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</head> <body> <h1>#Warn <span class="ver">[v1.0.95.00+]</span></h1> <p>Enables or disables warnings for specific conditions which may indicate an error, such as a typo or missing "global" declaration.</p> <pre class="Syntax"><span class="func">#Warn</span> <span class="optional">WarningType, WarningMode</span></pre> <h2 id="Parameters">Parâmetros</h2> <dl> <dt>WarningType</dt> <dd> <p>The type of warning to enable or disable. If omitted, it defaults to <i>All</i>.</p> <p id="UseUnset"><strong>UseUnsetLocal</strong> or <strong>UseUnsetGlobal</strong>: Warn when a variable is read without having previously been assigned a value or initialized with <a href="VarSetCapacity.htm">VarSetCapacity()</a>. If the variable is intended to be empty, assign an empty string to suppress this warning. <a href="IsSet.htm">IsSet()</a> can be used to determine whether reading a variable would raise this warning.</p> <p>This is split into separate warning types for locals and globals because it is more common to use a global variable without prior initialization, due to their persistent and script-wide nature. For this reason, some script authors may wish to enable this type of warning for locals but disable it for globals.</p> <pre>#Warn <em>;y := "" ; This would suppress the warning.</em> x := y <em>; y hasn't been assigned a value.</em></pre> <p id="UseEnv"><strong>UseEnv</strong>: Warn when an environment variable is automatically used in place of an empty script variable. This sometimes occurs when an environment variable's name unexpectedly matches a variable used by the script. This warning occurs when the variable is accessed, but never occurs if the script enables <a href="_NoEnv.htm">#NoEnv</a> (recommended for multiple reasons).</p> <pre>#Warn <em>;#NoEnv ; Add this if "temp" is not intended to be an environment variable.</em> <em>;EnvGet temp, TEMP ; This would copy the environment variable's value into the script variable.</em> temp := "" <em>; Despite this line, temp still seems to have a value.</em> MsgBox % temp <em>; This accesses the environment variable named "TEMP".</em></pre> <p id="LocalSameAsGlobal"><strong>LocalSameAsGlobal</strong>: Before the script starts to run, display a warning for each <em>undeclared</em> local variable which has the same name as a global variable. This is intended to prevent errors caused by forgetting to declare a global variable inside a function before attempting to access it. If the variable really was intended to be local, a declaration such as <code>local x</code> or <code>static y</code> can be used to suppress the warning. This warning is never shown for variables inside a <a href="../Functions.htm#ForceLocal">force-local</a> function.</p> <pre>#Warn g := 1 ShowG() { <em>; The warning is displayed even if the function is never called.</em> <em>;global g ; <-- This is required to access the global variable.</em> MsgBox % g <em>; Without the declaration, "g" is an empty local variable.</em> }</pre> <p id="ClassOverwrite"><strong>ClassOverwrite</strong> <span class="ver">[v1.1.27+]</span>: Before the script starts to run, show a warning for each assignment targetting a class variable. For example, <code>box := new Box</code> will show a warning if <em>Box</em> is a class, since this would overwrite the class (within the super-global variable, <em>Box</em>). Warnings are also shown for output variables of commands, but not ByRef parameters. Warnings are not shown for nested classes or dynamic variable references.</p> <p id="Unreachable"><strong>Unreachable</strong> <span class="ver">[v1.1.33+]</span>: Before the script starts to run, show a warning for each line that immediately follows a <code>Return</code>, <code>Break</code>, <code>Continue</code>, <code>Throw</code>, <code>Goto</code> or <code>Exit</code> at the same nesting level, unless that line is the target of a label. Although this does not detect all unreachable code, it detects common errors such as:</p> <ul> <li>Placing initialization code (such as an assignment or <a href="GroupAdd.htm">GroupAdd</a>) in between hotkey subroutines, when it should be in the <a href="../Language.htm#auto-execute-section">auto-execute section</a>.</li> <li>Placing the first line of a "multi-line" hotkey subroutine on the same line as the hotkey label. Doing so will make it a <a href="../Hotkeys.htm#Intro">single-line hotkey</a>, with an implicit <code>return</code> that prevents any subsequent lines from executing. Similarly, placing <code>return</code> after a single-line hotkey is redundant and will cause a warning.</li> <li>Placing a <a href="../Language.htm#subroutines">subroutine</a> inside another subroutine, breaking the flow of code.</li> </ul> <p>If the code is intended to be unreachable - such as if a <code>return</code> has been used to temporarily disable a block of code, or a hotkey or hotstring has been temporarily disabled by commenting it out - consider commenting out the unreachable code as well. Alternatively, the warning can be suppressed by defining a <a href="../misc/Labels.htm">label</a> above the first unreachable line.</p> <p><strong>All</strong>: Apply the given <em>WarningMode</em> to all supported warning types.</p> </dd> <dt>WarningMode</dt> <dd> <p>A value indicating how warnings should be delivered. If omitted, it defaults to <em>MsgBox</em>.</p> <p><strong>MsgBox</strong>: Show a message box describing the warning. Note that once the message box is dismissed, the script will continue as usual.</p> <p><strong>StdOut</strong> <span class="ver">[v1.1.04+]</span>: Send a description of the warning to <em>stdout</em> (the program's standard output stream), along with the filename and line number. This allows fancy editors such as SciTE to capture warnings without disrupting the script - the user can later jump to each offending line via the editor's output pane.</p> <p><strong>OutputDebug</strong>: Send a description of the warning to the debugger for display. If a debugger is not active, this will have no effect. For more details, see <a href="OutputDebug.htm">OutputDebug</a>.</p> <p><strong>Off</strong>: Disable warnings of the given <em>WarningType</em>.</p> </dd> </dl> <h2 id="Remarks">Remarks</h2> <p>By default, all warnings are off.</p> <p>Warnings can't be enabled or disabled at run-time; the settings are determined when a script loads. Therefore, the location in the script is not significant (and, like other directives, #Warn cannot be executed conditionally).</p> <p>However, the ordering of multiple #Warn directives is significant: the last occurrence that sets a given warning determines the mode for that warning. So, for example, the two statements below have the combined effect of enabling all warnings except UseEnv:</p> <pre>#Warn All #Warn UseEnv, Off EnvSet EnvVar, 1 x := EnvVar <em>; Okay since #NoEnv has not been used.</em> x := NotAnEnvVar <em>; Warning.</em> </pre> <h2 id="Related">Tópicos relacionados</h2> <p><a href="../Functions.htm#Local">Local and Global Variables</a></p> <h2 id="Examples">Exemplos</h2> <div class="ex" id="ExAllOff"> <p><a class="ex_number" href="#ExAllOff"></a> Disables all warnings. This is the default state.</p> <pre>#Warn All, Off</pre> </div> <div class="ex" id="ExOmitted"> <p><a class="ex_number" href="#ExOmitted"></a> Enables every type of warning and shows each warning in a message box.</p> <pre>#Warn</pre> </div> <div class="ex" id="ExUseUnsetLocalOutputDebug"> <p><a class="ex_number" href="#ExUseUnsetLocalOutputDebug"></a> Warns when a local variable is used before it is set and sends each warning to OutputDebug.</p> <pre>#Warn UseUnsetLocal, OutputDebug</pre> </div> </body> </html>