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If you plan to run your programs only on HP computers, the
effort to port your programs between HP computers is minimal and
the extra features that HP Pascal/HP-UX provides will make your
programming much easier. However, if you plan to port your programs
to another vendor's computer, the effort to do so will be proportional
to your use of nonstandard HP Pascal/HP-UX extensions. Even if the
system you are porting to has extensions, it is doubtful that the
extensions on that system have the same form as extensions on HP
Pascal/HP-UX. To determine which features are nonstandard in an HP Pascal/HP-UX
source file, include the $ANSI ON$
compiler option at the start of your source file or use the -A
command-line option. When you compile the source file using the -L
command-line option, the compiler generates a listing file that
shows where nonstandard features are used. Combined, the ANSI compiler
option and the -L
command-line option assure you that you are using only ANSI Standard
Pascal features or that you are aware of where you are using nonstandard
features. Porting Between Series 300/400 and
Series 700/800 | |
This section summarizes some of the HP Pascal/HP-UX language
features, both standard and nonstandard, that may cause problems
when porting Pascal programs between Series 300/400 and Series 700/800
as well as to or from other systems. Data Type Sizes and Alignments Table 1-6 “HP Pascal/HP-UX Data Types ” shows the sizes
and alignments of the Pascal data types on HP-UX architectures.
Packing significantly affects data type alignments and sizes. For
more specific information, refer to HP Pascal/HP-UX Reference
Manual; and HP Pascal/HP-UX Programmer's
Guide. On the Series 300/400, if the +A
command-line option is specified, any data types larger than two
bytes are aligned on a 2-byte boundary. Table 1-6 HP Pascal/HP-UX Data Types Type | Size (bytes) | Alignment (300/400) | Alignment (700/800) |
|---|
bit16 | 2 | Not supported | 2 | bit32 | 4 | Not supported | 4 | bit52 | 8 | Not supported | 4 | boolean | 1 | 1-byte | 1-byte | char | 1 | 1-byte | 1-byte | enumeration | 2 [1] | 2-byte | 1-, 2-, or 4-byte, based on declared
range | subrange of enumeration | 2Title not available [1] | same as host enumeration type | 2-byte or 4-byte, based on declared range | $extnaddr$
pointer | 8 | Not supported | 4 | integer | 4 | 4-byte | 4-byte | subrange of integer
≥ -32768 AND ≤ 32767 | 2Title not available [1] | 2-byte | 2-byte | subrange of integer
< -32768 OR > 32767 | 4 | 4-byte | 4-byte | longint | 8 | Not supported | 4-byte | longreal | 8 | 4-byte | 8-byte | pointer | 4 | 4-byte | 4-byte | real | 4 | 4-byte | 4-byte | set | Varies | Varies | Varies | shortint | 2 | Not supported | 2-byte |
The TRY/RECOVER
construct is supported on all HP-UX implementations. Escape codes
for errors differ significantly between the implementations. The mark
and release procedures
are supported on all HP-UX implementations. There are minor differences
in behavior but code is essentially portable.
Series 300/400 and 700/800 differ
in the way each allows association with an HP-UX file descriptor
in the reset
procedure. The association is not similar in
the associate
procedure. Series 700/800 uses an option string parameter on
reset, rewrite,
open, and append
procedures. Series 300/400 ignores this parameter. On the Series 700/800, if stdout
is a terminal, the output is unbuffered. If stdout
is a file, the output is line-buffered. Series 300/400 requires the declaration of stderr
after declaring it as a program parameter; Series 700/800 does not. Series 700/800 implements the fnum
function; Series 300/400 does not. Series 300/400 and 700/800 differ in how each handles
eof, get,
and put with
direct access files. The close
procedure has different default behavior on each system.
Modules are supported on all HP-UX
implementations but some syntactic and semantic differences exist.
