Verifier: Call verifyModule() from llc and opt

Change `llc` and `opt` to run `verifyModule()`.  This ensures that we
check the full module before `FunctionPass::doInitialization()` ever
gets called (I was getting crashes in `DwarfDebug` instead of verifier
failures when testing a WIP patch that checks operands of compile
units).  In `opt`, also move up debug-info-stripping so that it still
runs before verification.

There was a fair bit of broken code that was sitting in tree.
Interestingly, some were cases of a `select` that referred to itself in
`-instcombine` tests (apparently an intermediate result).  I split them
off to `*-noverify.ll` tests with RUN lines like this:

    opt < %s -S -disable-verify -instcombine | opt -S | FileCheck %s

This avoids verifying the input file (so we can get the broken code into
`-instcombine), but still verifies the output with a second call to
`opt` (to verify that `-instcombine` will clean it up like it should).

llvm-svn: 233432

1 files changed, 13 insertions, 4 deletions

diff --git a/llvm/tools/opt/opt.cpp b/llvm/tools/opt/opt.cpp
index c1e120af540..86fbed70036 100644
--- a/llvm/tools/opt/opt.cpp
+++ b/llvm/tools/opt/opt.cpp
@@ -25,6 +25,7 @@
 #include "llvm/Bitcode/BitcodeWriterPass.h"
 #include "llvm/CodeGen/CommandFlags.h"
 #include "llvm/IR/DataLayout.h"
+#include "llvm/IR/DebugInfo.h"
 #include "llvm/IR/IRPrintingPasses.h"
 #include "llvm/IR/LLVMContext.h"
 #include "llvm/IR/LegacyPassNameParser.h"
@@ -345,6 +346,18 @@ int main(int argc, char **argv) {
     return 1;
   }
 
+  // Strip debug info before running the verifier.
+  if (StripDebug)
+    StripDebugInfo(*M);
+
+  // Immediately run the verifier to catch any problems before starting up the
+  // pass pipelines.  Otherwise we can crash on broken code during
+  // doInitialization().
+  if (!NoVerify && verifyModule(*M, &errs())) {
+    errs() << argv[0] << ": " << InputFilename << ": error: does not verify\n";
+    return 1;
+  }
+
   // If we are supposed to override the target triple, do so now.
   if (!TargetTriple.empty())
     M->setTargetTriple(Triple::normalize(TargetTriple));
@@ -449,10 +462,6 @@ int main(int argc, char **argv) {
     NoOutput = true;
   }
 
-  // If the -strip-debug command line option was specified, add it.
-  if (StripDebug)
-    addPass(Passes, createStripSymbolsPass(true));
-
   // Create a new optimization pass for each one specified on the command line
   for (unsigned i = 0; i < PassList.size(); ++i) {
     if (StandardLinkOpts &&