[llvm-readelf/llvm-readobj] - Improved the error reporting in a few method related to versioning.

I was investigating a change previously discussed that eliminates an excessive
empty lines from the output when we report warnings and errors
(https://reviews.llvm.org/D70826#inline-639055) and found
that we need this refactoring or alike to achieve that.

The problem is that some of our functions that finds symbol versions just
fail instead of returning errors or printing warnings. Another problem
is that they might print a warning on the same line with the regular output.
In this patch I've splitted getting of the version information and dumping of it
for GNU printVersionSymbolSection(). I had to change a few methods to return
Error or Expected<> to do that properly.

Differential revision: https://reviews.llvm.org/D71118

4 files changed, 75 insertions, 15 deletions

diff --git a/llvm/test/Object/invalid.test b/llvm/test/Object/invalid.test
index 91a93b06b96..b47ba6f9fac 100644
--- a/llvm/test/Object/invalid.test
+++ b/llvm/test/Object/invalid.test
@@ -413,9 +413,9 @@ Symbols:
 ## Check llvm-readobj reports it.
 
 # RUN: yaml2obj %s --docnum=20 -o %t20
-# RUN: not llvm-readobj -dt %t20 2>&1 | FileCheck -DFILE=%t20 --check-prefix=INVALID-VERSION %s
+# RUN: llvm-readobj -dt %t20 2>&1 | FileCheck -DFILE=%t20 --check-prefix=INVALID-VERSION %s
 
-# INVALID-VERSION: error: '[[FILE]]': Invalid version entry
+# INVALID-VERSION: warning: '[[FILE]]': SHT_GNU_versym section refers to a version index 255 which is missing
 
 --- !ELF
 FileHeader:
diff --git a/llvm/test/tools/llvm-readobj/ELF/verdef-invalid.test b/llvm/test/tools/llvm-readobj/ELF/verdef-invalid.test
index f80e9383f70..e22ed6ee7ec 100644
--- a/llvm/test/tools/llvm-readobj/ELF/verdef-invalid.test
+++ b/llvm/test/tools/llvm-readobj/ELF/verdef-invalid.test
@@ -263,11 +263,12 @@ Sections:
 DynamicSymbols:
   - Name: foo
 
-## Check we error out when trying to print version symbols, but SHT_GNU_verdef is invalid due to any reason.
+## Check we report a warning when trying to print version symbols, but SHT_GNU_verdef
+## is invalid due to any reason.
 
 # RUN: yaml2obj %s --docnum=10 -o %t10
-# RUN: not llvm-readobj -V %t10 2>&1 | FileCheck %s --check-prefix=INVALID-VERDEF-LLVM -DFILE=%t10
-# RUN: not llvm-readelf -V %t10 2>&1 | FileCheck %s --check-prefix=INVALID-VERDEF-GNU -DFILE=%t10
+# RUN: llvm-readobj -V %t10 2>&1 | FileCheck %s --check-prefix=INVALID-VERDEF-LLVM -DFILE=%t10
+# RUN: llvm-readelf -V %t10 2>&1 | FileCheck %s --check-prefix=INVALID-VERDEF-GNU -DFILE=%t10
 
 # INVALID-VERDEF-LLVM:      VersionSymbols [
 # INVALID-VERDEF-LLVM-NEXT:    Symbol {
@@ -277,12 +278,14 @@ DynamicSymbols:
 # INVALID-VERDEF-LLVM-NEXT:    Symbol {
 # INVALID-VERDEF-LLVM-NEXT:    Version: 2
 # INVALID-VERDEF-LLVM-EMPTY:
-# INVALID-VERDEF-LLVM-NEXT:  error: '[[FILE]]': invalid SHT_GNU_verdef section with index 2: version definition 1 goes past the end of the section
+# INVALID-VERDEF-LLVM-NEXT:  warning: '[[FILE]]': invalid SHT_GNU_verdef section with index 2: version definition 1 goes past the end of the section
+# INVALID-VERDEF-LLVM-NEXT:    Name: foo@<corrupt>
 
