kbuild: rust: avoid creating temporary files

`rustc` outputs by default the temporary files (i.e. the ones saved by `-Csave-temps`, such as `*.rcgu*` files) in the current working directory when `-o` and `--out-dir` are not given (even if `--emit=x=path` is given, i.e. it does not use those for temporaries). Since out-of-tree modules are compiled from the `linux` tree, `rustc` then tries to create them there, which may not be accessible. Thus pass `--out-dir` explicitly, even if it is just for the temporary files. Similarly, do so for Rust host programs too. Reported-by: Raphael Nestler <[email protected]> Closes: Rust-for-Linux/linux#1015 Reported-by: Andrea Righi <[email protected]> Tested-by: Raphael Nestler <[email protected]> # non-hostprogs Tested-by: Andrea Righi <[email protected]> # non-hostprogs Fixes: 295d839 ("kbuild: specify output names separately for each emission type from rustc") Cc: [email protected] Signed-off-by: Miguel Ojeda <[email protected]> Tested-by: Martin Rodriguez Reboredo <[email protected]> Signed-off-by: Masahiro Yamada <[email protected]>
kubalewski · Jul 23, 2023 · df01b7c · df01b7c
1 parent 0817d25
commit df01b7c
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Showing 2 changed files with 9 additions and 2 deletions.
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
@@ -264,6 +264,9 @@ $(obj)/%.lst: $(src)/%.c FORCE
 
 rust_allowed_features := new_uninit
 
+# `--out-dir` is required to avoid temporaries being created by `rustc` in the
+# current working directory, which may be not accessible in the out-of-tree
+# modules case.
 rust_common_cmd = \
 	RUST_MODFILE=$(modfile) $(RUSTC_OR_CLIPPY) $(rust_flags) \
 	-Zallow-features=$(rust_allowed_features) \
@@ -272,7 +275,7 @@ rust_common_cmd = \
 	--extern alloc --extern kernel \
 	--crate-type rlib -L $(objtree)/rust/ \
 	--crate-name $(basename $(notdir $@)) \
-	--emit=dep-info=$(depfile)
+	--out-dir $(dir $@) --emit=dep-info=$(depfile)
 
 # `--emit=obj`, `--emit=asm` and `--emit=llvm-ir` imply a single codegen unit
 # will be used. We explicitly request `-Ccodegen-units=1` in any case, and

diff --git a/scripts/Makefile.host b/scripts/Makefile.host
@@ -86,7 +86,11 @@ hostc_flags    = -Wp,-MMD,$(depfile) \
 hostcxx_flags  = -Wp,-MMD,$(depfile) \
                  $(KBUILD_HOSTCXXFLAGS) $(HOST_EXTRACXXFLAGS) \
                  $(HOSTCXXFLAGS_$(target-stem).o)
-hostrust_flags = --emit=dep-info=$(depfile) \
+
+# `--out-dir` is required to avoid temporaries being created by `rustc` in the
+# current working directory, which may be not accessible in the out-of-tree
+# modules case.
+hostrust_flags = --out-dir $(dir $@) --emit=dep-info=$(depfile) \
                  $(KBUILD_HOSTRUSTFLAGS) $(HOST_EXTRARUSTFLAGS) \
                  $(HOSTRUSTFLAGS_$(target-stem))