Recommit: [DWARFYAML] Add support for referencing different abbrev tables.

The original commit (7ff0ace96db9164dcde232c36cab6519ea4fce8) was causing
build failure and was reverted in 6d242a73264ef1e3e128547f00e0fe2d20d3ada0

==================== Original Commit Message ====================
This patch adds support for referencing different abbrev tables. We use
'ID' to distinguish abbrev tables and use 'AbbrevTableID' to explicitly
assign an abbrev table to compilation units.

The syntax is:
```
debug_abbrev:
  - ID: 0
    Table:
      ...
  - ID: 1
    Table:
      ...
debug_info:
  - ...
    AbbrevTableID: 1 ## Reference the second abbrev table.
  - ...
    AbbrevTableID: 0 ## Reference the first abbrev table.
```

Reviewed By: jhenderson

Differential Revision: https://reviews.llvm.org/D83116

3 files changed, 300 insertions, 1 deletions

diff --git a/llvm/test/ObjectYAML/MachO/DWARF-debug_abbrev.yaml b/llvm/test/ObjectYAML/MachO/DWARF-debug_abbrev.yaml
index 607d6eb..91af7bdf 100644
--- a/llvm/test/ObjectYAML/MachO/DWARF-debug_abbrev.yaml
+++ b/llvm/test/ObjectYAML/MachO/DWARF-debug_abbrev.yaml
@@ -1,4 +1,7 @@
-# RUN: yaml2obj %s | obj2yaml | FileCheck %s
+## a) Test that yaml2obj is able to emit the __debug_abbrev section and obj2yaml is
+## able to convert it back.
+
+# RUN: yaml2obj --docnum=1 %s | obj2yaml | FileCheck %s
 
