[llvm-readobj] - Teach llvm-readobj to print dependencies of SHT_GNU_verdef and refac...

This patch changes single method of llvm-readobj.
It teaches SHT_GNU_verdef dumper to print version dependencies,
also it removes few fields from output that can be dumped with other keys
and slightly refactors code.
Testcase was also modified to match the changes.
Change is required for testcases of upcoming lld patches.

Differential revision: http://reviews.llvm.org/D21552

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@273417 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/test/tools/llvm-readobj/elf-versioninfo.test b/test/tools/llvm-readobj/elf-versioninfo.test
index c7c97b9..919120e 100644 (file)
--- a/test/tools/llvm-readobj/elf-versioninfo.test
+++ b/test/tools/llvm-readobj/elf-versioninfo.test
@@ -47,40 +47,29 @@ CHECK-NEXT:     }
 CHECK-NEXT:   ]
 CHECK-NEXT: }
 
-CHECK: Version definition {
-CHECK-NEXT:   Section Name: .gnu.version_d (70)
-CHECK-NEXT:   Address: 0x25C
-CHECK-NEXT:   Offset: 0x25C
-CHECK-NEXT:   Link: 2
-CHECK-NEXT:   Entries [
-CHECK-NEXT:     Entry {
-CHECK-NEXT:       Offset: 0x0
-CHECK-NEXT:       Rev: 1
-CHECK-NEXT:       Flags: 1
-CHECK-NEXT:       Index: 1
-CHECK-NEXT:       Cnt: 1
-CHECK-NEXT:       Hash: 430712
-CHECK-NEXT:       Name: blah
-CHECK-NEXT:     }
-CHECK-NEXT:     Entry {
-CHECK-NEXT:       Offset: 0x1C
-CHECK-NEXT:       Rev: 1
-CHECK-NEXT:       Flags: 0
-CHECK-NEXT:       Index: 2
-CHECK-NEXT:       Cnt: 1
-CHECK-NEXT:       Hash: 175630257
-CHECK-NEXT:       Name: VERSION1
-CHECK-NEXT:     }
-CHECK-NEXT:     Entry {
-CHECK-NEXT:       Offset: 0x38
-CHECK-NEXT:       Rev: 1
-CHECK-NEXT:       Flags: 0
-CHECK-NEXT:       Index: 3
-CHECK-NEXT:       Cnt: 2
-CHECK-NEXT:       Hash: 175630258
-CHECK-NEXT:       Name: VERSION2
-CHECK-NEXT:     }
-CHECK-NEXT:   ]
+CHECK:      SHT_GNU_verdef {
+CHECK-NEXT:   Definition {
+CHECK-NEXT:     Version: 1
+CHECK-NEXT:     Flags: Base (0x1)
+CHECK-NEXT:     Index: 1
+CHECK-NEXT:     Hash: 430712
+CHECK-NEXT:     Name: blah
+CHECK-NEXT:   }
+CHECK-NEXT:   Definition {
+CHECK-NEXT:     Version: 1
+CHECK-NEXT:     Flags: 0x0
+CHECK-NEXT:     Index: 2
+CHECK-NEXT:     Hash: 175630257
+CHECK-NEXT:     Name: VERSION1
+CHECK-NEXT:   }
+CHECK-NEXT:   Definition {
+CHECK-NEXT:     Version: 1
+CHECK-NEXT:     Flags: 0x0
+CHECK-NEXT:     Index: 3
+CHECK-NEXT:     Hash: 175630258
+CHECK-NEXT:     Name: VERSION2
+CHECK-NEXT:     Predecessor: VERSION1
+CHECK-NEXT:   }
 CHECK-NEXT: }
 
