentation Shell Prompts in Command ExamplesManual Documents in Hard Copy and in AnswerBook Readme FilesOther Related Documentation Hostname% imagetool floating-point.ps CD-ROM Introduction Standards Pascal Compiler FeaturesCompatibility XView Toolkit Text EditorsDebuggers Native Language Support Internationalization Licensing Locale Pascal 4.0 User’s Guide Pascal Programs Simple Pascal Program Compiling the Program Hostname% mv a.out temp Running the ProgramRenaming the Executable File Hostname% pc -o temp temp.p An Interactive Pascal Program Hello, are you listening? Redirecting I/OHostname% pc -o copy copy.p Goodbye, I must go now Using a File Name as a File Variable Using Pascal Traceback Where Did My Program Fail?Hostname% pc -o copy2 copy2.p Using a Sample Program with Segmentation Violation Compiling and Running the Program Using the -gOption Hostname% more a.out.trace Try compiling SegViol.p with -g Pascal Compiler Pc Version Number Compile and Link Sequence Hostname% mcs -p a.out grep Pascal Compiler Preprocessor cpp or cppas Language PreprocessorSource Optimizer File Name Extensions Accepted By pc Sufﬁx Description Hostname% pc -l rmc.p Option-Passing on the Command-LineOption-Passing in the Program Text Hostname% pc -o rmc rmc.p Option Description Options Hostname% pc options.p Bbinding Bsdmalloc Cg92 CalignCg89 Cond Config Dname=def Dryrun DalignFast Fns FnonstdFround=r Ftrap=t Hname Iname Help or -flagsIpathname Keeptmp Ldirectory Hostname% pc -l random.p Llib LibmieeeLibmil Misalign Nolib NativeNocx Nolibmil Notrace Olevel Hostname% limit datasize 16M Hostname% /usr/sbin/prtconf grep Memory OﬁlenameHostname% /usr/sbin/swap -s Hostname% pc -o myprog myprog.p -pg Using the -pOptionUsing the -pgOption Pic,-Kpic and -PIC,-KPIC Qpathpathname QoptionQproduce Rpathdir Pascal 4.0 User’s Guide Examples Hostname% pc -Rw rr.p Hostname% pc -Rw recvar.p Pascal main program, with.p with statement Commands to compile and execute with.pHostname% pc -Rw with.p Sbfast SlevelHostname% pc -S rmc.p Temp=dir Hostname% pc -temp=. hello.p Time Hostname% pc -time hello.p Uname Xarch=a Pascal 4.0 User’s Guide Value Meaning Limit the instruction set to V8 architecture Xcache=c S1/l1/a1 S1/l1/a1s2/l2/a2 S1/l1/a1s2/l2/a2s3/l3/a3 Xchip=c Example -xcache=16/32/41024/32/1speciﬁes the following Xcg89 Xcg92 Xlibmieee XildoffXildon Xlibmil XMerge XlibmoptXlicinfo Xnolib Xpg Xprofile=p -xprofileValues Xregs=r Example -xregs=appl,no%float Xsb Xsafe=memXsbfast Xspace Xtarget=t XtargetExpansions Pascal 4.0 User’s Guide Pascal Compiler Ztext Program Construction Management Units Using Program Units and Module Units Hostname% pc programunit.p moduleunit.p Compiling with UnitsProgram Construction and Management Using Units and Header Files Sharing Variables Between Units Here is a program unit that declares a variable Program Construction and Management Libraries Separate Compilation Working with Units Using Module Units Using Program UnitsSharing Variables and Routines Across Multiple Units Program unit Compiling without the -xlOptionSharing Public Variables Separate Compilation Using extern Option to Share Routines Using include Files to Share Variables and Routines Module unit, incmod.p, which also includes the ﬁle Commands to compile and execute incprog.p and incmod.pProgram unit, incprog.p, which includes the ﬁle Hostname% pc incprog.p incmod.p Using the -xlOption Using public var Declarations Commands to compile and execute pubvarprog.p and pubvarmod.p Using the define Variable Attribute Using the define Declaration Commands to compile and execute defvarprog.p and defvarmod.p Using include