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Ulm's Oberon Library:
CompilerLogs

NAME

CompilerLogs - provide log about loading and compilation processes

SYNOPSIS

TYPE Log = POINTER TO LogRec;
TYPE LogRec = RECORD (Disciplines.ObjectRec) END;



PROCEDURE Create(VAR log: Log; s: Streams.Stream);



PROCEDURE Open(log: Log; loglevel: INTEGER;
               VAR s: Streams.Stream) : BOOLEAN;



PROCEDURE SetLogLevel(log: Log; maxlevel: INTEGER);
PROCEDURE SetMaximalNestLevel(log: Log; maxnestlevel: INTEGER);
PROCEDURE Flatten(log: Log);
PROCEDURE EnterLevel(log: Log; VAR key: INTEGER);
PROCEDURE LeaveLevel(log: Log; key: INTEGER);



PROCEDURE LogLevel(log: Log) : INTEGER;
PROCEDURE NestLevel(log: Log) : INTEGER;

DESCRIPTION

CompilerLogs provides a filter and formatting tool for logs about loading and compilation processes. Filtering and formatting depends on two state variables belonging to each log:

The log level is the amount of detail that is requested. The minimal level is 0 (no log at all is to be given). Larger log levels may be given to ask for more detailed informations. A log level of -1 means that all informations are to be given without restrictions.
The nesting level depends on the current nesting of the loading and compilation process. Nesting levels are not limited due to the recursive nature of compilation and loading processes.

Create creates a log that emits its output onto s. The output stream should be line buffered to avoid any delays in seeing log messages.

Generating Logs

Log messages by the compiler or loader are created using Open. The log level of a log message must be positive and Open returns FALSE if this message is to be suppressed by the current filtering rules. No more than one log message stream returned by Open for a particular log must be open at any time to avoid mixups of different log messages.

The current nesting level is increased by EnterLevel and decreased by LeaveLevel. To assure proper nesting a key must be given to LeaveLevel that was previously returned by EnterLevel.

Filtering Logs

SetLogLevel allows to set the current log level. All log messages with a log level larger than maxlevel will be suppressed. A maxlevel of 0 causes all messages to be dropped, a maxlevel of -1 asks for all messages regardless of their log level.

SetMaximalNestLevel requests all log messages to be suppressed with a nesting level larger than maxnestlevel. A maxnestlevel of -1 removes restrictions regarding the nest level. This is the default setting.

By default, CompilerLogs intends its output according to the nest level of the individual log messages. Flatten suppresses any indentation and sets the maximal nesting level to -1 (unrestricted).

LogLevel and NestLevel return the current log and nesting level, respectively.

DIAGNOSTICS

CompilerLogs does not generate any error events on its own.

Ulm's Oberon Library: CompilerLogs