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Diffstat (limited to 'doc/dlt_for_developers.md')
| -rw-r--r-- | doc/dlt_for_developers.md | 69 |
1 files changed, 65 insertions, 4 deletions
diff --git a/doc/dlt_for_developers.md b/doc/dlt_for_developers.md index cd85de0..1b30f86 100644 --- a/doc/dlt_for_developers.md +++ b/doc/dlt_for_developers.md @@ -25,9 +25,15 @@ within the standard include directory. This example gives an overview of DLT usage inside an application by using a minimal code example. Detailed information about the API can be found later in this document. +Please note that the #include statement depends on the means by which you are +incorporating the DLT library into your project. The `<dlt/dlt.h>` form (i.e. +with a directory prefix) seen here is necessary when you are using the CMake +Config file (see below). If you are using pkg-config instead, then this #include +statement needs to refer to only `<dlt.h>`, due to the way the pkg-config module +exports the include directory. ``` -#include <dlt.h> +#include <dlt/dlt.h> DLT_DECLARE_CONTEXT(ctx); /* declare context */ @@ -62,14 +68,55 @@ string. On application cleanup, all DLT contexts, as well as the DLT application have to be unregistered. ### DLT with cmake -To use DLT with cmake, the following lines are the important ones: + +To use DLT with CMake, the recommended way is to use the CMake Config file +that is being generated as part of installation. + +You can thus: +``` +find_package(automotive-dlt) +... +target_link_libraries(myapp PRIVATE Genivi::DLT) +``` +which lets your project automatically gain all necessary compile and link flags +needed by libdlt, including the include directories. + +The generated CMake Config file follows "Modern CMake" convention and only +exports an IMPORTED CMake target; it does not set any variables. + +### DLT with pkg-config + +Alternatively to the CMake integration detailed above, it is also possible +to use DLT via pkg-config. This can also be done with CMake's PkgConfig +module as well. + +#### PkgConfig usage with "Modern CMake" + +Here, you let the PkgConfig module create targets as well; the target's name +is however determined by the PkgConfig module: + +``` +find_package(PkgConfig) +pkg_check_modules(DLT REQUIRED IMPORTED_TARGET automotive-dlt) +``` + +As per "Modern CMake", there are again no variables to be added, but only +a CMake target to be added to the link libraries: + +``` +target_link_libraries(myapp PRIVATE PkgConfig::DLT) +``` + +#### PkgConfig usage with "Legacy CMake" (<3.0) + +Here, you let the PkgConfig module only create variables, but not targets: ``` find_package(PkgConfig) pkg_check_modules(DLT REQUIRED automotive-dlt) ``` -to INCLUDE\_DIRECTORIES, add +to INCLUDE\_DIRECTORIES (or, since CMake 2.8.11, TARGET\_INCLUDE\_DIRECTORIES), add ``` ${DLT_INCLUDE_DIRS} @@ -78,7 +125,21 @@ ${DLT_INCLUDE_DIRS} and to TARGET\_LINK\_LIBRARIES: ``` -${DLT_LIBRARIES} +${DLT_LINK_LIBRARIES} (preferred, for CMake >= 3.12) +${DLT_LIBRARIES} (otherwise) +``` + +The contents of `${DLT_LIBRARIES}` do not include the library's path +(e.g. `-L/path/to/lib`), so if the library resides in a location that is not +on the linker's default search path, you'll either have to add that path +to LINK\_DIRECTORIES: +``` +link_directories(${DLT_LIBRARY_DIRS}) +``` +or, alternatively, not use `${DLT_LIBRARIES}`, but `${DLT_LDFLAGS}` instead, +which combines `${DLT_LIBRARIES}` and `${DLT_LIBRARY_DIRS}`: +``` +target_link_libraries(myapp ${DLT_LDFLAGS}) ``` ### Limitation |