Files Module unit Program unit, incprog2.p Module unit, incmod2.p Commands to compile and execute incprog2.p and incmod2.p Using externProgram unit, extprog.p Sharing Declarations in Multiple Units Commands to compile and execute extprog.p and extmod.pModule unit, extmod.p Pascal 4.0 User’s Guide C-Pascal Interface Compilation of Mixed-Language Programs Compatibility of Types for C and Pascal Hostname% cc -c myc.c Hostname% pc -calign myc.o mypascal.p Character Strings Precautions with Compatible TypesC-Pascal Interface Aggregate Types IncompatibilitiesArray Indexes Enumerated Types General Parameter Passing in C and Pascal Procedure Calls C-PascalPascal Set Types Commands to compile and execute Samp.p Variable Parameters Pascal procedure, SimVar.p Simple Types without -xl Simple Types with -xl Commands to compile and execute SimVar.p and SimVarMain.cPascal procedure Strings of Characters Fixed Arrays Commands to compile and execute StrVar.p and StrVarMain.cC main program Pascal procedure, FixVec.p Commands to compile and execute FixVec.p and FixVecMain.c Day = Univ Arrays 100 Conformant Arrays C-Pascal Interface 101 Example 1 Single-Dimension Array 102 Example 2 Multi-Dimension Array C-Pascal Interface 103 Example 3 Array of Characters 104 Records and Structures C-Pascal Interface 105 Commands to compile and execute StruChr.p and StruChrMain.c 106 Pascal routine C-Pascal Interface 107 Variant Records 108 Commands to compile and execute VarRec.p and VarRecMain.c C-Pascal Interface 109 Pascal Set Type 110 Pascal intset Type C-Pascal Interface 111 Value Parameters 112 Commands to compile and execute SimVal.p and SimValMain.c C-Pascal Interface 113 Arrays 114 Pascal function Function Return ValuesSimple Types C-Pascal Interface 115 Input and Output Commands to compile and execute RetReal.p and RetRealMain.cPascal procedure, IO.p C main program, IOMain.c 116 C function, SimRef.c Procedure Calls Pascal-CHostname% cc IO.o IOMain.c -lpc C-Pascal Interface 117 118 Pascal main program, StrVarMain.p C function, StrVar.cC-Pascal Interface 119 Incorrect use of string in static variable storage Commands to compile and execute StrVar.c120 Pascal main program Commands to compile and execute FixVec.cC function, FixVec.c C-Pascal Interface 121 C function, UniVec.c 122 C function, IntCA.c C-Pascal Interface 123 C function, StruChr.c Commands to compile and execute IntCA.c and IntCAMain.p124 Calign StruChr.o StruChrMain.p Commands to compile and execute StruChr.c and StruChrMain.pStruChr.c Out C function, VarRec.c 126 Commands to compile and execute VarRec.c Non-Pascal ProceduresC-Pascal Interface 127 128 C function, SimVal.c C-Pascal Interface 129 Commands to compile and execute SimVal.c 130 C function, RetReal.c Parameters That Are Pointers to ProceduresCommands to compile and execute RetReal.c and RetRealMain.p C function, ProcPar.c Procedures and Functions as Parameters 132 Global Variables in C and Pascal Pascal procedure, GloVar.pC-Pascal Interface 133 File-Passing Between Pascal and C C procedure, UseFilePtr.c134 C-Pascal Interface 135 136 C++-Pascal Interface Sample Interface Compatibility of Types for C++ and Pascal Procedure Calls C++-PascalPascal procedure, Samp, in the ﬁle, Samp.p ++ Name Encoding Hostname% pc -c Samp.p Arguments Passed by ReferenceC++ main program, SampMain.cc C++-Pascal Interface 139 Simple Types without the -xlOption Pascal procedure, SampRef, in the ﬁle, Samp.p140 C++ main program Commands to compile and execute SamRef.p and SamRefMain.ccSimple Types with the -xlOption Hostname% pc -c SamRef.p 142 Hostname% pc -c StrRef.p Commands to compile and execute