[llvm] [llvm][dwarfdump] Print the name (if available) of entities referenced by DW_AT_import (PR #171859)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-debuginfo

Author: Michael Buch (Michael137)

<details>
<summary>Changes</summary>

Instead of this:
```
0x00018cff:   DW_TAG_imported_declaration
                DW_AT_decl_line (12)
                DW_AT_import    (0x0000000000018cfb)
```
print:
```
0x00018cff:   DW_TAG_imported_declaration
                DW_AT_decl_line (12)
                DW_AT_import    (0x0000000000018cfb "platform")
```

Where `0x0000000000018cfb` in this example could be a `DW_TAG_module` with `DW_AT_name ("platform")`

---
Full diff: https://github.com/llvm/llvm-project/pull/171859.diff


2 Files Affected:

- (modified) llvm/lib/DebugInfo/DWARF/DWARFDie.cpp (+1-1) 
- (added) llvm/test/tools/llvm-dwarfdump/AArch64/DW_AT_import.yaml (+73) 


``````````diff
diff --git a/llvm/lib/DebugInfo/DWARF/DWARFDie.cpp b/llvm/lib/DebugInfo/DWARF/DWARFDie.cpp
index deafee80f559f..a10becb252006 100644
--- a/llvm/lib/DebugInfo/DWARF/DWARFDie.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFDie.cpp
@@ -246,7 +246,7 @@ static void dumpAttribute(raw_ostream &OS, const DWARFDie &Die,
   // having both the raw value and the pretty-printed value is
   // interesting. These attributes are handled below.
   if (Attr == DW_AT_specification || Attr == DW_AT_abstract_origin ||
-      Attr == DW_AT_call_origin) {
+      Attr == DW_AT_call_origin || Attr == DW_AT_import) {
     if (const char *Name =
             Die.getAttributeValueAsReferencedDie(FormValue).getName(
                 DINameKind::LinkageName))
diff --git a/llvm/test/tools/llvm-dwarfdump/AArch64/DW_AT_import.yaml b/llvm/test/tools/llvm-dwarfdump/AArch64/DW_AT_import.yaml
new file mode 100644
index 0000000000000..fec25bdd9ba30
--- /dev/null
+++ b/llvm/test/tools/llvm-dwarfdump/AArch64/DW_AT_import.yaml
@@ -0,0 +1,73 @@
+# RUN: yaml2obj %s | llvm-dwarfdump -verify - | FileCheck %s --check-prefix=VERIFY
+# VERIFY: No errors.
+#
+# RUN: yaml2obj %s | llvm-dwarfdump - | FileCheck %s
+# CHECK: DW_AT_import ({{.*}} "Foo")
+# CHECK: DW_AT_import ({{.*}} "")
+# CHECK: DW_AT_import ({{.*}})
+
+--- !ELF
+FileHeader:
+  Class:   ELFCLASS64
+  Data:    ELFDATA2LSB
+  Type:    ET_EXEC
+  Machine: EM_AARCH64
+DWARF:
+  debug_abbrev:
+    - ID:              0
+      Table:
+        - Code:            0x1
+          Tag:             DW_TAG_compile_unit
+          Children:        DW_CHILDREN_yes
+          Attributes:
+            - Attribute:       DW_AT_language
+              Form:            DW_FORM_data2
+        - Code:            0x2
+          Tag:             DW_TAG_imported_declaration
+          Children:        DW_CHILDREN_no
+          Attributes:
+            - Attribute: DW_AT_import
+              Form:      DW_FORM_ref4
+        - Code:            0x3
+          Tag:             DW_TAG_module
+          Children:        DW_CHILDREN_no
+          Attributes:
+            - Attribute: DW_AT_name
+              Form:      DW_FORM_string
+        - Code:            0x4
+          Tag:             DW_TAG_module
+          Children:        DW_CHILDREN_no
+
+  debug_info:
+     - Version:  5
+       UnitType: DW_UT_compile
+       AddrSize: 8
+       Entries:
+
+        - AbbrCode: 0x1
+          Values:
+            - Value: 0x04
+
+        - AbbrCode: 0x2
+          Values:
+            - Value: 0x1e
+
+        - AbbrCode: 0x2
+          Values:
+            - Value: 0x23
+
+        - AbbrCode: 0x2
+          Values:
+            - Value: 0x19
+
+        - AbbrCode: 0x3
+          Values:
+            - CStr: Foo
+
+        - AbbrCode: 0x3
+          Values:
+            - CStr: ''
+
+        - AbbrCode: 0x4
+        - AbbrCode: 0x0
+...

``````````

</details>


https://github.com/llvm/llvm-project/pull/171859