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-rw-r--r--Makerules46
1 files changed, 46 insertions, 0 deletions
diff --git a/Makerules b/Makerules
index 7e4077ee50..f62d5180e5 100644
--- a/Makerules
+++ b/Makerules
@@ -214,6 +214,52 @@ sed-remove-dotdot := -e 's@  *\([^ 	\/$$][^ 	\]*\)@ $$(..)\1@g' \
 		     -e 's@^\([^ 	\/$$][^ 	\]*\)@$$(..)\1@g'
 endif
 
+ifdef gen-py-const-headers
+# We'll use a static pattern rule to match .pysym files with their
+# corresponding generated .py files.
+# The generated .py files go in the submodule's dir in the glibc source dir.
+py-const-files := $(patsubst %.pysym,%.py,$(gen-py-const-headers))
+py-const-dir := $(objpfx)
+py-const := $(addprefix $(py-const-dir),$(py-const-files))
+py-const-script := $(..)scripts/gen-py-const.awk
+
+# This is a hack we use to generate .py files with constants for Python
+# pretty printers.  It works the same way as gen-as-const.
+# See scripts/gen-py-const.awk for details on how the awk | gcc mechanism
+# works.
+#
+# $@.tmp and $@.tmp2 are temporary files we use to store the partial contents
+# of the target file.  We do this instead of just writing on $@ because, if the
+# build process terminates prematurely, re-running Make wouldn't run this rule
+# since Make would see that the target file already exists (despite it being
+# incomplete).
+#
+# The sed line replaces "@name@SOME_NAME@value@SOME_VALUE@" strings from the
+# output of 'gcc -S' with "SOME_NAME = SOME_VALUE" strings.
+# The '-n' option, combined with the '/p' command, makes sed output only the
+# modified lines instead of the whole input file.  The output is redirected
+# to a .py file; we'll import it in the pretty printers file to read
+# the constants generated by gen-py-const.awk.
+# The regex has two capturing groups, for SOME_NAME and SOME_VALUE
+# respectively.  Notice SOME_VALUE may be prepended by a special character,
+# depending on the assembly syntax (e.g. immediates are prefixed by a '$'
+# in AT&T x86, and by a '#' in ARM).  We discard it using a complemented set
+# before the second capturing group.
+$(py-const): $(py-const-dir)%.py: %.pysym $(py-const-script) \
+	     $(common-before-compile)
+	$(make-target-directory)
+	$(AWK) -f $(py-const-script) $< \
+	       | $(CC) -S -o $@.tmp $(CFLAGS) $(CPPFLAGS) -x c -
+	echo '# GENERATED FILE\n' > $@.tmp2
+	echo '# Constant definitions for pretty printers.' >> $@.tmp2
+	echo '# See gen-py-const.awk for details.\n' >> $@.tmp2
+	sed -n -r 's/^.*@name@([^@]+)@value@[^[:xdigit:]Xx-]*([[:xdigit:]Xx-]+)@.*/\1 = \2/p' \
+	    $@.tmp >> $@.tmp2
+	mv -f $@.tmp2 $@
+	rm -f $@.tmp
+
+generated += $(py-const)
+endif  # gen-py-const-headers
 
 ifdef gen-as-const-headers
 # Generating headers for assembly constants.