 # INVALID-VERDEF-GNU:      Version symbols section '.gnu.version' contains 2 entries:
 # INVALID-VERDEF-GNU-NEXT:  Addr: 0000000000000000  Offset: 0x000040  Link: 5 (.dynsym)
-# INVALID-VERDEF-GNU-NEXT:   000:   0 (*local*)
-# INVALID-VERDEF-GNU-NEXT: error: '[[FILE]]': invalid SHT_GNU_verdef section with index 2: version definition 1 goes past the end of the section
+# INVALID-VERDEF-GNU-EMPTY:
+# INVALID-VERDEF-GNU-NEXT: warning: '[[FILE]]': unable to get a version for entry 1 of SHT_GNU_versym section with index 1: invalid SHT_GNU_verdef section with index 2: version definition 1 goes past the end of the section
+# INVALID-VERDEF-GNU-NEXT:   000: 0 (*local*) 2 (<corrupt>)
 
 --- !ELF
 FileHeader:
diff --git a/llvm/test/tools/llvm-readobj/ELF/verneed-invalid.test b/llvm/test/tools/llvm-readobj/ELF/verneed-invalid.test
index e8d75afe1e6..66c2d833a3a 100644
--- a/llvm/test/tools/llvm-readobj/ELF/verneed-invalid.test
+++ b/llvm/test/tools/llvm-readobj/ELF/verneed-invalid.test
@@ -10,7 +10,7 @@
 
 # GNU-VERNEED-NAME:      Version symbols section '.gnu.version' contains 2 entries:
 # GNU-VERNEED-NAME-NEXT:  Addr: 0000000000200210  Offset: 0x000040  Link: 5 (.dynsym)
-# GNU-VERNEED-NAME-NEXT:   000:   0 (*local*)       2 (*invalid*)
+# GNU-VERNEED-NAME-NEXT:   000:   0 (*local*)       2 (<corrupt>)
 
 # GNU-VERNEED-NAME:      Version needs section '.gnu.version_r' contains 1 entries:
 # GNU-VERNEED-NAME-NEXT:  Addr: 0000000000000000  Offset: 0x000044  Link: 6 (.dynstr)
@@ -86,9 +86,9 @@ DynamicSymbols:
 
 # GNU-NOLINK:      Version symbols section '.gnu.version' contains 2 entries:
 # GNU-NOLINK-NEXT:  Addr: 0000000000000000  Offset: 0x000040  Link: 5 (.dynsym)
-# GNU-NOLINK-NEXT:   000:   0 (*local*)
+# GNU-NOLINK-EMPTY:
 # GNU-NOLINK-NEXT: warning: '[[FILE]]': invalid string table linked to SHT_GNU_verneed section with index 2: invalid sh_type for string table section [index 0]: expected SHT_STRTAB, but got SHT_NULL
-# GNU-NOLINK-NEXT:   2 (<corrupt>)
+# GNU-NOLINK-NEXT:   000:   0 (*local*) 2 (<corrupt>)
 # GNU-NOLINK-EMPTY:
 # GNU-NOLINK:      Version needs section '.gnu.version_r' contains 1 entries:
 # GNU-NOLINK-NEXT:  Addr: 0000000000000000  Offset: 0x000044  Link: 0 ()
@@ -158,10 +158,23 @@ DynamicSymbols:
 ## We can't parse misaligned auxiliary version records.
 
 # RUN: yaml2obj --docnum=3 %s -o %t3
-# RUN: not llvm-readelf -V %t3 2>&1 | FileCheck %s -DFILE=%t3 --check-prefix=BROKEN-AUX
-# RUN: not llvm-readobj -V %t3 2>&1 | FileCheck %s -DFILE=%t3 --check-prefix=BROKEN-AUX
-
-# BROKEN-AUX: error: '[[FILE]]': invalid SHT_GNU_verneed section with index 2: found a misaligned auxiliary entry at offset 0x11
+# RUN: llvm-readelf -V %t3 2>&1 | FileCheck %s -DFILE=%t3 --check-prefix=BROKEN-AUX-GNU
+# RUN: llvm-readobj -V %t3 2>&1 | FileCheck %s -DFILE=%t3 --check-prefix=BROKEN-AUX-LLVM
+
+# BROKEN-AUX-GNU:       Version symbols section '.gnu.version' contains 1 entries:
+# BROKEN-AUX-GNU-NEXT:   Addr: 0000000000000000  Offset: 0x000040  Link: 5 (.dynsym)
+# BROKEN-AUX-GNU-EMPTY:
+# BROKEN-AUX-GNU-NEXT:  warning: '[[FILE]]': unable to get a version for entry 0 of SHT_GNU_versym section with index 1: invalid SHT_GNU_verneed section with index 2: found a misaligned auxiliary entry at offset 0x11
+# BROKEN-AUX-GNU-NEXT:   000:   2 (<corrupt>)
+
+# BROKEN-AUX-LLVM:       VersionSymbols [
+# BROKEN-AUX-LLVM-NEXT:    Symbol {
+# BROKEN-AUX-LLVM-NEXT:      Version: 2
+# BROKEN-AUX-LLVM-EMPTY:
+# BROKEN-AUX-LLVM-NEXT:  warning: '[[FILE]]': invalid SHT_GNU_verneed section with index 2: found a misaligned auxiliary entry at offset 0x11
+# BROKEN-AUX-LLVM-NEXT:      Name: @<corrupt>
+# BROKEN-AUX-LLVM-NEXT:    }
+# BROKEN-AUX-LLVM-NEXT:  ]
 