 --- !mach-o
 FileHeader:      
@@ -420,3 +423,69 @@ DWARF:
 #CHECK:       Attributes:      
 #CHECK:         - Attribute:       DW_AT_type
 #CHECK:           Form:            DW_FORM_ref4
+
+## b) Test that yaml2obj emits an error message when there are non-empty compilation
+## units and multiple abbrev tables are assigned the same ID.
+
+# RUN: not yaml2obj --docnum=2 %s 2>&1 | FileCheck %s --check-prefix=ID-COLLISION
+
+# ID-COLLISION: yaml2obj: error: the ID (1) of abbrev table with index 1 has been used by abbrev table with index 0
+
+--- !mach-o
+FileHeader:
+  magic:      0xFEEDFACF
+  cputype:    0x01000007
+  cpusubtype: 0x00000003
+  filetype:   0x0000000A
+  ncmds:      1
+  sizeofcmds: 232
+  flags:      0x00000000
+  reserved:   0x00000000
+LoadCommands:
+  - cmd:      LC_SEGMENT_64
+    cmdsize:  232
+    segname:  __DWARF
+    vmaddr:   0x00
+    vmsize:   0x00
+    fileoff:  0x00
+    filesize: 0x00
+    maxprot:  0
+    initprot: 0
+    nsects:   2
+    flags:    0
+    Sections:
+      - sectname:  __debug_abbrev
+        segname:   __DWARF
+        addr:      0x00
+        size:      24
+        offset:    528
+        align:     0
+        reloff:    0x00000000
+        nreloc:    0
+        flags:     0x00000000
+        reserved1: 0x00000000
+        reserved2: 0x00000000
+        reserved3: 0x00000000
+      - sectname:  __debug_info
+        segname:   __DWARF
+        addr:      0x00
+        size:      64
+        offset:    1070
+        align:     0
+        reloff:    0x00000000
+        nreloc:    0
+        flags:     0x00000000
+        reserved1: 0x00000000
+        reserved2: 0x00000000
+        reserved3: 0x00000000
+DWARF:
+  debug_abbrev:
+    - ID: 1
+    - ID: 1
+  debug_info:
+    - Version:    4
+      AbbrOffset: 0x00
+      Entries:
+        - AbbrCode: 1
+          Values:
+            - Value: 0x1234
diff --git a/llvm/test/ObjectYAML/MachO/DWARF-debug_info.yaml b/llvm/test/ObjectYAML/MachO/DWARF-debug_info.yaml
index 46bf522..7b9d5fa 100644
--- a/llvm/test/ObjectYAML/MachO/DWARF-debug_info.yaml
+++ b/llvm/test/ObjectYAML/MachO/DWARF-debug_info.yaml
@@ -514,6 +514,7 @@ DWARF:
 #      DWARF32:   debug_info:
 # DWARF32-NEXT:     - Length:        0x0000000000000075
 # DWARF32-NEXT:       Version:       4
+# DWARF32-NEXT:       AbbrevTableID: 0
 # DWARF32-NEXT:       AbbrOffset:    0
 # DWARF32-NEXT:       AddrSize:      8
 # DWARF32-NEXT:       Entries:
@@ -583,6 +584,7 @@ DWARF:
 #      DWARF32-YAML: debug_info:
 # DWARF32-YAML-NEXT:   - Length:        0x000000000000000C
 # DWARF32-YAML-NEXT:     Version:       4
+# DWARF32-YAML-NEXT:     AbbrevTableID: 0
 # DWARF32-YAML-NEXT:     AbbrOffset:    0
 # DWARF32-YAML-NEXT:     AddrSize:      8
 # DWARF32-YAML-NEXT:     Entries:
@@ -666,9 +668,234 @@ DWARF:
 # DWARF64-YAML-NEXT:   - Format:        DWARF64
 # DWARF64-YAML-NEXT:     Length:        0x000000000000000C
 # DWARF64-YAML-NEXT:     Version:       4
+# DWARF64-YAML-NEXT:     AbbrevTableID: 0
 # DWARF64-YAML-NEXT:     AbbrOffset:    0
 # DWARF64-YAML-NEXT:     AddrSize:      8
 # DWARF64-YAML-NEXT:     Entries:
 # DWARF64-YAML-NEXT:       - AbbrCode: 0x00000001
 # DWARF64-YAML-NEXT:         Values:
 # DWARF64-YAML-NEXT:           - Value: 0x0000000000001234
+
+## c) Test that yaml2obj is able to generate compilation units according to the
+## associated abbrev table that is referenced by the 'AbbrevTableID' and obj2yaml
+## is able to convert it back.
+
+# RUN: yaml2obj --docnum=3 %s | obj2yaml | FileCheck %s --check-prefix=MULTI-TABLES
+
+#      MULTI-TABLES: DWARF:
+# MULTI-TABLES-NEXT:   debug_abbrev:
+# MULTI-TABLES-NEXT:     - ID: 0
+# MULTI-TABLES-NEXT:       Table:
+# MULTI-TABLES-NEXT:         - Code:     0x0000000000000001
+# MULTI-TABLES-NEXT:           Tag:      DW_TAG_compile_unit
+# MULTI-TABLES-NEXT:           Children: DW_CHILDREN_no
+# MULTI-TABLES-NEXT:           Attributes:
