* "dummy loop to force pre-processed linker file generation" seems to
be unnecessary. It looks like the idea was copied from the
dependency of ULP-FSM preprocessed source files on the LD script.
* Can use add_dependencies instead of
set_target_properties(...LINK_DEPENDS...) which is more readable
* Use target_link_options instead of target_link_libraries, which is
supported starting from CMake 3.13. Unlike target_link_libraries,
it doesn't require manually quoting the pats.
This fixes the issue with build output not being colorized on Windows,
while the hints messages are colorized.
The issue occurred because sys.stdout and sys.stderr get overridden
by colorama.init() at runtime, but the default argument
output_stream=sys.stdout holds the reference to the"original"
sys.stdout.
colorama.init() (which, by the way, gets called via a curious chain
of imports, via idf_component_tools.manifest and tqdm package)
overrides standard streams, on Windows only. The overridden streams
contain logic to convert ANSI color codes into Windows Console API
calls to colorize the text.
Since read_and_write_stream function used the default value of
output_stream evaluated at module loading time, it was using the
original sys.stdout, not the one overridden by colorama.
One extra note is that while this does fix the coloring issue, the
solution is a bit fragile, as it relies on one of the following
(on Windows):
- colorama.init() is called (this can change if idf-component-manager
stops importing tqdm)
- Sufficiently new version of Windows 10 is used, and ANSI color codes
support is enabled in the Registry.
The actual output from the build tool (CMake/Ninja) may or may not
contain color escape codes, depending on various factors. The output
written to the log file should never include color escape codes,
though. This is because color escape codes in files are usually not
rendered as "color" in editors, and complicate reading. Also escape
codes would break the regular expressions used to display hints for
compilation errors.
If stdout is a TTY (meaning that the output is not redirected), tell
the build tool (GNU Make or Ninja) to enable colorized output.
GNU Make and Ninja also check if their stdout is redirected and
strip color escape sequences in that case. CLICOLOR_FORCE environment
variable overrides this behavior.
With this change, if the compiler was launched with the
-fcolor-diagnostics flag and idf.py output is not redirected, the
final output in the terminal will be colorized.
(-fcolor-diagnostics is handled at CMake level by the previous commit)
Related to https://github.com/espressif/esp-idf/issues/4162
Setting this option informs CMake that it should pass
-fcolor-diagnostics flag to the compiler.
(Colorized build system output, like from GNU Make, is produced even
without this flag.)
Note that if the build is done using Ninja and the build output is
redirected (not a TTY), Ninja will still strip the escape codes from
the output. For the case of idf.py, this is handled in the next
commit.
