Merge pull request #4611 from jcbrill/jbrill-mscommon-debug

Resolve 4605: enhance SCONS_MSCOMMON_DEBUG handling of invalid input

CHANGES.txt

@@ -12,6 +12,10 @@ NOTE: Python 3.6 support is deprecated and will be dropped in a future release.
 
 RELEASE  VERSION/DATE TO BE FILLED IN LATER
 
+  From Joseph Brill:
+    - Added error handling when creating MS VC detection debug log file specified by
+      SCONS_MSCOMMON_DEBUG
+
   From Dillan Mills:
     - Fix support for short options (`-x`).
 

RELEASE.txt

@@ -50,10 +50,11 @@ FIXES
   following the option, with no spaces (e.g. -j5 and not -j 5).
 - Fix a problem with compilation_db component initialization - the
   entries for assembler files were not being set up correctly.
-
 - On Darwin, PermissionErrors are now handled while trying to access
   /etc/paths.d. This may occur if SCons is invoked in a sandboxed environment
   (such as Nix).
+- Added error handling when creating MS VC detection debug log file specified by
+  SCONS_MSCOMMON_DEBUG
 
 - Fix nasm test for missing include file, cleanup.
 

SCons/Tool/MSCommon/common.py

@@ -34,15 +34,25 @@
 from subprocess import DEVNULL, PIPE
 from pathlib import Path
 
+import SCons.Errors
 import SCons.Util
 import SCons.Warnings
 
 class MSVCCacheInvalidWarning(SCons.Warnings.WarningOnByDefault):
     pass
 
+def _check_logfile(logfile):
+    if logfile and '"' in logfile:
+        err_msg = (
+            "SCONS_MSCOMMON_DEBUG value contains double quote character(s)\n"
+            f"  SCONS_MSCOMMON_DEBUG={logfile}"
+        )
+        raise SCons.Errors.UserError(err_msg)
+    return logfile
+
 # SCONS_MSCOMMON_DEBUG is internal-use so undocumented:
 # set to '-' to print to console, else set to filename to log to
-LOGFILE = os.environ.get('SCONS_MSCOMMON_DEBUG')
+LOGFILE = _check_logfile(os.environ.get('SCONS_MSCOMMON_DEBUG'))
 if LOGFILE:
     import logging
 
@@ -129,7 +139,15 @@ def format(self, record):
         log_handler = logging.StreamHandler(sys.stdout)
     else:
         log_prefix = ''
-        log_handler = logging.FileHandler(filename=LOGFILE)
+        try:
+            log_handler = logging.FileHandler(filename=LOGFILE)
+        except (OSError, FileNotFoundError) as e:
+            err_msg = (
+                "Could not create logfile, check SCONS_MSCOMMON_DEBUG\n"
+                f"  SCONS_MSCOMMON_DEBUG={LOGFILE}\n"
+                f"  {e.__class__.__name__}: {str(e)}"
+            )
+            raise SCons.Errors.UserError(err_msg)
     log_formatter = _CustomFormatter(log_prefix)
     log_handler.setFormatter(log_formatter)
     logger = logging.getLogger(name=__name__)