Adding changes to support GNU style archive library reading

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167853 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 118 insertions, 26 deletions

diff --git a/lib/Object/Archive.cpp b/lib/Object/Archive.cpp
index 2a5951ada5..b55dab8f85 100644
--- a/lib/Object/Archive.cpp
+++ b/lib/Object/Archive.cpp
@@ -122,7 +122,14 @@ error_code Archive::Child::getName(StringRef &Result) const {
                    + sizeof(ArchiveMemberHeader)
                    + Parent->StringTable->getSize()))
       return object_error::parse_failed;
-    Result = addr;
+
+    // GNU long file names end with a /.
+    if (Parent->kind() == K_GNU) {
+      StringRef::size_type End = StringRef(addr).find('/');
+      Result = StringRef(addr, End);
+    } else {
+      Result = addr;
+    }
     return object_error::success;
   } else if (name.startswith("#1/")) {
     APInt name_size;
@@ -187,15 +194,52 @@ Archive::Archive(MemoryBuffer *source, error_code &ec)
   child_iterator i = begin_children(false);
   child_iterator e = end_children();
 
-  if (i != e) ++i; // Nobody cares about the first member.
-  if (i != e) {
-    SymbolTable = i;
-    ++i;
-  }
-  if (i != e) {
-    StringTable = i;
-  }
+  StringRef name;
+  if ((ec = i->getName(name)))
+    return;
 
+  // Below is the pattern that is used to figure out the archive format
+  // GNU archive format
+  //  First member : / (points to the symbol table )
+  //  Second member : // (may exist, if it exists, points to the string table)
+  //  Note : The string table is used if the filename exceeds 15 characters
+  // BSD archive format
+  //  First member : __.SYMDEF (points to the symbol table)
+  //  There is no string table, if the filename exceeds 15 characters or has a 
+  //  embedded space, the filename has #1/<size>, The size represents the size 
+  //  of the filename that needs to be read after the archive header
+  // COFF archive format
+  //  First member : /
+  //  Second member : / (provides a directory of symbols)
+  //  Third member : // contains the string table, this is present even if the
+  //                    string table is empty
+  if (name == "/") {
+    SymbolTable = i;
+    StringTable = e;
+    if (i != e) ++i;
+    if ((ec = i->getName(name)))
+      return;
+    if (name[0] != '/') {
+      Format = K_GNU;
+    } else if ((name.size() > 1) && (name == "//")) { 
+      Format = K_GNU;
+      StringTable = i;
+      ++i;
+    } else  { 
+      Format = K_COFF;
+      if (i != e) {
+        SymbolTable = i;
+        ++i;
+      }
+      if (i != e) {
+        StringTable = i;
+      }
+    }
+  } else if (name == "__.SYMDEF") {
+    Format = K_BSD;
+    SymbolTable = i;
+    StringTable = e;
+  } 
   ec = object_error::success;
 }
 
@@ -222,17 +266,28 @@ error_code Archive::Symbol::getName(StringRef &Result) const {
 
 error_code Archive::Symbol::getMember(child_iterator &Result) const {
   const char *buf = Parent->SymbolTable->getBuffer()->getBufferStart();
-  uint32_t member_count = *reinterpret_cast<const support::ulittle32_t*>(buf);
   const char *offsets = buf + 4;
-  buf += 4 + (member_count * 4); // Skip offsets.
-  const char *indicies = buf + 4;
-
-  uint16_t offsetindex =
-    *(reinterpret_cast<const support::ulittle16_t*>(indicies)
-      + SymbolIndex);
-
-  uint32_t offset = *(reinterpret_cast<const support::ulittle32_t*>(offsets)
-                      + (offsetindex - 1));
+  uint32_t offset = 0;
+  if (Parent->kind() == K_GNU) {
+    offset = *(reinterpret_cast<const support::ubig32_t*>(offsets) 
+                          + SymbolIndex);
+  } else if (Parent->kind() == K_BSD) {
+    assert("BSD format is not supported");
+  } else {
+    uint32_t member_count = 0;
+    member_count = *reinterpret_cast<const support::ulittle32_t*>(buf);
+    buf += 4 + (member_count * 4); // Skip offsets.
+    const char *indicies = buf + 4;
+    uint16_t offsetindex =
+      *(reinterpret_cast<const support::ulittle16_t*>(indicies)
+        + SymbolIndex);
+    uint32_t *offsetaddr = 
+             (uint32_t *)(reinterpret_cast<const support::ulittle32_t*>(offsets)
+                          + (offsetindex - 1));
+    assert((const char *)offsetaddr < 
+           Parent->SymbolTable->getBuffer()->getBufferEnd());
+    offset = *(offsetaddr);
+  }
 
