Update BUILD.md

BUILD.md

@@ -264,16 +264,16 @@ It patches their CMake to correctly import its dependencies.
 
 ### Coverage report
 
-Coverage report is an additional feature intended for compilers GCC and Clang
-(including Apple Clang). It is generated by the build target `coverage_report`,
+Coverage report is intended for the developers working on unit tests and using compilers GCC
+or Clang (including Apple Clang). It is generated by the build target `coverage_report`,
 which is only enabled when `coverage` option is set, e.g. with
 `--options coverage=True` in `conan` or `-Dcoverage=ON` variable in `cmake`
 
-Prerequisites for coverage report are:
+Prerequisites for the coverage report:
 
 - [gcovr tool][5] (can be installed e.g. with [pip][6])
-- `gcov` for GCC (installed with compiler by default) or
-- `llvm-cov` for Clang (installed with compiler by default)
+- `gcov` for GCC (installed with the compiler by default) or
+- `llvm-cov` for Clang (installed with the compiler by default)
 - `Debug` build type
 
 Coverage report is created when the following steps are completed, in order:
@@ -282,7 +282,7 @@ Coverage report is created when the following steps are completed, in order:
    option mentioned above
 2. completed run of unit tests, which populates coverage capture data
 3. completed run of `gcovr` tool (which internally invokes either `gcov` or `llvm-cov`)
-   to assemble both instrumentation data and coverage capture data into a single report
+   to assemble both instrumentation data and coverage capture data into a coverage report
 
 Above steps are automated into a single target `coverage_report`. The instrumented
 `rippled` binary can be also used for regular development or testing work, at
@@ -295,28 +295,28 @@ The default coverage report format is Cobertura XML (used in CI), but the user
 can override it to any of the formats listed in `Builds/CMake/CodeCoverage.cmake`
 by setting `CODE_COVERAGE_REPORT_FORMAT` variable in `cmake`. It is also possible
 to generate more than one format at a time by setting `CODE_COVERAGE_EXTRA_ARGS`
-variable in `cmake`. The specific command line used to run `gcovr` tool will be
+variable in `cmake`. The specific command line used to run the `gcovr` tool will be
 displayed if `CODE_COVERAGE_VERBOSE` variable is set.
 
-The code coverage tool by default runs parallel unit tests with `--unittest-jobs`
-parameter set to the number of available CPU cores. This may cause spurious test
-errors on Apple. User can override unit test parallelism with
+By default, the code coverage tool runs parallel unit tests with `--unittest-jobs`
+ set to the number of available CPU cores. This may cause spurious test
+errors on Apple. Developers can override the number of unit test jobs with
 `CODE_COVERAGE_TEST_PARALLELISM` variable in `cmake`.
 
-Example with all the cmake variables:
+Example use with all cmake variables set:
 
 ```
 cd .build
 conan install .. --output-folder . --build missing --settings build_type=Debug
-cmake -DCMAKE_BUILD_TYPE=Debug -Dcoverage=ON -DCODE_COVERAGE_REPORT_FORMAT=html-details -DCODE_COVERAGE_EXTRA_ARGS="--json coverage_report.json --json-pretty"  -DCODE_COVERAGE_VERBOSE=ON -DCODE_COVERAGE_TEST_PARALLELISM=2 -DCMAKE_TOOLCHAIN_FILE:FILEPATH=build/generators/conan_toolchain.cmake ..
+cmake -DCMAKE_BUILD_TYPE=Debug -Dcoverage=ON -DCODE_COVERAGE_REPORT_FORMAT=html-details -DCODE_COVERAGE_EXTRA_ARGS="--json coverage_report.json --json-pretty --txt coverage_report.txt"  -DCODE_COVERAGE_VERBOSE=ON -DCODE_COVERAGE_TEST_PARALLELISM=2 -DCMAKE_TOOLCHAIN_FILE:FILEPATH=build/generators/conan_toolchain.cmake ..
 cmake --build . --target coverage_report
 ```
 
 After `coverage_report` target is completed, the generated coverage report will be
 stored inside the build directory, as either of:
 
-- file named `coverage_report` and a suitable extension for the report format, or
-- directory named `coverage_report` for `html-details` or `html-nested` report format.
+- file named `coverage_report.*`, with a suitable extension for the report format, or
+- directory named `coverage_report`, with `index.html` and other files inside, for `html-details` or `html-nested` report formats.
 
 
 ## Options