Add 'third_party/nix/' from commit 'be66c7a6b24e3c3c6157fd37b86c7203d14acf10' r/724

git-subtree-dir: third_party/nix
git-subtree-mainline: cf8cd640c1adf74a3706efbcb0ea4625da106fb2
git-subtree-split: be66c7a6b24e3c3c6157fd37b86c7203d14acf10

1 files changed, 14 insertions, 0 deletions

diff --git a/third_party/nix/mk/functions.mk b/third_party/nix/mk/functions.mk
new file mode 100644
index 0000000000..c48775db8c
--- /dev/null
+++ b/third_party/nix/mk/functions.mk
@@ -0,0 +1,14 @@
+# Utility function for recursively finding files, e.g.
+# ‘$(call rwildcard, path/to/dir, *.c *.h)’.
+rwildcard=$(foreach d,$(wildcard $1*),$(call rwildcard,$d/,$2) $(filter $(subst *,%,$2),$d))
+
+# Given a file name, produce the corresponding dependency file
+# (e.g. ‘foo/bar.o’ becomes ‘foo/.bar.o.dep’).
+filename-to-dep = $(dir $1).$(notdir $1).dep
+
+# Return the full path to a program by looking it up in $PATH, or the
+# empty string if not found.
+find-program = $(shell for i in $$(IFS=: ; echo $$PATH); do p=$$i/$(strip $1); if [ -e $$p ]; then echo $$p; break; fi; done)
+
+# Ensure that the given string ends in a single slash.
+add-trailing-slash = $(patsubst %/,%,$(1))/