1 files changed, 86 insertions, 0 deletions
diff --git a/lib/spack/external/macholib/SymbolTable.py b/lib/spack/external/macholib/SymbolTable.py
new file mode 100644
index 0000000000..bf4d383ab7
--- /dev/null
+++ b/lib/spack/external/macholib/SymbolTable.py
@@ -0,0 +1,86 @@
+"""
+Class to read the symbol table from a Mach-O header
+"""
+from __future__ import with_statement
+
+from macholib.mach_o import relocation_info, dylib_reference, dylib_module
+from macholib.mach_o import dylib_table_of_contents, nlist, nlist_64
+from macholib.mach_o import MH_CIGAM_64, MH_MAGIC_64
+import sys
+
+__all__ = ['SymbolTable']
+
+if sys.version_info[0] == 2:
+    range = xrange  # noqa: F821
+
+
+class SymbolTable(object):
+    def __init__(self, macho, header=None, openfile=None):
+        if openfile is None:
+            openfile = open
+        if header is None:
+            header = macho.headers[0]
+        self.macho_header = header
+        with openfile(macho.filename, 'rb') as fh:
+            self.symtab = header.getSymbolTableCommand()
+            self.dysymtab = header.getDynamicSymbolTableCommand()
+
+            if self.symtab is not None:
+                self.nlists = self.readSymbolTable(fh)
+
+            if self.dysymtab is not None:
+                self.readDynamicSymbolTable(fh)
+
+    def readSymbolTable(self, fh):
+        cmd = self.symtab
+        fh.seek(self.macho_header.offset + cmd.stroff)
+        strtab = fh.read(cmd.strsize)
+        fh.seek(self.macho_header.offset + cmd.symoff)
+        nlists = []
+
+        if self.macho_header.MH_MAGIC in [MH_MAGIC_64, MH_CIGAM_64]:
+            cls = nlist_64
+        else:
+            cls = nlist
+
+        for i in range(cmd.nsyms):
+            cmd = cls.from_fileobj(fh, _endian_=self.macho_header.endian)
+            if cmd.n_un == 0:
+                nlists.append((cmd, ''))
+            else:
+                nlists.append(
+                    (cmd, strtab[cmd.n_un:strtab.find(b'\x00', cmd.n_un)]))
+        return nlists
+
+    def readDynamicSymbolTable(self, fh):
+        cmd = self.dysymtab
+        nlists = self.nlists
+
+        self.localsyms = nlists[cmd.ilocalsym:cmd.ilocalsym+cmd.nlocalsym]
+        self.extdefsyms = nlists[cmd.iextdefsym:cmd.iextdefsym+cmd.nextdefsym]
+        self.undefsyms = nlists[cmd.iundefsym:cmd.iundefsym+cmd.nundefsym]
+        if cmd.tocoff == 0:
+            self.toc = None
+        else:
+            self.toc = self.readtoc(fh, cmd.tocoff, cmd.ntoc)
+
+    def readtoc(self, fh, off, n):
+        fh.seek(self.macho_header.offset + off)
+        return [dylib_table_of_contents.from_fileobj(fh) for i in range(n)]
+
+    def readmodtab(self, fh, off, n):
+        fh.seek(self.macho_header.offset + off)
+        return [dylib_module.from_fileobj(fh) for i in range(n)]
+
+    def readsym(self, fh, off, n):
+        fh.seek(self.macho_header.offset + off)
+        refs = []
+        for i in range(n):
+            ref = dylib_reference.from_fileobj(fh)
+            isym, flags = divmod(ref.isym_flags, 256)
+            refs.append((self.nlists[isym], flags))
+        return refs
+
+    def readrel(self, fh, off, n):
+        fh.seek(self.macho_header.offset + off)
+        return [relocation_info.from_fileobj(fh) for i in range(n)]