[DWARFLinker] Handle DW_OP_GNU_push_tls_address while check for variable location.

[avl]

Summary

The D147066 changed the way how DWARF location expressions are handled.
Now expressions are parsed and their operands are analysed. New handling
misses the DW_OP_GNU_push_tls_address extention. This patch adds handling
DW_OP_GNU_push_tls_address while checking for addresses.

[avl]

addressed formatting issue.

[JDevlieghere]

LGTM

[avl]

Thank you for the review!

llvm/lib/DWARFLinker/DWARFLinker.cpp

void DWARFLinker::cleanupAuxiliarryData(LinkContext &Context) {
   for (DIELoc *I : DIELocs)
     I->~DIELoc();
 
   DIEBlocks.clear();
   DIELocs.clear();
   DIEAlloc.Reset();
 }
 
+static bool isTlsAddressCode(uint8_t DW_OP_Code) {
+  return DW_OP_Code == dwarf::DW_OP_form_tls_address ||
+         DW_OP_Code == dwarf::DW_OP_GNU_push_tls_address;
+}
+
 std::optional<int64_t>
 DWARFLinker::getVariableRelocAdjustment(AddressesMap &RelocMgr,
                                         const DWARFDie &DIE) {
   assert((DIE.getTag() == dwarf::DW_TAG_variable ||
           DIE.getTag() == dwarf::DW_TAG_constant) &&
          "Wrong type of input die");
 
   const auto *Abbrev = DIE.getAbbreviationDeclarationPtr();
for (DWARFExpression::iterator It = Expression.begin();
     ++NextIt;
 
     const DWARFExpression::Operation &Op = *It;
     switch (Op.getCode()) {
     case dwarf::DW_OP_const4u:
     case dwarf::DW_OP_const8u:
     case dwarf::DW_OP_const4s:
     case dwarf::DW_OP_const8s:
-      if (NextIt == Expression.end() ||
-          NextIt->getCode() != dwarf::DW_OP_form_tls_address)
+      if (NextIt == Expression.end() || !isTlsAddressCode(NextIt->getCode()))
         break;
       [[fallthrough]];
     case dwarf::DW_OP_addr: {
       // Check relocation for the address.
       if (std::optional<int64_t> RelocAdjustment =
               RelocMgr.getExprOpAddressRelocAdjustment(
                   *U, Op, AttrOffset + CurExprOffset,
                   AttrOffset + Op.getEndOffset()))

