[llvm] r183743 - Require members of llvm.used to be named.

[Rafael Espindola]

Author: rafael
Date: Tue Jun 11 08:18:13 2013
New Revision: 183743

URL: http://llvm.org/viewvc/llvm-project?rev=183743&view=rev
Log:
Require members of llvm.used to be named.

The effect of llvm.used is to introduce an invisible reference, so this seems
a reasonable restriction. It will be used to provide an easy ordering of
the entries in llvm.used.

Modified:
    llvm/trunk/docs/LangRef.rst
    llvm/trunk/lib/IR/Verifier.cpp

Modified: llvm/trunk/docs/LangRef.rst
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/docs/LangRef.rst?rev=183743&r1=183742&r2=183743&view=diff
==============================================================================
--- llvm/trunk/docs/LangRef.rst (original)
+++ llvm/trunk/docs/LangRef.rst Tue Jun 11 08:18:13 2013
@@ -2932,8 +2932,8 @@ The '``llvm.used``' Global Variable
 
 The ``@llvm.used`` global is an array which has
 :ref:`appending linkage <linkage_appending>`. This array contains a list of
-pointers to global variables, functions and aliases which may optionally have a
-pointer cast formed of bitcast or getelementptr. For example, a legal
+pointers to named global variables, functions and aliases which may optionally
+have a pointer cast formed of bitcast or getelementptr. For example, a legal
 use of it is:
 
 .. code-block:: llvm
@@ -2948,11 +2948,11 @@ use of it is:
 
 If a symbol appears in the ``@llvm.used`` list, then the compiler, assembler,
 and linker are required to treat the symbol as if there is a reference to the
-symbol that it cannot see. For example, if a variable has internal linkage and
-no references other than that from the ``@llvm.used`` list, it cannot be
-deleted. This is commonly used to represent references from inline asms and
-other things the compiler cannot "see", and corresponds to
-"``attribute((used))``" in GNU C.
+symbol that it cannot see (which is why they have to be named). For example, if
+a variable has internal linkage and no references other than that from the
+``@llvm.used`` list, it cannot be deleted. This is commonly used to represent
+references from inline asms and other things the compiler cannot "see", and
+corresponds to "``attribute((used))``" in GNU C.
 
 On some targets, the code generator must emit a directive to the
 assembler or object file to prevent the assembler and linker from

Modified: llvm/trunk/lib/IR/Verifier.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/IR/Verifier.cpp?rev=183743&r1=183742&r2=183743&view=diff
==============================================================================
--- llvm/trunk/lib/IR/Verifier.cpp (original)
+++ llvm/trunk/lib/IR/Verifier.cpp Tue Jun 11 08:18:13 2013
@@ -467,6 +467,7 @@ void Verifier::visitGlobalVariable(Globa
           Assert1(
               isa<GlobalVariable>(V) || isa<Function>(V) || isa<GlobalAlias>(V),
               "invalid llvm.used member", V);
+          Assert1(V->hasName(), "members of llvm.used must be named", V);
         }
       }
     }