[sw/meson] Conditionally use `--no-pad-sections`
Clang doesn't support the assembler option `--no-pad-sections`. To work
around that, we only add that option if the compiler supports it (through
the `-Wa,option` syntax).
Signed-off-by: Luís Marques <luismarques@lowrisc.org>
diff --git a/meson.build b/meson.build
index dfc28b9..c8f67ee 100644
--- a/meson.build
+++ b/meson.build
@@ -38,9 +38,17 @@
optimize_size_args = [
'-Os', # General "Optimize for Size" Option
'-fvisibility=hidden', # Hide symbols by default
- '-Wa,--no-pad-sections', # Don't pad assembly sections
]
+if meson.get_compiler('c').has_argument('-Wa,--no-pad-sections')
+ # Don't pad assembly sections. This was originally added to avoid sections
+ # being padded to the alignment size. Specifically, .vectors was being
+ # padded to 256 bytes when aligning to that value, when it only needed to be
+ # 128 bytes long. Clang doesn't do this padding, so restricting this option
+ # to GCC doesn't waste space when compiling with Clang.
+ optimize_size_args += '-Wa,--no-pad-sections'
+endif
+
# The following flags are applied to *all* builds, both cross builds
# and native builds.
add_project_arguments(
