# phosphor-logging
phosphor logging provides mechanism for common event and logging creation based
on information from the journal log.

## To Build
```
To build this package, do the following steps:

    1. ./bootstrap.sh
    2. ./configure ${CONFIGURE_FLAGS}
    3. make

To clean the repository run `./bootstrap.sh clean`.
```
# Adding application specific error YAML
* This document captures steps for adding application specific error YAML files
  and generating local elog-errors.hpp header file for application use.
* Should cater for continuous integration (CI) build, bitbake image build, and
  local repository build.

## Continuous Integration (CI) build
 * Make is called on the repository that is modified.
 * Dependent packages are pulled based on the dependency list specified in the
   configure.ac script.

## Recipe build
 * Native recipes copy error YAML files to shared location.
 * phosphor-logging builds elog-errors.hpp by parsing the error YAML files from
   the shared location.

## Local repository build
 * Copies local error YAML files to the shared location in SDK
 * Make generates elog-errors.hpp by parsing the error YAML files from the
   shared location.

## Makefile changes
**Reference**
 * https://github.com/openbmc/openpower-debug-collector/blob/master/Makefile.am
### Export error YAML to shared location
*Modify Makefile.am to export newly added error YAML to shared location*
```
yamldir = ${datadir}/phosphor-dbus-yaml/yaml
nobase_yaml_DATA = \
    org/open_power/Host.errors.yaml
```
### Generate elog-errors.hpp using elog parser from SDK location
 * Add a conditional check "GEN_ERRORS"
 * Disable the check for recipe bitbake image build
 * Enable it for local repository build
 * If "GEN_ERRORS" is enabled, build generates elog-errors.hpp header file.
```
  # Generate phosphor-logging/elog-errors.hpp
  if GEN_ERRORS
  ELOG_MAKO ?= elog-gen-template.mako.hpp
  ELOG_DIR ?= ${OECORE_NATIVE_SYSROOT}${datadir}/phosphor-logging/elog
  ELOG_GEN_DIR ?= ${ELOG_DIR}/tools/
  ELOG_MAKO_DIR ?= ${ELOG_DIR}/tools/phosphor-logging/templates/
  YAML_DIR ?= ${OECORE_NATIVE_SYSROOT}${datadir}/phosphor-dbus-yaml/yaml
  phosphor-logging/elog-errors.hpp:
      @mkdir -p ${YAML_DIR}/org/open_power/
      @cp ${top_srcdir}/org/open_power/Host.errors.yaml \
        ${YAML_DIR}/org/open_power/Host.errors.yaml
      @mkdir -p `dirname $@`
      @chmod 777 $(ELOG_GEN_DIR)/elog-gen.py
      $(AM_V_at)$(PYTHON) $(ELOG_GEN_DIR)/elog-gen.py -y ${YAML_DIR} \
        -t ${ELOG_MAKO_DIR} -m ${ELOG_MAKO} -o $@
  endif
```

### Update BUILT_SOURCES
 * Append elog-errors.hpp to BUILT_SOURCES list and put it in conditional check
   GEN_ERRORS so that the elog-errors.hpp is generated only during local
   repository build.
```
    if GEN_ERRORS
    nobase_nodist_include_HEADERS += \
                phosphor-logging/elog-errors.hpp
    endif
    if GEN_ERRORS
    BUILT_SOURCES += phosphor-logging/elog-errors.hpp
    endif
```
### Conditional check for native build
 * As the same Makefile is used both for recipe image build and native recipe
   build, add a conditional to ensure that only installation of error yaml files
   happens during native build. It is not required to build repository during
   native build.
```
   if !INSTALL_ERROR_YAML
   endif
```
## Autotools changes
**Reference**
 * https://github.com/openbmc/openpower-debug-collector/blob/master/configure.ac

### Add option(argument) to enable/disable installing error yaml file
 * Install error yaml option(argument) is enabled for native recipe build
   and disabled for bitbake build.

 * When install error yaml option is disabled do not check for target specific
   packages in autotools configure script.

### Add option(argument) to install error yaml files
```
AC_ARG_ENABLE([install_error_yaml],
    AS_HELP_STRING([--enable-install_error_yaml],
    [Enable installing error yaml file]),[], [install_error_yaml=no])
AM_CONDITIONAL([INSTALL_ERROR_YAML],
    [test "x$enable_install_error_yaml" = "xyes"])
AS_IF([test "x$enable_install_error_yaml" != "xyes"], [
..
..
])
```
### Add option(argument) to enable/disable generating elog-errors header file
```
AC_ARG_ENABLE([gen_errors],
    AS_HELP_STRING([--enable-gen_errors], [Enable elog-errors.hpp generation ]),
    [],[gen_errors=yes])
AM_CONDITIONAL([GEN_ERRORS], [test "x$enable_gen_errors" != "xno"])
```

## Recipe changes
**Reference**
* https://github.com/openbmc/openbmc/blob/master/meta-openbmc-machines\
/meta-openpower/common/recipes-phosphor/debug/openpower-debug-collector.bb

### Extend recipe for native and nativesdk
* Extend the recipe for native and native SDK builds
```
BBCLASSEXTEND += "native nativesdk"
```
### Remove dependencies for native and native SDK build
* Native recipe caters only for copying error yaml files to shared location.
* For native and native SDK build remove dependency on packages that recipe
  build depends

#### Remove dependency on phosphor-logging for native build
```
DEPENDS_remove_class-native = "phosphor-logging"
```
#### Remove dependency on phosphor-logging for native SDK build
```
DEPENDS_remove_class-nativesdk = "phosphor-logging"
```
### Add install_error_yaml argument during native build
* Add package config to enable/disable install_error_yaml feature.
```
## Add package config to enable/disable install_error_yaml feature
PACKAGECONFIG ??= "install_error_yaml"
PACKAGECONFIG[install_error_yaml] = " \
        --enable-install_error_yaml, \
        --disable-install_error_yaml, ,\
        "
```
#### Enable install_error_yaml check for native build
```
PACKAGECONFIG_add_class-native = "install_error_yaml"
PACKAGECONFIG_add_class-nativesdk = "install_error_yaml"
```
#### Disable install_error_yaml during target build
```
PACKAGECONFIG_remove_class-target = "install_error_yaml"
```

### Disable generating elog-errors.hpp for bitbake build
* Disable gen_errors argument for bitbake image build as the application uses
  the elog-errors.hpp generated by phosphor-logging
* Argument is enabled by default for local repository build in the configure
  script of the local repository.
```
 XTRA_OECONF += "--disable-gen_errors"
```

## Local build
* During local build use --prefix=/usr for the configure script.

**Reference**
* https://github.com/openbmc/openpower-debug-collector/blob/master/README.md