build_flags¶These flags/options control preprocessing, compilation, assembly and linking processes:
Format |
Scope |
Description |
|---|---|---|
|
CPPDEFINES |
Predefine name as a macro, with definition 1. |
|
CPPDEFINES |
The contents of definition are tokenized and processed as if they
appeared during translation phase three in a |
|
CPPDEFINES |
Cancel any previous definition of name, either built in or provided
with a |
|
CPPFLAGS |
Bypass the compiler driver and pass option directly through to the preprocessor |
|
CCFLAGS |
Turns on all optional warnings which are desirable for normal code. |
|
CCFLAGS |
Make all warnings into hard errors. Source code which triggers warnings will be rejected. |
|
CCFLAGS |
Suppress all warnings, including those which GNU CPP issues by default. |
|
CCFLAGS |
Process file as if |
|
CPPPATH |
Add the directory dir to the list of directories to be searched for header files. |
|
ASFLAGS, CCFLAGS |
Pass option as an option to the assembler. If option contains commas, it is split into multiple options at the commas. |
|
LINKFLAGS |
Pass option as an option to the linker. If option contains commas, it is split into multiple options at the commas. |
|
LIBS |
Search the library named library when linking |
|
LIBPATH |
Add directory dir to the list of directories to be searched for
|
This option can be set by global environment variable
PLATFORMIO_BUILD_FLAGS.
Example:
[env:specific_defines]
build_flags = -DFOO -DBAR=1 -DFLOAT_VALUE=1.23457e+07
[env:string_defines]
build_flags = '-DHELLO="World!"' '-DWIFI_PASS="My password"'
[env:specific_inclibs]
build_flags = -I/opt/include -L/opt/lib -lfoo
[env:specific_ld_script]
build_flags = -Wl,-T/path/to/ld_script.ld
PlatformIO Core allows to run external command/script which outputs build flags. PIO will automatically parse the output and append flags to a build environment. You can use any shell or programming language.
This external command will be called on each platformio run command before building/uploading process.
Use Cases:
Macro with the latest VCS revision/tag “on-the-fly”
Generate dynamic headers (
*.h)Process media content before generating SPIFFS image
Make some changes to source code or related libraries
Note
If you need more advanced control and would like to apply changes to PIO Build System environment, please refer to Advanced options and use Pre/Post Extra Scripts.
Example:
[env:generate_flags_with_external_command]
build_flags = !cmd_or_path_to_script
Use Case: Get the latest GIT revision “on-the-fly”
Unix
[env:git_revision_macro]
build_flags = !echo "-DPIO_SRC_REV="$(git rev-parse HEAD)
Windows
You need to create a separate file named print_git_rev.bat and place it
near platformio.ini.
platformio.ini:
[env:git_revision_macro]
build_flags = !print_git_rev.bat
print_git_rev.bat:
@echo off
FOR /F "tokens=1 delims=" %%A in ('git rev-parse HEAD') do echo -DPIO_SRC_REV=%%A
For more detailed information about available flags/options go to:
src_build_flags¶An option src_build_flags has the same behavior like build_flags
but will be applied only for the project source code from
src_dir directory.
This option can be set by global environment variable
PLATFORMIO_SRC_BUILD_FLAGS.
build_unflags¶Remove base/initial flags which were set by development platform.
[env:unflags]
build_unflags = -Os -std=gnu++11
build_flags = -O2
src_filter¶This option allows to specify which source files should be included/excluded from build process. Filter supports 2 templates:
+<PATH> include template
-<PATH> exclude template
PATH MAST BE related from src_dir. All patterns will
be applied in theirs order.
GLOB Patterns are allowed.
By default, src_filter is predefined to
+<*> -<.git/> -<svn/> -<example/> -<examples/> -<test/> -<tests/>,
that means “includes ALL files, then
exclude .git and svn repository folders, example … folder.
This option can be set by global environment variable
PLATFORMIO_SRC_FILTER.