 --- !ELF
 FileHeader:
diff --git a/llvm/test/tools/llvm-readobj/ELF/versym-invalid.test b/llvm/test/tools/llvm-readobj/ELF/versym-invalid.test
index a88318e5f49..96c33dee1a3 100644
--- a/llvm/test/tools/llvm-readobj/ELF/versym-invalid.test
+++ b/llvm/test/tools/llvm-readobj/ELF/versym-invalid.test
@@ -218,3 +218,47 @@ Sections:
 DynamicSymbols:
   - Name: foo
   - Name: bar
+
+## Version index in a SHT_GNU_versym section overflows the version map.
+## Check we report it when trying to dump dynamic symbols.
+
+# RUN: yaml2obj %s --docnum=8 -o %t8
+# RUN: llvm-readobj --dyn-syms %t8 2>&1 \
+# RUN:   | FileCheck -DFILE=%t8 --implicit-check-not=warning --check-prefix=VERSION-OVERFLOW-LLVM %s
+# RUN: llvm-readelf --dyn-syms %t8 2>&1 \
+# RUN:   | FileCheck -DFILE=%t8 --implicit-check-not=warning --check-prefix=VERSION-OVERFLOW-GNU %s
+
+# VERSION-OVERFLOW-LLVM:       DynamicSymbols [
+# VERSION-OVERFLOW-LLVM-EMPTY:
+# VERSION-OVERFLOW-LLVM-NEXT:  warning: '[[FILE]]': SHT_GNU_versym section refers to a version index 255 which is missing
+# VERSION-OVERFLOW-LLVM-NEXT:    Symbol {
+# VERSION-OVERFLOW-LLVM-NEXT:      Name: @<corrupt> (0)
+# VERSION-OVERFLOW-LLVM:       warning: '[[FILE]]': SHT_GNU_versym section refers to a version index 254 which is missing
+# VERSION-OVERFLOW-LLVM-NEXT:    Symbol {
+# VERSION-OVERFLOW-LLVM-NEXT:      Name: foo@<corrupt> (5)
+# VERSION-OVERFLOW-LLVM:         Symbol {
+# VERSION-OVERFLOW-LLVM-NEXT:      Name: bar@<corrupt> (1)
+
+# VERSION-OVERFLOW-GNU:       Symbol table '.dynsym' contains 3 entries:
+# VERSION-OVERFLOW-GNU-NEXT:   Num:    Value          Size Type    Bind   Vis       Ndx Name
+# VERSION-OVERFLOW-GNU-EMPTY:
+# VERSION-OVERFLOW-GNU-NEXT:  warning: '[[FILE]]': SHT_GNU_versym section refers to a version index 255 which is missing
+# VERSION-OVERFLOW-GNU-NEXT:      0: 0000000000000000     0 NOTYPE  LOCAL  DEFAULT   UND @<corrupt>
+# VERSION-OVERFLOW-GNU-EMPTY:
+# VERSION-OVERFLOW-GNU-NEXT:  warning: '[[FILE]]': SHT_GNU_versym section refers to a version index 254 which is missing
+# VERSION-OVERFLOW-GNU-NEXT:      1: 0000000000000000     0 NOTYPE  LOCAL  DEFAULT   UND foo@<corrupt>
+# VERSION-OVERFLOW-GNU-NEXT:      2: 0000000000000000     0 NOTYPE  LOCAL  DEFAULT   UND bar@<corrupt
+
+--- !ELF
+FileHeader:
+  Class:   ELFCLASS64
+  Data:    ELFDATA2LSB
+  Type:    ET_DYN
+  Machine: EM_X86_64
+Sections:
+  - Name:    .gnu.version
+    Type:    SHT_GNU_versym
+    Entries: [ 0xFF, 0xFE, 0xFF ]
+DynamicSymbols:
+  - Name: foo
+  - Name: bar