For example, Series 700/800 requires that CONST,
TYPE, and VAR
declarations precede routine declarations within the EXPORT
section, whereas Series 300/400 permits them to be intermixed. Series 300/400 permits separate compilation only
within modules. Series 700/800 can compile outside modules by using
the SUBPROGRAM,
GLOBAL, and EXTERNAL
compiler options.
Assignment to Procedure Variables Assignment to a procedure variable has a different syntax
on each of the two architectures. On the Series 300/400, the maximum string size is 255 characters.
By specifying the LONGSTRINGS
compiler option, maximum string size is virtually unlimited. The
string size on Series 700/800 is unlimited. ANYVAR
is supported on all HP-UX implementations. Series 300/400 does not
perform checks to see if ANYVAR
values are legitimate. Series 700/800 passes size information with
ANYVAR parameters. On the Series 300/400, elements of packed arrays can be passed
as ANYVAR parameters
if you use the ALLOW_PACKED
compiler option. All HP-UX implementations support structured constants but
different restrictions may apply. Series 300/400 restricts their
use to the CONST
section and it does not do full type checking on variant-record
structured constants. There is a small difference in precision between the implementations
of longreal because
different bit-patterns are used. anyptr, globalanyptr, and localanyptr All HP-UX implementations have anyptr,
although minor differences exist. On Series 700/800, anyptr
is only assignment compatible, it is not type
compatible with pointer types. anyptr
is also a different size on Series 700/800: it is 64 bits. globalanyptr
and localanyptr
are implemented only on Series 700/800. Program parameters have slight semantic
differences between Series 300/400 and Series 700/800. Arguments for the +
operator with strings differ between Series 300/400 and Series 700/800.
For example, chr
cannot be used with +
on Series 700/800. Series 300/400 and Series 700/800 each generate
different listings.
Features Supported only on Series 300/400 You can use the addr
function to get the address of a constant. A procedure alias is evaluated before addr(alias)
is performed. packed array of char
does not require a lower bound of one for some operations.
Features Supported only on Series 700/800 waddress
accepts NIL or a NIL-valued pointer. A label is not allowed on the statement following
a recover statement. readonly
parameters are allowed. crunched
arrays and records are allowed. The following built-in functions are available: haveextension
haveoptvarparam
statement_number
susizeof |
The assert
procedure is defined. lobound
subrange expressions that start with "("
are allowed. Source is scanned that has been conditionally compiled
out. This allows NLS characters in conditionally compiled sections
of the source. $STANDARD_LEVEL 'HP_MODCAL'$
must be used before importing an argument. You must compile with $STANDARD_LEVEL 'EXT_MODCAL'$
to convert a pointer to an integer with ord(pointer_type), packed array of char
requires a lower bound of one.
Command-Line Options | |
Table 1-7 “Command-Line Options Specific to Series
300/400 ” summarizes the command-line
options that are available only on the Series 300/400 or that behave
differently on the Series 700/800. Table 1-7 Command-Line Options Specific to Series
300/400 Command Option | Effect |
|---|
+A | Use 2-byte alignment rules. | +bfpa | Affect floating-point operations. | +ffpa | Affect floating-point operations. | +l | Allow production of dynamically loaded
libraries. | -L | Produce a program listing in a file specified
by $LIST filename$. | +M | Use library calls for floating point. | +S | Use 4-byte alignment rules. | -T | Same as $TABLES ON$. | +U | Same as $ALLOW_PACKED ON$. |
