[llvm] 7686b29 - [DWARFYAML][debug_info] Teach yaml2obj emit correct DWARF64 unit header.

[Xing GUO via llvm-commits]

Author: Xing GUO
Date: 2020-06-26T19:25:26+08:00
New Revision: 7686b2958416e27b4076bbb231c06825dd446a41

URL: https://github.com/llvm/llvm-project/commit/7686b2958416e27b4076bbb231c06825dd446a41
DIFF: https://github.com/llvm/llvm-project/commit/7686b2958416e27b4076bbb231c06825dd446a41.diff

LOG: [DWARFYAML][debug_info] Teach yaml2obj emit correct DWARF64 unit header.

This patch helps teach yaml2obj emit correct DWARF64 unit header of the .debug_info section.

Reviewed By: jhenderson

Differential Revision: https://reviews.llvm.org/D82621

Added: 
    

Modified: 
    llvm/include/llvm/ObjectYAML/DWARFYAML.h
    llvm/lib/ObjectYAML/DWARFEmitter.cpp
    llvm/test/tools/yaml2obj/ELF/DWARF/debug-info.yaml

Removed: 
    


################################################################################
diff  --git a/llvm/include/llvm/ObjectYAML/DWARFYAML.h b/llvm/include/llvm/ObjectYAML/DWARFYAML.h
index f6dc4e07dc1a..73965dc6d570 100644
--- a/llvm/include/llvm/ObjectYAML/DWARFYAML.h
+++ b/llvm/include/llvm/ObjectYAML/DWARFYAML.h
@@ -120,7 +120,7 @@ struct Unit {
   InitialLength Length;
   uint16_t Version;
   llvm::dwarf::UnitType Type; // Added in DWARF 5
-  uint32_t AbbrOffset;
+  yaml::Hex64 AbbrOffset;
   uint8_t AddrSize;
   std::vector<Entry> Entries;
 };

diff  --git a/llvm/lib/ObjectYAML/DWARFEmitter.cpp b/llvm/lib/ObjectYAML/DWARFEmitter.cpp
index 8a938d321180..b9b8c0e52842 100644
--- a/llvm/lib/ObjectYAML/DWARFEmitter.cpp
+++ b/llvm/lib/ObjectYAML/DWARFEmitter.cpp
@@ -212,9 +212,13 @@ class DumpVisitor : public DWARFYAML::ConstVisitor {
     if (CU.Version >= 5) {
       writeInteger((uint8_t)CU.Type, OS, DebugInfo.IsLittleEndian);
       writeInteger((uint8_t)CU.AddrSize, OS, DebugInfo.IsLittleEndian);
-      writeInteger((uint32_t)CU.AbbrOffset, OS, DebugInfo.IsLittleEndian);
+      cantFail(writeVariableSizedInteger(CU.AbbrOffset,
+                                         CU.Length.isDWARF64() ? 8 : 4, OS,
+                                         DebugInfo.IsLittleEndian));
     } else {
-      writeInteger((uint32_t)CU.AbbrOffset, OS, DebugInfo.IsLittleEndian);
+      cantFail(writeVariableSizedInteger(CU.AbbrOffset,
+                                         CU.Length.isDWARF64() ? 8 : 4, OS,
+                                         DebugInfo.IsLittleEndian));
       writeInteger((uint8_t)CU.AddrSize, OS, DebugInfo.IsLittleEndian);
     }
   }

diff  --git a/llvm/test/tools/yaml2obj/ELF/DWARF/debug-info.yaml b/llvm/test/tools/yaml2obj/ELF/DWARF/debug-info.yaml
index f369dbe7e9bc..f69d664f21b5 100644
--- a/llvm/test/tools/yaml2obj/ELF/DWARF/debug-info.yaml
+++ b/llvm/test/tools/yaml2obj/ELF/DWARF/debug-info.yaml
@@ -669,3 +669,68 @@ DWARF:
         - AbbrCode: 1
           Values:
             - Value: 0x1234
+
+## j) Test that yaml2obj emits the correct DWARF64 unit headers.
+
+## DWARFv5 unit header.
+
+# RUN: yaml2obj --docnum=11 %s -o %t11.o
+# RUN: llvm-readelf --hex-dump=.debug_info %t11.o | \
+# RUN:   FileCheck %s --check-prefix=DWARFV5-HEADER
+
+#      DWARFV5-HEADER: Hex dump of section '.debug_info':
+# DWARFV5-HEADER-NEXT: 0x00000000 ffffffff 0c000000 00000000 05000208 ................
+##                                ^-------------------------          unit_length (12-byte)
+##                                                           ^---     version (2-byte)
+##                                                               ^-   unit_type (1-byte)
+##                                                                 ^- address_size (1-byte)
+# DWARFV5-HEADER-NEXT: 0x00000010 34120000 00000000                   4.......
+##                                ^----------------                   debug_abbrev_offset (8-byte)
+
+--- !ELF
+FileHeader:
+  Class:   ELFCLASS64
+  Data:    ELFDATA2LSB
+  Type:    ET_EXEC
+  Machine: EM_X86_64
+DWARF:
+  debug_info:
+    - Length:
+        TotalLength:   0xffffffff
+        TotalLength64: 0x0c
+      Version:    5
+      UnitType:   DW_UT_type
+      AbbrOffset: 0x1234
+      AddrSize:   8
+      Entries:    []
+
+## DWARFv4 unit header.
+
+# RUN: yaml2obj --docnum=12 %s -o %t12.o
+# RUN: llvm-readelf --hex-dump=.debug_info %t12.o | \
+# RUN:   FileCheck %s --check-prefix=DWARFV4-HEADER
+
+#      DWARFV4-HEADER: Hex dump of section '.debug_info':
+# DWARFV4-HEADER-NEXT: 0x00000000 ffffffff 0c000000 00000000 04003412 ..............4.
+##                                ^-------------------------          unit_length (12-byte)
+##                                                           ^---     version (2-byte)
+##                                                               ^--- debug_abbrev_offset (8-byte)
+# DWARFV4-HEADER-NEXT: 0x00000010 00000000 000008                     .......
+##                                -------------
+##                                             ^-                     address_size (1-byte)
+
+--- !ELF
+FileHeader:
+  Class:   ELFCLASS64
+  Data:    ELFDATA2LSB
+  Type:    ET_EXEC
+  Machine: EM_X86_64
+DWARF:
+  debug_info:
+    - Length:
+        TotalLength:   0xffffffff
+        TotalLength64: 0x0c
+      Version:    4
+      AbbrOffset: 0x1234
+      AddrSize:   8
+      Entries:    []