DWARF type hashing: pointers to members
Includes a test case/FIXME demonstrating a bug/limitation in pointer to
member hashing. To be honest I'm not sure why we don't just always use
summary hashing for referenced types... but perhaps I'm missing
something.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193175 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/unittests/CodeGen/DIEHashTest.cpp b/unittests/CodeGen/DIEHashTest.cpp
index 1ac8b3d..32030c1 100644
--- a/unittests/CodeGen/DIEHashTest.cpp
+++ b/unittests/CodeGen/DIEHashTest.cpp
@@ -264,4 +264,182 @@
ASSERT_EQ(0xad211c8c3b31e57ULL, MD5Res);
}
+
+// struct foo { foo foo::*mem; };
+TEST(DIEHashTest, PtrToMember) {
+ DIE Foo(dwarf::DW_TAG_structure_type);
+ DIEInteger Eight(8);
+ Foo.addValue(dwarf::DW_AT_byte_size, dwarf::DW_FORM_data1, &Eight);
+ DIEString FooStr(&Eight, "foo");
+ Foo.addValue(dwarf::DW_AT_name, dwarf::DW_FORM_strp, &FooStr);
+
+ DIE *Mem = new DIE(dwarf::DW_TAG_member);
+ DIEString MemStr(&Eight, "mem");
+ Mem->addValue(dwarf::DW_AT_name, dwarf::DW_FORM_strp, &MemStr);
+ DIEInteger Zero(0);
+ Mem->addValue(dwarf::DW_AT_data_member_location, dwarf::DW_FORM_data1, &Zero);
+
+ DIE PtrToFooMem(dwarf::DW_TAG_ptr_to_member_type);
+ DIEEntry FooEntry(&Foo);
+ PtrToFooMem.addValue(dwarf::DW_AT_type, dwarf::DW_FORM_ref4, &FooEntry);
+ PtrToFooMem.addValue(dwarf::DW_AT_containing_type, dwarf::DW_FORM_ref4, &FooEntry);
+
+ DIEEntry PtrToFooMemRef(&PtrToFooMem);
+ Mem->addValue(dwarf::DW_AT_type, dwarf::DW_FORM_ref4, &PtrToFooMemRef);
+
+ Foo.addChild(Mem);
+
+ uint64_t MD5Res = DIEHash().computeTypeSignature(&Foo);
+
+ ASSERT_EQ(0x852e0c9ff7c04ebULL, MD5Res);
+}
+
+// Check that the hash for a pointer-to-member matches regardless of whether the
+// pointed-to type is a declaration or a definition.
+//
+// struct bar; // { };
+// struct foo { bar foo::*mem; };
+TEST(DIEHashTest, PtrToMemberDeclDefMatch) {
+ DIEInteger Zero(0);
+ DIEInteger One(1);
+ DIEInteger Eight(8);
+ DIEString FooStr(&Eight, "foo");
+ DIEString BarStr(&Eight, "bar");
+ DIEString MemStr(&Eight, "mem");
+ uint64_t MD5ResDecl;
+ {
+ DIE Bar(dwarf::DW_TAG_structure_type);
+ Bar.addValue(dwarf::DW_AT_name, dwarf::DW_FORM_strp, &BarStr);
+ Bar.addValue(dwarf::DW_AT_declaration, dwarf::DW_FORM_flag_present, &One);
+
+ DIE Foo(dwarf::DW_TAG_structure_type);
+ Foo.addValue(dwarf::DW_AT_byte_size, dwarf::DW_FORM_data1, &Eight);
+ Foo.addValue(dwarf::DW_AT_name, dwarf::DW_FORM_strp, &FooStr);
+
+ DIE *Mem = new DIE(dwarf::DW_TAG_member);
+ Mem->addValue(dwarf::DW_AT_name, dwarf::DW_FORM_strp, &MemStr);
+ Mem->addValue(dwarf::DW_AT_data_member_location, dwarf::DW_FORM_data1,
+ &Zero);
+
+ DIE PtrToFooMem(dwarf::DW_TAG_ptr_to_member_type);
+ DIEEntry BarEntry(&Bar);
+ PtrToFooMem.addValue(dwarf::DW_AT_type, dwarf::DW_FORM_ref4, &BarEntry);
+ DIEEntry FooEntry(&Foo);
+ PtrToFooMem.addValue(dwarf::DW_AT_containing_type, dwarf::DW_FORM_ref4,
+ &FooEntry);
+
+ DIEEntry PtrToFooMemRef(&PtrToFooMem);
+ Mem->addValue(dwarf::DW_AT_type, dwarf::DW_FORM_ref4, &PtrToFooMemRef);
+
+ Foo.addChild(Mem);
+
+ MD5ResDecl = DIEHash().computeTypeSignature(&Foo);
+ }
+ uint64_t MD5ResDef;
+ {
+ DIE Bar(dwarf::DW_TAG_structure_type);
+ Bar.addValue(dwarf::DW_AT_name, dwarf::DW_FORM_strp, &BarStr);
+ Bar.addValue(dwarf::DW_AT_byte_size, dwarf::DW_FORM_data1, &One);
+
+ DIE Foo(dwarf::DW_TAG_structure_type);
+ Foo.addValue(dwarf::DW_AT_byte_size, dwarf::DW_FORM_data1, &Eight);
+ Foo.addValue(dwarf::DW_AT_name, dwarf::DW_FORM_strp, &FooStr);
+
+ DIE *Mem = new DIE(dwarf::DW_TAG_member);
+ Mem->addValue(dwarf::DW_AT_name, dwarf::DW_FORM_strp, &MemStr);
+ Mem->addValue(dwarf::DW_AT_data_member_location, dwarf::DW_FORM_data1,
+ &Zero);
+
+ DIE PtrToFooMem(dwarf::DW_TAG_ptr_to_member_type);
+ DIEEntry BarEntry(&Bar);
+ PtrToFooMem.addValue(dwarf::DW_AT_type, dwarf::DW_FORM_ref4, &BarEntry);
+ DIEEntry FooEntry(&Foo);
+ PtrToFooMem.addValue(dwarf::DW_AT_containing_type, dwarf::DW_FORM_ref4,
+ &FooEntry);
+
+ DIEEntry PtrToFooMemRef(&PtrToFooMem);
+ Mem->addValue(dwarf::DW_AT_type, dwarf::DW_FORM_ref4, &PtrToFooMemRef);
+
+ Foo.addChild(Mem);
+
+ MD5ResDef = DIEHash().computeTypeSignature(&Foo);
+ }
+ ASSERT_EQ(MD5ResDef, MD5ResDecl);
+}
+
+// Check that the hash for a pointer-to-member matches regardless of whether the
+// pointed-to type is a declaration or a definition.
