Add support for hashing attributes with DW_FORM_block. This required

passing down an AsmPrinter instance so we could compute the size of
the block which could be target specific. All of the test cases in
the unittest don't have any target specific data so we can use a NULL
AsmPrinter there. This also depends upon block data being added as
integers.

We can now hash the entire fission-cu.ll compile unit so turn the
flag on there with the hash value.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201752 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/AsmPrinter/DIEHash.cpp

@@ -17,6 +17,7 @@
 #include "DIE.h"
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/StringRef.h"
+#include "llvm/CodeGen/AsmPrinter.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/Dwarf.h"
 #include "llvm/Support/Endian.h"
@@ -269,6 +270,15 @@ void DIEHash::hashDIEEntry(dwarf::Attribute Attribute, dwarf::Tag Tag,
   computeHash(Entry);
 }
 
+// Hash all of the values in a block like set of values. This assumes that
+// all of the data is going to be added as integers.
+void DIEHash::hashBlockData(const SmallVectorImpl<DIEValue *> &Values) {
+  for (SmallVectorImpl<DIEValue *>::const_iterator I = Values.begin(),
+                                                   E = Values.end();
+       I != E; ++I)
+    Hash.update((uint64_t)cast<DIEInteger>(*I)->getValue());
+}
+
 // Hash an individual attribute \param Attr based on the type of attribute and
 // the form.
 void DIEHash::hashAttribute(AttrEntry Attr, dwarf::Tag Tag) {
@@ -321,6 +331,22 @@ void DIEHash::hashAttribute(AttrEntry Attr, dwarf::Tag Tag) {
     addULEB128(dwarf::DW_FORM_flag);
     addULEB128((int64_t)cast<DIEInteger>(Value)->getValue());
     break;
+  case dwarf::DW_FORM_exprloc:
+  case dwarf::DW_FORM_block1:
+  case dwarf::DW_FORM_block2:
+  case dwarf::DW_FORM_block4:
+  case dwarf::DW_FORM_block:
+    addULEB128('A');
+    addULEB128(Attribute);
+    addULEB128(dwarf::DW_FORM_block);
+    if (isa<DIEBlock>(Value)) {
+      addULEB128(cast<DIEBlock>(Value)->ComputeSize(AP));
+      hashBlockData(cast<DIEBlock>(Value)->getValues());
+    } else {
+      addULEB128(cast<DIELoc>(Value)->ComputeSize(AP));
+      hashBlockData(cast<DIELoc>(Value)->getValues());
+    }
+    break;
   default:
     llvm_unreachable("Add support for additional forms");
   }

lib/CodeGen/AsmPrinter/DIEHash.h

@@ -17,6 +17,7 @@
 
 namespace llvm {
 
+class AsmPrinter;
 class CompileUnit;
 
 /// \brief An object containing the capability of hashing and adding hash
@@ -84,6 +85,8 @@ class DIEHash {
   };
 
 public:
+  DIEHash(AsmPrinter *A = NULL) : AP(A) {}
+
   /// \brief Computes the ODR signature.
   uint64_t computeDIEODRSignature(const DIE &Die);
 
@@ -122,6 +125,10 @@ private:
   /// \brief Hashes the attributes in \param Attrs in order.
   void hashAttributes(const DIEAttrs &Attrs, dwarf::Tag Tag);
 
+  /// \brief Hashes the data in a block like DIEValue, e.g. DW_FORM_block or
+  /// DW_FORM_exprloc.
+  void hashBlockData(const SmallVectorImpl<DIEValue *> &Values);
+
   /// \brief Hashes an individual attribute.
   void hashAttribute(AttrEntry Attr, dwarf::Tag Tag);
 
@@ -143,6 +150,7 @@ private:
 
 private:
   MD5 Hash;
+  AsmPrinter *AP;
   DenseMap<const DIE *, unsigned> Numbering;
 };
 }

lib/CodeGen/AsmPrinter/DwarfDebug.cpp

@@ -1007,7 +1007,7 @@ void DwarfDebug::finalizeModuleInfo() {
         // This should be a unique identifier when we want to build .dwp files.
         uint64_t ID = 0;
         if (GenerateCUHash) {
-          DIEHash CUHash;
+          DIEHash CUHash(Asm);
           ID = CUHash.computeCUSignature(*TheU->getUnitDie());
         }
         TheU->addUInt(TheU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,

test/DebugInfo/X86/fission-cu.ll

@@ -1,4 +1,4 @@
-; RUN: llc -split-dwarf=Enable -O0 %s -mtriple=x86_64-unknown-linux-gnu -filetype=obj -o %t
+; RUN: llc -split-dwarf=Enable -generate-cu-hash -O0 %s -mtriple=x86_64-unknown-linux-gnu -filetype=obj -o %t
 ; RUN: llvm-dwarfdump -debug-dump=all %t | FileCheck %s
 ; RUN: llvm-readobj --relocations %t | FileCheck --check-prefix=OBJ %s
 
