Have stripDebugInfo() also strip !llvm.loop annotations from all

instructions.

The !llvm.loop annotations consist of pointers into the debug info, so
when stripping the debug info (particularly important when it is
malformed!) !llvm.loop annotations need to be stripped as well, or
else the malformed debug info stays around.  This patch applies the
stripping to all instructions, not just terminator instructions.

rdar://73687049

Differential Revision: https://reviews.llvm.org/D96181

Author: adrian-prantl

llvm/lib/IR/DebugInfo.cpp

@@ -338,18 +338,13 @@ bool llvm::stripDebugInfo(Function &F) {
         Changed = true;
         I.setDebugLoc(DebugLoc());
       }
-    }
-
-    auto *TermInst = BB.getTerminator();
-    if (!TermInst)
-      // This is invalid IR, but we may not have run the verifier yet
-      continue;
-    if (auto *LoopID = TermInst->getMetadata(LLVMContext::MD_loop)) {
-      auto *NewLoopID = LoopIDsMap.lookup(LoopID);
-      if (!NewLoopID)
-        NewLoopID = LoopIDsMap[LoopID] = stripDebugLocFromLoopID(LoopID);
-      if (NewLoopID != LoopID)
-        TermInst->setMetadata(LLVMContext::MD_loop, NewLoopID);
+      if (auto *LoopID = I.getMetadata(LLVMContext::MD_loop)) {
+        auto *NewLoopID = LoopIDsMap.lookup(LoopID);
+        if (!NewLoopID)
+          NewLoopID = LoopIDsMap[LoopID] = stripDebugLocFromLoopID(LoopID);
+        if (NewLoopID != LoopID)
+          I.setMetadata(LLVMContext::MD_loop, NewLoopID);
+      }
     }
   }
   return Changed;

llvm/test/Verifier/llvm.loop-cu-strip.ll

@@ -0,0 +1,21 @@
+; RUN: llvm-as -disable-output < %s -o /dev/null 2>&1 | FileCheck %s
+; RUN: llvm-as < %s -o - | llvm-dis - | FileCheck %s --check-prefix=CHECK-STRIP
+; CHECK: DICompileUnit not listed in llvm.dbg.cu
+; CHECK: ignoring invalid debug info in
+; CHECK-NOT: DICompileUnit not listed in llvm.dbg.cu
+declare hidden void @g() local_unnamed_addr #1 align 2
+define hidden void @f() {
+  tail call void @g() #2, !llvm.loop !5
+  ret void
+}
+!llvm.module.flags = !{!0, !1}
+!0 = !{i32 2, !"Dwarf Version", i32 4}
+!1 = !{i32 2, !"Debug Info Version", i32 3}
+; CHECK-STRIP: ![[MD:.*]] = distinct !{![[MD]], !"fake loop metadata"}
+!5 = distinct !{!5, !6, !6, !"fake loop metadata"}
+!6 = !DILocation(line: 1325, column: 3, scope: !7)
+!7 = distinct !DISubprogram(name: "f", scope: !8, file: !8, line: 1324, type: !9, scopeLine: 1324, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition, unit: !11)
+!8 = !DIFile(filename: "/", directory: "f.cpp")
+!9 = !DISubroutineType(types: !10)
+!10 = !{}
+!11 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !8)