Warnings when compiling

[fatherbushido]

I have many messages when compiling since few revs:

Spoiler

 

ElevationHandlers.cpp
../../../source/gui/CInput.cpp: In member function ‘virtual InReaction CInput::ManuallyHandleEvent(const SDL_Event_*)’:
../../../source/gui/CInput.cpp:486:17: warning: this statement may fall through [-Wimplicit-fallthrough=]
    cooked = '\n'; // Change to '\n' and do default:
                 ^
../../../source/gui/CInput.cpp:489:3: note: here
   default: // Insert a character
   ^~~~~~~
Patch.cpp
CStrIntern.cpp
CommandHandlers.cpp
In member function ‘void CInput::UpdateText(int, int, int)’:
cc1plus: warning: ‘void* __builtin_memset(void*, int, long unsigned int)’: specified size 18446744073709551612 exceeds maximum object size 9223372036854775807 [-Wstringop-overflow=]
ObjectManager.cpp
MapHandlers.cpp
CCmpFootprint.cpp
Filesystem.cpp
GUIManager.cpp
CCmpCommandQueue.cpp
Globals.cpp
GameView.cpp
SavedGame.cpp
ICmpUnitRenderer.cpp
TerrainHandlers.cpp
ICmpObstructionManager.cpp
ShaderDefines.cpp
CCmpOwnership.cpp
CProgressBar.cpp
ICmpVisibility.cpp
CGUI.cpp
In file included from ../../../source/pch/atlas/precompiled.h:24:0:
../../../source/tools/atlas/GameInterface/Messages.h: In function ‘void AtlasMessage::fGetTerrainGroupPreviews(AtlasMessage::qGetTerrainGroupPreviews*)’:
../../../source/tools/atlas/GameInterface/Messages.h:285:8: warning: ‘#‘target_mem_ref’ not supported by dump_expr#<expression error>’ may be used uninitialized in this function [-Wmaybe-uninitialized]
 struct sTerrainTexturePreview
        ^~~~~~~~~~~~~~~~~~~~~~
../../../source/tools/atlas/GameInterface/Messages.h:285:8: warning: ‘#‘target_mem_ref’ not supported by dump_expr#<expression error>’ may be used uninitialized in this function [-Wmaybe-uninitialized]
../../../source/tools/atlas/GameInterface/Messages.h:285:8: warning: ‘#‘target_mem_ref’ not supported by dump_expr#<expression error>’ may be used uninitialized in this function [-Wmaybe-uninitialized]
../../../source/tools/atlas/GameInterface/Messages.h:285:8: warning: ‘#‘target_mem_ref’ not supported by dump_expr#<expression error>’ may be used uninitialized in this function [-Wmaybe-uninitialized]
 struct sTerrainTexturePreview
        ^~~~~~~~~~~~~~~~~~~~~~
../../../source/tools/atlas/GameInterface/Messages.h:285:8: warning: ‘#‘target_mem_ref’ not supported by dump_expr#<expression error>’ may be used uninitialized in this function [-Wmaybe-uninitialized]
../../../source/tools/atlas/GameInterface/Messages.h:285:8: warning: ‘#‘target_mem_ref’ not supported by dump_expr#<expression error>’ may be used uninitialized in this function [-Wmaybe-uninitialized]
Pyrogenesis.cpp

[...]

