[PATCH] D56571: [RFC prototype] Implementation of asm-goto support in LLVM

[Yu, Jennifer via cfe-commits]

Syntax for asm goto:
Syntax:
  asm [volatile] goto ( AssemblerTemplate
                      :
                      : InputOperands
                      : Clobbers
                      : GotoLabels)

Only input is allowed.  Output is not allowed
Thanks.
Jennifer

-----Original Message-----
From: Eli Friedman via Phabricator [mailto:reviews at reviews.llvm.org] 
Sent: Thursday, January 10, 2019 5:58 PM
To: craig.topper at gmail.com; Keane, Erich <erich.keane at intel.com>; ndesaulniers at google.com; chandlerc at gmail.com; Yu, Jennifer <jennifer.yu at intel.com>; syaghmour at apple.com
Cc: efriedma at codeaurora.org; srhines at google.com; eraman at google.com; cfe-commits at lists.llvm.org
Subject: [PATCH] D56571: [RFC prototype] Implementation of asm-goto support in LLVM

efriedma added a comment.

Missing changes to lib/Analysis/CFG.cpp.



================
Comment at: lib/Sema/SemaStmtAsm.cpp:470
+    if (NS->isGCCAsmGoto() &&
+        Exprs[ConstraintIdx]->getStmtClass() == Stmt::AddrLabelExprClass)
+      break;
----------------
This looks suspicious; an AddrLabelExpr could be an input or output, e.g. `"r"(&&foo)`.


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https://reviews.llvm.org/D56571