<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/92216>92216</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            [llvm-cov][MC/DC] "Branch not found in Decisions" when handling variadic macros
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            new issue
      </td>
    </tr>

    <tr>
      <th>Assignees</th>
      <td>
      </td>
    </tr>

    <tr>
      <th>Reporter</th>
      <td>
          whentojump
      </td>
    </tr>
</table>

<pre>
    I hit this problem in https://elixir.bootlin.com/linux/v6.1.83/source/kernel/rcu/tasks.h#L1621

A reduced user-space program is:

```c
#define FOO(x, ...) "", ##__VA_ARGS__
#define ZERO 0
int main() { FOO(, 1 && ZERO); }
```

Compiler explorer [link](https://godbolt.org/#g:!((g:!((g:!((h:codeEditor,i:(filename:'1',fontScale:14,fontUsePx:'0',j:1,lang:c%2B%2B,selection:(endColumn:33,endLineNumber:3,positionColumn:33,positionLineNumber:3,selectionStartColumn:33,selectionStartLineNumber:3,startColumn:33,startLineNumber:3),source:'%23define+FOO(x,+...)+%22%22,+%23%23__VA_ARGS__%0A%23define+ZERO+0%0Aint+main()+%7B+FOO(,+1+%26%26+ZERO)%3B+%7D'),l:'5',n:'1',o:'C%2B%2B+source+%231',t:'0')),k:50,l:'4',n:'0',o:'',s:0,t:'0'),(g:!((g:!((h:compiler,i:(compiler:clang_assertions_trunk,filters:(b:'0',binary:'1',binaryObject:'1',commentOnly:'0',debugCalls:'1',demangle:'0',directives:'0',execute:'1',intel:'0',libraryCode:'1',trim:'1',verboseDemangling:'0'),flagsViewOpen:'1',fontScale:14,fontUsePx:'0',j:1,lang:c%2B%2B,libs:!(),options:'-fprofile-instr-generate+-fcoverage-mapping+-fcoverage-mcdc',overrides:!(),selection:(endColumn:1,endLineNumber:1,positionColumn:1,positionLineNumber:1,selectionStartColumn:1,selectionStartLineNumber:1,startColumn:1,startLineNumber:1),source:1),l:'5',n:'0',o:'+x86-64+clang+(assertions+trunk)+(Editor+%231)',t:'0')),k:50,l:'4',m:50,n:'0',o:'',s:0,t:'0'),(g:!((h:tool,i:(args:'--show-mcdc',argsPanelShown:'0',compilerName:'x86-64+clang+(assertions+trunk)',editorid:1,fontScale:14,fontUsePx:'0',j:1,monacoEditorHasBeenAutoOpened:'1',monacoEditorOpen:'1',monacoStdin:'1',stdin:'',stdinPanelShown:'1',toolId:llvm-covtrunk,treeid:0,wrap:'1'),l:'5',n:'0',o:'llvm-cov+(clang-only)+x86-64+clang+(assertions+trunk)+(Editor+%231,+Compiler+%231)',t:'0')),header:(),l:'4',m:50,n:'0',o:'',s:0,t:'0')),k:50,l:'3',n:'0',o:'',t:'0')),l:'2',n:'0',o:'',t:'0')),version:4).

Note that despite the same message, this issue should be different than #87000 and with #89869 locally applied I'm still seeing the same problem.

cc @evodius96 @chapuni 
</pre>
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