[Debugify] Print errors and warnings to stderr

[gramanas]

Summary

Currently debugify clutters the terminal with it's output.
With this patch all the errors and warnings output generated goes to stderr.

The PASS or FAIL still ends up in stdout.

This change let's us use debugify without taking away the ability to pipe the output to other llvm tools.

A followup patch will dump the errors/warnings and the generated IR with the problem to a file.

[gramanas]

Just like llvm-lit I left the PASS or FAIL to stdout.

On second thoughts this breaks the piping as well. Should I move it to the error stream as well?

[vsk]

In D46941#1101155, @gramanas wrote:

Just like llvm-lit I left the PASS or FAIL to stdout.

On second thoughts this breaks the piping as well. Should I move it to the error stream as well?

Yes, it’d be great to have piping working with ‘opt -debugify’.

[gramanas]

• [Debugify] All output now goes to stderr

[vsk]

LGTM, thanks!

[gramanas]

Test that debugify can be safely used with piping

[gramanas]

The tests were missing the input file argument

[gramanas]

The output of the tests should go to /dev/null

[gramanas]

fix mistake in tests

[gramanas]

• ...

[vsk]

Thanks for cleaning up the tests further. I think it's worthwhile to not have run lines which clutter up the output because it slows down the llvm-lit -a -Dopt="opt -debugify ..." workflow.

Looks good.

[gramanas]

commited r332642

test/DebugInfo/debugify-each.ll

-; RUN: opt -debugify-each -O3 -S -o /dev/null < %s > %t
+; RUN: opt -debugify-each -O3 -S -o /dev/null < %s 2> %t
 ; RUN: FileCheck %s -input-file=%t -check-prefix=MODULE-PASS
 ; RUN: FileCheck %s -input-file=%t -check-prefix=FUNCTION-PASS
 
-; RUN: opt -enable-debugify -debugify-each -O3 -S -o /dev/null < %s > %t
+; RUN: opt -enable-debugify -debugify-each -O3 -S -o /dev/null < %s 2> %t
 ; RUN: FileCheck %s -input-file=%t -check-prefix=MODULE-PASS
 ; RUN: FileCheck %s -input-file=%t -check-prefix=FUNCTION-PASS
 
-; RUN: opt -debugify-each -instrprof -instrprof -sroa -sccp -S -o /dev/null < %s > %t
+; RUN: opt -debugify-each -instrprof -instrprof -sroa -sccp -S -o /dev/null < %s 2> %t
 ; RUN: FileCheck %s -input-file=%t -check-prefix=MODULE-PASS
 ; RUN: FileCheck %s -input-file=%t -check-prefix=FUNCTION-PASS
 
+; Verify that debugify each can be safely used with piping
+; RUN: opt -debugify-each -O1 < %s | opt -O2 -o /dev/null
+
 define void @foo() {
   ret void
 }
 
 define void @bar() {
   ret void
 }
 

test/DebugInfo/debugify.ll

 ; RUN: opt -debugify -S -o - < %s | FileCheck %s
 ; RUN: opt -passes=debugify -S -o - < %s | FileCheck %s
 
 ; RUN: opt -debugify -debugify -S -o - < %s 2>&1 | \
 ; RUN:   FileCheck %s -check-prefix=CHECK-REPEAT
 ; RUN: opt -passes=debugify,debugify -S -o - < %s 2>&1 | \
 ; RUN:   FileCheck %s -check-prefix=CHECK-REPEAT
 
 ; RUN: opt -debugify -check-debugify -S -o - < %s | \
 ; RUN:   FileCheck %s -implicit-check-not="CheckModuleDebugify: FAIL"
 ; RUN: opt -passes=debugify,check-debugify -S -o - < %s | \
 ; RUN:   FileCheck %s -implicit-check-not="CheckModuleDebugify: FAIL"
 ; RUN: opt -enable-debugify -passes=verify -S -o - < %s | \
 ; RUN:   FileCheck %s -implicit-check-not="CheckModuleDebugify: FAIL"
 