llvm/test/tools/dsymutil/X86/tls-variable.test

+## This test checks that thread local storage variables
+## are preserved.
+
+# RUN: yaml2obj %s -o %t.o
+# RUN: echo '---' > %t2.map
+# RUN: echo "triple:          'x86_64-apple-darwin'" >> %t2.map
+# RUN: echo 'objects:'  >> %t2.map
+# RUN: echo " -  filename: '%t.o'" >> %t2.map
+# RUN: echo '    symbols:' >> %t2.map
+# RUN: echo '      - { sym: __Z3foov, objAddr: 0x0, binAddr: 0x10000, size: 0x10 }' >> %t2.map
+# RUN: echo '...' >> %t2.map
+# RUN: dsymutil -y %t2.map --keep-function-for-static -f -o - | llvm-dwarfdump -a - | FileCheck %s
+
+# CHECK: file format Mach-O 64-bit x86-64
+# CHECK: .debug_info contents:
+# CHECK: Compile Unit:
+# CHECK: DW_TAG_compile_unit
+# CHECK: DW_AT_name{{.*}}"CU1"
+# CHECK: DW_TAG_subprogram
+# CHECK: DW_AT_name{{.*}}"foo"
+# CHECK: DW_TAG_variable
+# CHECK: DW_AT_name{{.*}}"var1"
+# CHECK: DW_AT_location        (DW_OP_const8u 0x10001, DW_OP_GNU_push_tls_address)
+# CHECK: DW_AT_name{{.*}}"var2"
+# CHECK: DW_AT_location        (DW_OP_const8u 0x10001, DW_OP_form_tls_address)
+
+--- !mach-o
+FileHeader:
+  magic:      0xFEEDFACF
+  cputype:    0x01000007
+  cpusubtype: 0x00000003
+  filetype:   0x00000001
+  ncmds:      2
+  sizeofcmds: 376
+  flags:      0x00002000
+  reserved:   0x00000000
+LoadCommands:
+  - cmd:      LC_SEGMENT_64
+    cmdsize:  232
+    segname:  ''
+    vmaddr:   0x00
+    vmsize:   0x300
+    fileoff:  0x300
+    filesize: 0x300
+    maxprot:  7
+    initprot: 7
+    nsects:   2
+    flags:    0
+    Sections:
+      - sectname:  __debug_abbrev
+        segname:   __DWARF
+        addr:      0x000000000000000F
+        size:      0x27
+        offset:    0x00000380
+        align:     0
+        reloff:    0x00000000
+        nreloc:    0
+        flags:     0x02000000
+        reserved1: 0x00000000
+        reserved2: 0x00000000
+        reserved3: 0x00000000
+      - sectname:  __debug_info
+        segname:   __DWARF
+        addr:      0x000000000000100
+        size:      0x54
+        offset:    0x00000410
+        align:     0
+        reloff:    0x00000600
+        nreloc:    2
+        flags:     0x02000000
+        reserved1: 0x00000000
+        reserved2: 0x00000000
+        reserved3: 0x00000000
+        relocations:
+          - address:         0x32
+            symbolnum:       1
+            pcrel:           true
+            length:          3
+            extern:          true
+            type:            0
+            scattered:       false
+            value:           0
+          - address:         0x47
+            symbolnum:       1
+            pcrel:           true
+            length:          3
+            extern:          true
+            type:            0
+            scattered:       false
+            value:           0
+  - cmd:             LC_SYMTAB
+    cmdsize:         24
+    symoff:          0x700
+    nsyms:           2
+    stroff:          0x720
+    strsize:         10
+LinkEditData:
+  NameList:
+    - n_strx:          1
+      n_type:          0x0F
+      n_sect:          1
+      n_desc:          0
+      n_value:         0
+    - n_strx:          1
+      n_type:          0x0F
+      n_sect:          1
+      n_desc:          0
+      n_value:         0
+  StringTable:
+    - ''
+    - '__Z3foov'
+    - ''
+DWARF:
+  debug_abbrev:
+    - Table:
+      - Tag:      DW_TAG_compile_unit
+        Children: DW_CHILDREN_yes
+        Attributes:
+          - Attribute: DW_AT_producer
+            Form:      DW_FORM_string
+          - Attribute: DW_AT_language
+            Form:      DW_FORM_data2
+          - Attribute: DW_AT_name
+            Form:      DW_FORM_string
+      - Tag:      DW_TAG_subprogram
+        Children: DW_CHILDREN_yes
+        Attributes:
+          - Attribute: DW_AT_name
+            Form:      DW_FORM_string
+          - Attribute: DW_AT_type
+            Form:      DW_FORM_ref4
+      - Tag:      DW_TAG_variable
+        Children: DW_CHILDREN_no
+        Attributes:
+          - Attribute: DW_AT_name
+            Form:      DW_FORM_string
+          - Attribute: DW_AT_type
+            Form:      DW_FORM_ref4
+          - Attribute: DW_AT_location
+            Form:      DW_FORM_exprloc
+      - Tag:      DW_TAG_base_type
+        Children: DW_CHILDREN_no
+        Attributes:
+          - Attribute: DW_AT_name
+            Form:      DW_FORM_string
+  debug_info:
+    - Version: 4
+      Entries:
+        - AbbrCode: 1
+          Values:
+            - CStr: by_hand
+            - Value:  0x04
+            - CStr: CU1
+        - AbbrCode: 4
+          Values:
+            - CStr: int
+        - AbbrCode: 2
+          Values:
+            - CStr: foo
+            - Value: 0x1a
+        - AbbrCode: 3
+          Values:
+            - CStr: var1
+            - Value:  0x0000001a
+            - BlockData:
+                - 0x0e
+                - 0x00
+                - 0x00
+                - 0x01
+                - 0x00
+                - 0x00
+                - 0x00
+                - 0x00
+                - 0x00
+                - 0xe0
+        - AbbrCode: 3
+          Values:
+            - CStr: var2
+            - Value:  0x0000001a
+            - BlockData:
+                - 0x0e
+                - 0x00
+                - 0x00
+                - 0x01
+                - 0x00
+                - 0x00
+                - 0x00
+                - 0x00
+                - 0x00
+                - 0x9b
+        - AbbrCode: 0
+        - AbbrCode: 0
+...