AtlasObjectXML.cpp
SkyManager.cpp
../../../source/tools/atlas/AtlasObject/AtlasObjectXML.cpp: In function ‘std::__cxx11::wstring fromXmlChar(const xmlChar*)’:
../../../source/tools/atlas/AtlasObject/AtlasObjectXML.cpp:96:31: warning: this statement may fall through [-Wimplicit-fallthrough=]
   case 5: ch += *source++; ch <<= 6;
                            ~~~^~~~~
../../../source/tools/atlas/AtlasObject/AtlasObjectXML.cpp:97:3: note: here
   case 4: ch += *source++; ch <<= 6;
   ^~~~
../../../source/tools/atlas/AtlasObject/AtlasObjectXML.cpp:97:31: warning: this statement may fall through [-Wimplicit-fallthrough=]
   case 4: ch += *source++; ch <<= 6;
                            ~~~^~~~~
../../../source/tools/atlas/AtlasObject/AtlasObjectXML.cpp:98:3: note: here
   case 3: ch += *source++; ch <<= 6;
   ^~~~
../../../source/tools/atlas/AtlasObject/AtlasObjectXML.cpp:98:31: warning: this statement may fall through [-Wimplicit-fallthrough=]
   case 3: ch += *source++; ch <<= 6;
                            ~~~^~~~~
../../../source/tools/atlas/AtlasObject/AtlasObjectXML.cpp:99:3: note: here
   case 2: ch += *source++; ch <<= 6;
   ^~~~
../../../source/tools/atlas/AtlasObject/AtlasObjectXML.cpp:99:31: warning: this statement may fall through [-Wimplicit-fallthrough=]
   case 2: ch += *source++; ch <<= 6;
                            ~~~^~~~~
../../../source/tools/atlas/AtlasObject/AtlasObjectXML.cpp:100:3: note: here
   case 1: ch += *source++; ch <<= 6;
   ^~~~
../../../source/tools/atlas/AtlasObject/AtlasObjectXML.cpp:100:31: warning: this statement may fall through [-Wimplicit-fallthrough=]
   case 1: ch += *source++; ch <<= 6;
                            ~~~^~~~~
../../../source/tools/atlas/AtlasObject/AtlasObjectXML.cpp:101:3: note: here
   case 0: ch += *source++;
   ^~~~
../../../source/tools/atlas/AtlasObject/AtlasObjectXML.cpp: In constructor ‘toXmlChar::toXmlChar(const wstring&)’:
../../../source/tools/atlas/AtlasObject/AtlasObjectXML.cpp:67:49: warning: this statement may fall through [-Wimplicit-fallthrough=]
    case 4: *--target = ((ch | 0x80) & 0xBF); ch >>= 6;
                                              ~~~^~~~~
../../../source/tools/atlas/AtlasObject/AtlasObjectXML.cpp:68:4: note: here
    case 3: *--target = ((ch | 0x80) & 0xBF); ch >>= 6;
    ^~~~
../../../source/tools/atlas/AtlasObject/AtlasObjectXML.cpp:68:49: warning: this statement may fall through [-Wimplicit-fallthrough=]
    case 3: *--target = ((ch | 0x80) & 0xBF); ch >>= 6;
                                              ~~~^~~~~
../../../source/tools/atlas/AtlasObject/AtlasObjectXML.cpp:69:4: note: here
    case 2: *--target = ((ch | 0x80) & 0xBF); ch >>= 6;
    ^~~~
../../../source/tools/atlas/AtlasObject/AtlasObjectXML.cpp:69:49: warning: this statement may fall through [-Wimplicit-fallthrough=]
    case 2: *--target = ((ch | 0x80) & 0xBF); ch >>= 6;
                                              ~~~^~~~~
../../../source/tools/atlas/AtlasObject/AtlasObjectXML.cpp:70:4: note: here
    case 1: *--target = (char)(ch | firstByteMark[bytesToWrite]);
    ^~~~
ICmpMotion.cpp
AtlasObjectJS.cpp
format.cpp
ICmpMirage.cpp
ICmpMinimap.cpp
precompiled.cpp
PostprocManager.cpp
Preprocessor.cpp
TerrainRenderer.cpp
../../../source/ps/Preprocessor.cpp: In member function ‘CPreprocessor::Token CPreprocessor::GetArgument(CPreprocessor::Token&, bool)’:
../../../source/ps/Preprocessor.cpp:773:23: warning: this statement may fall through [-Wimplicit-fallthrough=]
                 Error (Line, "Unfinished list of arguments");
                 ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../../../source/ps/Preprocessor.cpp:774:13: note: here
             case Token::TK_ERROR:
             ^~~~
../../../source/ps/Preprocessor.cpp: In member function ‘CPreprocessor::Token CPreprocessor::GetArguments(int&, CPreprocessor::Token*&, bool)’:
../../../source/ps/Preprocessor.cpp:846:23: warning: this statement may fall through [-Wimplicit-fallthrough=]
                 Error (Line, "Unfinished list of arguments");
                 ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../../../source/ps/Preprocessor.cpp:847:13: note: here
             case Token::TK_ERROR:
             ^~~~
../../../source/ps/Preprocessor.cpp: In member function ‘CPreprocessor::Token CPreprocessor::Parse(const CPreprocessor::Token&)’:
../../../source/ps/Preprocessor.cpp:1276:17: warning: this statement may fall through [-Wimplicit-fallthrough=]
                 if (empty_lines)
                 ^~
../../../source/ps/Preprocessor.cpp:1285:13: note: here
             case Token::TK_WHITESPACE:
             ^~~~
ICmpVisual.cpp