@@ -61,7 +61,7 @@
 ; CHECK: DW_AT_GNU_dwo_name [DW_FORM_strp] ( .debug_str[0x00000000] = "baz.dwo")
 ; CHECK: DW_AT_GNU_addr_base [DW_FORM_sec_offset]                   (0x00000000)
 ; CHECK: DW_AT_comp_dir [DW_FORM_strp]     ( .debug_str[0x00000008] = "/usr/local/google/home/echristo/tmp")
-; CHECK: DW_AT_GNU_dwo_id [DW_FORM_data8]  (0x0000000000000000)
+; CHECK: DW_AT_GNU_dwo_id [DW_FORM_data8]  (0x1f1f859683d49324)
 ; CHECK: DW_AT_low_pc [DW_FORM_addr]       (0x0000000000000000)
 
 ; Check that the rest of the compile units have information.
@@ -73,7 +73,7 @@
 ; CHECK-NOT: DW_AT_low_pc
 ; CHECK-NOT: DW_AT_stmt_list
 ; CHECK-NOT: DW_AT_comp_dir
-; CHECK: DW_AT_GNU_dwo_id [DW_FORM_data8]  (0x0000000000000000)
+; CHECK: DW_AT_GNU_dwo_id [DW_FORM_data8]  (0x1f1f859683d49324)
 ; CHECK: DW_TAG_variable
 ; CHECK: DW_AT_name [DW_FORM_GNU_str_index]     ( indexed (00000002) string = "a")
 ; CHECK: DW_AT_type [DW_FORM_ref4]       (cu + 0x{{[0-9a-f]*}} => {[[TYPE:0x[0-9a-f]*]]})

unittests/CodeGen/DIEHashTest.cpp

@@ -594,4 +594,59 @@ TEST(DIEHashTest, MemberSdata) {
   uint64_t MD5Res = DIEHash().computeTypeSignature(A);
   ASSERT_EQ(0x9a216000dd3788a7ULL, MD5Res);
 }
+
+// Derived from:
+// struct A {
+//   const static float PI = 3.14;
+// };
+// A a;
+TEST(DIEHashTest, MemberBlock) {
+  DIE A(dwarf::DW_TAG_structure_type);
+  DIEInteger One(1);
+  DIEString AStr(&One, "A");
+  A.addValue(dwarf::DW_AT_name, dwarf::DW_FORM_strp, &AStr);
+  A.addValue(dwarf::DW_AT_byte_size, dwarf::DW_FORM_data1, &One);
+  A.addValue(dwarf::DW_AT_decl_file, dwarf::DW_FORM_data1, &One);
+  A.addValue(dwarf::DW_AT_decl_line, dwarf::DW_FORM_data1, &One);
+
+  DIEInteger Four(4);
+  DIEString FStr(&One, "float");
+  DIE *FloatTyDIE = new DIE(dwarf::DW_TAG_base_type);
+  FloatTyDIE->addValue(dwarf::DW_AT_byte_size, dwarf::DW_FORM_data1, &Four);
+  FloatTyDIE->addValue(dwarf::DW_AT_encoding, dwarf::DW_FORM_data1, &Four);
+  FloatTyDIE->addValue(dwarf::DW_AT_name, dwarf::DW_FORM_strp, &FStr);
+
+  DIEEntry FloatTy(FloatTyDIE);
+  DIE *PITyDIE = new DIE(dwarf::DW_TAG_const_type);
+  PITyDIE->addValue(dwarf::DW_AT_type, dwarf::DW_FORM_ref4, &FloatTy);
+
+  DIEEntry PITy(PITyDIE);
+  DIE *PI = new DIE(dwarf::DW_TAG_member);
+  DIEString PIStr(&One, "PI");
+  DIEInteger Two(2);
+  PI->addValue(dwarf::DW_AT_name, dwarf::DW_FORM_strp, &PIStr);
+  PI->addValue(dwarf::DW_AT_decl_file, dwarf::DW_FORM_data1, &One);
+  PI->addValue(dwarf::DW_AT_decl_line, dwarf::DW_FORM_data1, &Two);
+  PI->addValue(dwarf::DW_AT_type, dwarf::DW_FORM_ref4, &PITy);
+  PI->addValue(dwarf::DW_AT_external, dwarf::DW_FORM_flag_present, &One);
+  PI->addValue(dwarf::DW_AT_declaration, dwarf::DW_FORM_flag_present, &One);
+
+  DIEBlock *PIBlock = new DIEBlock();
+  DIEInteger Blk1(0xc3);
+  DIEInteger Blk2(0xf5);
+  DIEInteger Blk3(0x48);
+  DIEInteger Blk4(0x40);
+
+  PIBlock->addValue((dwarf::Attribute)0, dwarf::DW_FORM_data1, &Blk1);
+  PIBlock->addValue((dwarf::Attribute)0, dwarf::DW_FORM_data1, &Blk2);
+  PIBlock->addValue((dwarf::Attribute)0, dwarf::DW_FORM_data1, &Blk3);
+  PIBlock->addValue((dwarf::Attribute)0, dwarf::DW_FORM_data1, &Blk4);
+
+  PI->addValue(dwarf::DW_AT_const_value, dwarf::DW_FORM_block1, PIBlock);
+
+  A.addChild(PI);
+
+  uint64_t MD5Res = DIEHash().computeTypeSignature(A);
+  ASSERT_EQ(0x493af53ad3d3f651ULL, MD5Res);
+}
 }