[PATCH] Add a missing munmap_list move constructor

[PATCH] Add a missing munmap_list move constructor

[Saagar Jha]

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Clang warns if the default implementation of a function is requested but it is implicitly deleted. This was happening to compile_module because it didn’t have a move constructor for its munmap_list member, so I went ahead and added one since it already had a move assignment operator defined for it and this seemed like an oversight.


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From 3ed7e54dfc5b3ab0a6033a239f8d6a457cb91f92 Mon Sep 17 00:00:00 2001
From: Saagar Jha <saagar@saagarjha.com>
Date: Wed, 23 Sep 2020 22:16:17 -0700
Subject: [PATCH] Add a missing munmap_list move constructor

compile_module attempts to request a move constructor, but because
munmap_list doesn't have one it gets implicitly deleted. This is an
warning on clang under -Wdefaulted-function-deleted (which is enabled by
default).

gdb/ChangeLog:

	* compile/compile-object-load.h: Give munmap_list a move
	constructor.
---
 gdb/ChangeLog                     | 5 +++++
 gdb/compile/compile-object-load.h | 1 +
 2 files changed, 6 insertions(+)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 241f3e7027..3aa3255b37 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,8 @@
+2020-09-23  Saagar Jha  <saagar@saagarjha.com>
+
+	* compile/compile-object-load.h: Give munmap_list a move
+	constructor.
+
 2020-09-23  Tom Tromey  <tom@tromey.com>
 
 	PR symtab/25470:
diff --git a/gdb/compile/compile-object-load.h b/gdb/compile/compile-object-load.h
index 0254390109..166d442ad0 100644
--- a/gdb/compile/compile-object-load.h
+++ b/gdb/compile/compile-object-load.h
@@ -30,6 +30,7 @@ struct munmap_list
   DISABLE_COPY_AND_ASSIGN (munmap_list);
 
   munmap_list &operator= (munmap_list &&) = default;
+  munmap_list (munmap_list &&) = default;
 
   /* Add a region to the list.  */
   void add (CORE_ADDR addr, CORE_ADDR size);
-- 
2.28.0

Re: [PATCH] Add a missing munmap_list move constructor

[Simon Marchi]

On 2020-09-24 1:22 a.m., Saagar Jha wrote:
> Clang warns if the default implementation of a function is requested but it is implicitly deleted. This was happening to compile_module because it didn’t have a move constructor for its munmap_list member, so I went ahead and added one since it already had a move assignment operator defined for it and this seemed like an oversight.
>

When fixing a compilation failure, please always include a paste of the
error in the commit message.  But the change itself looks good to me.

If you are compiling with clang I presume you also see this error in
macroexp.c?

    /home/simark/src/binutils-gdb/gdb/macroexp.c:125:3: error: definition of implicit copy constructor for 'macro_buffer' is deprecated because it has a user-declared destructor [-Werror,-Wdeprecated-copy-dtor]
      ~macro_buffer ()
      ^

I've tried to look into it in the past but I didn't manage to fix it.
The ownership model in there is a big bowl of spaghetti.

Simon

Re: [PATCH] Add a missing munmap_list move constructor

[Saagar Jha]

No, actually I’m not seeing that error; this is what I was trying to fix (yes, I’ll put it into the commit message when I update the patch):

In file included from compile/compile-object-load.c:21:
compile/compile-object-load.h:56:3: error: explicitly defaulted move constructor is implicitly deleted [-Werror,-Wdefaulted-function-deleted]
  compile_module (compile_module &&other) = default;
  ^
compile/compile-object-load.h:86:22: note: move constructor of 'compile_module' is implicitly deleted because field 'munmap_list' has a deleted move constructor
  struct munmap_list munmap_list;
                     ^
compile/compile-object-load.h:30:28: note: 'munmap_list' has been explicitly marked deleted here
  DISABLE_COPY_AND_ASSIGN (munmap_list);
                           ^
To be clear, I am building GDB for macOS and found this because my CI told me about it: https://travis-ci.com/github/saagarjha/binutils-gdb. Until now the build has been green, so I am assuming that the compiler I have been using either doesn’t warn on the issue or that code looks fine to it…in any case, for the code it’s complaining about I think we should be able to take guidance on ownership from the copy assignment operator right above that destructor.

