Diff of /sml/trunk/HISTORY

Parent Directory | Revision Log | Patch

	revision 677, Mon Jun 26 00:56:56 2000 UTC	revision 678, Tue Jun 27 07:51:09 2000 UTC
#	Line 13	Line 13
13	Description:	Description:
14	----------------------------------------------------------------------	----------------------------------------------------------------------
15	Name: Matthias Blume	Name: Matthias Blume
16		Date: 2000/06/27 16:51:00 JST
17		Tag: blume-20000627-noweb
18		Description:
19
20		Changes:
21
22		1. Implemented "subdir" and "witness" options for noweb tool.
23		This caused some slight internal changes in CM's tool implementation.
24		2. Fixed bug in "tool plugin" mechanism.  This is essentially cleaning
25		some remaining issues from earlier path anchor changes.
26		3. Updated CM manual accordingly.
27
28		4. Changed implementation of back-tracing so that I now consider it
29		ready for prime-time.
30
31		In particular, you don't have to explicitly trigger the back-trace
32		anymore.  Instead, if you are running BTrace-instrumented code and
33		there is an uncaught exception (regardless of whether or not it was
34		raised in instrumented code), the top-level evalloop will print
35		the back-trace.
36
37		Features:
38
39		- Instrumented and uninstrumented code work together seemlessly.
40		(Of course, uninstrumented code is never mentioned in actual
41		back-traces.)
42
43		- Asymptotic time- and space-complexity of instrumented code is
44		equal to that of uninstrumented code.  (This means that
45		tail-recursion is preserved by the instrumentation phase.)
46
47		- Modules whose code has been instrumented in different sessions
48		work together without problem.
49
50		- There is no penalty whatsoever on uninstrumented code.
51
52		- There is no penalty on "raise" expressions, even in
53		instrumented code.
54
55		A potential bug (or perhaps it is a feature, too):
56
57		A back-trace reaches no further than the outermost instrumented
58		non-trivial "raise".  Here, a "trivial" raise is one that is the
59		sole RHS of a "handle" rule.  Thus, back-traces reach trough
60
61		<exp> handle e => raise e
62
63		and even
64
65		<exp> handle Foo => raise Bar
66
67		and, of course, through
68
69		<exp> handle Foo => ...
70
71		if the exception was not Foo.
72
73		Back-traces always reach right through any un-instrumented code
74		including any of its "handle" expressions, trivial or not.
75
76		To try this out, do the following:
77
78		- Erase all existing binfiles for your program.
79		(You may keep binfiles for those modules where you think you
80		definitely don't need back-tracing.)
81		- Turn on back-trace instrumentation:
82		SMLofNJ.Internals.BTrace.mode (SOME true);
83		- Recompile your program.  (I.e., run "CM.make" or "use".)
84		- You may now turn instrumentation off again (if you want):
85		SMLofNJ.Internals.BTrace.mode (SOME false);
86		- Run your program as usual.  If it raises an exception that
87		reaches the interactive toplevel, then a back-trace will
88		automatically be printed.  After that, the toplevel loop
89		will print the exception history as usual.
90
91		----------------------------------------------------------------------
92		Name: Matthias Blume
93	Date: 2000/06/26 09:56:46 JST	Date: 2000/06/26 09:56:46 JST
94	Tag: blume-20000626-setup	Tag: blume-20000626-setup
95	Description:	Description:

---

Colored Diff Long Colored Diff Unidiff Context Diff Side by Side

Legend: Removed from v.677   changed lines   Added in v.678

---

root@smlnj-gforge.cs.uchicago.edu	ViewVC Help
Powered by ViewVC 1.0.0