[Lldb-commits] [lldb] [lldb] Add windows support for LLDB_EXPORT_ALL_SYMBOLS (PR #67628)

[Walter Erquinigo via lldb-commits]

================
@@ -0,0 +1,100 @@
+"""A tool for extracting a list of private lldb symbols to export for MSVC.
+
+When exporting symbols from a dll or exe we either need to mark the symbols in
+the source code as __declspec(dllexport) or supply a list of symbols to the
+linker. Private symbols in LLDB don't explicitly specific dllexport, so we
+automate that by examining the symbol table.
+"""
+
+import argparse
+import os
+import re
+import subprocess
+import sys
+
+
+def extract_symbols(nm_path: str, lib: str):
+    """Extract all of the private lldb symbols from the given path to llvm-nm and
+    library to extract from."""
+
+    # Matches mangled symbols containing 'lldb_private'.
+    lldb_sym_re = r"0* [BT] (?P<symbol>[?]+[^?].*lldb_private.*)"
+
+    # '-g' means we only get global symbols.
+    # '-p' do not waste time sorting the symbols.
+    process = subprocess.Popen(
+        [nm_path, "-g", "-p", lib],
+        bufsize=1,
+        stdout=subprocess.PIPE,
+        stdin=subprocess.PIPE,
+        universal_newlines=True,
+    )
+    process.stdin.close()
+
+    lldb_symbols = set()
+    for line in process.stdout:
+        match = re.match(lldb_sym_re, line)
+        if match:
+            symbol = match.group("symbol")
+            assert symbol.count(" ") == 0, (
+                "Regex matched too much, probably got undecorated name as well"
+            )
+            # Deleting destructors start with ?_G or ?_E and can be discarded
+            # because link.exe gives you a warning telling you they can't be
+            # exported if you don't.
+            if symbol.startswith("??_G") or symbol.startswith("??_E"):
+                continue
+            lldb_symbols.add(symbol)
+
+    return lldb_symbols
+
+
+def main():
+    parser = argparse.ArgumentParser(description="Generate LLDB dll exports")
+    parser.add_argument(
+        "-o", metavar="file", type=str, help="The name of the resultant export file."
+    )
+    parser.add_argument("--nm", help="Path to the llvm-nm executable.")
+    parser.add_argument(
+        "libs",
+        metavar="lib",
+        type=str,
+        nargs="+",
+        help="The libraries to extract symbols from.",
+    )
+    args = parser.parse_args()
+
+    # Get the list of libraries to extract symbols from
+    libs = list()
+    for lib in args.libs:
+        # When invoked by cmake the arguments are the cmake target names of the
+        # libraries, so we need to add .lib/.a to the end and maybe lib to the
+        # start to get the filename. Also allow objects.
+        suffixes = [".lib", ".a", ".obj", ".o"]
+        if not any([lib.endswith(s) for s in suffixes]):
+            for s in suffixes:
+                if os.path.exists(lib + s):
+                    lib = lib + s
+                    break
+                if os.path.exists("lib" + lib + s):
+                    lib = "lib" + lib + s
+                    break
----------------
walter-erquinigo wrote:

I'd rewrite this like 
```suggestion
            for suffix in suffixes:
               for path in [lib + suffix, "lib" + lib + suffix]:
                 if os.path.exists(path):
                   lib = path
                   break
```

https://github.com/llvm/llvm-project/pull/67628