1 files changed, 117 insertions, 0 deletions
diff --git a/Tools/c-analyzer/c_analyzer/symbols/_nm.py b/Tools/c-analyzer/c_analyzer/symbols/_nm.py
new file mode 100644
index 0000000000..f3a75a6d4b
--- /dev/null
+++ b/Tools/c-analyzer/c_analyzer/symbols/_nm.py
@@ -0,0 +1,117 @@
+import os.path
+import shutil
+
+from c_analyzer.common import util, info
+
+from .info import Symbol
+
+
+# XXX need tests:
+# * iter_symbols
+
+NM_KINDS = {
+        'b': Symbol.KIND.VARIABLE,  # uninitialized
+        'd': Symbol.KIND.VARIABLE,  # initialized
+        #'g': Symbol.KIND.VARIABLE,  # uninitialized
+        #'s': Symbol.KIND.VARIABLE,  # initialized
+        't': Symbol.KIND.FUNCTION,
+        }
+
+SPECIAL_SYMBOLS = {
+        # binary format (e.g. ELF)
+        '__bss_start',
+        '__data_start',
+        '__dso_handle',
+        '_DYNAMIC',
+        '_edata',
+        '_end',
+        '__environ@@GLIBC_2.2.5',
+        '_GLOBAL_OFFSET_TABLE_',
+        '__JCR_END__',
+        '__JCR_LIST__',
+        '__TMC_END__',
+        }
+
+
+def _is_special_symbol(name):
+    if name in SPECIAL_SYMBOLS:
+        return True
+    if '@@GLIBC' in name:
+        return True
+    return False
+
+
+def iter_symbols(binfile, *,
+                 nm=None,
+                 handle_id=None,
+                 _which=shutil.which,
+                 _run=util.run_cmd,
+                 ):
+    """Yield a Symbol for each relevant entry reported by the "nm" command."""
+    if nm is None:
+        nm = _which('nm')
+        if not nm:
+            raise NotImplementedError
+    if handle_id is None:
+        handle_id = info.ID
+
+    argv = [nm,
+            '--line-numbers',
+            binfile,
+            ]
+    try:
+        output = _run(argv)
+    except Exception:
+        if nm is None:
+            # XXX Use dumpbin.exe /SYMBOLS on Windows.
+            raise NotImplementedError
+        raise
+    for line in output.splitlines():
+        (name, kind, external, filename, funcname,
+         ) = _parse_nm_line(line)
+        if kind != Symbol.KIND.VARIABLE:
+            continue
+        elif _is_special_symbol(name):
+            continue
+        yield Symbol(
+                id=handle_id(filename, funcname, name),
+                kind=kind,
+                external=external,
+                )
+
+
+def _parse_nm_line(line):
+    _origline = line
+    _, _, line = line.partition(' ')  # strip off the address
+    line = line.strip()
+
+    kind, _, line = line.partition(' ')
+    line = line.strip()
+    external = kind.isupper()
+    kind = NM_KINDS.get(kind.lower(), Symbol.KIND.OTHER)
+
+    name, _, filename = line.partition('\t')
+    name = name.strip()
+    if filename:
+        filename = os.path.relpath(filename.partition(':')[0])
+    else:
+        filename = info.UNKNOWN
+
+    name, islocal = _parse_nm_name(name, kind)
+    funcname = info.UNKNOWN if islocal else None
+    return name, kind, external, filename, funcname
+
+
+def _parse_nm_name(name, kind):
+    if kind != Symbol.KIND.VARIABLE:
+        return name, None
+    if _is_special_symbol(name):
+        return name, None
+
+    actual, sep, digits = name.partition('.')
+    if not sep:
+        return name, False
+
+    if not digits.isdigit():
+        raise Exception(f'got bogus name {name}')
+    return actual, True