<head>
<title>Exception Handling in LLVM</title>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
- <meta name="description"
+ <meta name="description"
content="Exception Handling in LLVM.">
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</head>
<li><a href="#llvm_eh_sjlj_setjmp"><tt>llvm.eh.sjlj.setjmp</tt></a></li>
<li><a href="#llvm_eh_sjlj_longjmp"><tt>llvm.eh.sjlj.longjmp</tt></a></li>
<li><a href="#llvm_eh_sjlj_lsda"><tt>llvm.eh.sjlj.lsda</tt></a></li>
+ <li><a href="#llvm_eh_sjlj_callsite"><tt>llvm.eh.sjlj.callsite</tt></a></li>
</ol></li>
<li><a href="#asm">Asm Table Formats</a>
<ol>
<!-- *********************************************************************** -->
-<div class="doc_section"><a name="introduction">Introduction</a></div>
+<div class="doc_section"><a name="introduction">Introduction</a></div>
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<div class="doc_text">
<li><tt>__cxa_begin_catch</tt> takes a exception structure reference as an
argument and returns the value of the exception object.</li>
- <li><tt>__cxa_end_catch</tt> takes a exception structure reference as an
- argument. This function clears the exception from the exception space.
- Note: a rethrow from within the catch may replace this call with
- a <tt>__cxa_rethrow</tt>.</li>
+ <li><tt>__cxa_end_catch</tt> takes no arguments. This function:<br><br>
+ <ol>
+ <li>Locates the most recently caught exception and decrements its handler
+ count,</li>
+ <li>Removes the exception from the "caught" stack if the handler count
+ goes to zero, and</li>
+ <li>Destroys the exception if the handler count goes to zero, and the
+ exception was not re-thrown by throw.</li>
+ </ol>
+ <p>Note: a rethrow from within the catch may replace this call with
+ a <tt>__cxa_rethrow</tt>.</p></li>
</ul>
</div>
<div class="doc_text">
<pre>
- i8* %<a href="#llvm_eh_exception">llvm.eh.exception</a>( )
+ i8* %<a href="#llvm_eh_exception">llvm.eh.exception</a>()
</pre>
<p>This intrinsic returns a pointer to the exception structure.</p>
<div class="doc_text">
<pre>
- i32 %<a href="#llvm_eh_selector">llvm.eh.selector.i32</a>(i8*, i8*, i8*, ...)
- i64 %<a href="#llvm_eh_selector">llvm.eh.selector.i64</a>(i8*, i8*, i8*, ...)
+ i32 %<a href="#llvm_eh_selector">llvm.eh.selector</a>(i8*, i8*, i8*, ...)
</pre>
<p>This intrinsic is used to compare the exception with the given type infos,
<div class="doc_text">
<pre>
- i32 %<a href="#llvm_eh_typeid_for">llvm.eh.typeid.for.i32</a>(i8*)
- i64 %<a href="#llvm_eh_typeid_for">llvm.eh.typeid.for.i64</a>(i8*)
+ i32 %<a href="#llvm_eh_typeid_for">llvm.eh.typeid.for</a>(i8*)
</pre>
<p>This intrinsic returns the type info index in the exception table of the
</div>
+<!-- ======================================================================= -->
+<div class="doc_subsubsection">
+ <a name="llvm_eh_sjlj_longjmp">llvm.eh.sjlj.longjmp</a>
+</div>
+
+<div class="doc_text">
+
+<pre>
+ void %<a href="#llvm_eh_sjlj_longjmp">llvm.eh.sjlj.setjmp</a>(i8*)
+</pre>
+
+<p>The <a href="#llvm_eh_sjlj_longjmp"><tt>llvm.eh.sjlj.longjmp</tt></a>
+ intrinsic is used to implement <tt>__builtin_longjmp()</tt> for SJLJ
+ style exception handling. The single parameter is a pointer to a
+ buffer populated by <a href="#llvm_eh_sjlj_setjmp">
+ <tt>llvm.eh.sjlj.setjmp</tt></a>. The frame pointer and stack pointer
+ are restored from the buffer, then control is transfered to the
+ destination address.</p>
+
+</div>
<!-- ======================================================================= -->
<div class="doc_subsubsection">
<a name="llvm_eh_sjlj_lsda">llvm.eh.sjlj.lsda</a>
<div class="doc_text">
<pre>
- i8* %<a href="#llvm_eh_sjlj_lsda">llvm.eh.sjlj.lsda</a>( )
+ i8* %<a href="#llvm_eh_sjlj_lsda">llvm.eh.sjlj.lsda</a>()
</pre>
<p>Used for SJLJ based exception handling, the <a href="#llvm_eh_sjlj_lsda">
</div>
+<!-- ======================================================================= -->
+<div class="doc_subsubsection">
+ <a name="llvm_eh_sjlj_callsite">llvm.eh.sjlj.callsite</a>
+</div>
+
+<div class="doc_text">
+
+<pre>
+ void %<a href="#llvm_eh_sjlj_callsite">llvm.eh.sjlj.callsite</a>(i32)
+</pre>
+
+<p>For SJLJ based exception handling, the <a href="#llvm_eh_sjlj_callsite">
+ <tt>llvm.eh.sjlj.callsite</tt></a> intrinsic identifies the callsite value
+ associated with the following invoke instruction. This is used to ensure
+ that landing pad entries in the LSDA are generated in the matching order.</p>
+
+</div>
+
<!-- ======================================================================= -->
<div class="doc_section">
<a name="asm">Asm Table Formats</a>
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