[XCOFF] [llvm-objdump] Add XCOFF recognition of debug section types under `--section-headers` option.

[Esme]

Summary

This is a child patch derived from D102603 to add XCOFF recognition of debug section types.

[Higuoxing]

LGTM, thanks! But please wait until another reviewer is happy about this change :)

P.S. You can click the Edit Related Revisions ... button on the right side to add a parent or a child patch.

[shchenz]

LGTM too with some nits.

llvm/test/tools/llvm-objdump/XCOFF/section-headers.test

30

nit: two Address?

45

I understand this is for testing purposes. But STYP_DEBUG is specific for stabstrings and .dwinfo is specific for dwarf on AIX, I think it is not a good idea to make them together.
Maybe you can use .debug section for STYP_DEBUG.

49

Nit: should we put the RUN lines together at the front of this file?

[jhenderson]

llvm/test/tools/llvm-objdump/XCOFF/section-headers-truncate.test

1

Didn't notice this before, but it sounds like this functionality is unrelated to the debug section types, so should be split off into its own patch.

llvm/test/tools/llvm-objdump/XCOFF/section-headers.test

3

I think you can drop the quotes around the option name. I'd also normalise the order to match the previous comment (i.e. -h/--section-headers).

4

Delete this blank line, so that the comment is clearly tied to the specific test case.

48

Delete this blank line, so that the comment is clearly tied to the specific test case.

49

Nit: should we put the RUN lines together at the front of this file?

I don't think we should do this. The RUN/CHECK/YAML blocks are for two somewhat distinct test cases, so shouldn't be intermixed. Intermixing them would make the test harder to follow.

[Esme]

Address comment.

[jhenderson]

LGTM, thanks!

llvm/include/llvm/Object/XCOFFObjectFile.h

public:
   uint64_t getSectionSize(DataRefImpl Sec) const override;
   Expected<ArrayRef<uint8_t>>
   getSectionContents(DataRefImpl Sec) const override;
   uint64_t getSectionAlignment(DataRefImpl Sec) const override;
   bool isSectionCompressed(DataRefImpl Sec) const override;
   bool isSectionText(DataRefImpl Sec) const override;
   bool isSectionData(DataRefImpl Sec) const override;
   bool isSectionBSS(DataRefImpl Sec) const override;
+  bool isDebugSection(DataRefImpl Sec) const override;
 
   bool isSectionVirtual(DataRefImpl Sec) const override;
   relocation_iterator section_rel_begin(DataRefImpl Sec) const override;
   relocation_iterator section_rel_end(DataRefImpl Sec) const override;
 
   void moveRelocationNext(DataRefImpl &Rel) const override;
 
   /// \returns the relocation offset with the base address of the containing

llvm/lib/Object/XCOFFObjectFile.cpp

bool XCOFFObjectFile::isSectionData(DataRefImpl Sec) const {
   return Flags & (XCOFF::STYP_DATA | XCOFF::STYP_TDATA);
 }
 
 bool XCOFFObjectFile::isSectionBSS(DataRefImpl Sec) const {
   uint32_t Flags = getSectionFlags(Sec);
   return Flags & (XCOFF::STYP_BSS | XCOFF::STYP_TBSS);
 }
 
+bool XCOFFObjectFile::isDebugSection(DataRefImpl Sec) const {
+  uint32_t Flags = getSectionFlags(Sec);
+  return Flags & (XCOFF::STYP_DEBUG | XCOFF::STYP_DWARF);
+}
+
 bool XCOFFObjectFile::isSectionVirtual(DataRefImpl Sec) const {
   return is64Bit() ? toSection64(Sec)->FileOffsetToRawData == 0
                    : toSection32(Sec)->FileOffsetToRawData == 0;
 }
 
 relocation_iterator XCOFFObjectFile::section_rel_begin(DataRefImpl Sec) const {
   if (is64Bit())
     report_fatal_error("64-bit support not implemented yet");

llvm/test/tools/llvm-objdump/XCOFF/section-headers-truncate.test

+## Truncate the file to end before the section header table ends.
+# RUN: yaml2obj %s -o %t.o
+# RUN: %python -c "with open('%/t.o', 'r+b') as input: input.truncate(24)"
+# RUN: not llvm-objdump --section-headers %t.o 2>&1 \
+# RUN:  | FileCheck --check-prefix=ERROR %s
+
+# ERROR: The end of the file was unexpectedly encountered
+
+--- !XCOFF
+FileHeader:
+  MagicNumber:          0x1DF
+Sections:
+  - Name:               .text
+    Size:               0x8
+    Flags:              [ STYP_TEXT ]

llvm/test/tools/llvm-objdump/XCOFF/section-headers.test

-# RUN: llvm-objdump --section-headers %p/Inputs/xcoff-section-headers.o | \
-# RUN: FileCheck %s
+## Test various details of llvm-objdump -h/--section-headers for XCOFF.
 