   const char *Loc = Parent->getData().begin() + offset;
   size_t Size = sizeof(ArchiveMemberHeader) +
@@ -253,10 +308,20 @@ Archive::Symbol Archive::Symbol::getNext() const {
 
 Archive::symbol_iterator Archive::begin_symbols() const {
   const char *buf = SymbolTable->getBuffer()->getBufferStart();
-  uint32_t member_count = *reinterpret_cast<const support::ulittle32_t*>(buf);
-  buf += 4 + (member_count * 4); // Skip offsets.
-  uint32_t symbol_count = *reinterpret_cast<const support::ulittle32_t*>(buf);
-  buf += 4 + (symbol_count * 2); // Skip indices.
+  if (kind() == K_GNU) {
+    uint32_t symbol_count = 0;
+    symbol_count = *reinterpret_cast<const support::ubig32_t*>(buf);
+    buf += sizeof(uint32_t) + (symbol_count * (sizeof(uint32_t)));
+  } else if (kind() == K_BSD) {
+    assert("BSD archive format is not supported");
+  } else {
+    uint32_t member_count = 0;
+    uint32_t symbol_count = 0;
+    member_count = *reinterpret_cast<const support::ulittle32_t*>(buf);
+    buf += 4 + (member_count * 4); // Skip offsets.
+    symbol_count = *reinterpret_cast<const support::ulittle32_t*>(buf);
+    buf += 4 + (symbol_count * 2); // Skip indices.
+  }
   uint32_t string_start_offset =
     buf - SymbolTable->getBuffer()->getBufferStart();
   return symbol_iterator(Symbol(this, 0, string_start_offset));
@@ -264,9 +329,36 @@ Archive::symbol_iterator Archive::begin_symbols() const {
 
 Archive::symbol_iterator Archive::end_symbols() const {
   const char *buf = SymbolTable->getBuffer()->getBufferStart();
-  uint32_t member_count = *reinterpret_cast<const support::ulittle32_t*>(buf);
-  buf += 4 + (member_count * 4); // Skip offsets.
-  uint32_t symbol_count = *reinterpret_cast<const support::ulittle32_t*>(buf);
+  uint32_t symbol_count = 0;
+  if (kind() == K_GNU) {
+    symbol_count = *reinterpret_cast<const support::ubig32_t*>(buf);
+    buf += sizeof(uint32_t) + (symbol_count * (sizeof(uint32_t)));
+  } else if (kind() == K_BSD) {
+    assert("BSD archive format is not supported");
+  } else {
+    uint32_t member_count = 0;
+    member_count = *reinterpret_cast<const support::ulittle32_t*>(buf);
+    buf += 4 + (member_count * 4); // Skip offsets.
+    symbol_count = *reinterpret_cast<const support::ulittle32_t*>(buf);
+  }
   return symbol_iterator(
     Symbol(this, symbol_count, 0));
 }
+
+Archive::child_iterator Archive::findSym(StringRef name) const {
+  Archive::symbol_iterator bs = begin_symbols();
+  Archive::symbol_iterator es = end_symbols();
+  Archive::child_iterator result;
+  
+  StringRef symname;
+  for (; bs != es; ++bs) {
+    if (bs->getName(symname))
+        return end_children();
+    if (symname == name) {
+      if (bs->getMember(result))
+        return end_children();
+      return result;
+    }
+  }
+  return end_children();
+}