Clang warning fixes

[emoon]

No description provided.

[ocornut]

Thanks!

[emoon]

np!

I also noticed that when you build the opengl_example you get this

g++ -I/usr/local/Cellar/glew/1.10.0/include -I/usr/local/include -I../../ -c -o main.o main.cpp
main.cpp:63:79: warning: offset of on non-POD type 'ImDrawVert' [-Winvalid-offsetof]
        glVertexPointer(2, GL_FLOAT, sizeof(ImDrawVert), (void*)(vtx_buffer + offsetof(ImDrawVert, pos)));
                                                                              ^                    ~~~
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../lib/clang/6.0/include/stddef.h:87:24: note: expanded from macro 'offsetof'
#define offsetof(t, d) __builtin_offsetof(t, d)
                       ^
main.cpp:64:81: warning: offset of on non-POD type 'ImDrawVert' [-Winvalid-offsetof]
        glTexCoordPointer(2, GL_FLOAT, sizeof(ImDrawVert), (void*)(vtx_buffer + offsetof(ImDrawVert, uv)));
                                                                                ^                    ~~
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../lib/clang/6.0/include/stddef.h:87:24: note: expanded from macro 'offsetof'
#define offsetof(t, d) __builtin_offsetof(t, d)
                       ^
main.cpp:65:86: warning: offset of on non-POD type 'ImDrawVert' [-Winvalid-offsetof]
        glColorPointer(4, GL_UNSIGNED_BYTE, sizeof(ImDrawVert), (void*)(vtx_buffer + offsetof(ImDrawVert, col)));
                                                                                     ^                    ~~~
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../lib/clang/6.0/include/stddef.h:87:24: note: expanded from macro 'offsetof'
#define offsetof(t, d) __builtin_offsetof(t, d)
                       ^
3 warnings generated.
g++ -I/usr/local/Cellar/glew/1.10.0/include -I/usr/local/include -I../../ -c -o ../../imgui.o ../../imgui.cpp
g++ -o imgui_example main.o ../../imgui.o -I/usr/local/Cellar/glew/1.10.0/include -I/usr/local/include -I../../ -framework OpenGL -framework Cocoa -framework IOKit -framework CoreVideo -L/usr/local/Cellar/glew/1.10.0/lib -L/usr/local/lib -lglew -lglfw3
Build complete for Mac OS X

I wasn't sure how you want to address this so I figured I let you know instead.

[ocornut]

Arghh c++, finding new ways to get in your way. I'll add an offsetof macro.

[emoon]

It sure does.

[emoon]

Btw something that may be of interest for you is Travis-CI:

http://docs.travis-ci.com/user/languages/cpp/

It will allow you to setup so you can have builds of your project (for non-windows platforms) being compiled and report errors.

I haven't tried it myself (as I need Windows support) but might be worth considering and it seems quite simple to setup.

[benblo]

I still get warnings, even with the OFFSETOF () macro ;)

g++ -I../../ -I../libs/gl3w `pkg-config --cflags glfw3` -Wall -Wformat -c -o imgui_impl_glfw_gl3.o imgui_impl_glfw_gl3.cpp
imgui_impl_glfw_gl3.cpp: In function ‘bool ImGui_ImplGlfwGL3_CreateDeviceObjects()’:
imgui_impl_glfw_gl3.cpp:260: warning: invalid access to non-static data member ‘ImDrawVert::pos’  of NULL object
imgui_impl_glfw_gl3.cpp:260: warning: (perhaps the ‘offsetof’ macro was used incorrectly)
imgui_impl_glfw_gl3.cpp:261: warning: invalid access to non-static data member ‘ImDrawVert::uv’  of NULL object
imgui_impl_glfw_gl3.cpp:261: warning: (perhaps the ‘offsetof’ macro was used incorrectly)
imgui_impl_glfw_gl3.cpp:262: warning: invalid access to non-static data member ‘ImDrawVert::col’  of NULL object
imgui_impl_glfw_gl3.cpp:262: warning: (perhaps the ‘offsetof’ macro was used incorrectly)

On Centos 6 btw.
I suppose those are harmless?

[ocornut]

They are harmless, but it'd be interesting to know how your compiler librairies implement the (lowercase) offsetof() macro themselves.

[benblo]

No idea :) pretty new to Linux & gcc.
But your macro doesn't make use of it at all right? All I see is this voodoo:
#define OFFSETOF(TYPE, ELEMENT) ((size_t)&(((TYPE *)0)->ELEMENT))

[Keenuts]

Hi :)

If the clang, if we use the sanitizer for undefined behaviors, the IM_OFFSETOF macro raises some errors at run-time.

A workaround could be to do this:

#if defined(__clang__)
# define IM_OFFSETOF(_TYPE, _MEMBER) offsetof(_TYPE, _MEMBER)
#else
# define IM_OFFSETOF(_TYPE,_MEMBER)  ((size_t)&(((_TYPE*)0)->_MEMBER))
#endif

Would you be OK with something like that ?

[ocornut]

Hello, could you specify what are the warnings and in which version of Clang? Thank you.

[Keenuts]

yes sure, the I had the issue on both clang 6 and clang 8.0.1.

To reproduce:

• clone the repo, branch master
• go to examples/example_glfw_opengl3
• edit Makefile
• build & run

@@ 12
-#CXX = clang++
+CXX = clang++

@@ 21
-CXXFLAGS = -I../ -I../../
+CXXFLAGS = -I../ -I../../ -fsanitize=undefined -fsanitize-recover=all

@@ 30
-SOURCES += ../libs/gl3w/GL/gl3w.c
-CXXFLAGS += -I../libs/gl3w
+#SOURCES += ../libs/gl3w/GL/gl3w.c
+#CXXFLAGS += -I../libs/gl3w

-# CXXFLAGS = -lGLEW -DIMGUI_IMPL_OPENGL_LOADER_GLEW
+CXXFLAGS += -lGLEW -DIMGUI_IMPL_OPENGL_LOADER_GLEW

../imgui_impl_opengl3.cpp:216:113: runtime error: member access within null pointer of type 'ImDrawVert'
../imgui_impl_opengl3.cpp:217:113: runtime error: member access within null pointer of type 'ImDrawVert'
../imgui_impl_opengl3.cpp:218:113: runtime error: member access within null pointer of type 'ImDrawVert'

[ocornut]

Thank you @Keenuts. My next question was to find out in which version of Clang this appeared, but it seems to be a C++11 thing so I am now using offsetof() on all C++11 compliant compilers. All my local compiler tests seems to be passing.

[Keenuts]

Oh cool, thanks!