+# MULTI-TABLES-NEXT:             - Attribute: DW_AT_low_pc
+# MULTI-TABLES-NEXT:               Form:      DW_FORM_addr
+# MULTI-TABLES-NEXT:     - ID: 1
+# MULTI-TABLES-NEXT:       Table:
+# MULTI-TABLES-NEXT:         - Code:     0x0000000000000001
+# MULTI-TABLES-NEXT:           Tag:      DW_TAG_compile_unit
+# MULTI-TABLES-NEXT:           Children: DW_CHILDREN_no
+# MULTI-TABLES-NEXT:           Attributes:
+# MULTI-TABLES-NEXT:             - Attribute: DW_AT_low_pc
+# MULTI-TABLES-NEXT:               Form:      DW_FORM_data4
+# MULTI-TABLES-NEXT:     - ID: 2
+# MULTI-TABLES-NEXT:       Table:
+# MULTI-TABLES-NEXT:         - Code:     0x0000000000000001
+# MULTI-TABLES-NEXT:           Tag:      DW_TAG_compile_unit
+# MULTI-TABLES-NEXT:           Children: DW_CHILDREN_no
+# MULTI-TABLES-NEXT:           Attributes:
+# MULTI-TABLES-NEXT:             - Attribute: DW_AT_low_pc
+# MULTI-TABLES-NEXT:               Form:      DW_FORM_udata
+# MULTI-TABLES-NEXT:   debug_info:
+# MULTI-TABLES-NEXT:     - Length:        0x000000000000000C
+# MULTI-TABLES-NEXT:       Version:       4
+# MULTI-TABLES-NEXT:       AbbrevTableID: 1
+# MULTI-TABLES-NEXT:       AbbrOffset:    0x0000000000000008
+# MULTI-TABLES-NEXT:       AddrSize:      8
+# MULTI-TABLES-NEXT:       Entries:
+# MULTI-TABLES-NEXT:         - AbbrCode: 0x00000001
+# MULTI-TABLES-NEXT:           Values:
+# MULTI-TABLES-NEXT:             - Value: 0x0000000000001234
+# MULTI-TABLES-NEXT:     - Length:        0x000000000000000C
+# MULTI-TABLES-NEXT:       Version:       4
+# MULTI-TABLES-NEXT:       AbbrevTableID: 1
+# MULTI-TABLES-NEXT:       AbbrOffset:    0x0000000000000008
+# MULTI-TABLES-NEXT:       AddrSize:      8
+# MULTI-TABLES-NEXT:       Entries:
+# MULTI-TABLES-NEXT:         - AbbrCode: 0x00000001
+# MULTI-TABLES-NEXT:           Values:
+# MULTI-TABLES-NEXT:             - Value: 0x0000000000004321
+# MULTI-TABLES-NEXT:     - Length:        0x0000000000000010
+# MULTI-TABLES-NEXT:       Version:       4
+# MULTI-TABLES-NEXT:       AbbrevTableID: 0
+# MULTI-TABLES-NEXT:       AbbrOffset:    0x0000000000000000
+# MULTI-TABLES-NEXT:       AddrSize:      8
+# MULTI-TABLES-NEXT:       Entries:
+# MULTI-TABLES-NEXT:         - AbbrCode: 0x00000001
+# MULTI-TABLES-NEXT:           Values:
+# MULTI-TABLES-NEXT:             - Value: 0x0000000000005678
+# MULTI-TABLES-NEXT:     - Length:        0x000000000000000B
+# MULTI-TABLES-NEXT:       Version:       4
+# MULTI-TABLES-NEXT:       AbbrevTableID: 2
+# MULTI-TABLES-NEXT:       AbbrOffset:    0x0000000000000010
+# MULTI-TABLES-NEXT:       AddrSize:      8
+# MULTI-TABLES-NEXT:       Entries:
+# MULTI-TABLES-NEXT:         - AbbrCode: 0x00000001
+# MULTI-TABLES-NEXT:           Values:
+# MULTI-TABLES-NEXT:             - Value: 0x0000000000008765
+# MULTI-TABLES-NEXT: ...
+
+--- !mach-o
+FileHeader:
+  magic:      0xFEEDFACF
+  cputype:    0x01000007
+  cpusubtype: 0x00000003
+  filetype:   0x0000000A
+  ncmds:      1
+  sizeofcmds: 232
+  flags:      0x00000000
+  reserved:   0x00000000
+LoadCommands:
+  - cmd:      LC_SEGMENT_64
+    cmdsize:  232
+    segname:  __DWARF
+    vmaddr:   0x00
+    vmsize:   0x00
+    fileoff:  0x00
+    filesize: 0x00
+    maxprot:  0
+    initprot: 0
+    nsects:   2
+    flags:    0
+    Sections:
+      - sectname:  __debug_abbrev
+        segname:   __DWARF
+        addr:      0x00
+        size:      24
+        offset:    528
+        align:     0
+        reloff:    0x00000000
+        nreloc:    0
+        flags:     0x00000000
+        reserved1: 0x00000000
+        reserved2: 0x00000000
+        reserved3: 0x00000000
+      - sectname:  __debug_info
+        segname:   __DWARF
+        addr:      0x00
+        size:      67
+        offset:    1070
+        align:     0
+        reloff:    0x00000000
+        nreloc:    0
+        flags:     0x00000000
+        reserved1: 0x00000000
+        reserved2: 0x00000000
+        reserved3: 0x00000000
+DWARF:
