[llvm] r309657 - [MetaRenamer] Leave `@main` alone.

[Davide Italiano via llvm-commits]

Author: davide
Date: Mon Jul 31 22:14:45 2017
New Revision: 309657

URL: http://llvm.org/viewvc/llvm-project?rev=309657&view=rev
Log:
[MetaRenamer] Leave `@main` alone.

To the best of my knowledge -metarenamer is used in two cases:
1) obfuscate names, when e.g. they contain informations that
can't be shared.
2) Improve clarity of the textual IR for testcases.

One of the usecases if getting the output of `opt` and passing it
to the lli interpreter to run the test. If metarenamer renames
@main, lli can't find an entry point.

Added:
    llvm/trunk/test/Transforms/MetaRenamer/main.ll
Modified:
    llvm/trunk/lib/Transforms/Utils/MetaRenamer.cpp

Modified: llvm/trunk/lib/Transforms/Utils/MetaRenamer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/MetaRenamer.cpp?rev=309657&r1=309656&r2=309657&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/MetaRenamer.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/MetaRenamer.cpp Mon Jul 31 22:14:45 2017
@@ -123,7 +123,11 @@ namespace {
             TLI.getLibFunc(F, Tmp))
           continue;
 
-        F.setName(renamer.newName());
+        // Leave @main alone. The output of -metarenamer might be passed to
+        // lli for execution and the latter needs a main entry point.
+        if (Name != "main")
+          F.setName(renamer.newName());
+
         runOnFunction(F);
       }
       return true;

Added: llvm/trunk/test/Transforms/MetaRenamer/main.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/MetaRenamer/main.ll?rev=309657&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/MetaRenamer/main.ll (added)
+++ llvm/trunk/test/Transforms/MetaRenamer/main.ll Mon Jul 31 22:14:45 2017
@@ -0,0 +1,15 @@
+; Make sure @main is left untouched.
+; RUN: opt -metarenamer -S %s | FileCheck %s
+
+; CHECK: define void @main
+; CHECK: call void @main
+
+define void @main() {
+  call void @patatino()
+  ret void
+}
+
+define void @patatino() {
+  call void @main()
+  ret void
+}