#defineDiretivaOptional
Defines identifiers, manifest constants, or pseudofunctions expanded by the preprocessor.
FOUNDATIONPublished
AdvPL compiler directives
#define · #undef · #include · #ifdef · #ifndef · #else · #endif · #command · #translateControl preprocessing, share definitions, and select which source blocks reach the compiler.
Overview
Directives are handled by the preprocessor before compilation. A useful analogy is preparing a recipe before baking: headers are included, symbols expanded, syntax translated, and blocks selected; the compiler receives only the resulting source. #define and #include are conceptually similar to C/C++, but #include is not a complete modern module system.
Syntax
#define · #undef · #include · #ifdef · #ifndef · #else · #endif · #command · #translateParameters
#undefDiretivaOptional
Removes an active definition from the point where the directive appears.
#includeDiretivaOptional
Inserts a header file at the current point using the compiler include path.
#ifdefDiretivaOptional
Includes a block in compilation only when a given identifier is defined.
#ifndefDiretivaOptional
Includes a block only when a given identifier is not defined.
#else e #endifDiretivaOptional
Provides the alternative path and closes conditional compilation blocks.
#command e #translateDiretivaOptional
Creates syntax-transformation rules applied by the preprocessor.
Constant and conditional compilation
#define LIMITE_ITENS 100
#define LOG_DETALHADO
User Function ExDiretivas()
Local nItens := 120
#ifdef LOG_DETALHADO
ConOut("Itens recebidos: " + CValToChar(nItens))
#endif
If nItens > LIMITE_ITENS
MsgAlert("Limite excedido")
EndIf
ReturnExpected result
Symbols are resolved before compilation; runtime If remains a runtime decision.
Default value with #ifndef
#ifndef TAMANHO_LOTE
#define TAMANHO_LOTE 50
#endif
User Function ExLote()
ConOut("Tamanho do lote: " + CValToChar(TAMANHO_LOTE))
ReturnExpected result
The default is used only if no earlier definition exists.
Specific include
#include "TOTVS.ch"
#include "FWMVCDef.ch"
User Function ExCabecalhos()
// Utilize símbolos do Framework MVC somente após incluir
// o cabeçalho compatível com o ambiente.
ReturnExpected result
Header content participates in source preprocessing.
- Directives run before execution; runtime If/Else makes decisions while the routine runs.
- Use manifest constants to remove magic values, conditional compilation only when needed, and release-compatible includes.
- Use runtime configuration for values that must change without recompilation.
- #command and #translate are advanced; application clarity usually matters more than new syntax.
- Never put secrets in #define.
- Avoid client-specific compilation symbols when runtime parameters or extensions solve the problem.
- Do not assume every source needs both PROTHEUS.CH and TOTVS.CH.
- AAdd() is a library function, not a #command invention.