Table 1-8 “Command-Line Options Specific to Series
700/800 ” summarizes the command
line compiler options that are available only on the Series 700/800
or that behave differently on the Series 300/400. Table 1-8 Command-Line Options Specific to Series
700/800 Command Option | Effect |
|---|
+C | Convert MPE file names to HP-UX names. | +DAmodel | Generate object code for a particular
version of the PA-RISC architecture. | +DSmodel | Perform instruction scheduling tuned
for a particular implementation of the PA-RISC architecture. | -L | Produce a program listing to stdout. | +N | Turn off generation of notes. | +O0,
+O1, +O2,
+O3, +O4 | Set optimization level. | +O[no]aggressive,
+O[no]all,
+O[no]conservative,
+O[no]dataprefetch,
+O[no]limit,
+O[no]size,
+O[no]entrysched,
+O[no]fastaccess,
+O[no]fltacc,
+O[no]initcheck,
+O[no]libcalls,
+O[no]loopunroll,
+O[no]moveflops,
+O[no]pipeline,
+O[no]procelim,
+O[no]regionsched,
+O[no]regreassoc | Modify optimization. | -S | Produce assembly output. | +k | Generate long-displacement code sequences
for referencing global data. | -y | Generate additional information needed
by static analysis tools. | +z
and +Z | Produce PIC object for shared libraries. |
Compiler Options | |
The HP Pascal/HP-UX compilers support a wide range of compiler
options. Some options are identical on all systems. Some options
are unique to a particular system. Some options have different semantics
and slightly different syntax from one system to the other. For
portable code, keep compiler options to a minimum and avoid options
that affect the semantics of the language or enable system level
programming extensions. For example, avoid using the $SYSPROG$
option on the Series 300/400. Table 1-9 “Compiler Options Specific to Series 300/400” lists options that
are specific to Series 300/400 as well as options that have the
same name on Series 700/800 but different semantics. Table 1-9 Compiler Options Specific to Series 300/400 Compiler Option | Effect |
|---|
ALLOW_PACKED | Allows ANYVAR
parameter passing of fields in packed records and arrays, and SIZEOF
using packed fields and arrays. | ANSI
[1] | The compiler issues an error message
when it encounters a feature in the source code that is illegal
in ANSI/ISO Standard Pascal. It must be placed at the top of the
file. | CODETitle not available | Selects whether a code file is generated.
This option is not allowed within a procedure body. | CODE_OFFSETSTitle not available | Causes PC offsets to be included in the
listing. This option is not allowed within a procedure body. | DEBUG | Causes line number debugging information
to be included in the object code. | FLOAT_HDW | Controls generation of code for floating-point
hardware. | IF/ELSE/ENDIFTitle not available | Controls conditional compilation. Refer
to the HP Pascal/HP-UX Reference Manual;
for the Series 300/400 for details. | LINENUM | Sets listing line number. | LINES
Title not available | Specifies number of lines per page on
a listing. Default value is 60. | LITERAL_ALIASTitle not available | Determines the case-sensitivity of an
alias name. | LONGSTRINGS | Extends the maximum length of strings
from 255 characters to virtually any length. | RANGETitle not available | Does run-time checks for range errors. | SAVE_CONST | Controls scope of structured constants. | SEARCHTitle not available | Specifies files to be used to satisfy
IMPORT declarations.
This option must be the last option on an option list. | SEARCH_SIZE | Changes number of external files that
can be searched. The default is 9. | STANDARD_LEVELTitle not available | Defines the compatibility level with
various versions of Pascal. | TABLESTitle not available | Turns on the listing of symbol tables.
