From 0eba9bcf82b3f7b913738c2b52fc5483b916890c Mon Sep 17 00:00:00 2001
From: Simon Atanasyan <simon@atanasyan.com>
Date: Sat, 2 Dec 2017 13:06:35 +0000
Subject: [llvm-readobj] Print static MIPS GOT

If a linked binary file contains a dynamic section, the GOT layout
defined by the dynamic section entries. In a statically linked file
the GOT is just a series of entries. This change teaches `llvm-readobj`
to print the GOT in that case. That provides a feature parity with GNU
`readelf`.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@319616 91177308-0d34-0410-b5e6-96231b3b80d8
---
 tools/llvm-readobj/ELFDumper.cpp | 85 ++++++++++++++++++++++++++--------------
 1 file changed, 55 insertions(+), 30 deletions(-)

(limited to 'tools')

diff --git a/tools/llvm-readobj/ELFDumper.cpp b/tools/llvm-readobj/ELFDumper.cpp
index df01e265798..8bc088afe43 100644
--- a/tools/llvm-readobj/ELFDumper.cpp
+++ b/tools/llvm-readobj/ELFDumper.cpp
@@ -1910,6 +1910,7 @@ public:
   MipsGOTParser(ELFDumper<ELFT> *Dumper, const ELFO *Obj,
                 Elf_Dyn_Range DynTable, ScopedPrinter &W);
 
+  void parseStaticGOT();
   void parseGOT();
   void parsePLT();
 
@@ -1926,6 +1927,7 @@ private:
   std::size_t getGOTTotal(ArrayRef<uint8_t> GOT) const;
   const GOTEntry *makeGOTIter(ArrayRef<uint8_t> GOT, std::size_t EntryNum);
 
+  void printLocalGOT(const Elf_Shdr *GOTShdr, size_t Num);
   void printGotEntry(uint64_t GotAddr, const GOTEntry *BeginIt,
                      const GOTEntry *It);
   void printGlobalGotEntry(uint64_t GotAddr, const GOTEntry *BeginIt,
@@ -1965,6 +1967,50 @@ MipsGOTParser<ELFT>::MipsGOTParser(ELFDumper<ELFT> *Dumper, const ELFO *Obj,
   }
 }
 
+template <class ELFT>
+void MipsGOTParser<ELFT>::printLocalGOT(const Elf_Shdr *GOTShdr, size_t Num) {
+  ArrayRef<uint8_t> GOT = unwrapOrError(Obj->getSectionContents(GOTShdr));
+
+  const GOTEntry *GotBegin = makeGOTIter(GOT, 0);
+  const GOTEntry *GotEnd = makeGOTIter(GOT, Num);
+  const GOTEntry *It = GotBegin;
+
+  W.printHex("Canonical gp value", GOTShdr->sh_addr + 0x7ff0);
+  {
+    ListScope RS(W, "Reserved entries");
+
+    {
+      DictScope D(W, "Entry");
+      printGotEntry(GOTShdr->sh_addr, GotBegin, It++);
+      W.printString("Purpose", StringRef("Lazy resolver"));
+    }
+
+    if (It != GotEnd && (*It >> (sizeof(GOTEntry) * 8 - 1)) != 0) {
+      DictScope D(W, "Entry");
+      printGotEntry(GOTShdr->sh_addr, GotBegin, It++);
+      W.printString("Purpose", StringRef("Module pointer (GNU extension)"));
+    }
+  }
+  {
+    ListScope LS(W, "Local entries");
+    for (; It != GotEnd; ++It) {
+      DictScope D(W, "Entry");
+      printGotEntry(GOTShdr->sh_addr, GotBegin, It);
+    }
+  }
+}
+
+template <class ELFT> void MipsGOTParser<ELFT>::parseStaticGOT() {
+  const Elf_Shdr *GOTShdr = findSectionByName(*Obj, ".got");
+  if (!GOTShdr) {
+    W.startLine() << "Cannot find .got section.\n";
+    return;
+  }
+
+  DictScope GS(W, "Static GOT");
+  printLocalGOT(GOTShdr, GOTShdr->sh_size / sizeof(GOTEntry));
+}
+
 template <class ELFT> void MipsGOTParser<ELFT>::parseGOT() {
   // See "Global Offset Table" in Chapter 5 in the following document
   // for detailed GOT description.
@@ -2007,42 +2053,17 @@ template <class ELFT> void MipsGOTParser<ELFT>::parseGOT() {
   if (*DtLocalGotNum + GlobalGotNum > getGOTTotal(GOT))
     report_fatal_error("Number of GOT entries exceeds the size of GOT section");
 
-  const GOTEntry *GotBegin = makeGOTIter(GOT, 0);
-  const GOTEntry *GotLocalEnd = makeGOTIter(GOT, *DtLocalGotNum);
-  const GOTEntry *It = GotBegin;
-
   DictScope GS(W, "Primary GOT");
+  printLocalGOT(GOTShdr, *DtLocalGotNum);
 
-  W.printHex("Canonical gp value", GOTShdr->sh_addr + 0x7ff0);
-  {
-    ListScope RS(W, "Reserved entries");
-
-    {
-      DictScope D(W, "Entry");
-      printGotEntry(GOTShdr->sh_addr, GotBegin, It++);
-      W.printString("Purpose", StringRef("Lazy resolver"));
-    }
-
-    if (It != GotLocalEnd && (*It >> (sizeof(GOTEntry) * 8 - 1)) != 0) {
-      DictScope D(W, "Entry");
-      printGotEntry(GOTShdr->sh_addr, GotBegin, It++);
-      W.printString("Purpose", StringRef("Module pointer (GNU extension)"));
-    }
-  }
-  {
-    ListScope LS(W, "Local entries");
-    for (; It != GotLocalEnd; ++It) {
-      DictScope D(W, "Entry");
-      printGotEntry(GOTShdr->sh_addr, GotBegin, It);
-    }
-  }
   {
     ListScope GS(W, "Global entries");
 
+    const GOTEntry *GotBegin = makeGOTIter(GOT, 0);
     const GOTEntry *GotGlobalEnd =
         makeGOTIter(GOT, *DtLocalGotNum + GlobalGotNum);
     const Elf_Sym *GotDynSym = DynSymBegin + *DtGotSym;
-    for (; It != GotGlobalEnd; ++It) {
+    for (auto It = makeGOTIter(GOT, *DtLocalGotNum); It != GotGlobalEnd; ++It) {
       DictScope D(W, "Entry");
       printGlobalGotEntry(GOTShdr->sh_addr, GotBegin, It, GotDynSym++,
                           StrTable);
@@ -2197,8 +2218,12 @@ template <class ELFT> void ELFDumper<ELFT>::printMipsPLTGOT() {
   }
 
   MipsGOTParser<ELFT> GOTParser(this, Obj, dynamic_table(), W);
-  GOTParser.parseGOT();
-  GOTParser.parsePLT();
+  if (dynamic_table().empty())
+    GOTParser.parseStaticGOT();
+  else {
+    GOTParser.parseGOT();
+    GOTParser.parsePLT();
+  }
 }
 
 static const EnumEntry<unsigned> ElfMipsISAExtType[] = {
-- 
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