-# RUN: llvm-objdump --section-headers %p/Inputs/xcoff-long-sec-names.o | \
-# RUN: FileCheck --check-prefix=LONG %s
+## Check the `--section-headers/-h` prints the type of sections correctly.
 
-# RUN: not llvm-objdump --section-headers 2>&1 \
-# RUN: %p/Inputs/xcoff-section-headers-truncate.o | FileCheck \
-# RUN: --check-prefix=ERROR %s
+# RUN: yaml2obj %s --docnum=1 -o %t-type.o
+# RUN: llvm-objdump --section-headers %t-type.o | FileCheck %s
 
-# ERROR: The end of the file was unexpectedly encountered
-
-# CHECK: xcoff-section-headers.o:      file format aixcoff-rs6000
-# CHECK: Sections:
-# CHECK: Idx Name          Size     VMA      Type
-# CHECK:   0 .text         00000080 00000000 TEXT
-# CHECK:   1 .data         00000024 00000080 DATA
-# CHECK:   2 .bss          00000004 000000a4 BSS
-# CHECK:   3 .tdata        00000008 00000000 DATA
-# CHECK:   4 .tbss         00000004 00000008 BSS
-
-# xcoff-section-headers.o Compiled with IBM XL C/C++ for AIX, V16.1.0
-# test.c:
-# int a;
-# int b = 12345;
-# __thread int c;
-# __thread double d = 3.14159;
-#
-# int func(void)  {
-#   return a;
-# }
+# CHECK:      Sections:
+# CHECK-NEXT: Idx Name          Size     VMA      Type
+# CHECK-NEXT:   0 .text         00000008 00000008 TEXT
+# CHECK-NEXT:   1 .data         00000004 00000000 DATA
+# CHECK-NEXT:   2 .bss          00000000 00000010 BSS
+# CHECK-NEXT:   3 .tdata        00000004 00000000 DATA
+# CHECK-NEXT:   4 .tbss         00000000 00000000 BSS
+# CHECK-NEXT:   5 .dwline       00000046 00000000 DEBUG
+# CHECK-NEXT:   6 .dwinfo       00000046 00000000 DEBUG
+
+--- !XCOFF
+FileHeader:
+  MagicNumber:          0x1DF
+Sections:
+  - Name:               .text
+    Address:            0x8
+    Size:               0x8
+    Flags:              [ STYP_TEXT ]
+  - Name:               .data
+    Size:               0x4
+    Flags:              [ STYP_DATA ]
+  - Name:               .bss
+    Address:            0x20
+    Size:               0x0
+    Address:            0x10
+    Flags:              [ STYP_BSS ]
+  - Name:               .tdata
+    Size:               0x4
+    Flags:              [ STYP_TDATA ]
+  - Name:               .tbss
+    Size:               0x0
+    Flags:              [ STYP_TBSS ]
+  - Name:               .dwline
+    Size:               0x46
+    Flags:              [ STYP_DWARF ]
+  - Name:               .dwinfo
+    Size:               0x46
+    Flags:              [ STYP_DEBUG ]
+
+## Check the `--section-headers/-h` option prints long section names.
+
+# RUN: yaml2obj %s --docnum=2 -o %t-longname.o
+# RUN: llvm-objdump --section-headers %t-longname.o \
+# RUN:   | FileCheck %s --check-prefix=LONG
 
-# LONG: xcoff-long-sec-names.o:      file format aixcoff-rs6000
-# LONG: Sections:
-# LONG: Idx Name          Size     VMA      Type
-# LONG:   0 .dwarnge      00000004 00000000
-# LONG:   1 .dwpbnms      00000004 00000000
-# LONG:   2 .dwpbtyp      00000004 00000000
-
-# xcoff-long-sec-names.o was generated by assembling the following .s file:
-#  .dwsect 0x30000 # .dwpbnms section
-#  .dwsect 0x40000 # .dwpbtyp section
-#  .dwsect 0x50000 # .dwarnge section
+# LONG:      Sections:
+# LONG-NEXT: Idx Name          Size     VMA      Type
+# LONG-NEXT:   0 .dwarnge      00000004 00000000 
+# LONG-NEXT:   1 .dwpbnms      00000004 00000000 
+# LONG-NEXT:   2 .dwpbtyp      00000004 00000000 
+
+--- !XCOFF
+FileHeader:
+  MagicNumber:          0x1DF
+Sections:
+  - Name:               .dwarnge
+    Size:               0x4
+    Flags:              [ STYP_PAD ]
+  - Name:               .dwpbnms
+    Size:               0x4
+    Flags:              [ STYP_PAD ]
+  - Name:               .dwpbtyp
+    Size:               0x4
+    Flags:              [ STYP_PAD ]