[DebugInfo] Simplify DIEInteger::SizeOf().

[ikudrin]

Summary

An AsmPrinter should always be provided to the method because some forms depend on its parameters. The only place in the codebase which passed a nullptr value was found in the unit tests, so the patch updates it to use some dummy AsmPrinter instead.

[ikudrin]

D87008 added creating a test AsmPrinter to the CodeGen unit tests, so it is now possible to fix the DIEHashTest.MemberBlock so that it provides an instance to the tested class.

[dblaikie]

Looks good - thanks!

llvm/unittests/CodeGen/DIEHashTest.cpp

34–39

I'd probably roll this into getAsmPrinter - but up to you.

[ikudrin]

llvm/unittests/CodeGen/DIEHashTest.cpp

34–39

ASSERT_THAT_EXPECTED breaks compilation if placed in a non-void function.

[dblaikie]

llvm/unittests/CodeGen/DIEHashTest.cpp

34–39

Fair enough - seems a bit subtle, but I don't have great alternative suggestions. Thanks for explaining!

llvm/lib/CodeGen/AsmPrinter/DIE.cpp

case dwarf::DW_FORM_sdata:
     return;
   default: llvm_unreachable("DIE Value form not supported yet");
   }
 }
 
 /// SizeOf - Determine size of integer value in bytes.
 ///
 unsigned DIEInteger::SizeOf(const AsmPrinter *AP, dwarf::Form Form) const {
-  dwarf::FormParams Params = {0, 0, dwarf::DWARF32};
-  if (AP)
-    Params = {AP->getDwarfVersion(), uint8_t(AP->getPointerSize()),
+  assert(AP && "AsmPrinter is required to set FormParams");
+  dwarf::FormParams Params = {AP->getDwarfVersion(),
+                              uint8_t(AP->getPointerSize()),
                               AP->OutStreamer->getContext().getDwarfFormat()};
 
   if (Optional<uint8_t> FixedSize = dwarf::getFixedFormByteSize(Form, Params))
     return *FixedSize;
 
   switch (Form) {
   case dwarf::DW_FORM_GNU_str_index:
   case dwarf::DW_FORM_GNU_addr_index:
   case dwarf::DW_FORM_ref_udata:

llvm/unittests/CodeGen/DIEHashTest.cpp

 //===- llvm/unittest/CodeGen/DIEHashTest.cpp ------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 #include "../lib/CodeGen/AsmPrinter/DIEHash.h"
+#include "TestAsmPrinter.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/BinaryFormat/Dwarf.h"
 #include "llvm/CodeGen/DIE.h"
 #include "llvm/CodeGen/DwarfStringPoolEntry.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/Format.h"
+#include "llvm/Support/Host.h"
+#include "llvm/Testing/Support/Error.h"
 #include "gtest/gtest.h"
 
 using namespace llvm;
 
 namespace {
 
 // Test fixture
 class DIEHashTest : public testing::Test {
 public:
   BumpPtrAllocator Alloc;
 
 private:
   StringMap<DwarfStringPoolEntry> Pool;
+  std::unique_ptr<TestAsmPrinter> TestPrinter;
+
+  void setupTestPrinter() {
+    auto ExpectedTestPrinter = TestAsmPrinter::create(
+        sys::getDefaultTargetTriple(), /*DwarfVersion=*/4, dwarf::DWARF32);
+    ASSERT_THAT_EXPECTED(ExpectedTestPrinter, Succeeded());
+    TestPrinter = std::move(ExpectedTestPrinter.get());
+  }
 
 public:
   DIEString getString(StringRef S) {
     DwarfStringPoolEntry Entry = {nullptr, 1, 1};
     return DIEString(DwarfStringPoolEntryRef(
         *Pool.insert(std::make_pair(S, Entry)).first, Entry.isIndexed()));
   }
+
+  AsmPrinter *getAsmPrinter() {
+    if (!TestPrinter)
+      setupTestPrinter();
+    return TestPrinter ? TestPrinter->getAP() : nullptr;
+  }
 };
 
 TEST_F(DIEHashTest, Data1) {
   DIEHash Hash;
   DIE &Die = *DIE::get(Alloc, dwarf::DW_TAG_base_type);
   DIEInteger Size(4);
   Die.addValue(Alloc, dwarf::DW_AT_byte_size, dwarf::DW_FORM_data1, Size);
   uint64_t MD5Res = Hash.computeTypeSignature(Die);

 }
 
 // Derived from:
 // struct A {
 //   const static float PI = 3.14;
 // };
 // A a;
 TEST_F(DIEHashTest, MemberBlock) {
+  if (!this->getAsmPrinter())
+    // TODO: Use GTEST_SKIP() when GTest is updated to version 1.10.0
+    return;
+
   DIE &A = *DIE::get(Alloc, dwarf::DW_TAG_structure_type);
   DIEInteger One(1);
   DIEString AStr = getString("A");
   A.addValue(Alloc, dwarf::DW_AT_name, dwarf::DW_FORM_strp, AStr);
   A.addValue(Alloc, dwarf::DW_AT_byte_size, dwarf::DW_FORM_data1, One);
   A.addValue(Alloc, dwarf::DW_AT_decl_file, dwarf::DW_FORM_data1, One);
   A.addValue(Alloc, dwarf::DW_AT_decl_line, dwarf::DW_FORM_data1, One);
 
TEST_F(DIEHashTest, MemberBlock) {
   PIBlock.addValue(Alloc, (dwarf::Attribute)0, dwarf::DW_FORM_data1, Blk3);
   PIBlock.addValue(Alloc, (dwarf::Attribute)0, dwarf::DW_FORM_data1, Blk4);
 
   PI->addValue(Alloc, dwarf::DW_AT_const_value, dwarf::DW_FORM_block1,
                &PIBlock);
 
   A.addChild(std::move(PI));
 
-  uint64_t MD5Res = DIEHash().computeTypeSignature(A);
+  uint64_t MD5Res = DIEHash(this->getAsmPrinter()).computeTypeSignature(A);
   ASSERT_EQ(0x493af53ad3d3f651ULL, MD5Res);
 }
 }