[llvm-objdump] - Print relocation record in a GNU format.

This fixes the https://bugs.llvm.org/show_bug.cgi?id=41355.

Previously with -r we printed relocation section name instead of the target section name.
It was like this: "RELOCATION RECORDS FOR [.rel.text]"
Now it is: "RELOCATION RECORDS FOR [.text]"

Also when relocation target section has more than one relocation section,
we did not combine the output. Now we do.

Differential revision: https://reviews.llvm.org/D61312

llvm-svn: 360143

1 files changed, 23 insertions, 11 deletions

diff --git a/llvm/tools/llvm-objdump/llvm-objdump.cpp b/llvm/tools/llvm-objdump/llvm-objdump.cpp
index 77307bf6fbb..ea3922bbbb1 100644
--- a/llvm/tools/llvm-objdump/llvm-objdump.cpp
+++ b/llvm/tools/llvm-objdump/llvm-objdump.cpp
@@ -1447,22 +1447,34 @@ void printRelocations(const ObjectFile *Obj) {
   if (!Obj->isRelocatableObject())
     return;
 
+  // Build a mapping from relocation target to a vector of relocation
+  // sections. Usually, there is an only one relocation section for
+  // each relocated section.
+  MapVector<SectionRef, std::vector<SectionRef>> SecToRelSec;
   for (const SectionRef &Section : ToolSectionFilter(*Obj)) {
     if (Section.relocation_begin() == Section.relocation_end())
       continue;
+    const SectionRef TargetSec = *Section.getRelocatedSection();
+    SecToRelSec[TargetSec].push_back(Section);
+  }
+
+  for (std::pair<SectionRef, std::vector<SectionRef>> &P : SecToRelSec) {
     StringRef SecName;
-    error(Section.getName(SecName));
+    error(P.first.getName(SecName));
     outs() << "RELOCATION RECORDS FOR [" << SecName << "]:\n";
-    for (const RelocationRef &Reloc : Section.relocations()) {
-      uint64_t Address = Reloc.getOffset();
-      SmallString<32> RelocName;
-      SmallString<32> ValueStr;
-      if (Address < StartAddress || Address > StopAddress || getHidden(Reloc))
-        continue;
-      Reloc.getTypeName(RelocName);
-      error(getRelocationValueString(Reloc, ValueStr));
-      outs() << format(Fmt.data(), Address) << " " << RelocName << " "
-             << ValueStr << "\n";
+
+    for (SectionRef Section : P.second) {
+      for (const RelocationRef &Reloc : Section.relocations()) {
+        uint64_t Address = Reloc.getOffset();
+        SmallString<32> RelocName;
+        SmallString<32> ValueStr;
+        if (Address < StartAddress || Address > StopAddress || getHidden(Reloc))
+          continue;
+        Reloc.getTypeName(RelocName);
+        error(getRelocationValueString(Reloc, ValueStr));
+        outs() << format(Fmt.data(), Address) << " " << RelocName << " "
+               << ValueStr << "\n";
+      }
     }
     outs() << "\n";
   }