+//
+// struct bar; // { };
+// struct foo { bar bar::*mem; };
+TEST(DIEHashTest, PtrToMemberDeclDefMisMatch) {
+ DIEInteger Zero(0);
+ DIEInteger One(1);
+ DIEInteger Eight(8);
+ DIEString FooStr(&Eight, "foo");
+ DIEString BarStr(&Eight, "bar");
+ DIEString MemStr(&Eight, "mem");
+ uint64_t MD5ResDecl;
+ {
+ DIE Bar(dwarf::DW_TAG_structure_type);
+ Bar.addValue(dwarf::DW_AT_name, dwarf::DW_FORM_strp, &BarStr);
+ Bar.addValue(dwarf::DW_AT_declaration, dwarf::DW_FORM_flag_present, &One);
+
+ DIE Foo(dwarf::DW_TAG_structure_type);
+ Foo.addValue(dwarf::DW_AT_byte_size, dwarf::DW_FORM_data1, &Eight);
+ Foo.addValue(dwarf::DW_AT_name, dwarf::DW_FORM_strp, &FooStr);
+
+ DIE *Mem = new DIE(dwarf::DW_TAG_member);
+ Mem->addValue(dwarf::DW_AT_name, dwarf::DW_FORM_strp, &MemStr);
+ Mem->addValue(dwarf::DW_AT_data_member_location, dwarf::DW_FORM_data1,
+ &Zero);
+
+ DIE PtrToFooMem(dwarf::DW_TAG_ptr_to_member_type);
+ DIEEntry BarEntry(&Bar);
+ PtrToFooMem.addValue(dwarf::DW_AT_type, dwarf::DW_FORM_ref4, &BarEntry);
+ PtrToFooMem.addValue(dwarf::DW_AT_containing_type, dwarf::DW_FORM_ref4,
+ &BarEntry);
+
+ DIEEntry PtrToFooMemRef(&PtrToFooMem);
+ Mem->addValue(dwarf::DW_AT_type, dwarf::DW_FORM_ref4, &PtrToFooMemRef);
+
+ Foo.addChild(Mem);
+
+ MD5ResDecl = DIEHash().computeTypeSignature(&Foo);
+ }
+ uint64_t MD5ResDef;
+ {
+ DIE Bar(dwarf::DW_TAG_structure_type);
+ Bar.addValue(dwarf::DW_AT_name, dwarf::DW_FORM_strp, &BarStr);
+ Bar.addValue(dwarf::DW_AT_byte_size, dwarf::DW_FORM_data1, &One);
+
+ DIE Foo(dwarf::DW_TAG_structure_type);
+ Foo.addValue(dwarf::DW_AT_byte_size, dwarf::DW_FORM_data1, &Eight);
+ Foo.addValue(dwarf::DW_AT_name, dwarf::DW_FORM_strp, &FooStr);
+
+ DIE *Mem = new DIE(dwarf::DW_TAG_member);
+ Mem->addValue(dwarf::DW_AT_name, dwarf::DW_FORM_strp, &MemStr);
+ Mem->addValue(dwarf::DW_AT_data_member_location, dwarf::DW_FORM_data1,
+ &Zero);
+
+ DIE PtrToFooMem(dwarf::DW_TAG_ptr_to_member_type);
+ DIEEntry BarEntry(&Bar);
+ PtrToFooMem.addValue(dwarf::DW_AT_type, dwarf::DW_FORM_ref4, &BarEntry);
+ PtrToFooMem.addValue(dwarf::DW_AT_containing_type, dwarf::DW_FORM_ref4,
+ &BarEntry);
+
+ DIEEntry PtrToFooMemRef(&PtrToFooMem);
+ Mem->addValue(dwarf::DW_AT_type, dwarf::DW_FORM_ref4, &PtrToFooMemRef);
+
+ Foo.addChild(Mem);
+
+ MD5ResDef = DIEHash().computeTypeSignature(&Foo);
+ }
+ // FIXME: This seems to be a bug in the DWARF type hashing specification that
+ // only uses the brief name hashing for types referenced via DW_AT_type. In
+ // this case the type is referenced via DW_AT_containing_type and full hashing
+ // causes a hash to differ when the containing type is a declaration in one TU
+ // and a definition in another.
+ ASSERT_NE(MD5ResDef, MD5ResDecl);
+}
}