[binutils-gdb] [gdb] Fix rethrow exception slicing in insert_bp_location

[binutils-gdb] [gdb] Fix rethrow exception slicing in insert_bp_location

[Tom de Vries]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=b2829fcf9b594ad9933d649cb089efa5b63a2b89

commit b2829fcf9b594ad9933d649cb089efa5b63a2b89
Author: Tom de Vries <tdevries@suse.de>
Date:   Mon Oct 24 14:20:49 2022 +0200

    [gdb] Fix rethrow exception slicing in insert_bp_location
    
    The preferred way of rethrowing an exception is by using throw without
    expression, because it avoids object slicing of the exception [1].
    
    Fix this in insert_bp_location.
    
    Tested on x86_64-linux.
    
    [1] https://en.cppreference.com/w/cpp/language/throw
    
    Approved-By: Andrew Burgess <aburgess@redhat.com>

Diff:
---
 gdb/breakpoint.c | 28 +++++++++++++++++++++-------
 1 file changed, 21 insertions(+), 7 deletions(-)

diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c
index a0653f189b9..a001e78cfb4 100644
--- a/gdb/breakpoint.c
+++ b/gdb/breakpoint.c
@@ -2647,6 +2647,24 @@ breakpoint_kind (const struct bp_location *bl, CORE_ADDR *addr)
     return gdbarch_breakpoint_kind_from_pc (bl->gdbarch, addr);
 }
 
+#define RETHROW_ON_TARGET_CLOSE_ERROR(E)				\
+  do									\
+    {									\
+      if ((E).reason != 0)						\
+	{								\
+	  /* Can't set the breakpoint.  */				\
+									\
+	  if ((E).error == TARGET_CLOSE_ERROR)				\
+	    /* If the target has closed then it will have deleted any	\
+	       breakpoints inserted within the target inferior, as a	\
+	       result any further attempts to interact with the		\
+	       breakpoint objects is not possible.  Just rethrow the	\
+	       error.  Don't use E to rethrow, to prevent object	\
+	       slicing of the exception.  */				\
+	    throw;							\
+	}								\
+    } while (0)
+
 /* Insert a low-level "breakpoint" of some type.  BL is the breakpoint
    location.  Any error messages are printed to TMP_ERROR_STREAM; and
    DISABLED_BREAKS, and HW_BREAKPOINT_ERROR are used to report problems.
@@ -2734,6 +2752,7 @@ insert_bp_location (struct bp_location *bl,
 	    }
 	  catch (gdb_exception &e)
 	    {
+	      RETHROW_ON_TARGET_CLOSE_ERROR (e);
 	      bp_excpt = std::move (e);
 	    }
 	}
@@ -2773,6 +2792,7 @@ insert_bp_location (struct bp_location *bl,
 		    }
 		  catch (gdb_exception &e)
 		    {
+		      RETHROW_ON_TARGET_CLOSE_ERROR (e);
 		      bp_excpt = std::move (e);
 		    }
 
@@ -2797,6 +2817,7 @@ insert_bp_location (struct bp_location *bl,
 		}
 	      catch (gdb_exception &e)
 		{
+		  RETHROW_ON_TARGET_CLOSE_ERROR (e);
 		  bp_excpt = std::move (e);
 		}
 	    }
@@ -2811,13 +2832,6 @@ insert_bp_location (struct bp_location *bl,
       if (bp_excpt.reason != 0)
 	{
 	  /* Can't set the breakpoint.  */
-
-	  /* If the target has closed then it will have deleted any
-	     breakpoints inserted within the target inferior, as a result
-	     any further attempts to interact with the breakpoint objects
-	     is not possible.  Just rethrow the error.  */
-	  if (bp_excpt.error == TARGET_CLOSE_ERROR)
-	    throw bp_excpt;
 	  gdb_assert (bl->owner != nullptr);
 
 	  /* In some cases, we might not be able to insert a