From 6bf322101bebac03b63fb068fcd3158f795bcee3 Mon Sep 17 00:00:00 2001
From: Rafael Espindola <rafael.espindola@gmail.com>
Date: Wed, 24 Jun 2015 19:57:32 +0000
Subject: Make computeSymbolSizes never fail.

On ELF that was already the case since getting the size of a symbol
never fails.

On MachO and COFF we could fail trying to get the section of a symbol. But
we don't really need the section, just the section number to know if two
symbols are in the same section or not.

llvm-svn: 240580
---
 llvm/lib/Object/COFFObjectFile.cpp  | 12 ++++++++++++
 llvm/lib/Object/MachOObjectFile.cpp | 10 ++++++++++
 llvm/lib/Object/SymbolSize.cpp      | 38 ++++++++++++++++++++++---------------
 3 files changed, 45 insertions(+), 15 deletions(-)

(limited to 'llvm/lib/Object')

diff --git a/llvm/lib/Object/COFFObjectFile.cpp b/llvm/lib/Object/COFFObjectFile.cpp
index 07f9d6ed232..797ee1a7cda 100644
--- a/llvm/lib/Object/COFFObjectFile.cpp
+++ b/llvm/lib/Object/COFFObjectFile.cpp
@@ -258,6 +258,11 @@ COFFObjectFile::getSymbolSection(DataRefImpl Ref,
   return std::error_code();
 }
 
+unsigned COFFObjectFile::getSymbolSectionID(SymbolRef Sym) const {
+  COFFSymbolRef Symb = getCOFFSymbol(Sym.getRawDataRefImpl());
+  return Symb.getSectionNumber();
+}
+
 void COFFObjectFile::moveSectionNext(DataRefImpl &Ref) const {
   const coff_section *Sec = toSec(Ref);
   Sec += 1;
@@ -311,6 +316,13 @@ bool COFFObjectFile::isSectionBSS(DataRefImpl Ref) const {
   return (Sec->Characteristics & BssFlags) == BssFlags;
 }
 
+unsigned COFFObjectFile::getSectionID(SectionRef Sec) const {
+  uintptr_t Offset =
+      uintptr_t(Sec.getRawDataRefImpl().p) - uintptr_t(SectionTable);
+  assert((Offset % sizeof(coff_section)) == 0);
+  return (Offset / sizeof(coff_section)) + 1;
+}
+
 bool COFFObjectFile::isSectionVirtual(DataRefImpl Ref) const {
   const coff_section *Sec = toSec(Ref);
   // In COFF, a virtual section won't have any in-file 
diff --git a/llvm/lib/Object/MachOObjectFile.cpp b/llvm/lib/Object/MachOObjectFile.cpp
index cb98f05bfcc..62a0d60f338 100644
--- a/llvm/lib/Object/MachOObjectFile.cpp
+++ b/llvm/lib/Object/MachOObjectFile.cpp
@@ -483,6 +483,12 @@ std::error_code MachOObjectFile::getSymbolSection(DataRefImpl Symb,
   return std::error_code();
 }
 
+unsigned MachOObjectFile::getSymbolSectionID(SymbolRef Sym) const {
+  MachO::nlist_base Entry =
+      getSymbolTableEntryBase(this, Sym.getRawDataRefImpl());
+  return Entry.n_sect - 1;
+}
+
 void MachOObjectFile::moveSectionNext(DataRefImpl &Sec) const {
   Sec.d.a++;
 }
@@ -559,6 +565,10 @@ bool MachOObjectFile::isSectionBSS(DataRefImpl Sec) const {
           SectionType == MachO::S_GB_ZEROFILL);
 }
 
+unsigned MachOObjectFile::getSectionID(SectionRef Sec) const {
+  return Sec.getRawDataRefImpl().d.a;
+}
+
 bool MachOObjectFile::isSectionVirtual(DataRefImpl Sec) const {
   // FIXME: Unimplemented.
   return false;
diff --git a/llvm/lib/Object/SymbolSize.cpp b/llvm/lib/Object/SymbolSize.cpp
index 2da71f1fa24..276deaaddd7 100644
--- a/llvm/lib/Object/SymbolSize.cpp
+++ b/llvm/lib/Object/SymbolSize.cpp
@@ -9,7 +9,9 @@
 
 #include "llvm/Object/SymbolSize.h"
 #include "llvm/ADT/STLExtras.h"
+#include "llvm/Object/COFF.h"
 #include "llvm/Object/ELFObjectFile.h"
+#include "llvm/Object/MachO.h"
 
 using namespace llvm;
 using namespace object;
@@ -19,25 +21,33 @@ struct SymEntry {
   symbol_iterator I;
   uint64_t Address;
   unsigned Number;
-  SectionRef Section;
+  unsigned SectionID;
 };
 }
 
 static int compareAddress(const SymEntry *A, const SymEntry *B) {
-  if (A->Section == B->Section)
-    return A->Address - B->Address;
-  if (A->Section < B->Section)
-    return -1;
-  if (A->Section == B->Section)
-    return 0;
-  return 1;
+  if (A->SectionID != B->SectionID)
+    return A->SectionID - B->SectionID;
+  return A->Address - B->Address;
 }
 
 static int compareNumber(const SymEntry *A, const SymEntry *B) {
   return A->Number - B->Number;
 }
 
-ErrorOr<std::vector<std::pair<SymbolRef, uint64_t>>>
+static unsigned getSectionID(const ObjectFile &O, SectionRef Sec) {
+  if (auto *M = dyn_cast<MachOObjectFile>(&O))
+    return M->getSectionID(Sec);
+  return cast<COFFObjectFile>(O).getSectionID(Sec);
+}
+
+static unsigned getSymbolSectionID(const ObjectFile &O, SymbolRef Sym) {
+  if (auto *M = dyn_cast<MachOObjectFile>(&O))
+    return M->getSymbolSectionID(Sym);
+  return cast<COFFObjectFile>(O).getSymbolSectionID(Sym);
+}
+
+std::vector<std::pair<SymbolRef, uint64_t>>
 llvm::object::computeSymbolSizes(const ObjectFile &O) {
   std::vector<std::pair<SymbolRef, uint64_t>> Ret;
 
@@ -54,16 +64,14 @@ llvm::object::computeSymbolSizes(const ObjectFile &O) {
   for (symbol_iterator I = O.symbol_begin(), E = O.symbol_end(); I != E; ++I) {
     SymbolRef Sym = *I;
     uint64_t Value = Sym.getValue();
-    section_iterator SecI = O.section_end();
-    if (std::error_code EC = Sym.getSection(SecI))
-      return EC;
-    Addresses.push_back({I, Value, SymNum, *SecI});
+    Addresses.push_back({I, Value, SymNum, getSymbolSectionID(O, Sym)});
     ++SymNum;
   }
-  for (const SectionRef Sec : O.sections()) {
+  for (SectionRef Sec : O.sections()) {
     uint64_t Address = Sec.getAddress();
     uint64_t Size = Sec.getSize();
-    Addresses.push_back({O.symbol_end(), Address + Size, 0, Sec});
+    Addresses.push_back(
+        {O.symbol_end(), Address + Size, 0, getSectionID(O, Sec)});
   }
   array_pod_sort(Addresses.begin(), Addresses.end(), compareAddress);
 
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