[IR] Introduce helpers to skip debug instructions (NFC)
This patch introduces two helpers to make it easier to ignore debug
intrinsics:
- Instruction::getNextNonDebugInstruction()
This is just like Instruction::getNextNode(), except that it skips debug
info.
- skipDebugInfo(BasicBlock::iterator)
A free function which advances a BasicBlock iterator past any debug
info. This is a no-op when the iterator already points to a non-debug
instruction.
Part of: llvm.org/PR37728
Related to: https://reviews.llvm.org/D47874
Differential Revision: https://reviews.llvm.org/D48305
llvm-svn: 335083
diff --git a/llvm/unittests/IR/InstructionsTest.cpp b/llvm/unittests/IR/InstructionsTest.cpp
index 40a1d82..69e7454 100644
--- a/llvm/unittests/IR/InstructionsTest.cpp
+++ b/llvm/unittests/IR/InstructionsTest.cpp
@@ -7,6 +7,7 @@
//
//===----------------------------------------------------------------------===//
+#include "llvm/AsmParser/Parser.h"
#include "llvm/IR/Instructions.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/Analysis/ValueTracking.h"
@@ -21,6 +22,7 @@
#include "llvm/IR/Module.h"
#include "llvm/IR/NoFolder.h"
#include "llvm/IR/Operator.h"
+#include "llvm/Support/SourceMgr.h"
#include "gmock/gmock-matchers.h"
#include "gtest/gtest.h"
#include <memory>
@@ -28,6 +30,14 @@
namespace llvm {
namespace {
+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("InstructionsTests", errs());
+ return Mod;
+}
+
TEST(InstructionsTest, ReturnInst) {
LLVMContext C;
@@ -829,5 +839,44 @@
EXPECT_TRUE(ShuffleVectorInst::isTransposeMask(ConstantVector::get({C1, C3})));
}
+TEST(InstructionsTest, SkipDebug) {
+ LLVMContext C;
+ std::unique_ptr<Module> M = parseIR(C,
+ R"(
+ declare void @llvm.dbg.value(metadata, metadata, metadata)
+
+ define void @f() {
+ entry:
+ call void @llvm.dbg.value(metadata i32 0, metadata !11, metadata !DIExpression()), !dbg !13
+ ret void
+ }
+
+ !llvm.dbg.cu = !{!0}
+ !llvm.module.flags = !{!3, !4}
+ !0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 6.0.0", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !2)
+ !1 = !DIFile(filename: "t2.c", directory: "foo")
+ !2 = !{}
+ !3 = !{i32 2, !"Dwarf Version", i32 4}
+ !4 = !{i32 2, !"Debug Info Version", i32 3}
+ !8 = distinct !DISubprogram(name: "f", scope: !1, file: !1, line: 1, type: !9, isLocal: false, isDefinition: true, scopeLine: 1, isOptimized: false, unit: !0, retainedNodes: !2)
+ !9 = !DISubroutineType(types: !10)
+ !10 = !{null}
+ !11 = !DILocalVariable(name: "x", scope: !8, file: !1, line: 2, type: !12)
+ !12 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+ !13 = !DILocation(line: 2, column: 7, scope: !8)
+ )");
+ ASSERT_TRUE(M);
+ Function *F = cast<Function>(M->getNamedValue("f"));
+ BasicBlock &BB = F->front();
+
+ // The first non-debug instruction is the terminator.
+ auto *Term = BB.getTerminator();
+ EXPECT_EQ(Term, BB.begin()->getNextNonDebugInstruction());
+ EXPECT_EQ(Term->getIterator(), skipDebugInfo(BB.begin()));
+
+ // After the terminator, there are no non-debug instructions.
+ EXPECT_EQ(nullptr, Term->getNextNonDebugInstruction());
+}
+
} // end anonymous namespace
} // end namespace llvm