<p dir="ltr">Thanks Nick, this is nicer than my local solution!</p>
<div class="gmail_quote">On 8 Jan 2014 02:59, "Nick Kledzik" <<a href="mailto:kledzik@apple.com">kledzik@apple.com</a>> wrote:<br type="attribution"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
Author: kledzik<br>
Date: Tue Jan  7 20:52:58 2014<br>
New Revision: 198728<br>
<br>
URL: <a href="http://llvm.org/viewvc/llvm-project?rev=198728&view=rev" target="_blank">http://llvm.org/viewvc/llvm-project?rev=198728&view=rev</a><br>
Log:<br>
[mach-o] properly extract atom content from subrange of section content<br>
<br>
Modified:<br>
    lld/trunk/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp<br>
    lld/trunk/unittests/MachOTests/MachONormalizedFileToAtomsTests.cpp<br>
<br>
Modified: lld/trunk/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/lld/trunk/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp?rev=198728&r1=198727&r2=198728&view=diff" target="_blank">http://llvm.org/viewvc/llvm-project/lld/trunk/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp?rev=198728&r1=198727&r2=198728&view=diff</a><br>

==============================================================================<br>
--- lld/trunk/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp (original)<br>
+++ lld/trunk/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp Tue Jan  7 20:52:58 2014<br>
@@ -34,13 +34,38 @@ namespace lld {<br>
 namespace mach_o {<br>
 namespace normalized {<br>
<br>
+static uint64_t nextSymbolAddress(const NormalizedFile &normalizedFile,<br>
+                                const Symbol &symbol) {<br>
+  uint64_t symbolAddr = symbol.value;<br>
+  uint8_t symbolSectionIndex = symbol.sect;<br>
+  const Section &section = normalizedFile.sections[symbolSectionIndex - 1];<br>
+  // If no symbol after this address, use end of section address.<br>
+  uint64_t closestAddr = section.address + section.content.size();<br>
+  for (const Symbol &s : normalizedFile.globalSymbols) {<br>
+    if (s.sect != symbolSectionIndex)<br>
+      continue;<br>
+    uint64_t sValue = s.value;<br>
+    if (sValue <= symbolAddr)<br>
+      continue;<br>
+    if (sValue < closestAddr)<br>
+      closestAddr = s.value;<br>
+  }<br>
+  return closestAddr;<br>
+}<br>
+<br>
 static ErrorOr<std::unique_ptr<lld::File>><br>
 normalizedObjectToAtoms(const NormalizedFile &normalizedFile, StringRef path) {<br>
   std::unique_ptr<MachOFile> file(new MachOFile(path));<br>
<br>
-  for (auto &sym : normalizedFile.globalSymbols) {<br>
-    file->addDefinedAtom(<a href="http://sym.name" target="_blank">sym.name</a>,<br>
-                         normalizedFile.sections[sym.sect - 1].content);<br>
+ for (const Symbol &sym : normalizedFile.globalSymbols) {<br>
+    // Mach-O symbol table does have size in it, so need to scan ahead<br>
+    // to find symbol with next highest address.<br>
+    const Section &section = normalizedFile.sections[sym.sect - 1];<br>
+    uint64_t offset = sym.value - section.address;<br>
+    uint64_t size = nextSymbolAddress(normalizedFile, sym) - sym.value;<br>
+    ArrayRef<uint8_t> atomContent = llvm::makeArrayRef(&section.content[offset],<br>
+                                                      size);<br>
+    file->addDefinedAtom(<a href="http://sym.name" target="_blank">sym.name</a>, atomContent);<br>
   }<br>
<br>
   assert(normalizedFile.localSymbols.empty() &&<br>
<br>
