Harbour Reference Guide


Compiler Options

Compiler Options


Invoking the Harbour compiler:

harbour <file[.prg]> [options]
harbour [options] <file[.prg]>
harbour [options] <file[.prg]> [options]

The command line options have to be separated by at least one space. The option can start with either '/' character or '-' character.

The Harbour command line options:

/a automatic memvar declaration

This causes all variables declared by PARAMETER, PRIVATE or PUBLIC statements to be automatically declared as MEMVAR variables.

/b debug info

The compiler generates all information required for debugging

/d<id>[=<val>] #define <id>

/es[<level>] set exit severity

/es or /es0 = all warnings are ignored and exit code returned by the compiler (accessed by DOS ERRORLEVEL command) is equal to 0 if there are no errors in compiled source file.

/es1 = any warnings generate a non=zero exit code, but output is still created.

/es2 = all warnings are treated as errors and no output file is created. The exit code is set to a non=zero value.

/g<type> output type generated is <type>

/gc output type: C source (.c) (default)

/gf output type: Windows/DOS OBJ32 (.obj)

/gh output type: Harbour Portable Object (.hrb)

/gj output type: Java source (.java)

/gp output type: Pascal source (.pas)

/gr output type: Windows resource (.rc)

/i<path> add #include file search path

/l suppress line number information

The compiler does not generate the source code line numbers in the output file. The PROCLINE() function will return 0 for modules compiled using this option.

/m compile current module only

/n no implicit starting procedure

The compiler does not create a procedure with the same name as the compiled file. This means that any declarations placed before the first PROCEDURE or FUNCTION statement have file= wide scope and can be accessed/used in all functions/procedures defined in the compiled source file. All executable statements placed at the beginning of the file and before the first PROCEDURE/FUNCTION statement are ignored.

/o<path> output file drive and/or path

/p generate pre=processed output (.ppo) file

The compiler only creates the file that contains the result of pre=processing the source file.

/q quiet

The compiler does not print any messages during compiling (except the copyright info).

/q0 be really quiet and don't display even the copyright info

/r[<lib>] request linker to search <lib> (or none)

Currently not supported in Harbour.

/s syntax check only

The compiler checks the syntax only. No output file is generated.

/t<path> path for temp file creation

Currently not used in Harbour (the Harbour compiler does not create any temporary files).

/u[<file>] use command definition set in <file> (or none)

/v variables are assumed M=>

All undeclared or unaliased variables are assumed MEMVAR variables (private or public variables). If this switch is not used then the scope of such variables is checked at runtime.

/w[<level>] set warning level number (0..4, default 1)

/w0 = no warnings

/w or /w1 = Clipper compatible warnings

/w2 = some useful warnings missed in Clipper

/w3 = warnings generated for Harbour language extensions and also enables strong type checking but only warns against declared types, or types which may be calculated at compile time

/w4 = Enables warning about suspicious operations, which means if you mix undeclared types, or types which can not be calculated at compile time,together with declared types, a warning will be generated.

/x[<prefix>] set symbol init function name prefix (for .c only)

Sets the prefix added to the generated symbol init function name (in C output currently). This function is generated automatically for every PRG module compiled. This additional prefix can be used to suppress problems with duplicated symbols during linking an application with some third party libraries.

/y trace lex & yacc activity

The Harbour compiler uses the FLEX and YACC utilities to parse the source code and to generate the required output file. This option traces the activity of these utilities.

/z suppress logical shortcutting (.and. & .or.)

/10 restrict symbol length to 10 characters

All variable and function names are cut to maximum 10 characters.

Compilation in batch mode.

@<file> compile list of modules in <file>

Not supported yet.

Known incompatibilities between harbour and clipper compilers


If you want a 100% compatible compile and runtime libraries then you have to define HARBOUR_STRICT_CLIPPER_COMPATIBILITY. This option should be defined in the file include/hbsetup.h (in fact this option is placed in a comment by default = you need to remove the /* */ characters only). This change has to be done before invoking the make utility.

Handling of undeclared variables

When a value is assigned to an undeclared variable and the '=v' command line option is not used, then the Clipper compiler assumes that the variable is a PRIVATE or a PUBLIC variable and generates POPM (pop memvar) opcode.

When the value of an undeclared variable is accessed and the '=v' command line option is not used, the Clipper compiler generates PUSHV (push variable) opcode that determines the type of variable at runtime. If a field with the requested name exists in the current workarea then its value is used. If there is no field then a PRIVATE or a PUBLIC variable is used (if exists).

The Harbour compiler generates an opcode to determine the type of variable at runtime (POPVARIABLE or PUSHVARIABLE) in both cases (assignment and access).

The difference can be checked by the following code:

PROCEDURE MAIN() PRIVATE myname DBCREATE( "TEST", { { "MYNAME", "C", 10, 0} } ) USE test NEW SELECT test APPEND BLANK FIELD=>myname := "FIELD" MEMVAR=>myname := "MEMVAR" myname := myname + " assigned" // In Clipper: "FIELD", In Harbour: "FIELD assigned" ? FIELD=>myname // In Clipper: "MEMVAR assigned", In Harbour: "MEMVAR" ? MEMVAR=>myname USE RETURN

Passing an undeclared variable by the reference

The Clipper compiler uses the special opcode PUSHP to pass a reference to an undeclared variable ( '@' operator ). The type of passed variable is checked at runtime (field or memvar). However, field variables cannot be passed by reference. This means that Clipper checks the memvar variable only and doesn't look for a field. This is the reason why the Harbour compiler uses the usual PUSHMEMVARREF opcode in such cases. Notice that the runtime behavior is the same in Clipper and in Harbour = only the generated opcodes are different.

Handling of object messages

The HARBOUR_STRICT_CLIPPER_COMPATIBILITY setting determines the way chained send messages are handled.

For example, the following code:

a:b( COUNT() ):c += 1

will be handled as:

a:b( COUNT() ):c := a:b( COUNT() ):c + 1

in strict Clipper compatibility mode and

temp := a:b( COUNT() ), temp:c += 1

in non=strict mode.

In practice, Clipper will call the COUNT() function two times: the first time before addition and the second one after addition. In Harbour, COUNT() will be called only once, before addition.

The Harbour (non=strict) method is:
1) faster
2) it guarantees that the same instance variable of the same object will be changed

(See also: source/compiler/expropt.c)

Initialization of static variables

There is a difference in the initialization of static variables that are initialized with a codeblock that refers to a local variable. For example:

PROCEDURE TEST() LOCAL MyLocalVar STATIC MyStaticVar := {|| MyLocalVar } MyLocalVar :=0 ? EVAL( MyStaticVar ) RETURN

The above code compiles fine in Clipper, but it generates a runtime error Error/BASE 1132 Bound error: array access
Called form (b)STATICS$(0)

In Harbour this code generates a compile time error: Error E0009 Illegal variable (b) initializer: 'MyLocalVar'

Both Clipper and Harbour are handling all local variables used in a codeblock in a special way: they are detached from the local stack of function/procedure where they are declared. This allows access to these variables after the exit from a function/procedure. However, all static variables are initialized in a separate procedure
('STATICS$' in Clipper and '(_INITSTATICS)' in Harbour) before the main procedure and before all INIT procedures. The local variables don't exist on the eval stack when static variables are initialized, so they cannot be detached.


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Last updated on 2001/07/30