> On Sep 24, 2020, at 08:27, Simon Marchi <simark@simark.ca> wrote:
> 
> On 2020-09-24 1:22 a.m., Saagar Jha wrote:
>> Clang warns if the default implementation of a function is requested but it is implicitly deleted. This was happening to compile_module because it didn’t have a move constructor for its munmap_list member, so I went ahead and added one since it already had a move assignment operator defined for it and this seemed like an oversight.
>> 
> 
> When fixing a compilation failure, please always include a paste of the
> error in the commit message.  But the change itself looks good to me.
> 
> If you are compiling with clang I presume you also see this error in
> macroexp.c?
> 
>    /home/simark/src/binutils-gdb/gdb/macroexp.c:125:3: error: definition of implicit copy constructor for 'macro_buffer' is deprecated because it has a user-declared destructor [-Werror,-Wdeprecated-copy-dtor]
>      ~macro_buffer ()
>      ^
> 
> I've tried to look into it in the past but I didn't manage to fix it.
> The ownership model in there is a big bowl of spaghetti.
> 
> Simon

[PATCH] Add a missing munmap_list move constructor

[Saagar Jha]

compile_module attempts to request a move constructor, but because
munmap_list doesn't have one it gets implicitly deleted. This is an
warning on clang under -Wdefaulted-function-deleted (which is enabled by
default):

In file included from compile/compile-object-load.c:21:
compile/compile-object-load.h:56:3: error: explicitly defaulted move constructor is implicitly deleted [-Werror,-Wdefaulted-function-deleted]
  compile_module (compile_module &&other) = default;
  ^
compile/compile-object-load.h:86:22: note: move constructor of 'compile_module' is implicitly deleted because field 'munmap_list' has a deleted move constructor
  struct munmap_list munmap_list;
                     ^
compile/compile-object-load.h:30:28: note: 'munmap_list' has been explicitly marked deleted here
  DISABLE_COPY_AND_ASSIGN (munmap_list);
                           ^

gdb/ChangeLog:

	* compile/compile-object-load.h: Give munmap_list a move
	constructor.
---
 gdb/ChangeLog                     | 5 +++++
 gdb/compile/compile-object-load.h | 1 +
 2 files changed, 6 insertions(+)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 3872a8d9cb..043c6a4c72 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,8 @@
+2020-09-25  Saagar Jha  <saagar@saagarjha.com>
+
+	* compile/compile-object-load.h: Give munmap_list a move
+	constructor.
+
 2020-09-24  Tom Tromey  <tromey@adacore.com>
 
 	PR tui/26638:
diff --git a/gdb/compile/compile-object-load.h b/gdb/compile/compile-object-load.h
index 0254390109..166d442ad0 100644
--- a/gdb/compile/compile-object-load.h
+++ b/gdb/compile/compile-object-load.h
@@ -30,6 +30,7 @@ struct munmap_list
   DISABLE_COPY_AND_ASSIGN (munmap_list);
 
   munmap_list &operator= (munmap_list &&) = default;
+  munmap_list (munmap_list &&) = default;
 
   /* Add a region to the list.  */
   void add (CORE_ADDR addr, CORE_ADDR size);
-- 
2.28.0

[PATCH] Add a missing munmap_list move constructor

[Saagar Jha]

compile_module attempts to request a move constructor, but because
munmap_list doesn't have one it gets implicitly deleted. This is an
warning on clang under -Wdefaulted-function-deleted (which is enabled by
default):

In file included from compile/compile-object-load.c:21:
compile/compile-object-load.h:56:3: error: explicitly defaulted move constructor is implicitly deleted [-Werror,-Wdefaulted-function-deleted]
  compile_module (compile_module &&other) = default;
  ^
compile/compile-object-load.h:86:22: note: move constructor of 'compile_module' is implicitly deleted because field 'munmap_list' has a deleted move constructor
  struct munmap_list munmap_list;
                     ^
compile/compile-object-load.h:30:28: note: 'munmap_list' has been explicitly marked deleted here
  DISABLE_COPY_AND_ASSIGN (munmap_list);
                           ^

gdb/ChangeLog:

