Improve natvis for llvm::SmallString so that it correctly displays only the valid portion of the string

amaiorano · amaiorano · commit d9af48a93174 · 2016-12-21T01:05:29.000Z
The usual method, and the one employed before my change, of displaying strings in natvis is to make use of the "<variable>,s" format specifier; however, this method only works for null-terminated strings. My fix here is to use the "<pointer>,[size]" format specifier to display a bounded array, and then cast it to "const char*", which in the MSVC debugger has the desired effect of rendering the character array as a string. Differential Revision: https://reviews.llvm.org/D27972 llvm-svn: 290224
diff --git a/llvm/utils/LLVMVisualizers/llvm.natvis b/llvm/utils/LLVMVisualizers/llvm.natvis
@@ -56,8 +56,8 @@ For later versions of Visual Studio, no setup is required.
     </Expand>
   </Type>
   <Type Name="llvm::SmallString&lt;*&gt;">
-    <DisplayString>{BeginX,s}</DisplayString>
-    <StringView>BeginX,s</StringView>
+    <DisplayString>{(const char*)BeginX,[(char*)EndX - (char*)BeginX] na}</DisplayString>
+    <StringView>(const char*)BeginX,[(char*)EndX - (char*)BeginX]</StringView>
     <Expand>
       <Item Name="[size]">(char*)EndX - (char*)BeginX</Item>
       <Item Name="[capacity]">(char*)CapacityX - (char*)BeginX</Item>
