Don't assume break/continue inside a TRY block works

In C++, this:

	try
	  {
	    break;
	  }
	catch (..)
	  {}

is invalid.  However, because our TRY/CATCH macros support it in C,
the C++ version of those macros support it too.  To catch such
assumptions, this adds a (disabled) hack that maps TRY/CATCH to raw
C++ try/catch.  Then it goes through all instances that building on
x86_64 GNU/Linux trips on, fixing them.

This isn't strictly necessary yet, but I think it's nicer to try to
keep the tree in a state where it's easier to eliminate the TRY/CATCH
macros.

gdb/ChangeLog:
2015-10-29  Pedro Alves  <palves@redhat.com>

	* dwarf2-frame-tailcall.c (dwarf2_tailcall_sniffer_first): Don't
	assume that "break" breaks out of a TRY/CATCH.
	* python/py-framefilter.c (py_print_single_arg): Don't assume
	"continue" breaks out of a TRY/CATCH.
	* python/py-value.c (valpy_binop_throw): New function, factored
	out from ...
	(valpy_binop): ... this.
	(valpy_richcompare_throw): New function, factored
	out from ...
	(valpy_richcompare): ... this.
	* solib.c (solib_read_symbols): Don't assume "break" breaks out
	of a TRY/CATCH.
	* common/common-exceptions.h [USE_RAW_CXX_TRY]
	<TRY/CATCH/END_CATCH>: Define as 1-1 wrappers around try/catch.

1 files changed, 16 insertions, 0 deletions

diff --git a/gdb/common/common-exceptions.h b/gdb/common/common-exceptions.h
index 2e6a6d9..51795b1 100644
--- a/gdb/common/common-exceptions.h
+++ b/gdb/common/common-exceptions.h
@@ -195,6 +195,14 @@ struct exception_try_scope
   void *saved_state;
 };
 
+/* Define this to build with TRY/CATCH mapped directly to raw
+   try/catch.  GDB won't work correctly, but building that way catches
+   code tryin to break/continue out of the try block, along with
+   spurious code between the TRY and the CATCH block.  */
+//#define USE_RAW_CXX_TRY
+
+#ifndef USE_RAW_CXX_TRY
+
 /* We still need to wrap TRY/CATCH in C++ so that cleanups and C++
    exceptions can coexist.  The TRY blocked is wrapped in a
    do/while(0) so that break/continue within the block works the same
@@ -216,6 +224,14 @@ struct exception_try_scope
   {						\
     exception_rethrow ();			\
   }
+#else
+
+#define TRY try
+#define CATCH(EXCEPTION, MASK) \
+  catch (struct gdb_exception ## _ ## MASK &EXCEPTION)
+#define END_CATCH
+
+#endif
 
 /* The exception types client code may catch.  They're just shims
    around gdb_exception that add nothing but type info.  Which is used