[DebugInfo] Update loop metadata in stripNonLineTableDebugInfo
Summary:
Have stripNonLineTableDebugInfo() attach updated !llvm.loop metadata to
an instruction (instead of updating and then discarding the metadata).
This fixes "!dbg attachment points at wrong subprogram for function"
errors seen while archiving an iOS app.
It would be nice -- as a follow-up -- to catch this issue earlier,
perhaps by modifying the verifier to constrain where DILocations are
allowed. Any alternative suggestions appreciated.
rdar://61982466
Reviewers: aprantl, dsanders
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D79200
diff --git a/llvm/unittests/IR/DebugInfoTest.cpp b/llvm/unittests/IR/DebugInfoTest.cpp
index 9324790..c7ec3a9 100644
--- a/llvm/unittests/IR/DebugInfoTest.cpp
+++ b/llvm/unittests/IR/DebugInfoTest.cpp
@@ -6,11 +6,25 @@
//
//===----------------------------------------------------------------------===//
+#include "llvm/IR/DebugInfo.h"
+#include "llvm/AsmParser/Parser.h"
#include "llvm/IR/DebugInfoMetadata.h"
+#include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/Module.h"
+#include "llvm/IR/Verifier.h"
+#include "llvm/Support/SourceMgr.h"
#include "gtest/gtest.h"
using namespace llvm;
+static std::unique_ptr<Module> parseIR(LLVMContext &C, const char *IR) {
+ SMDiagnostic Err;
+ std::unique_ptr<Module> Mod = parseAssemblyString(IR, Err, C);
+ if (!Mod)
+ Err.print("DebugInfoTest", errs());
+ return Mod;
+}
+
namespace {
TEST(DINodeTest, getFlag) {
@@ -79,4 +93,56 @@
#undef CHECK_SPLIT
}
+TEST(StripTest, LoopMetadata) {
+ LLVMContext C;
+ std::unique_ptr<Module> M = parseIR(C, R"(
+ define void @f() !dbg !5 {
+ ret void, !dbg !10, !llvm.loop !11
+ }
+
+ !llvm.dbg.cu = !{!0}
+ !llvm.debugify = !{!3, !3}
+ !llvm.module.flags = !{!4}
+
+ !0 = distinct !DICompileUnit(language: DW_LANG_C, file: !1, producer: "debugify", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2)
+ !1 = !DIFile(filename: "loop.ll", directory: "/")
+ !2 = !{}
+ !3 = !{i32 1}
+ !4 = !{i32 2, !"Debug Info Version", i32 3}
+ !5 = distinct !DISubprogram(name: "f", linkageName: "f", scope: null, file: !1, line: 1, type: !6, scopeLine: 1, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !7)
+ !6 = !DISubroutineType(types: !2)
+ !7 = !{!8}
+ !8 = !DILocalVariable(name: "1", scope: !5, file: !1, line: 1, type: !9)
+ !9 = !DIBasicType(name: "ty32", size: 32, encoding: DW_ATE_unsigned)
+ !10 = !DILocation(line: 1, column: 1, scope: !5)
+ !11 = distinct !{!11, !10, !10}
+)");
+
+ // Look up the debug info emission kind for the CU via the loop metadata
+ // attached to the terminator. If, when stripping non-line table debug info,
+ // we update the terminator's metadata correctly, we should be able to
+ // observe the change in emission kind for the CU.
+ auto getEmissionKind = [&]() {
+ Instruction &I = *M->getFunction("f")->getEntryBlock().getFirstNonPHI();
+ MDNode *LoopMD = I.getMetadata(LLVMContext::MD_loop);
+ return cast<DILocation>(LoopMD->getOperand(1))
+ ->getScope()
+ ->getSubprogram()
+ ->getUnit()
+ ->getEmissionKind();
+ };
+
+ EXPECT_EQ(getEmissionKind(), DICompileUnit::FullDebug);
+
+ bool Changed = stripNonLineTableDebugInfo(*M);
+ EXPECT_TRUE(Changed);
+
+ EXPECT_EQ(getEmissionKind(), DICompileUnit::LineTablesOnly);
+
+ bool BrokenDebugInfo = false;
+ bool HardError = verifyModule(*M, &errs(), &BrokenDebugInfo);
+ EXPECT_FALSE(HardError);
+ EXPECT_FALSE(BrokenDebugInfo);
+}
+
} // end namespace