Modified: lld/trunk/unittests/MachOTests/MachONormalizedFileToAtomsTests.cpp<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/lld/trunk/unittests/MachOTests/MachONormalizedFileToAtomsTests.cpp?rev=198728&r1=198727&r2=198728&view=diff" target="_blank">http://llvm.org/viewvc/llvm-project/lld/trunk/unittests/MachOTests/MachONormalizedFileToAtomsTests.cpp?rev=198728&r1=198727&r2=198728&view=diff</a><br>

==============================================================================<br>
--- lld/trunk/unittests/MachOTests/MachONormalizedFileToAtomsTests.cpp (original)<br>
+++ lld/trunk/unittests/MachOTests/MachONormalizedFileToAtomsTests.cpp Tue Jan  7 20:52:58 2014<br>
@@ -20,42 +20,50 @@ using llvm::ErrorOr;<br>
 using namespace lld::mach_o::normalized;<br>
 using namespace llvm::MachO;<br>
<br>
-unsigned countDefinedAtoms(const lld::File &file) {<br>
-  unsigned count = 0;<br>
-  for (const auto &d : file.defined()) {<br>
-    (void)d;<br>
-    ++count;<br>
-  }<br>
-  return count;<br>
-}<br>
-<br>
 TEST(ToAtomsTest, empty_obj_x86_64) {<br>
   NormalizedFile f;<br>
   f.arch = lld::MachOLinkingContext::arch_x86_64;<br>
   ErrorOr<std::unique_ptr<const lld::File>> atom_f = normalizedToAtoms(f, "");<br>
   EXPECT_FALSE(!atom_f);<br>
-  EXPECT_EQ(0U, countDefinedAtoms(**atom_f));<br>
+  EXPECT_EQ(0U, (*atom_f)->defined().size());<br>
 }<br>
<br>
 TEST(ToAtomsTest, basic_obj_x86_64) {<br>
   NormalizedFile f;<br>
   f.arch = lld::MachOLinkingContext::arch_x86_64;<br>
   Section textSection;<br>
-  static const uint8_t contentBytes[] = { 0x55, 0x48, 0x89, 0xE5,<br>
-                                          0x31, 0xC0, 0x5D, 0xC3 };<br>
+  static const uint8_t contentBytes[] = { 0x90, 0xC3, 0xC3 };<br>
   const unsigned contentSize = sizeof(contentBytes) / sizeof(contentBytes[0]);<br>
   textSection.content.insert(textSection.content.begin(), contentBytes,<br>
                              &contentBytes[contentSize]);<br>
   f.sections.push_back(textSection);<br>
-  Symbol mainSymbol;<br>
-  mainSymbol.name = "_main";<br>
-  mainSymbol.type = N_SECT;<br>
-  mainSymbol.sect = 1;<br>
-  f.globalSymbols.push_back(mainSymbol);<br>
+  Symbol fooSymbol;<br>
+  fooSymbol.name = "_foo";<br>
+  fooSymbol.type = N_SECT;<br>
+  fooSymbol.sect = 1;<br>
+  fooSymbol.value = 0;<br>
+  f.globalSymbols.push_back(fooSymbol);<br>
+  Symbol barSymbol;<br>
+  barSymbol.name = "_bar";<br>
+  barSymbol.type = N_SECT;<br>
+  barSymbol.sect = 1;<br>
+  barSymbol.value = 2;<br>
+  f.globalSymbols.push_back(barSymbol);<br>
+<br>
   ErrorOr<std::unique_ptr<const lld::File>> atom_f = normalizedToAtoms(f, "");<br>
   EXPECT_FALSE(!atom_f);<br>
-  EXPECT_EQ(1U, countDefinedAtoms(**atom_f));<br>
-  const lld::DefinedAtom *singleAtom = *(*atom_f)->defined().begin();<br>
-  llvm::ArrayRef<uint8_t> atomContent(singleAtom->rawContent());<br>
-  EXPECT_EQ(0, memcmp(atomContent.data(), contentBytes, contentSize));<br>
+  const lld::File &file = **atom_f;<br>
+  EXPECT_EQ(2U, file.defined().size());<br>
+  lld::File::defined_iterator it = file.defined().begin();<br>
+  const lld::DefinedAtom *atom1 = *it;<br>
+  ++it;<br>
+  const lld::DefinedAtom *atom2 = *it;<br>
+  EXPECT_TRUE(atom1->name().equals("_foo"));<br>
+  EXPECT_EQ(2U, atom1->rawContent().size());<br>
+  EXPECT_EQ(0x90, atom1->rawContent()[0]);<br>
+  EXPECT_EQ(0xC3, atom1->rawContent()[1]);<br>
+<br>
+  EXPECT_TRUE(atom2->name().equals("_bar"));<br>
+  EXPECT_EQ(1U, atom2->rawContent().size());<br>
+  EXPECT_EQ(0xC3, atom2->rawContent()[0]);<br>
 }<br>
<br>
<br>
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</blockquote></div>