Use 'CURDIR' make variable in Genode make files

The bash-builtin 'pwd' command uses the 'st_dev' and 'st_ino' members of
the 'stat' struct to compare the path from the 'PWD' environment variable
with the path returned by 'getcwd()'. These members don't get set
correctly in Noux and therefore the 'pwd' command sometimes returns wrong
results when building Genode in Noux. With this patch the 'CURDIR' make
variable gets used instead of calling 'pwd'.

Fixes #454.

base/mk/lib.mk

@@ -174,5 +174,5 @@ $(LIB_SO): $(STATIC_LIBS) $(OBJECTS) $(wildcard $(LD_SCRIPT_SO))
 	                $(LIBGCC)
 
 $(INSTALL_SO):
-	$(VERBOSE)ln -sf `pwd`/$(LIB_SO) $@
+	$(VERBOSE)ln -sf $(CURDIR)/$(LIB_SO) $@
 

base/mk/prg.mk

@@ -190,7 +190,7 @@ $(TARGET): $(LINK_ITEMS) $(wildcard $(LD_SCRIPTS))
 	$(VERBOSE)libs=$(LIB_CACHE_DIR); $(LD_CMD) -o $@
 
 $(INSTALL_DIR)/$(TARGET): $(TARGET)
-	$(VERBOSE)ln -sf `pwd`/$(TARGET) $@
+	$(VERBOSE)ln -sf $(CURDIR)/$(TARGET) $@
 else
 $(TARGET):
 $(INSTALL_DIR)/$(TARGET): $(TARGET)

tool/builddir/build.mk

@@ -37,9 +37,8 @@
 
 -include etc/build.conf
 
-PWD            := $(shell pwd)
-BUILD_BASE_DIR := $(PWD)
-INSTALL_DIR    := $(PWD)/bin
+BUILD_BASE_DIR := $(CURDIR)
+INSTALL_DIR    := $(CURDIR)/bin
 
 export BASE_DIR         ?= ../base
 export REPOSITORIES     ?= $(BASE_DIR:%base=%base-linux) $(BASE_DIR)