+  debug_abbrev:
+    - Table:
+        - Code:     1
+          Tag:      DW_TAG_compile_unit
+          Children: DW_CHILDREN_no
+          Attributes:
+            - Attribute: DW_AT_low_pc
+              Form:      DW_FORM_addr
+    - ID: 2
+      Table:
+        - Code:     1
+          Tag:      DW_TAG_compile_unit
+          Children: DW_CHILDREN_no
+          Attributes:
+            - Attribute: DW_AT_low_pc
+              Form:      DW_FORM_data4
+    - ID: 1
+      Table:
+        - Code:     1
+          Tag:      DW_TAG_compile_unit
+          Children: DW_CHILDREN_no
+          Attributes:
+            - Attribute: DW_AT_low_pc
+              Form:      DW_FORM_udata
+  debug_info:
+    - Version:       4
+      AbbrevTableID: 2
+      AbbrOffset:    8
+      Entries:
+        - AbbrCode: 1
+          Values:
+            - Value: 0x1234
+    - Version:       4
+      AbbrevTableID: 2
+      AbbrOffset:    8
+      Entries:
+        - AbbrCode: 1
+          Values:
+            - Value: 0x4321
+    - Version:       4
+      AbbrevTableID: 0
+      AbbrOffset:    0
+      Entries:
+        - AbbrCode: 1
+          Values:
+            - Value: 0x5678
+    - Version:       4
+      AbbrevTableID: 1
+      AbbrOffset:    16
+      Entries:
+        - AbbrCode: 1
+          Values:
+            - Value: 0x8765
+
+## d) Test that yaml2obj emits an error message when a compilation unit doesn't have
+## an associated abbrev table.
+
+# RUN: not yaml2obj --docnum=4 %s 2>&1 | FileCheck %s --check-prefix=MISSING-ABBREV
+
+# MISSING-ABBREV: yaml2obj: error: cannot find abbrev table whose ID is 0 for compilation unit with index 0
+
+--- !mach-o
+FileHeader:
+  magic:      0xFEEDFACF
+  cputype:    0x01000007
+  cpusubtype: 0x00000003
+  filetype:   0x0000000A
+  ncmds:      1
+  sizeofcmds: 232
+  flags:      0x00000000
+  reserved:   0x00000000
+LoadCommands:
+  - cmd:      LC_SEGMENT_64
+    cmdsize:  152
+    segname:  __DWARF
+    vmaddr:   0x00
+    vmsize:   0x00
+    fileoff:  0x00
+    filesize: 0x00
+    maxprot:  0
+    initprot: 0
+    nsects:   2
+    flags:    0
+    Sections:
+      - sectname:  __debug_info
+        segname:   __DWARF
+        addr:      0x00
+        size:      64
+        offset:    1070
+        align:     0
+        reloff:    0x00000000
+        nreloc:    0
+        flags:     0x00000000
+        reserved1: 0x00000000
+        reserved2: 0x00000000
+        reserved3: 0x00000000
+DWARF:
+  debug_info:
+    - Version:    4
+      AbbrOffset: 0x00
+      Entries:
+        - AbbrCode: 1
+          Values:
+            - Value: 0x1234
diff --git a/llvm/test/ObjectYAML/MachO/DWARF5-debug_info.yaml b/llvm/test/ObjectYAML/MachO/DWARF5-debug_info.yaml
index d63be60..d016b8c 100644
--- a/llvm/test/ObjectYAML/MachO/DWARF5-debug_info.yaml
+++ b/llvm/test/ObjectYAML/MachO/DWARF5-debug_info.yaml
@@ -515,6 +515,7 @@ DWARF:
 # DWARF32-NEXT:     - Length:        0x0000000000000076
 # DWARF32-NEXT:       Version:       5
 # DWARF32-NEXT:       UnitType:      DW_UT_compile
+# DWARF32-NEXT:       AbbrevTableID: 0
 # DWARF32-NEXT:       AbbrOffset:    0
 # DWARF32-NEXT:       AddrSize:      8
 # DWARF32-NEXT:       Entries:
@@ -585,6 +586,7 @@ DWARF:
 # DWARF32-YAML-NEXT:   - Length:        0x000000000000000C
 # DWARF32-YAML-NEXT:     Version:       5
 # DWARF32-YAML-NEXT:     UnitType:      DW_UT_compile
+# DWARF32-YAML-NEXT:     AbbrevTableID: 0
 # DWARF32-YAML-NEXT:     AbbrOffset:    0x0000000000000000
 # DWARF32-YAML-NEXT:     AddrSize:      8
 # DWARF32-YAML-NEXT:     Entries:
@@ -670,6 +672,7 @@ DWARF:
 # DWARF64-YAML-NEXT:     Length:        0x0000000000000014
 # DWARF64-YAML-NEXT:     Version:       5
 # DWARF64-YAML-NEXT:     UnitType:      DW_UT_compile
+# DWARF64-YAML-NEXT:     AbbrevTableID: 0
 # DWARF64-YAML-NEXT:     AbbrOffset:    0x0000000000000000
 # DWARF64-YAML-NEXT:     AddrSize:      8
 # DWARF64-YAML-NEXT:     Entries: