I have a cdylib that I am copying and then using in the debugger with the goal of hot reloading on build. However, the .pdb file for it is not copied. Because of this, when building, sometimes the pdb is locked by the debugger and the build fails.
With cpp / cl, I can pass a link arg from the build batch file -PDB:foo%random%.pdb to achieve my goal. I am not sure how I can do the same with cargo build.
Does anyone have any insights how I can do this?
Related
I'm porting a large project to linux. I wrote all the CMakeLists.txt files, and everything compiles in my machine.
For whatever reason we still use TFS. The old version, not git with TFS.
I'm working in my own branch, but that branch has no build definition for linux. Before I check in, I want to be sure that everything compiles on the server too. So I need to merge my branch to another one, and submit that shelve set to the build job.
In my machine everything compiles fine. But when I run the build in the server, applying a shelveset to the branch that has a linux build definition, I get an error from the build, saying
CMake Error at
/myproject/subproject/CMakeLists.txt:165 (add_library):
Cannot find source file:
/myproject/subproject/IInternalTransactionManager.h
Tried extensions .c .C .c++ .cc .cpp .cxx .cu .m .M .mm .h .hh .h++ .hm
.hpp .hxx .in .txx
Indeed, that file is not there. Cmake complains about the file not being in the sources directory, which is true, because it is in another directory. But the fact is that I'm not asking for it either! My CMakeFiles.txt file does not include that file. That file is a header which is used in a few files, contains only classes definitions (no implementations), and the directory in which myHeader.h resides has been defined in include_directories. My CMakeLists.txt looks something like this:
set(PROJECT_NAME project)
project(${PROJECT_NAME})
include_directories(
../_include
)
set(source_files
main.cpp
file_that_includes_myHeader.cpp
)
add_library( ${PROJECT_NAME} STATIC ${source_files} )
and my file structure is something like:
/myproject/subproject/main.cpp
/myproject/subproject/file_that_includes_myHeader.cpp
/myproject/subproject/CMakeLists.txt
/myproject/_include/myHeader.h
So, why should cmake complaining about a missing file, if such file is not included in the CMakeLists.txt file? And why would this happen only the build in TFS? My guess is that there is something wrong when applying the shelvetset and is not related to my code, but I cannot prove it.
I compared the code after the shelveset is applyied, and still in that version the CMakeLists.txt does not mention myHeader.h
Or, there is some rule about including headers in CMakeLists.txt files which I'm not aware of.
So, after expending too much debuging I contacted the team in charge of the build process. And as it turns out, the building process in the TFS building definition was definetly NOT what I expected. And of course this was not documented.
Our development is mostly in windows (by far). The linux build has a step before building: a script is launched which parses each Visual Studio project file, gets the included files, and substitutes the source files in the CMakeLists.txt files with the one parsed from VS. Right or wrong, is just the way it is.
I could build the linux build in my local machine because everything was done correctly. The windows build worked too, even though the VS project files sometimes included some files which were not in the source directory but in some header only directory, and somehow that compiled. I guess because the directory was defined in the include directory. But When the CMakeLists.txt files were updated, cmake complained (rightly so) about not finding the files.
So, if anybody experiences similar issues, contact your devops team or whoever is in charge of such things.
I encountered a build issue with visual studio's 'link.exe' tool, and at some point, which I would have normally investigated by passing my build command as an argument to linux's strace -efile tool to get a dump of all the files considered by the linker, which couldn't be found and which were selected. But of course, we're on Windows this time, and strace is not an option.
the problem was indeed the linker picking the wrong file when I said ntoskrnl.lib on the command line
the root cause was an invalid %LIB% contents that wasn't matching the include paths passed to cl.exe calls
Question: how could I force link.exe to reveal the full path of the files it is linking (including .lib) ? (and save myself this hassle next time)
I'm porting an SDK written in C++ from Windows to Linux. There are other binaries, but at its simplest, our SDK is this:
core.dll - implicitly loaded DLL ("libcore.so" shared library on Linux)
tests.exe - an app use to test the DLL (uses google test)
All of my binaries must live in one folder somewhere that apps can find. I've achieved that on Windows. I wanted to achieve the same thing in Linux. I'm failing miserably
To illustrate, Here's the basic project tree. We use CMake. After I build I've got
mysdk
|---CMakeLists.txt (has add_subdirectory() statements for "tests" and "core")
|---/tests (source code + CMakeLists.txt)
|---/core (source code + CMakeLists.txt)
|---/build (all build ouput, CMake output, etc)
|---tests (build output)
|---core (build output)
The goal is to "flatten" the "build" tree and put all the binary outputs of tests, core, etc into one folder.
I tried adding CMake's "install" command, to each of my CMakeLists.txt files (e.g. install(TARGETS core DESTINATION bin). I then then executed sudo make install after my normal build. This put all my binaries in /usr/local/bin with no errors. But when I ran tests from there, it failed to find libcore.so, even though it was sitting right there in the same folder
tests: error while loading shared libraries: libcore.so: Cannot open shared object file: No such file or directory
I read up on the LD_LIBRARY_PATH environment variable and so tried adding that folder (/usr/local/bin) into it and running. I can see I've properly altered LD_LIBRARY_PATH but it still doesn't work. "tests" still can't find libcore.so. I even tried changing the PATH environment variable as well. Same result.
In frustration, I tried brute-force copying the output binaries to a temporary subfolder (of /mysdk/build) and running tests from there. To my surprise it ran.
Then I realized why: Instead of loading the local copy of libcore.so it had loaded the one from the build output folder (as if the full path were "baked in" to the app at build time). Subsequently deleting that build-output copy of libcore.so made "tests" fail altogether as before, instead of loading the local copy. So maybe the path really was baked in.
I'm at a loss. I've read the CMake tutorial and reference. It makes this sound so easy. Aside from the obvious (What am I doing wrong?) I would appreciate if anyone could answer any of the following questions:
What is the correct way to control where my app looks for my shared libraries?
Is there a relationship between my project build structure and how my binaries must then appear when installed?
Am I even close to the right way of doing this?
Is it possible I've somehow inadvertently "baked" (into my app) full paths to my shared libraries? Is that a thing? I use all CMAKE variables in my CMakeLists files.
You can run ldd file to print the shared object dependencies for file. It will tell you where are its dependencies being read from.
You can export the environment variable LD_LIBRARY_PATH with the paths you want the linker to look for. If a dependency is not found, try adding the path where that dependency is located at to LD_LIBRARY_PATH and then run ldd again (make sure you export the variable).
Also, make sure the dependencies have the right permissions.
Updating LD_LIBRARY_PATH is an option. Another option is using RPATH. Please check the example.
https://github.com/mustafagonul/cmake-examples/blob/master/005-executable-with-shared-library/CMakeLists.txt
cmake_minimum_required(VERSION 2.8)
# Project
project(005-executable-with-shared-library)
# Directories
set(example_BIN_DIR bin)
set(example_INC_DIR include)
set(example_LIB_DIR lib)
set(example_SRC_DIR src)
# Library files
set(library_SOURCES ${example_SRC_DIR}/library.cpp)
set(library_HEADERS ${example_INC_DIR}/library.h)
set(executable_SOURCES ${example_SRC_DIR}/main.cpp)
# Setting RPATH
# See https://cmake.org/Wiki/CMake_RPATH_handling
set(CMAKE_INSTALL_RPATH ${CMAKE_INSTALL_PREFIX}/${example_LIB_DIR})
# Add library to project
add_library(library SHARED ${library_SOURCES})
# Include directories
target_include_directories(library PUBLIC ${CMAKE_CURRENT_SOURCE_DIR}/${example_INC_DIR})
# Add executable to project
add_executable(executable ${executable_SOURCES})
# Linking
target_link_libraries(executable PRIVATE library)
# Install
install(TARGETS executable DESTINATION ${example_BIN_DIR})
install(TARGETS library DESTINATION ${example_LIB_DIR})
install(FILES ${library_HEADERS} DESTINATION ${example_INC_DIR})
Disclaimer: Am a C# developer trying to understand a few C++ fundamentals
Have created a command line project which has the .lib of a DLL file linked under Linker > Input > Additional dependencies, and also has the location of the header files specified under C/C++ > General > Additional Include Directories. Ran a build and all compiled okay, with the .exe being built in the Debug/Release dir.
Problem is I also expected the .dll file the project depends on to be there (just like when you add a reference in a .Net project) - but it isn't. When launching the .exe it complains that it can't find the DLL. Fair enough, but why didn't the VC++ put the DLL there if it knows it's required?
And is there a "best practice" to ensuring the dependent DLL files are in the output dir, other than manually copying them there? I have a project that will require use of some third-party libraries, and I was hoping the IDE would help me manage them...
Big thanks for any guidance given!
If you create solution which contains exe and dll, all output files are created in $(SolutionDir) Debug or Release subdirectories, and exe runs successfully. Otherwise, you have one of the following options:
Copy Dll in Post-build step to directory where it is available for loading (usually .exe directory)
Add Dll directory to PATH.
So I have scons working with an alternate build location (build/ for my output files, src/ for my input files) and it works great. Except for one thing.
I'm using an IDE (TI Code Composer 4) to debug my program. I point the IDE at the output executable to run it, and what it uses for the source files for debugging is the build/ directory. I don't really care, except when I go to edit the file in the IDE, for example main.cpp, the file is really build/main.cpp which gets clobbered as soon as I run scons again. I have to remember to edit src/main.cpp instead. I am aware of this issue and yet I make the same mistake often.
Is there a way to have scons make the source files it copies into the build path read-only? (I'd ask how to get TI CCS4 to use the right source files when it is debugging an executable, but I doubt I'd get any answers.)
This page has information about wrapping InstallTargets with a chmod call.
FYI, the scons user list is quite active with many knowledgeable people and you can get answers pretty quickly.
You could always tell scons not to duplicate source files in the build directory:
SConscript('src/SConscript', variant_dir='build', duplicate=0)