[PATCH] D99382: Add -disable-verify flag to llvm-link.

[Nick Lewycky via Phabricator via llvm-commits]

nickwasmer created this revision.
nickwasmer added reviewers: tejohnson, tra, jdoerfert.
nickwasmer added a project: LLVM.
nickwasmer requested review of this revision.
Herald added a subscriber: llvm-commits.

This flag allows the developer to see the result of linking even if it fails the verifier, as a step in debugging cases where the linked module fails the verifier. Same as opt -disable-verify.

No test is introduced. I don't want to write a test that relies on any manner of producing an invalid output that is a bug that should be fixed, as then the test would break if a bug is fixed.

There's an alternative that I considered but did not implement. Unlike opt, llvm-link has many intermediate outputs as it links more files and runs the verifier on each one. We could instead have a flag that outputs a module and stop after running the verifier and seeing a failure. This would allow us to find issues closer to the source, but it also requires that the verifier not crash on the invalid input in question.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D99382

Files:
  llvm/tools/llvm-link/llvm-link.cpp


Index: llvm/tools/llvm-link/llvm-link.cpp
===================================================================
--- llvm/tools/llvm-link/llvm-link.cpp
+++ llvm/tools/llvm-link/llvm-link.cpp
@@ -110,6 +110,9 @@
     cl::desc("Preserve use-list order when writing LLVM assembly."),
     cl::init(false), cl::Hidden);
 
+static cl::opt<bool>
+NoVerify("disable-verify", cl::desc("Do not run the verifier"), cl::Hidden);
+
 static ExitOnError ExitOnErr;
 
 // Read the specified bitcode file in and return it. This routine searches the
@@ -311,7 +314,7 @@
     // Load the specified source module.
     auto &SrcModule = ModuleLoaderCache(argv0, FileName);
 
-    if (verifyModule(SrcModule, &errs())) {
+    if (!NoVerify && verifyModule(SrcModule, &errs())) {
       errs() << argv0 << ": " << FileName;
       WithColor::error() << "input module is broken!\n";
       return false;
@@ -372,7 +375,7 @@
     // Note that when ODR merging types cannot verify input files in here When
     // doing that debug metadata in the src module might already be pointing to
     // the destination.
-    if (DisableDITypeMap && verifyModule(*M, &errs())) {
+    if (DisableDITypeMap && !NoVerify && verifyModule(*M, &errs())) {
       errs() << argv0 << ": " << File << ": ";
       WithColor::error() << "input module is broken!\n";
       return false;
@@ -471,7 +474,7 @@
     return 1;
   }
 
-  if (verifyModule(*Composite, &errs())) {
+  if (!NoVerify && verifyModule(*Composite, &errs())) {
     errs() << argv[0] << ": ";
     WithColor::error() << "linked module is broken!\n";
     return 1;


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