DebugInfo: Introduce the notion of "form classes"

Summary:
Use DWARF4 table of form classes to fetch attributes from DIE
in a more consistent way. This shouldn't change the functionality and
serves as a refactoring for upcoming change: DW_AT_high_pc has different
semantics depending on its form class.

Reviewers: dblaikie, echristo

Reviewed By: echristo

CC: echristo, llvm-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D1961

llvm-svn: 193553

1 files changed, 17 insertions, 0 deletions

diff --git a/llvm/unittests/DebugInfo/DWARFFormValueTest.cpp b/llvm/unittests/DebugInfo/DWARFFormValueTest.cpp
index 04b859bdb9d..e7216b3726f 100644
--- a/llvm/unittests/DebugInfo/DWARFFormValueTest.cpp
+++ b/llvm/unittests/DebugInfo/DWARFFormValueTest.cpp
@@ -28,4 +28,21 @@ TEST(DWARFFormValue, FixedFormSizes) {
   EXPECT_EQ(0, DWARFFormValue::getFixedFormSizes(16, 2));
 }
 
+bool isFormClass(uint16_t Form, DWARFFormValue::FormClass FC) {
+  return DWARFFormValue(Form).isFormClass(FC);
+}
+
+TEST(DWARFFormValue, FormClass) {
+  EXPECT_TRUE(isFormClass(DW_FORM_addr, DWARFFormValue::FC_Address));
+  EXPECT_FALSE(isFormClass(DW_FORM_data8, DWARFFormValue::FC_Address));
+  EXPECT_TRUE(isFormClass(DW_FORM_data8, DWARFFormValue::FC_Constant));
+  EXPECT_TRUE(isFormClass(DW_FORM_data8, DWARFFormValue::FC_SectionOffset));
+  EXPECT_TRUE(
+      isFormClass(DW_FORM_sec_offset, DWARFFormValue::FC_SectionOffset));
+  EXPECT_TRUE(isFormClass(DW_FORM_GNU_str_index, DWARFFormValue::FC_String));
+  EXPECT_TRUE(isFormClass(DW_FORM_GNU_addr_index, DWARFFormValue::FC_Address));
+  EXPECT_FALSE(isFormClass(DW_FORM_ref_addr, DWARFFormValue::FC_Address));
+  EXPECT_TRUE(isFormClass(DW_FORM_ref_addr, DWARFFormValue::FC_Reference));
+}
+
 } // end anonymous namespace