 RUN: llvm-readobj -V %p/Inputs/verneed.elf-x86-64 | FileCheck %s --check-prefix=VERNEED

diff --git a/tools/llvm-readobj/ELFDumper.cpp b/tools/llvm-readobj/ELFDumper.cpp
index 1f45b79..84e368e 100644 (file)
--- a/tools/llvm-readobj/ELFDumper.cpp
+++ b/tools/llvm-readobj/ELFDumper.cpp
@@ -530,21 +530,19 @@ static void printVersionDefinitionSection(ELFDumper<ELFT> *Dumper,
                                           const ELFO *Obj,
                                           const typename ELFO::Elf_Shdr *Sec,
                                           ScopedPrinter &W) {
-  DictScope SD(W, "Version definition");
+  typedef typename ELFO::Elf_Verdef VerDef;
+  typedef typename ELFO::Elf_Verdaux VerdAux;
+
+  DictScope SD(W, "SHT_GNU_verdef");
   if (!Sec)
     return;
-  StringRef Name = unwrapOrError(Obj->getSectionName(Sec));
-  W.printNumber("Section Name", Name, Sec->sh_name);
-  W.printHex("Address", Sec->sh_addr);
-  W.printHex("Offset", Sec->sh_offset);
-  W.printNumber("Link", Sec->sh_link);
 
-  unsigned verdef_entries = 0;
   // The number of entries in the section SHT_GNU_verdef
   // is determined by DT_VERDEFNUM tag.
+  unsigned VerDefsNum = 0;
   for (const typename ELFO::Elf_Dyn &Dyn : Dumper->dynamic_table()) {
     if (Dyn.d_tag == DT_VERDEFNUM)
-      verdef_entries = Dyn.d_un.d_val;
+      VerDefsNum = Dyn.d_un.d_val;
   }
   const uint8_t *SecStartAddress =
       (const uint8_t *)Obj->base() + Sec->sh_offset;
@@ -553,22 +551,32 @@ static void printVersionDefinitionSection(ELFDumper<ELFT> *Dumper,
   const typename ELFO::Elf_Shdr *StrTab =
       unwrapOrError(Obj->getSection(Sec->sh_link));
 
-  ListScope Entries(W, "Entries");
-  for (unsigned i = 0; i < verdef_entries; ++i) {
-    if (P + sizeof(typename ELFO::Elf_Verdef) > SecEndAddress)
+  while (VerDefsNum--) {
+    if (P + sizeof(VerDef) > SecEndAddress)
       report_fatal_error("invalid offset in the section");
-    auto *VD = reinterpret_cast<const typename ELFO::Elf_Verdef *>(P);
-    DictScope Entry(W, "Entry");
-    W.printHex("Offset", (uintptr_t)P - (uintptr_t)SecStartAddress);
-    W.printNumber("Rev", VD->vd_version);
-    // FIXME: print something more readable.
-    W.printNumber("Flags", VD->vd_flags);
+
+    auto *VD = reinterpret_cast<const VerDef *>(P);
+    DictScope Def(W, "Definition");
+    W.printNumber("Version", VD->vd_version);
+    W.printEnum("Flags", VD->vd_flags, makeArrayRef(SymVersionFlags));
     W.printNumber("Index", VD->vd_ndx);
-    W.printNumber("Cnt", VD->vd_cnt);
     W.printNumber("Hash", VD->vd_hash);
     W.printString("Name",
                   StringRef((const char *)(Obj->base() + StrTab->sh_offset +
                                            VD->getAux()->vda_name)));
+    if (!VD->vd_cnt)
+      report_fatal_error("at least one definition string must exist");
+    if (VD->vd_cnt > 2)
+      report_fatal_error("more than one predecessor is not expected");
+
+    if (VD->vd_cnt == 2) {
+      const uint8_t *PAux = P + VD->vd_aux + VD->getAux()->vda_next;
+      const VerdAux *Aux = reinterpret_cast<const VerdAux *>(PAux);
+      W.printString("Predecessor",
+                    StringRef((const char *)(Obj->base() + StrTab->sh_offset +
+                                             Aux->vda_name)));
+    }
+
     P += VD->vd_next;
   }
 }