Initial commit

tools/linktracer.py

@@ -0,0 +1,118 @@
+#!/usr/bin/env python3
+
+import re
+import subprocess
+import tempfile
+import pprint
+
+ARCHIVE_RE = r'([^(]*)(\([^)]*\))?'
+
+def trace_source_files(linker, cmdline):
+    with tempfile.NamedTemporaryFile() as mapfile:
+        output = subprocess.check_output([linker, f'-Wl,--Map={mapfile.name}', *cmdline])
+
+        # intentionally use generator here
+        idx = 0 
+        lines = [ line.rstrip() for line in mapfile.read().decode().splitlines() if line.strip() ]
+        
+        for idx, line in enumerate(lines[idx:], start=idx):
+            #print('Dropping', line)
+            if line == 'Linker script and memory map':
+                break
+
+        idx += 1
+        objects = []
+        symbols = {}
+        sections = {}
+        current_object = None
+        last_offset = None
+        last_symbol = None
+        cont_sec = None
+        cont_ind = None
+        current_section = None
+        for idx, line in enumerate(lines[idx:], start=idx):
+            print(f'Processing >{line}')
+            if line.startswith('LOAD'):
+                _load, obj = line.split()
+                objects.append(obj)
+                continue
+
+            if line.startswith('OUTPUT'):
+                break
+
+            m = re.match(r'^( ?)([^ ]+)? +(0x[0-9a-z]+) +(0x[0-9a-z]+)?(.*)?$', line)
+            if m is None:
+                m = re.match(r'^( ?)([^ ]+)?$', line)
+                if m:
+                    cont_ind, cont_sec = m.groups()
+                else:
+                    cont_ind, cont_sec = None, None
+                last_offset, last_symbol = None, None
+                continue
+            indent, sec, offx, size, sym_or_src = m.groups()
+            if sec is None:
+                sec = cont_sec
+                ind = cont_ind
+            cont_sec = None
+            cont_ind = None
+            print(f'vals: indent={indent} sec={sec} offx={offx} size={size} sym_or_src={sym_or_src}')
+            if not re.match('^[a-zA-Z_0-9<>():*]+$', sym_or_src):
+                continue
+
+            if indent == '':
+                print(f'Section: {sec} 0x{size:x}')
+                current_section = sec
+                sections[sec] = size
+                last_offset = None
+                last_symbol = None
+                continue
+
+            if offx is not None:
+                offx = int(offx, 16)
+            if size is not None:
+                size = int(size, 16)
+
+            if size is not None and sym_or_src is not None:
+                # archive/object line
+                archive, _member = re.match(ARCHIVE_RE, sym_or_src).groups()
+                current_object = archive
+                last_offset = offx
+            else:
+                if sym_or_src is not None:
+                    assert size is None
+                    if last_offset is not None:
+                        last_size = offx - last_offset
+                        symbols[last_symbol] = (last_size, current_section)
+                        print(f'Symbol: {last_symbol} 0x{last_size:x} @{current_section}')
+                    last_offset = offx
+                    last_symbol = sym_or_src
+
+        idx += 1
+
+        for idx, line in enumerate(lines[idx:], start=idx):
+            if line == 'Cross Reference Table':
+                break
+
+        idx += 1
+
+        # map which symbol was pulled from which object in the end
+        used_defs = {}
+        for line in lines:
+            *left, right = line.split()
+
+            archive, _member = re.match(ARCHIVE_RE, right).groups()
+            if left:
+                used_defs[''.join(left)] = archive
+
+        #pprint.pprint(symbols)
+
+
+if __name__ == '__main__':
+    import argparse
+    parser = argparse.ArgumentParser()
+    parser.add_argument('linker_binary')
+    parser.add_argument('linker_args', nargs=argparse.REMAINDER)
+    args = parser.parse_args()
+
+    source_files = trace_source_files(args.linker_binary, args.linker_args)
+