	* compile/compile-object-load.h: Give munmap_list a move
	constructor.
---
 gdb/ChangeLog                     | 5 +++++
 gdb/compile/compile-object-load.h | 1 +
 2 files changed, 6 insertions(+)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 3872a8d9cb..043c6a4c72 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,8 @@
+2020-09-25  Saagar Jha  <saagar@saagarjha.com>
+
+	* compile/compile-object-load.h: Give munmap_list a move
+	constructor.
+
 2020-09-24  Tom Tromey  <tromey@adacore.com>
 
 	PR tui/26638:
diff --git a/gdb/compile/compile-object-load.h b/gdb/compile/compile-object-load.h
index 0254390109..166d442ad0 100644
--- a/gdb/compile/compile-object-load.h
+++ b/gdb/compile/compile-object-load.h
@@ -30,6 +30,7 @@ struct munmap_list
   DISABLE_COPY_AND_ASSIGN (munmap_list);
 
   munmap_list &operator= (munmap_list &&) = default;
+  munmap_list (munmap_list &&) = default;
 
   /* Add a region to the list.  */
   void add (CORE_ADDR addr, CORE_ADDR size);
-- 
2.28.0

Re: [PATCH] Add a missing munmap_list move constructor

[Simon Marchi]

On 2020-09-25 3:05 a.m., Saagar Jha wrote:
> compile_module attempts to request a move constructor, but because
> munmap_list doesn't have one it gets implicitly deleted. This is an
> warning on clang under -Wdefaulted-function-deleted (which is enabled by
> default):
>
> In file included from compile/compile-object-load.c:21:
> compile/compile-object-load.h:56:3: error: explicitly defaulted move constructor is implicitly deleted [-Werror,-Wdefaulted-function-deleted]
>   compile_module (compile_module &&other) = default;
>   ^
> compile/compile-object-load.h:86:22: note: move constructor of 'compile_module' is implicitly deleted because field 'munmap_list' has a deleted move constructor
>   struct munmap_list munmap_list;
>                      ^
> compile/compile-object-load.h:30:28: note: 'munmap_list' has been explicitly marked deleted here
>   DISABLE_COPY_AND_ASSIGN (munmap_list);
>                            ^
>
> gdb/ChangeLog:
>
> 	* compile/compile-object-load.h: Give munmap_list a move
> 	constructor.

Thanks, I pushed it.  FYI, I tweaked the ChangeLog entry to include the
structure name in parenthesis:

	* compile/compile-object-load.h (struct munmap_list): Add
	explicitly-defined move constructor.

Simon

Re: [PATCH] Add a missing munmap_list move constructor

[Saagar Jha]

Thanks, the code seems to build cleanly now :)

> On Sep 25, 2020, at 07:58, Simon Marchi <simark@simark.ca> wrote:
> 
> On 2020-09-25 3:05 a.m., Saagar Jha wrote:
>> compile_module attempts to request a move constructor, but because
>> munmap_list doesn't have one it gets implicitly deleted. This is an
>> warning on clang under -Wdefaulted-function-deleted (which is enabled by
>> default):
>> 
>> In file included from compile/compile-object-load.c:21:
>> compile/compile-object-load.h:56:3: error: explicitly defaulted move constructor is implicitly deleted [-Werror,-Wdefaulted-function-deleted]
>>  compile_module (compile_module &&other) = default;
>>  ^
>> compile/compile-object-load.h:86:22: note: move constructor of 'compile_module' is implicitly deleted because field 'munmap_list' has a deleted move constructor
>>  struct munmap_list munmap_list;
>>                     ^
>> compile/compile-object-load.h:30:28: note: 'munmap_list' has been explicitly marked deleted here
>>  DISABLE_COPY_AND_ASSIGN (munmap_list);
>>                           ^
>> 
>> gdb/ChangeLog:
>> 
>> 	* compile/compile-object-load.h: Give munmap_list a move
>> 	constructor.
> 
> Thanks, I pushed it.  FYI, I tweaked the ChangeLog entry to include the
> structure name in parenthesis:
> 
> 	* compile/compile-object-load.h (struct munmap_list): Add
> 	explicitly-defined move constructor.
> 
> Simon