-; RUN: opt -debugify -strip -check-debugify -S -o - < %s | \
+; RUN: opt -debugify -strip -check-debugify -S -o - < %s 2>&1 | \
 ; RUN:   FileCheck %s -check-prefix=CHECK-FAIL
 
-; RUN: opt -enable-debugify -strip -S -o - < %s | \
+; RUN: opt -enable-debugify -strip -S -o - < %s 2>&1 | \
 ; RUN:   FileCheck %s -check-prefix=CHECK-FAIL
 
-; RUN: opt -enable-debugify -S -o - < %s | FileCheck %s -check-prefix=PASS
+; RUN: opt -enable-debugify -S -o - < %s 2>&1 | FileCheck %s -check-prefix=PASS
+
+; Verify that debugify can be safely used with piping
+; RUN: opt -enable-debugify -O1 < %s | opt -O2 -o /dev/null
+; RUN: opt -debugify -mem2reg -check-debugify < %s | opt -O2 -o /dev/null
 
 ; CHECK-LABEL: define void @foo
 define void @foo() {
 ; CHECK: ret void, !dbg ![[RET1:.*]]
   ret void
 }
 
 ; CHECK-LABEL: define i32 @bar

test/Transforms/Mem2Reg/PromoteMemToRegister.ll

 ; Simple sanity check testcase.  Both alloca's should be eliminated.
-; RUN: opt < %s -debugify -mem2reg -check-debugify -S | FileCheck %s
+; RUN: opt < %s -debugify -mem2reg -check-debugify -S 2>&1 | FileCheck %s
 
 ; CHECK-NOT: alloca
 ; CHECK: CheckModuleDebugify [{{.*}}]: PASS
 
 define double @testfunc(i32 %i, double %j) {
   %I = alloca i32   ; <i32*> [#uses=4]
   %J = alloca double    ; <double*> [#uses=2]
   store i32 %i, i32* %I

tools/opt/Debugify.cpp

for (Instruction &I : instructions(F)) {
         continue;
 
       auto DL = I.getDebugLoc();
       if (DL && DL.getLine() != 0) {
         MissingLines.reset(DL.getLine() - 1);
         continue;
       }
 
-      outs() << "ERROR: Instruction with empty DebugLoc in function ";
-      outs() << F.getName() << " --";
-      I.print(outs());
-      outs() << "\n";
+      errs() << "ERROR: Instruction with empty DebugLoc in function ";
+      errs() << F.getName() << " --";
+      I.print(errs());
+      errs() << "\n";
       HasErrors = true;
     }
 
     // Find missing variables.
     for (Instruction &I : instructions(F)) {
       auto *DVI = dyn_cast<DbgValueInst>(&I);
       if (!DVI)
         continue;
 
       unsigned Var = ~0U;
       (void)to_integer(DVI->getVariable()->getName(), Var, 10);
       assert(Var <= OriginalNumVars && "Unexpected name for DILocalVariable");
       MissingVars.reset(Var - 1);
     }
   }
 
   // Print the results.
   for (unsigned Idx : MissingLines.set_bits())
-    outs() << "WARNING: Missing line " << Idx + 1 << "\n";
+    errs() << "WARNING: Missing line " << Idx + 1 << "\n";
 
   for (unsigned Idx : MissingVars.set_bits())
-    outs() << "ERROR: Missing variable " << Idx + 1 << "\n";
+    errs() << "ERROR: Missing variable " << Idx + 1 << "\n";
   HasErrors |= MissingVars.count() > 0;
 
-  outs() << Banner << " [" << NameOfWrappedPass << "]: "
+  errs() << Banner << " [" << NameOfWrappedPass << "]: "
          << (HasErrors ? "FAIL" : "PASS") << '\n';
   if (HasErrors) {
-    outs() << "Module IR Dump\n";
-    M.print(outs(), nullptr, false);
+    errs() << "Module IR Dump\n";
+    M.print(errs(), nullptr, false);
   }
 
   // Strip the Debugify Metadata if required.
   if (Strip) {
     StripDebugInfo(M);
     M.eraseNamedMetadata(NMD);
     return true;
   }