[llvm-readobj] - Improve test of --elf-hash-histogram option.

[grimar]

Summary

This test missed the check of histograms printed for .hash sections.
It was removed by mistake in D71606 where I tried to get rid of precompiled objects
and seems did not realize that time that both SHT_GNU_HASH and SHT_HASH sections
were tested and not just GNU version.

Also it never tested aliases for the --elf-hash-histogram option.

[jhenderson]

llvm/test/tools/llvm-readobj/ELF/hash-histogram.test

8

Perhaps add a blank line before this comment.

21

You probably need to make this HIST-NEXT and/or add HIST-EMPTY before it to show that there are no more lines after the previous table.

26

Similarly, adding a HIST-EMPTY at the end here would be wise.

57–58

Up to you, but you could avoid this macro by setting the AddressAlign property of the .hash section to some size, e.g. 0x100, and then just use that.

[grimar]

• Addressed review comments.

llvm/test/tools/llvm-readobj/ELF/hash-histogram.test

57–58

And alternative is to swap the order of .hash and .gnu.hash: the size of .hash is the same for 32/64 bit cases.
I've done it.

[jhenderson]

LGTM.

llvm/test/tools/llvm-readobj/ELF/hash-histogram.test

 ## Here we test the --elf-hash-histogram command line option.
 
-## This test case checks how we built a histogram for a GNU hash section.
-## We check both 32-bit and 64-bit inputs.
+## This test case checks how we built histograms for hash sections.
 
 # RUN: yaml2obj --docnum=1 -D BITS=32 %s -o %t1-32.o
-# RUN: llvm-readelf --elf-hash-histogram %t1-32.o | FileCheck %s --check-prefix=GNU-HASH
+# RUN: llvm-readelf --elf-hash-histogram %t1-32.o | FileCheck %s --check-prefix=HIST
+
+## Test --histogram and -I aliases.
+# RUN: llvm-readelf --histogram %t1-32.o | FileCheck %s --check-prefix=HIST
+# RUN: llvm-readelf -I %t1-32.o | FileCheck %s --check-prefix=HIST
 
 # RUN: yaml2obj --docnum=1 -D BITS=64 %s -o %t1-64.o
-# RUN: llvm-readelf --elf-hash-histogram %t1-64.o | FileCheck %s --check-prefix=GNU-HASH
+# RUN: llvm-readelf --elf-hash-histogram %t1-64.o | FileCheck %s --check-prefix=HIST
 
-# GNU-HASH:      Histogram for `.gnu.hash' bucket list length (total of 3 buckets)
-# GNU-HASH-NEXT:  Length  Number     % of total  Coverage
-# GNU-HASH-NEXT:       0  1          ( 33.3%)       0.0%
-# GNU-HASH-NEXT:       1  1          ( 33.3%)      25.0%
-# GNU-HASH-NEXT:       2  0          (  0.0%)      25.0%
-# GNU-HASH-NEXT:       3  1          ( 33.3%)     100.0%
+# HIST:      Histogram for bucket list length (total of 3 buckets)
+# HIST-NEXT:  Length  Number     % of total  Coverage
+# HIST-NEXT:       0  2          ( 66.7%)       0.0%
+# HIST-NEXT:       1  0          (  0.0%)       0.0%
+# HIST-NEXT:       2  0          (  0.0%)       0.0%
+# HIST-NEXT:       3  1          ( 33.3%)     100.0%
+# HIST-NEXT: Histogram for `.gnu.hash' bucket list length (total of 3 buckets)
+# HIST-NEXT:  Length  Number     % of total  Coverage
+# HIST-NEXT:       0  1          ( 33.3%)       0.0%
+# HIST-NEXT:       1  1          ( 33.3%)      25.0%
+# HIST-NEXT:       2  0          (  0.0%)      25.0%
+# HIST-NEXT:       3  1          ( 33.3%)     100.0%
+# HIST-NOT:  {{.}}
 
 --- !ELF
 FileHeader:
   Class:   ELFCLASS[[BITS]]
   Data:    ELFDATA2LSB
   Type:    ET_DYN
   Machine: EM_386
 Sections:
+  - Name:   .hash
+    Type:   SHT_HASH
+    Flags:  [ SHF_ALLOC ]
+    Bucket: [ 6, 4, 5 ]
+    Chain:  [ 0, 0, 1, 0, 2 ]
   - Name:  .gnu.hash
     Type:  SHT_GNU_HASH
     Flags: [ SHF_ALLOC ]
     Header:
       SymNdx: 0x1
       Shift2: 0x0
     BloomFilter: [ 0x0 ]
     HashBuckets: [ 0x00000001, 0x00000004, 0x00000000 ]
     HashValues:  [ 0x0B887388, 0xECD54542, 0x7C92E3BB, 0x1C5871D9 ]
   - Name:  .dynamic
     Type:  SHT_DYNAMIC
     Flags: [ SHF_WRITE, SHF_ALLOC ]
     Entries:
-      - Tag:   DT_GNU_HASH
+      - Tag:   DT_HASH
         Value: 0x0
+      - Tag:   DT_GNU_HASH
+## sizeof(.hash) == 0x28.
+        Value: 0x28
       - Tag:   DT_NULL
         Value: 0x0
 DynamicSymbols:
   - Name: a
   - Name: b
   - Name: c
   - Name: d
 ProgramHeaders:
   - Type:  PT_LOAD
     Sections:
+      - Section: .hash
       - Section: .gnu.hash
       - Section: .dynamic
 
 ## Show that we report a warning for a hash table which contains an entry of
 ## the bucket array pointing to a cycle.
 
 # RUN: yaml2obj --docnum=2 %s -o %t2.o
 # RUN: llvm-readelf --elf-hash-histogram 2>&1 %t2.o | FileCheck -DFILE=%t2.o %s --check-prefix=BROKEN