[Lldb-commits] [PATCH] D37651: Fix for bug 34532 - A few rough corners related to post-mortem debugging (core/minidump)

Tue Sep 12 13:34:15 PDT 2017

The first one is a nice example of what we don't want to crash on. Before the switch to StringRef, hostname could be NULL. After it, StringRef handily crashed for us instead of dutifully just setting itself to the empty string. I say this is exactly the kind of crash we don't want. But thanks to StringRefs assertive behavior, this became a crash when it never should have. 

> On Sep 12, 2017, at 1:16 PM, Zachary Turner <zturner at google.com> wrote:
> 
> 
> 
> On Tue, Sep 12, 2017 at 1:04 PM Jim Ingham <jingham at apple.com <mailto:jingham at apple.com>> wrote:
> 
> I don't see any evidence for lldb suffering from "a huge class of bugs that we are willfully ignoring..." particularly ones that would be easily caught if we just had more asserts.  Can you give some examples?
> 
> Probably all of these, for starters:
> 
> D:\src\llvm-mono>git log --grep "Don't crash" lldb
> commit 4ad5334bfcff803f3765e444785b8f9d3a73c683
> Author: Greg Clayton <gclayton at apple.com <mailto:gclayton at apple.com>>
> Date:   Mon Jul 24 16:47:04 2017 +0000
> 
>     Don't crash when hostname is empty. StringRef will assert and kill your program.
> 
> commit f7b079263a751fdf3adea8e549803aaf92d465f8
> Author: Sean Callanan <scallanan at apple.com <mailto:scallanan at apple.com>>
> Date:   Fri Aug 26 18:12:39 2016 +0000
> 
>     Don't crash when trying to capture persistent variables in a block.
> 
>     Reports an error instead.  We can fix this later to make persistent variables
>     work, but right now we hit an LLVM assertion if we get this wrong.
> 
>     <rdar://problem/27770298>
> 
> commit f3647763b02ddef65c6244f91939d997f7733ecd
> Author: Greg Clayton <gclayton at apple.com <mailto:gclayton at apple.com>>
> Date:   Mon May 16 20:07:38 2016 +0000
> 
>     Don't crash when OS plug-in returns None from any of the functions we might call.
> 
>     <rdar://problem/24489419>
> 
> commit f67e0b92fbd9e0bc0267ae5210478c85a44b8afc
> Author: Greg Clayton <gclayton at apple.com <mailto:gclayton at apple.com>>
> Date:   Thu May 12 22:36:47 2016 +0000
> 
>     Don't crash when a process' task port goes bad.
> 
>     <rdar://problem/26256049>
> 
> commit 0ac65423e2ba99a42b246d191520ff13bdca5cb0
> Author: Greg Clayton <gclayton at apple.com <mailto:gclayton at apple.com>>
> Date:   Tue Mar 15 21:58:28 2016 +0000
> 
>     Don't crash if the TypeSP is empty.
> 
> commit 7043340bc58b0d751fcf66001f62cbf0d9527623
> Author: Greg Clayton <gclayton at apple.com <mailto:gclayton at apple.com>>
> Date:   Fri Feb 12 00:07:16 2016 +0000
> 
>     Don't crash if we have a DIE that has a DW_AT_ranges attribute and yet the SymbolFileDWARF doesn't have a DebugRanges. If this happens print a nice error message to prompt the user to file a bug and attach the offending DWARF file so we can get the correct compiler fixed.
> 
>     <rdar://problem/24458016>
> 
> commit 0d1591d3b74d518b9edd7482f65976092c14e951
> Author: Greg Clayton <gclayton at apple.com <mailto:gclayton at apple.com>>
> Date:   Wed Oct 28 20:49:34 2015 +0000
> 
>     Don't crash when opening a fuzzed mach-o file that has bad dyld trie data.
> 
>     <rdar://problem/21991784>
> 
> commit d7019a8d5ccd5dfdb79d74312ef449b734627ec3
> Author: Greg Clayton <gclayton at apple.com <mailto:gclayton at apple.com>>
> Date:   Fri Aug 14 23:15:48 2015 +0000
> 
>     Don't crash if we don't have a type system for a language.
> 
> commit b5838b5a4870ba8f620e7a5733038f02f45b1a78
> Author: Greg Clayton <gclayton at apple.com <mailto:gclayton at apple.com>>
> Date:   Thu Aug 13 23:16:15 2015 +0000
> 
>     Don't crash when we have a .a file that contains an object with a 16 character name. Any calls to std::string::erase must be bounds checked.
> 
>     <rdar://problem/22260988>
> 
> commit 4234fd5de6adb471728df83670ebbe0ae3c7ee68
> Author: Greg Clayton <gclayton at apple.com <mailto:gclayton at apple.com>>
> Date:   Tue Aug 11 21:01:32 2015 +0000
> 
>     Don't crash if the file we want to touch doesn't exist.
> 
> commit b385164c734997af6367271d33dc1c4618bfb754
> Author: Greg Clayton <gclayton at apple.com <mailto:gclayton at apple.com>>
> Date:   Mon Jul 13 22:08:16 2015 +0000
> 
>     Don't crash if we are unable to get the member type.
> 
>     <rdar://problem/21624447>
> 
> commit a5deec8dc9a9e7fd977049f6fb5977796906e8ca
> Author: Sean Callanan <scallanan at apple.com <mailto:scallanan at apple.com>>
> Date:   Thu May 28 20:06:40 2015 +0000
> 
>     Don't crash if we don't have a process and need
>     to check for alternate manglings.
> 
> commit 4427526ffa55675b623702452ff6e13c33c79763
> Author: Greg Clayton <gclayton at apple.com <mailto:gclayton at apple.com>>
> Date:   Fri May 15 22:31:18 2015 +0000
> 
>     Don't crash if we have bad debug info that has a DW_TAG_inheritance with a bad DW_AT_type reference. Emit an error with instructions to file a bug.
> 
>     <rdar://problem/20944860>
> 
> commit 4506ae8792a5b726133a58d1bc887313bceccd93
> Author: Greg Clayton <gclayton at apple.com <mailto:gclayton at apple.com>>
> Date:   Fri May 15 22:20:29 2015 +0000
> 
>     Don't crash if a function has no name by calling 'strcmp(name, "main")'.
> 
>     <rdar://problem/20925061>
> 

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