TABLES cannot
be used within a procedure body. | UNDERSCORE | Causes ALIAS
parameters to have an underscore added as a prefix. | XREFTitle not available | Used with LIST ON,
the listing includes a cross reference for each function, procedure,
and outer block. |
Table 1-10 “Compiler Options Specific to Series 700/800” lists options that
are specific to Series 700/800 as well as options that have the
same name on Series 300/400 but different semantics. Table 1-10 Compiler Options Specific to Series 700/800 Compiler Option | Effect |
|---|
ALIGNMENT | Changes storage alignment for types other
than strings and file types. | ANSI
[1] | The compiler issues an error message
when it encounters a feature in the source code that is illegal
in ANSI Standard Pascal. $ANSI ON$
is equivalent to $STANDARD_LEVEL 'ANSI'$. | ASSERT_HALT | Causes the program to halt if the assert
function fails. | ASSUME | Sets optimizer assumptions. | BUILDINT | Causes the compiler to build an intrinsic
file rather than an object code file. | CHECK_ACTUAL_PARM | Sets level of type checking of actual
parameters for separately compiled functions or procedures. | CHECK_FORMAL_PARM | Sets level of type checking of formal
parameters for separately compiled functions or procedures. | CODETitle not available | Generates object code after parsing a
compilation block. | CODE_OFFSETSTitle not available | When $LIST ON$
is used, the compiler prints a table that contains the statement
number and offset of each executable statement that it lists. | CONVERT_MPE_NAME | Converts file names in the BUILDINT,
INCLUDE, LISTINTR,
and SYSINTR compiler
options from MPE format to HP-UX format. | COPYRIGHT | Causes a copyright string to be placed
into object code. | COPYRIGHT_DATE | Sets the date that appears in the copyright
notice. This option must be used with the COPYRIGHT
compiler option. | EXTERNAL | Used in conjunction with the GLOBAL
option, EXTERNAL
enables you to compile one program as two or more compilation units. | EXTNADDR | Specifies long pointer accessing. | GLOBAL | Used in conjunction with the EXTERNAL
option, GLOBAL
enables you to compile one program as two or more compilation units. | GPROF | Generates code for profiling. | HEAP_COMPACT | When used with HEAP_DISPOSE ON,
free space in the heap is concatenated. | HEAP_DISPOSE | The predefined procedure dispose
frees space in the heap so that the predefined procedure new
can reallocate it. | HP_DESTINATION | HP_DESTINATION 'ARCHITECTURE
generates object code for a particular version of of the PA-RISC
architecture. HP_DESTINATION 'SCHEDULER
performs instruction scheduling tuned for a particular implementation
of the PA-RISC architecture. | IF/ELSE/ENDIF
Title not available | Controls conditional compilation. Refer
to the HP Pascal/HP-UX Reference Manual;
for the Series 700/800 for details. | INLINE | Causes a procedure call to be replaced
by inline code. | KEEPASMBTitle not available | Causes the compiler to preserve an assembly
file for the source file. | LINES | Specifies number of lines per page on
a listing. Default value is 59. | LIST_CODE | When used with LIST ON,
a mnemonic listing of object code is produced. | LISTINTR | List an intrinsic file to a specified
file. | LITERAL_ALIAS
Title not available | $LITERAL_ALIAS ON$
causes the compiler to differentiate between uppercase and lowercase
letters for aliases. $LITERAL_ALIAS OFF$
causes the compiler to downshift aliases. | LOCALITY | Causes a locality name to be written
to the object file for performance. | MLIBRARY | Specifies an alternate file into which
the module export text is to be written. | NOTES | Causes helpful compiler notes to be printed
on the program listing. | OPTIMIZE | Sets the level of optimization. | OS | Specifies the operating system under
which a program is to be run. | RANGETitle not available | The compiler generates range-checking
code. | S300_EXTNAMES | Changes external names to a form consistent
with Series 300/400 conventions. | SEARCHTitle not available | Specifies one or more files for the compiler
to search for module definitions. | SHLIB_CODE | Generates PIC object code that you can
use to create libraries. | SKIP_TEXT | Causes the compiler to ignore source
code. | STANDARD_LEVELTitle not available | Defines the compatibility level with
various versions of Pascal. | STATEMENT_NUMBER | When enabled, the compiler generates
a special instruction to identify a code sequence with its corresponding
Pascal statement. | SUBPROGRAM | Causes the compiler to emit code for
specified level-one routines only. This option enables you to compile
selected routines of a program. | SYMDEBUG | Emits debugger information for xdb. | SYSINTR | Specifies the intrinsic file to be searched
for information on intrinsic routines. | TABLESTitle not available | When used with LIST ON,
the listing includes an identifier map for each compilation block. | TITLE | Specifies the title to appear on subsequent
pages of the program listing. | UPPERCASE | All external names, including aliases,
are shifted to uppercase. | VERSION | Specifies a version stamp to be placed
in the object file. | XREF
Title not available | When used with LIST ON,
the listing includes a cross reference for each function, procedure,
and outer block. |
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