[analyzer] Update alpha and potential checker documentation, esp. alpha.valist

[ddcc]

Summary

Move alpha.valist from potential to alpha since it was implemented in D15227

Cleanup some HTML comments, add a missing link

[zaks.anna]

Thank you for the cleanup!
Anna.

cfe/trunk/www/analyzer/alpha_checks.html

 Experimental checkers in addition to the <a href = "available_checks.html">
 Default Checkers</a>. These are checkers with known issues or limitations that
 keep them from being on by default. They are likely to have false positives.
 Bug reports are welcome but will likely not be investigated for some time.
 Patches welcome!
 <ul>
 <li><a href="#core_alpha_checkers">Core Alpha Checkers</a></li>
 <li><a href="#cplusplus_alpha_checkers">C++ Alpha Checkers</a></li>
+<li><a href="#valist_alpha_checkers">Variable Argument Alpha Checkers</a></li>
 <li><a href="#deadcode_alpha_checkers">Dead Code Alpha Checkers</a></li>
 <li><a href="#osx_alpha_checkers">OS X Alpha Checkers</a></li>
 <li><a href="#security_alpha_checkers">Security Alpha Checkers</a></li>
 <li><a href="#unix_alpha_checkers">Unix Alpha Checkers</a></li>
 </ul>
 
-<!------------------------------ core alpha ----------------------------------->
+<!-- ============================= core alpha ============================= -->
 <h3 id="core_alpha_checkers">Core Alpha Checkers</h3>
 <table class="checkers">
 <colgroup><col class="namedescr"><col class="example"></colgroup>
 <thead><tr><td>Name, Description</td><td>Example</td></tr></thead>
 
 <tbody>
 <tr><td><div class="namedescr expandable"><span class="name">
 alpha.core.BoolAssignment</span><span class="lang">

 int test(struct s *p) {
   return sizeof(p); 
     // warn: sizeof(ptr) can produce an unexpected result
 }
 </pre></div></div></td></tr>
 
 </tbody></table>
 
-<!--------------------------- cplusplus alpha --------------------------------->
+<!-- =========================== cplusplus alpha =========================== -->
 <h3 id="cplusplus_alpha_checkers">C++ Alpha Checkers</h3>
 <table class="checkers">
 <colgroup><col class="namedescr"><col class="example"></colgroup>
 <thead><tr><td>Name, Description</td><td>Example</td></tr></thead>
 
 <tbody>
 <tr><td><div class="namedescr expandable"><span class="name">
 alpha.cplusplus.NewDeleteLeaks</span><span class="lang">
~A() {
     this-&gt;f(); // warn
   }
   virtual void f();
 };
 </pre></div></div></td></tr>
 
 </tbody></table>
 
-<!--------------------------- dead code alpha --------------------------------->
+
+
+<!-- =============================== va_list =============================== -->
+<h3 id="valist_alpha_checkers">Variable Argument Alpha Checkers</h3>
+<table class="checkers">
+<colgroup><col class="namedescr"><col class="example"></colgroup>
+<thead><tr><td>Name, Description</td><td>Example</td></tr></thead>
+
+<tbody>
+<tr><td><div class="namedescr expandable"><span class="name">
+alpha.valist.CopyToSelf</span><span class="lang">
+(C)</span><div class="descr">
+Calls to the <code>va_copy</code> macro should not copy onto itself.</div></div></td>
+<td><div class="exampleContainer expandable">
+<div class="example"><pre>
+#include &lt;stdarg.h&gt;
+
+void test(int x, ...) {
+  va_list args;
+  va_start(args, x);
+  va_copy(args, args); // warn
+  va_end(args);
+}
+</pre></div></div></td></tr>
+
+<tr><td><div class="namedescr expandable"><span class="name">
+alpha.valist.Uninitialized</span><span class="lang">
+(C)</span><div class="descr">
+Calls to the <code>va_arg</code>, <code>va_copy</code>, or
+<code>va_end</code> macro must happen after calling <code>va_start</code> and
+before calling <code>va_end</code>.</div></div></td>
+<td><div class="exampleContainer expandable">
+<div class="example"><pre>
+#include &lt;stdarg.h&gt;
+
+void test(int x, ...) {
+  va_list args;
+  int y = va_arg(args, int); // warn
+}
+</pre></div>
+<div class="example"><pre>
+#include &lt;stdarg.h&gt;
+
+void test(int x, ...) {
+  va_list args;
+  va_start(args, x);
+  va_end(args);
+  int z = va_arg(args, int); // warn
+}
+</pre></div></div></td></tr>
+
+<tr><td><div class="namedescr expandable"><span class="name">
+alpha.valist.Unterminated</span><span class="lang">
+(C)</span><div class="descr">
+Every <code>va_start</code> must be matched by a <code>va_end</code>. A va_list
+can only be ended once.</div></div></td>
+<td><div class="exampleContainer expandable">
+<div class="example"><pre>
+#include &lt;stdarg.h&gt;
+
+void test(int x, ...) {
+  va_list args;
+  va_start(args, x);
+  int y = x + va_arg(args, int);
+} // warn: missing va_end
+</pre></div></div></td></tr>
+
+</tbody></table>
+
+<!-- =========================== dead code alpha =========================== -->
 <h3 id="deadcode_alpha_checkers">Dead Code Alpha Checkers</h3>
 <table class="checkers">
 <colgroup><col class="namedescr"><col class="example"></colgroup>
 <thead><tr><td>Name, Description</td><td>Example</td></tr></thead>
 
 <tbody>
 <tr><td><div class="namedescr expandable"><span class="name">
 alpha.deadcode.UnreachableCode</span><span class="lang">