 

 

[Stan`]

@vladislavbelov @elexis

[vladislavbelov]

It looks like you have enabled -Wimplicit-fallthrough in GCC/Clang. And to prevent this, you need to add a comment like or disable the option:

case 0:
...
// fall through
case 1:

https://stackoverflow.com/questions/45129741/gcc-7-wimplicit-fallthrough-warnings-and-portable-way-to-clear-them

https://dzone.com/articles/implicit-fallthrough-in-gcc-7

Edited August 19, 2017 by vladislavbelov

[fatherbushido]

40 minutes ago, stanislas69 said:

@vladislavbelov @elexis

I guess that I could have done that myself?

[Stan`]

@fatherbushido You didn't so I thought it might help. Apologies.

[fatherbushido]

3 minutes ago, stanislas69 said:

@fatherbushido You didn't so I thought it might help. Apologies.

no problem

[elexis]

refs D740

[fatherbushido]

Thx for the ref.

@vladislavbelov: some warnings seem not related to that, do they?

edit: those ones remain

Spoiler

In file included from ../../../source/pch/atlas/precompiled.h:24:0:
../../../source/tools/atlas/GameInterface/Messages.h: In function ‘void AtlasMessage::fGetTerrainGroupPreviews(AtlasMessage::qGetTerrainGroupPreviews*)’:
../../../source/tools/atlas/GameInterface/Messages.h:285:8: warning: ‘#‘target_mem_ref’ not supported by dump_expr#<expression error>’ may be used uninitialized in this function [-Wmaybe-uninitialized]
 struct sTerrainTexturePreview
        ^~~~~~~~~~~~~~~~~~~~~~
../../../source/tools/atlas/GameInterface/Messages.h:285:8: warning: ‘#‘target_mem_ref’ not supported by dump_expr#<expression error>’ may be used uninitialized in this function [-Wmaybe-uninitialized]
../../../source/tools/atlas/GameInterface/Messages.h:285:8: warning: ‘#‘target_mem_ref’ not supported by dump_expr#<expression error>’ may be used uninitialized in this function [-Wmaybe-uninitialized]
../../../source/tools/atlas/GameInterface/Messages.h:285:8: warning: ‘#‘target_mem_ref’ not supported by dump_expr#<expression error>’ may be used uninitialized in this function [-Wmaybe-uninitialized]
 struct sTerrainTexturePreview
        ^~~~~~~~~~~~~~~~~~~~~~
../../../source/tools/atlas/GameInterface/Messages.h:285:8: warning: ‘#‘target_mem_ref’ not supported by dump_expr#<expression error>’ may be used uninitialized in this function [-Wmaybe-uninitialized]
../../../source/tools/atlas/GameInterface/Messages.h:285:8: warning: ‘#‘target_mem_ref’ not supported by dump_expr#<expression error>’ may be used uninitialized in this function [-Wmaybe-uninitialized]
CinemaHandler.cpp

and

Spoiler

Renderer.cpp
In member function ‘void CInput::UpdateText(int, int, int)’:
cc1plus: warning: ‘void* __builtin_memset(void*, int, long unsigned int)’: specified size 18446744073709551612 exceeds maximum object size 9223372036854775807 [-Wstringop-overflow=]
JSInterface_VFS.cpp