StrRef.p and StrRefMain.ccC++-Pascal Interface 143 Hostname% pc -c FixVec.p 144 C++-Pascal Interface 145 Hostname% pc -c DaysOfWeek.p -calignoption146 Hostname% pc -c StruChr.p Commands to compile and execute StruChr.pC++-Pascal Interface 147 148 C++-Pascal Interface 149 Hostname% pc -calign -c DayWeather.p Arguments Passed by ValueHostname% pc -c DayWeather.p 150 C++-Pascal Interface 151 Commands to compile and execute SimVal.p 152 Hostname% pc -c RetReal.p Commands to compile and execute RetReal.pC++-Pascal Interface 153 Pascal function, IO.p Input and OutputHostname% pc -c RetShortReal.p 154 Hostname% CC IO.o IOMain.cc -lpc hostname% a.out Procedure Calls Pascal-C++C++ main program, IOMain.cc C++-Pascal Interface 155 C++ function, SimRef.cc Simple Types Passed by Reference156 C++-Pascal Interface 157 C++ function, SimVal.cc 158 Commands to compile and execute SimVal.cc C++-Pascal Interface 159 C++ function, RetReal.cc 160 Global Variables in C++ and Pascal Pascal procedure, GloVar.p C++ main program, GloVarMain.ccCommands to compile and execute GloVar.p and GloVarMain.cc C++-Pascal Interface 161 Pascal File Pointers to C++ C++ procedure162 FORTRAN-Pascal Interface Compiler Mixed-Language Programs Compatibility of Types for Fortran and Pascal 164 Real Integer Integer*2 FORTRAN-Pascal Interface 165 166 General Parameter-Passing in Fortran and Pascal Multidimensional ArraysFORTRAN-Pascal Interface 167 Procedure Calls FORTRAN-Pascal 168 Fortran main program Commands to compile and execute SimVar.pFORTRAN-Pascal Interface 169 Fortran main program, StrVarmain.f Pascal procedure, StrVar.p170 Fortran main program, FixVecmain.f Commands to compile and execute StrVar.p and StrVarmain.fFORTRAN-Pascal Interface 171 Commands to compile and execute FixVec.p 172 Commands to compile and execute UniVec.p and UniVecmain.f FORTRAN-Pascal Interface 173 Commands to compile and execute IntCA.p 174 Fortran main program, ChrCAmain.f Commands to compile and execute ChrCA.pFORTRAN-Pascal Interface 175 176 FORTRAN-Pascal Interface 177 178 FORTRAN-Pascal Interface 179 180 FORTRAN-Pascal Interface 181 Commands to compile and execute SimVal.p and SimValmain.f 182 Pointers Pascal procedure, ChrCAx.pCommands to compile and execute ChrCAx.p FORTRAN-Pascal Interface 183 Commands to compile and execute PastPtr.p 184 Fortran main program, RetRealmain.f Procedure Calls Pascal-FORTRANFORTRAN-Pascal Interface 185 Fortran subroutine 186 FORTRAN-Pascal Interface 187 Fortran subroutine, StrVar.f 188 Hostname% f77 -c StrVar.f Commands to compile and execute StrVar.f and StrVarmain.pCharacter Dummy Arguments Hostname% pc StrVar.o StrVarmain.p -lpfc -lF77 Following example illustrates this method 190 Commands to compile and execute FixVec.f FORTRAN-Pascal Interface 191 Pascal main program, UniVecmain.p Fortran subroutine, UniVec.f192 Hostname% f77 -c UniVec.f Commands to compile and execute UniVec.f and UniVecmain.pFORTRAN-Pascal Interface 193 Fortran subroutine, StruChr.f 194 Hostname% pc StruChr.o StruChrmain.p -lpfc -lF77 Commands to compile and execute StruChr.f and StruChrmain.pHostname% f77 -c StruChr.f FORTRAN-Pascal Interface 195 196 FORTRAN-Pascal Interface 197 198 FORTRAN-Pascal Interface 199 200 Hostname% pc PassPtr.o PassPtrmain.p -lpfc -lF77 Commands to compile and execute PassPtr.f and PassPtrmain.pHostname% f77 -c PassPtr.f Fortran function, RetReal.f Routines as Parameters Commands to compile and execute RetReal.f and RetRealmain.p202 FORTRAN-Pascal Interface 203 204 Compiler Syntax Errors Error DiagnosticsIllegal Characters Digits in Real Numbers String Errors206 Error Diagnostics 207 