digitalmars.D - Visual Studio Code, Code-D and Microsoft's Visual C++ Debugger
- Void-995 (68/68) Sep 19 2018 Good time of day, everyone
- Vladimir Panteleev (10/12) Sep 19 2018 DMD used to have the switch -gc, which meant to emit debug
Good time of day, everyone
Recently I've got myself into D Language again, but got a problem
with debugging on Windows, obviously. While Visual D with Mago
provides pretty comfortable workflow, I highly appreciate what
Code D did with it's more closer and tight integrating with
DScanner and DFormat, better DUB workflow and so on... The
biggest problem there is debugging on Windows OS. GDB from either
Microsoft's C/C++ plugin (ms-vscode.cpptools) or WebFreak's
Native Debug (webfreak.debug) didn't took me anywhere. Broken
Mago-MI integration in WebFreak's Native Debug (which I have
"fixed" locally after few moves around) didn't took me far as
well, the best I got was something bad about Stack Frame.
Meanwhile, the original Microsoft's Visual C++ Debugger
(cppvsdbg) is working pretty much flawless with D. With the
problem, of course, not being able to show what is inside of the
slice/dynamic arrays. Having "fun" with Natvis (The Visual Studio
Natvis framework lets you customize the way Visual Studio
displays native types in debugger variable windows) I found that
giving D types to catch won't work as Visual C++ Debugger
(cppvsdbg) is expecting valid C++ names to work with.
I mostly gave up there, but then I found interesting trick that
Visual Rust and Rust plugin for Visual Studio Code are using.
They added option to compiler to write debug information as
that's C++ code (so they doesn't have to come up with their own
debugger for Windows), with pretty simple trick in rustc and
simplest Natvis file they then have integrated into PDB that they
ship with it. So I've tried to apply that to DMD and see what
will happen.
Currently, as matter of experiment, I've changed it on my side
permanently, but thinking about adding new flag to DMD. The
change was about this big:
// --------------------------------
diff --git a/src/dmd/hdrgen.d b/src/dmd/hdrgen.d
index d9eca8721..a02c6bfef 100644
--- a/src/dmd/hdrgen.d
+++ b/src/dmd/hdrgen.d
-814,8 +814,9 public:
else
{
L1:
+ buf.writestring("__dlang::__darray<");
visitWithMask(t.next, t.mod);
- buf.writestring("[]");
+ buf.writestring(">");
}
}
// --------------------------------
Now, equipped with that one and fairly small Natvis file that can
be integrated into DMD somewhere and/or Code D, I've got nice
views with flawlessly working Visual C++ Debugger on my D code.
For matter of showcase, links with the screenshots:
1)
https://cdn.discordapp.com/attachments/463259852311887874/491953617545330689/unknown.png
2)
https://cdn.discordapp.com/attachments/463259852311887874/491956446469029888/unknown.png
This one can be further expanded with correct expanding of
string, wstring, dstring and/or any other built-in
interesting/specific/complex types from D. What people working on
DMD think about adding something likes this? Will it break
everything? What if that will be added as DMD command line option
to make life easier for end user on Windows for their own
projects (at least they may enable that temporary while
debugging, so it won't add side effects to anything else)?
P.S. Even without any optional switch that haven't broke Mago on
Visual D, so working with D, especially debugging, can become
far, far easier than it's now. Even with this small change I'm
able to continue working on my project without thinking twice why
I haven't stayed on C++.
Sep 19 2018
On Wednesday, 19 September 2018 at 14:22:13 UTC, Void-995 wrote:[...]Cool!What if that will be added as DMD command line optionDMD used to have the switch -gc, which meant to emit debug information but pretend to be C as much as possible. It was removed as it wasn't considered necessary any more, but this looks like the perfect use case for it. I suppose it's not possible to make Natvis understand D symbols? Rainer Schuetze would be the person closest to this topic, I think. Doesn't Visual D already have something in it to get the VS debugger to understand some D types better?
Sep 19 2018
On Wednesday, 19 September 2018 at 14:29:27 UTC, Vladimir Panteleev wrote:On Wednesday, 19 September 2018 at 14:22:13 UTC, Void-995 wrote:Unfortunately you can't make Natvis to understand D symbols as to do pretty much whatever, but that's not usable much as it complex for this matter from my point of view). I think Visual D is using Mago internally via DLLs or something, and doing it's own thing. Something like -gc would be great to have again (I guess I missed that one), even -gcpp (to pretend it's C++) that can be used by pretty printing in GDB (fairly simple changes in Python scripts from printing standard C++ stuff) and Microsoft's Debugger. So the classes, namespaces, containers, dynamic arrays can be easily represented with actually having structure and sense from C++ point of view.[...]Cool!What if that will be added as DMD command line optionDMD used to have the switch -gc, which meant to emit debug information but pretend to be C as much as possible. It was removed as it wasn't considered necessary any more, but this looks like the perfect use case for it. I suppose it's not possible to make Natvis understand D symbols? Rainer Schuetze would be the person closest to this topic, I think. Doesn't Visual D already have something in it to get the VS debugger to understand some D types better?
Sep 19 2018
Void-995 <void995 gmail.com> On Wednesday, 19 September 2018 at 14:37:32 UTC, Void-995 wrote:On Wednesday, 19 September 2018 at 14:29:27 UTC, Vladimir Panteleev wrote:Forgot to mention that Microsoft added partial support (that may be more than sufficient for D case) to their C/C++ in VS code for both GDB and LLDB. So this one may be useful to make debugging more friendly on Linux and Mac as well![...]Unfortunately you can't make Natvis to understand D symbols as Studio to do pretty much whatever, but that's not usable much extremely complex for this matter from my point of view). I think Visual D is using Mago internally via DLLs or something, and doing it's own thing. Something like -gc would be great to have again (I guess I missed that one), even -gcpp (to pretend it's C++) that can be used by pretty printing in GDB (fairly simple changes in Python scripts from printing standard C++ stuff) and Microsoft's Debugger. So the classes, namespaces, containers, dynamic arrays can be easily represented with actually having structure and sense from C++ point of view.
Sep 19 2018
On Wednesday, 19 September 2018 at 14:29:27 UTC, Vladimir Panteleev wrote:On Wednesday, 19 September 2018 at 14:22:13 UTC, Void-995 wrote:Thanks for pointing me at -gc. That's way better place to continue needed work for making Natvis working properly and happy. Of course, the start is ugly, bat that's the start: https://www.dropbox.com/s/vb5fjwclrzcwl3l/dmd-return-of-gc-for-natvis-0001.diff?dl=0[...]Cool!What if that will be added as DMD command line optionDMD used to have the switch -gc, which meant to emit debug information but pretend to be C as much as possible. It was removed as it wasn't considered necessary any more, but this looks like the perfect use case for it. I suppose it's not possible to make Natvis understand D symbols? Rainer Schuetze would be the person closest to this topic, I think. Doesn't Visual D already have something in it to get the VS debugger to understand some D types better?
Sep 20 2018