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authorDavid Blaikie <dblaikie@gmail.com>2013-10-25 18:38:43 +0000
committerDavid Blaikie <dblaikie@gmail.com>2013-10-25 18:38:43 +0000
commita954618c6e6c5f94d3cedc0b6bc19dbc49e56ac2 (patch)
treee3bf6e25cc80684422154e73ad3d949bdad767ba
parented400c710890313116aeea9a070dce7956da44d1 (diff)
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DIEHash: Summary hashing of nested types
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193427 91177308-0d34-0410-b5e6-96231b3b80d8
-rw-r--r--include/llvm/Support/Dwarf.h28
-rw-r--r--lib/CodeGen/AsmPrinter/DIEHash.cpp25
-rw-r--r--lib/CodeGen/AsmPrinter/DIEHash.h2
-rw-r--r--unittests/CodeGen/DIEHashTest.cpp19
4 files changed, 73 insertions, 1 deletions
diff --git a/include/llvm/Support/Dwarf.h b/include/llvm/Support/Dwarf.h
index f3f4274..23bbd1c 100644
--- a/include/llvm/Support/Dwarf.h
+++ b/include/llvm/Support/Dwarf.h
@@ -141,6 +141,34 @@ enum Tag LLVM_ENUM_INT_TYPE(uint16_t) {
DW_TAG_hi_user = 0xffff
};
+inline bool isType(Tag T) {
+ switch (T) {
+ case DW_TAG_array_type:
+ case DW_TAG_class_type:
+ case DW_TAG_interface_type:
+ case DW_TAG_enumeration_type:
+ case DW_TAG_pointer_type:
+ case DW_TAG_reference_type:
+ case DW_TAG_rvalue_reference_type:
+ case DW_TAG_string_type:
+ case DW_TAG_structure_type:
+ case DW_TAG_subroutine_type:
+ case DW_TAG_union_type:
+ case DW_TAG_ptr_to_member_type:
+ case DW_TAG_set_type:
+ case DW_TAG_subrange_type:
+ case DW_TAG_base_type:
+ case DW_TAG_const_type:
+ case DW_TAG_file_type:
+ case DW_TAG_packed_type:
+ case DW_TAG_volatile_type:
+ case DW_TAG_typedef:
+ return true;
+ default:
+ return false;
+ }
+}
+
enum Attribute LLVM_ENUM_INT_TYPE(uint16_t) {
// Attributes
DW_AT_sibling = 0x01,
diff --git a/lib/CodeGen/AsmPrinter/DIEHash.cpp b/lib/CodeGen/AsmPrinter/DIEHash.cpp
index b8b2bd2..1826467 100644
--- a/lib/CodeGen/AsmPrinter/DIEHash.cpp
+++ b/lib/CodeGen/AsmPrinter/DIEHash.cpp
@@ -384,6 +384,18 @@ void DIEHash::addAttributes(const DIE &Die) {
hashAttributes(Attrs, Die.getTag());
}
+void DIEHash::hashNestedType(const DIE &Die, StringRef Name) {
+ // 7.27 Step 7
+ // ... append the letter 'S',
+ addULEB128('S');
+
+ // the tag of C,
+ addULEB128(Die.getTag());
+
+ // and the name.
+ addString(Name);
+}
+
// Compute the hash of a DIE. This is based on the type signature computation
// given in section 7.27 of the DWARF4 standard. It is the md5 hash of a
// flattened description of the DIE.
@@ -398,8 +410,19 @@ void DIEHash::computeHash(const DIE &Die) {
// Then hash each of the children of the DIE.
for (std::vector<DIE *>::const_iterator I = Die.getChildren().begin(),
E = Die.getChildren().end();
- I != E; ++I)
+ I != E; ++I) {
+ // 7.27 Step 7
+ // If C is a nested type entry or a member function entry, ...
+ if (isType((*I)->getTag())) {
+ StringRef Name = getDIEStringAttr(**I, dwarf::DW_AT_name);
+ // ... and has a DW_AT_name attribute
+ if (!Name.empty()) {
+ hashNestedType(**I, Name);
+ continue;
+ }
+ }
computeHash(**I);
+ }
// Following the last (or if there are no children), append a zero byte.
Hash.update(makeArrayRef((uint8_t)'\0'));
diff --git a/lib/CodeGen/AsmPrinter/DIEHash.h b/lib/CodeGen/AsmPrinter/DIEHash.h
index da373de..b9cf7ce 100644
--- a/lib/CodeGen/AsmPrinter/DIEHash.h
+++ b/lib/CodeGen/AsmPrinter/DIEHash.h
@@ -137,6 +137,8 @@ private:
/// \brief Hashes a reference to a previously referenced type DIE.
void hashRepeatedTypeReference(dwarf::Attribute Attribute, unsigned DieNumber);
+ void hashNestedType(const DIE &Die, StringRef Name);
+
private:
MD5 Hash;
DenseMap<const DIE *, unsigned> Numbering;
diff --git a/unittests/CodeGen/DIEHashTest.cpp b/unittests/CodeGen/DIEHashTest.cpp
index 6f71462..fb6f4b3 100644
--- a/unittests/CodeGen/DIEHashTest.cpp
+++ b/unittests/CodeGen/DIEHashTest.cpp
@@ -477,4 +477,23 @@ TEST(DIEHashTest, RefUnnamedType) {
ASSERT_EQ(0x954e026f01c02529ULL, MD5Res);
}
+
+// struct { struct bar { }; };
+TEST(DIEHashTest, NestedType) {
+ DIE Unnamed(dwarf::DW_TAG_structure_type);
+ DIEInteger One(1);
+ Unnamed.addValue(dwarf::DW_AT_byte_size, dwarf::DW_FORM_data1, &One);
+
+ DIE *Foo = new DIE(dwarf::DW_TAG_structure_type);
+ DIEString FooStr(&One, "foo");
+ Foo->addValue(dwarf::DW_AT_name, dwarf::DW_FORM_strp, &FooStr);
+ Foo->addValue(dwarf::DW_AT_byte_size, dwarf::DW_FORM_data1, &One);
+
+ Unnamed.addChild(Foo);
+
+ uint64_t MD5Res = DIEHash().computeTypeSignature(Unnamed);
+
+ // The exact same hash GCC produces for this DIE.
+ ASSERT_EQ(0xde8a3b7b43807f4aULL, MD5Res);
+}
}