Replacements, Insertions, and DeletionsHostname% pc synerr.p Undeﬁned or Improper Identiﬁers Expected Symbols and Malformed Constructs208 Hostname% pc synerr2.p Error Diagnostics 209Expected and Unexpected End-of-ﬁle Pascal program, mism.p Incompatible Types Compiler Semantic ErrorsFormat of the Error Diagnostics 210 Error Diagnostics 211 Procedure and Function Type ErrorsScalar Class Expression Diagnostics Scalar Error Messages212 This program generates the following error messages Error Diagnostics 213 Type Equivalence 214 Unreachable Statements Error Diagnostics 215Pascal program, unreached.p Unused Variables, Constants, Types, Labels, and Routines Goto StatementUninitialized Variables Hostname% pc unreached.p Runtime Errors Compiler Panics, I/O ErrorsError Diagnostics 217 218 Error Diagnostics 219 220 XView Toolkit Overview Object-Oriented Programming ToolsObjects 222 Drawable Object Window Icon Pascal InterfaceXView Toolkit 223 Header Files Attribute ProceduresCompiling with Libraries Names Attribute Lists XView Toolkit 225 Here, mymenu is an object of type XVobject HandlesData Types 226 An Example Conversion of C to PascalCoding Fragment XView Toolkit 227 Pascal 228 Sample Translation of an XView Function to Pascal XView Toolkit 229 Sample Program 230 Menu Demo Program XView Toolkit 231 Panelbutton 232 Math Libraries Contents of the Math Libraries Libm Functions Math Libraries 235 Ieee Support Functions 236 Ieeevalues IeeefunctionsMath Libraries 237 Ieeeretrospective Sparc Libraries238 Arithmetic Exceptions Math Libraries 239 Math Library Exception-Handling Function matherr 240 Math Libraries 241 Libsunmath Support for Ieee Modes and Exceptions 242 Math Libraries 243 244 Pascal Preprocessor Conditional Variables Compiler Directives 246 %config Directive Pascal Preprocessor 247 Hostname% pc -xl config.p hostname% a.out 248 %debug Directive Output when you deﬁne twoOutput when you deﬁne foo Pascal Preprocessor 249 Hostname% pc -xl -cond debug.p hostname% a.out %else Directive250 Pascal program, ifthenelse.p Hostname% pc -xl -config red ifthenelse.p hostname% a.out%elseif Directive Pascal Preprocessor 251 Pascal program Hostname% pc -xl -config blue elseif.p hostname% a.out%elseifdef Directive 252 Pascal Preprocessor 253 Hostname% pc -xl -config bird2 ifdef.p hostname% a.out %enable Directive254 %endif Directive %error DirectiveHostname% pc -xl enable.p hostname% a.out Pascal Preprocessor 255 %exit Directive Error.p256 Hostname% pc -xl exitdirective.p hostname% a.out %if DirectivePascal Preprocessor 257 %ifdef Directive 258 %include Directive Pascal Preprocessor 259 Module unit, includemod.p %list Directive260 Pascal program, list.p Pascal Preprocessor 261 List.p %nolist Directive262 %warning Directive %slibrary Directive%var Directive Pascal Preprocessor 263 Pc -xl warning.p Output when you compile warning.p without the -configoption264 Error Messages 266 Error Messages 267 Fourth argument to function must be of type type, not type 268 Error Messages 269 Function requires a to be an unpacked array, not type 270 Error Messages 271 272 Error Messages 273 274 Error Messages 275 Identiﬁer Unknown option for procedure pointer ignored option 276 Error Messages 277 278 Error Messages 279 280 Error Messages 281 Cannot mix sets with integers and reals as operands of type 282 Error Messages 283 284 Error Messages 285 286 Error Messages 287 288 Error Messages 289 Multiply defined label in case, lines number and number 290 Error Messages 291 292 Error Messages 293 OUT 294 Error Messages 295 296 Index 297 298 Index 299 300 Index 301 302 Index 303 304 Index 305 306 Index 307 Marques