 // Objective-C
 void test(id x) {
   return;
   [x retain]; // warn
 }
 </pre></div></div></td></tr>
 </tbody></table>
 
-<!---------------------------- OS X alpha -------------------------------------->
+<!-- ============================== OS X alpha ============================== -->
 <h3 id="osx_alpha_checkers">OS X Alpha Checkers</h3>
 <table class="checkers">
 <colgroup><col class="namedescr"><col class="example"></colgroup>
 <thead><tr><td>Name, Description</td><td>Example</td></tr></thead>
 
 <tbody>
 <tr><td><div class="namedescr expandable"><span class="name">
 alpha.osx.cocoa.Dealloc</span><span class="lang">

 @end
 
 @implementation MissingInvalidationMethodDecl
 @end
 </pre></div></div></td></tr>
 
 </tbody></table>
 
-<!------------------------- security alpha ------------------------------------>
+<!-- =========================== security alpha =========================== -->
 <h3 id="security_alpha_checkers">Security Alpha Checkers</h3>
 <table class="checkers">
 <colgroup><col class="namedescr"><col class="example"></colgroup>
 <thead><tr><td>Name, Description</td><td>Example</td></tr></thead>
 
 <tbody>
 <tr><td><div class="namedescr expandable"><span class="name">
 alpha.security.ArrayBound</span><span class="lang">
void test() {
   scanf("%zd", &ts); // 'ts' marked as tainted
   int *p = (int *)malloc(ts * sizeof(int)); 
     // warn: untrusted data as bufer size
 }
 </pre></div></div></td></tr>
 
 </tbody></table>
 
-<!--------------------------- unix alpha -------------------------------------->
+<!-- ============================= unix alpha ============================= -->
 <h3 id="unix_alpha_checkers">Unix Alpha Checkers</h3>
 <table class="checkers">
 <colgroup><col class="namedescr"><col class="example"></colgroup>
 <thead><tr><td>Name, Description</td><td>Example</td></tr></thead>
 
 <tbody>
 <tr><td><div class="namedescr expandable"><span class="name">
 alpha.unix.Chroot</span><span class="lang">

cfe/trunk/www/analyzer/potential_checkers.html

 void test(A *dst, A *src) {
   ::new (dst) A(*dst); // warn (should be 'src')
 }
 </pre></div></div></td>
 <td class="aligned"><!--rdar://problem/13688366--></td></tr>
 
 </table>
 
-<!-- =============================== va_list =============================== -->
-<h3>va_list</h3>
-<table class="checkers">
-<col class="namedescr"><col class="example"><col class="progress">
-<thead><tr><td>Name, Description</td><td>Example</td><td>Progress</td></tr></thead>
-
-<tr><td><div class="namedescr expandable"><span class="name">
-valist.Uninitialized</span><span class="lang">
-(C)</span><div class="descr">
-Calls to the <code>va_arg</code>, <code>va_copy</code>, or
-<code>va_end</code> macro must happen after calling <code>va_start</code> and
-before calling <code>va_end</code>.</div></div></td>
-<td><div class="exampleContainer expandable">
-<div class="example"><pre>
-#include &lt;stdarg.h&gt;
-
-void test(int x, ...) {
-  va_list args;
-  int y = va_arg(args, int); // warn
-}
-</pre></div>
-<div class="example"><pre>
-#include &lt;stdarg.h&gt;
-
-void test(int x, ...) {
-  va_list args;
-  va_start(args, x); 
-  va_end(args);
-  int z = va_arg(args, int); // warn
-}
-</pre></div></div></td>
-<td class="aligned"><a href="http://llvm.org/bugs/show_bug.cgi?id=16812">
-PR16811</a></td></tr>
-
-<tr><td><div class="namedescr expandable"><span class="name">
-valist.Unterminated</span><span class="lang">
-(C)</span><div class="descr">
-Every <code>va_start</code> must be matched by a <code>va_end</code>. A va_list
-can only be ended once.
-
-<i>This should be folded into the generalized "ownership checker"
-described on the <a href="open_projects.html">
-Open Projects</a> page.</i></div></div></td>
-<td><div class="exampleContainer expandable">
-<div class="example"><pre>
-#include &lt;stdarg.h&gt;
-
-void test(int x, ...) {
-  va_list args;
-  va_start(args, x);
-  int y = x + va_arg(args, int);
-} // warn: missing va_end
-</pre></div></div></td>
-<td class="aligned"><a href="http://llvm.org/bugs/show_bug.cgi?id=16812">
-PR16812</a></td></tr>
-
-</table>
-
 <!-- ============================== exceptions ============================= -->
 <h3>exceptions</h3>
 <table class="checkers">
 <col class="namedescr"><col class="example"><col class="progress">
 <thead><tr><td>Name, Description</td><td>Example</td><td>Progress</td></tr></thead>
 
 <tr><td><div class="namedescr expandable"><span class="name">
 exceptions.ThrowSpecButNotThrow</span><span class="lang">

 </pre></div>
 <div class="example"><pre>
 void test() {
   int x = 7, zero = 0;
   x = x - zero;
    // warn: the right operand to '-' is always 0
 }
 </pre></div></div></td>
-<td class="aligned">removed from alpha.deadcode.* at r198476</td></tr>
+<td class="aligned">removed from alpha.deadcode.* at
+<a href="https://reviews.llvm.org/rL198476">r198476</a></td></tr>
 
 </table>
 
 <!-- ================================ POSIX ================================ -->
 <h3>POSIX</h3>
 <table class="checkers">
 <col class="namedescr"><col class="example"><col class="progress">
 <thead><tr><td>Name, Description</td><td>Example</td><td>Progress</td></tr></thead>