[GlobalISel] fix crash in IRTranslator, MachineIRBuilder when translating @llvm.dbg.value intrinsic and using -debug

[gargaroff]

Summary

Fix crash when using -debug caused by the GlobalISel observer trying to print
an incomplete DBG_VALUE instruction. This was caused by the MachineIRBuilder
using buildInstr, which immediately inserts the instruction causing print,
instead of using BuildMI to first build up the instruction and using
insertInstr when finished.

Add RUN-line to existing debug-insts.ll test with -debug flag set to make sure
no crash is happening.

Also fixed a missing %s in the 2nd RUN-line of the same test.

[arsenm]

llvm/lib/CodeGen/GlobalISel/MachineIRBuilder.cpp

100

buildInstrNoInsert?

[gargaroff]

use buildInstrNoInsert instead of BuildMI

[gargaroff]

llvm/lib/CodeGen/GlobalISel/MachineIRBuilder.cpp

100

Thanks! Didn't realize that there is such a helper.

[gargaroff]

Ping

[gargaroff]

Ping

[gargaroff]

I've updated the reviewers, since this is obviously not going forward otherwise. Hope it's ok with all of you!

[MaskRay]

llvm/test/CodeGen/AArch64/GlobalISel/debug-insts.ll

3

-debug needs REQUIRES: asserts

I fixed it.

[gargaroff]

llvm/test/CodeGen/AArch64/GlobalISel/debug-insts.ll

3

Thank you very much! I wasn't aware of this.

llvm/lib/CodeGen/GlobalISel/MachineIRBuilder.cpp

 MachineInstrBuilder MachineIRBuilder::buildConstDbgValue(const Constant &C,
                                                          const MDNode *Variable,
                                                          const MDNode *Expr) {
   assert(isa<DILocalVariable>(Variable) && "not a variable");
   assert(cast<DIExpression>(Expr)->isValid() && "not an expression");
   assert(
       cast<DILocalVariable>(Variable)->isValidLocationForIntrinsic(getDL()) &&
       "Expected inlined-at fields to agree");
-  auto MIB = buildInstr(TargetOpcode::DBG_VALUE);
+  auto MIB = buildInstrNoInsert(TargetOpcode::DBG_VALUE);
   if (auto *CI = dyn_cast<ConstantInt>(&C)) {
     if (CI->getBitWidth() > 64)
       MIB.addCImm(CI);
     else
       MIB.addImm(CI->getZExtValue());
   } else if (auto *CFP = dyn_cast<ConstantFP>(&C)) {
     MIB.addFPImm(CFP);
   } else {
     // Insert %noreg if we didn't find a usable constant and had to drop it.
     MIB.addReg(0U);
   }
 
-  return MIB.addImm(0).addMetadata(Variable).addMetadata(Expr);
+  MIB.addImm(0).addMetadata(Variable).addMetadata(Expr);
+  return insertInstr(MIB);
 }
 
 MachineInstrBuilder MachineIRBuilder::buildDbgLabel(const MDNode *Label) {
   assert(isa<DILabel>(Label) && "not a label");
   assert(cast<DILabel>(Label)->isValidLocationForIntrinsic(State.DL) &&
          "Expected inlined-at fields to agree");
   auto MIB = buildInstr(TargetOpcode::DBG_LABEL);
 

llvm/test/CodeGen/AArch64/GlobalISel/debug-insts.ll

 ; RUN: llc -global-isel -mtriple=aarch64 %s -stop-after=irtranslator -o - | FileCheck %s
-; RUN: llc -mtriple=aarch64 -global-isel --global-isel-abort=0 -o /dev/null
+; RUN: llc -mtriple=aarch64 -global-isel --global-isel-abort=0 %s -o /dev/null
+; RUN: llc -mtriple=aarch64 -global-isel --global-isel-abort=0 %s -o /dev/null -debug
 
 ; CHECK-LABEL: name: debug_declare
 ; CHECK: stack:
 ; CHECK:    - { id: {{.*}}, name: in.addr, type: default, offset: 0, size: {{.*}}, alignment: {{.*}},
 ; CHECK-NEXT: callee-saved-register: '', callee-saved-restored: true,
 ; CHECK-NEXT: debug-info-variable: '!11', debug-info-expression: '!DIExpression()',
 define void @debug_declare(i32 %in) #0 !dbg !7 {
 entry: