[llvm-branch-commits] [llvm] release/23.x: [DebugInfo] Don't assert on missing template parameter names (#211412) (PR #211457)

[Tobias Hieta via llvm-branch-commits]

https://github.com/tru updated https://github.com/llvm/llvm-project/pull/211457

>From 060d53f28f9692cb29c4900774adb6d47c00d482 Mon Sep 17 00:00:00 2001
From: Jonas Devlieghere <jonas at devlieghere.com>
Date: Wed, 22 Jul 2026 22:52:56 -0500
Subject: [PATCH] [DebugInfo] Don't assert on missing template parameter names
 (#211412)

The DWARF verifier reconstructs simplified template names through
DWARFTypePrinter to compare them against the original DW_AT_name. On
malformed input, a template parameter can have no recoverable name,
which tripped assert(RawName) and aborted instead of letting the
verifier report the problem.

Assisted-by: Claude

rdar://182715403
(cherry picked from commit bdddd134c1af6b0c5196ea944edf4c5c76019306)
---
 .../llvm/DebugInfo/DWARF/DWARFTypePrinter.h   |  6 +-
 .../X86/verify_simplified_template_names.yaml | 83 +++++++++++++++++++
 2 files changed, 87 insertions(+), 2 deletions(-)
 create mode 100644 llvm/test/tools/llvm-dwarfdump/X86/verify_simplified_template_names.yaml

diff --git a/llvm/include/llvm/DebugInfo/DWARF/DWARFTypePrinter.h b/llvm/include/llvm/DebugInfo/DWARF/DWARFTypePrinter.h
index 81a5e54a71145..6e1b8de48c913 100644
--- a/llvm/include/llvm/DebugInfo/DWARF/DWARFTypePrinter.h
+++ b/llvm/include/llvm/DebugInfo/DWARF/DWARFTypePrinter.h
@@ -505,7 +505,8 @@ bool DWARFTypePrinter<DieType>::appendTemplateParameters(DieType D,
           T.getTag() == dwarf::DW_TAG_ptr_to_member_type)
         continue;
       const char *RawName = detail::toString(T.find(dwarf::DW_AT_name));
-      assert(RawName);
+      if (!RawName)
+        continue;
       StringRef Name = RawName;
       auto V = C.find(dwarf::DW_AT_const_value);
       bool IsQualifiedChar = false;
@@ -604,7 +605,8 @@ bool DWARFTypePrinter<DieType>::appendTemplateParameters(DieType D,
     if (C.getTag() == dwarf::DW_TAG_GNU_template_template_param) {
       const char *RawName =
           detail::toString(C.find(dwarf::DW_AT_GNU_template_name));
-      assert(RawName);
+      if (!RawName)
+        continue;
       StringRef Name = RawName;
       Sep();
       OS << Name;
diff --git a/llvm/test/tools/llvm-dwarfdump/X86/verify_simplified_template_names.yaml b/llvm/test/tools/llvm-dwarfdump/X86/verify_simplified_template_names.yaml
new file mode 100644
index 0000000000000..6bf5c550bd74e
--- /dev/null
+++ b/llvm/test/tools/llvm-dwarfdump/X86/verify_simplified_template_names.yaml
@@ -0,0 +1,83 @@
+# RUN: yaml2obj %s | not llvm-dwarfdump --verify - 2>&1 | FileCheck %s
+
+## The --verify path reconstructs simplified template names via
+## DWARFTypePrinter to compare them against the original DW_AT_name. Template
+## parameters whose name cannot be recovered must be diagnosed as an
+## unreconstructable name rather than aborting the verifier with an assertion.
+## This covers both name lookups that used to assert:
+##   - a DW_TAG_template_value_parameter whose DW_AT_type resolves to a type
+##     with no DW_AT_name, and
+##   - a DW_TAG_GNU_template_template_param with no DW_AT_GNU_template_name.
+
+# CHECK-NOT: Assertion
+# CHECK: error: Simplified template DW_AT_name could not be reconstituted:
+# CHECK-NEXT: original: Foo<int>
+# CHECK-NEXT: reconstituted: Foo<>
+
+--- !ELF
+FileHeader:
+  Class:    ELFCLASS64
+  Data:     ELFDATA2LSB
+  Type:     ET_REL
+  Machine:  EM_X86_64
+DWARF:
+  debug_str:
+    - "clang"
+    - "_STN|Foo|<int>"
+  debug_abbrev:
+    - Table:
+        - Code:            0x0000000000000001
+          Tag:             DW_TAG_compile_unit
+          Children:        DW_CHILDREN_yes
+          Attributes:
+            - Attribute:       DW_AT_name
+              Form:            DW_FORM_strp
+            - Attribute:       DW_AT_language
+              Form:            DW_FORM_data2
+        - Code:            0x0000000000000002
+          Tag:             DW_TAG_base_type
+          Children:        DW_CHILDREN_no
+          Attributes:      []
+        - Code:            0x0000000000000003
+          Tag:             DW_TAG_structure_type
+          Children:        DW_CHILDREN_yes
+          Attributes:
+            - Attribute:       DW_AT_name
+              Form:            DW_FORM_strp
+        - Code:            0x0000000000000004
+          Tag:             DW_TAG_template_value_parameter
+          Children:        DW_CHILDREN_no
+          Attributes:
+            - Attribute:       DW_AT_type
+              Form:            DW_FORM_ref4
+            - Attribute:       DW_AT_const_value
+              Form:            DW_FORM_sdata
+        - Code:            0x0000000000000005
+          Tag:             DW_TAG_GNU_template_template_param
+          Children:        DW_CHILDREN_no
+          Attributes:      []
+  debug_info:
+    - Version:         4
+      AbbrOffset:      0x0000000000000000
+      AddrSize:        8
+      Entries:
+        - AbbrCode:        0x00000001
+          Values:
+            - Value:           0x0000000000000000
+            - Value:           0x0000000000000004
+        - AbbrCode:        0x00000002
+          Values:          []
+        - AbbrCode:        0x00000003
+          Values:
+            - Value:           0x0000000000000006
+        - AbbrCode:        0x00000004
+          Values:
+            - Value:           0x0000000000000012
+            - Value:           0x0000000000000000
+        - AbbrCode:        0x00000005
+          Values:          []
+        - AbbrCode:        0x00000000
+          Values:          []
+        - AbbrCode:        0x00000000
+          Values:          []
+...