 

[vladislavbelov]

1 hour ago, fatherbushido said:

cc1plus: warning: ‘void* __builtin_memset(void*, int, long unsigned int)’: specified size 18446744073709551612 exceeds maximum object size 9223372036854775807 [-Wstringop-overflow=]

We don't use memset/__builtin_memset directly inside CInput at all. So it looks like a compiler issue (wrong message or something else):

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79095

1 hour ago, fatherbushido said:

In file included from ../../../source/pch/atlas/precompiled.h:24:0:
../../../source/tools/atlas/GameInterface/Messages.h: In function ‘void AtlasMessage::fGetTerrainGroupPreviews(AtlasMessage::qGetTerrainGroupPreviews*)’:
../../../source/tools/atlas/GameInterface/Messages.h:285:8: warning: ‘#‘target_mem_ref’ not supported by dump_expr#<expression error>’ may be used uninitialized in this function [-Wmaybe-uninitialized]
 struct sTerrainTexturePreview
        ^~~~~~~~~~~~~~~~~~~~~~

It looks like the compile can't follow some call stack. We use threads/events in Atlas (to send between wxWidgets/Pyrogenesis), so the compiler can't find a place where the var was really initialized. By the code there is only the one place where it has assigned AFAIK.

Edited August 20, 2017 by vladislavbelov

[eecsninja]

Resurrecting an old thread...

I just built 0AD for the first time and saw a bunch of these compiler warnings:

../../../source/tools/atlas/AtlasObject/AtlasObjectXML.cpp: In function ‘std::__cxx11::wstring fromXmlChar(const xmlChar*)’:
../../../source/tools/atlas/AtlasObject/AtlasObjectXML.cpp:96:31: warning: this statement may fall through [-Wimplicit-fallthrough=]
   case 5: ch += *source++; ch <<= 6;
                            ~~~^~~~~

To get my feet wet with 0AD, I think I can rewrite the code to avoid these warnings and be a little cleaner.

1. These break-less case statements are all repetitive. I could replace them with for loops.
2. The number of cases (and if I were to make the change in #1, loop iterations) is hard-coded. They should be replaced with a constant for more clarity.

Let me know what you think.

[Lion.Kanzen]

2 minutes ago, eecsninja said:

Resurrecting an old thread...

I just built 0AD for the first time and saw a bunch of these compiler warnings:

../../../source/tools/atlas/AtlasObject/AtlasObjectXML.cpp: In function ‘std::__cxx11::wstring fromXmlChar(const xmlChar*)’:
../../../source/tools/atlas/AtlasObject/AtlasObjectXML.cpp:96:31: warning: this statement may fall through [-Wimplicit-fallthrough=]
   case 5: ch += *source++; ch <<= 6;
                            ~~~^~~~~

To get my feet wet with 0AD, I think I can rewrite the code to avoid these warnings and be a little cleaner.

1. These break-less case statements are all repetitive. I could replace them with for loops.
2. The number of cases (and if I were to make the change in #1, loop iterations) is hard-coded. They should be replaced with a constant for more clarity.

Let me know what you think.

We need the warnings.

 

[eecsninja]

^^^

I can't tell why we need the warnings when I read over the thread. What's the reason?

[Stan`]

4 hours ago, eecsninja said:

^^^

I can't tell why we need the warnings when I read over the thread. What's the reason?

Hey @eecsninja

Have you read on how to contribute yet ? If not I'd suggest your read GettingStartedProgrammers and SubmittingPatches on trac.wildfiregames.com I can't promise your changes will make it to the game but they are most likely welcome. 

Regards,

[s0600204]

For what it's worth, the warnings above for AtlasObjectXML.cpp concerning the implicit fallthroughs should no longer occur as the code has been rewritten to no longer need the break-less switch...case statements at all.

@eecsninja, thank you for your patch. It is unfortunate that it wasn't included (due to it being superseded by work being undertaken pursuing another objective), but we appreciate the effort .