tools/tsort_init_ops.sh: new script

This script retrieves all initialization operation dependencies, taking
all build options into account, and attempts a topological sort, failing
in case loops are detected.

It's automatically run by the build system as a dependency of the kernel
binary.

4 files changed, 60 insertions, 3 deletions

diff --git a/.gitignore b/.gitignore
index 452070dc..265e3aa5 100644
--- a/.gitignore
+++ b/.gitignore
@@ -14,5 +14,6 @@ x15.lds
 /configure
 /stamp-h1
 /x15
+/x15.sorted_init_ops
 /doc/*\.[1-9]
 /doc/*\.[1-9]\.html
diff --git a/Makefile.am b/Makefile.am
index 50baae96..413ac6db 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -57,10 +57,13 @@ SUFFIXES += .9 .9.html .9.xml .9.txt
 	$(AM_V_GEN)$(A2X) $(A2X_FLAGS) -f manpage --xsltproc-opts="-o $(abs_top_builddir)/$@" $<
 
 bin_PROGRAMS = x15
-x15_DEPENDENCIES = arch/$(arch)/x15.lds
-MOSTLYCLEANFILES += arch/$(arch)/x15.lds
+x15_DEPENDENCIES = arch/$(arch)/x15.lds x15.sorted_init_ops
+MOSTLYCLEANFILES += $(x15_DEPENDENCIES)
 x15_SOURCES =
 x15_LDFLAGS = -nostdlib -Xlinker -T arch/$(arch)/x15.lds
 x15_LDADD = -lgcc
 
 include Makefrag.am
+
+x15.sorted_init_ops: $(filter %.c,$(x15_SOURCES))
+	$(AM_V_GEN)$(top_srcdir)/tools/tsort_init_ops.sh "$(COMPILE)" "$@" $^
diff --git a/Makefrag.am b/Makefrag.am
index 8c2e35e7..1b39b724 100644
--- a/Makefrag.am
+++ b/Makefrag.am
@@ -1,7 +1,9 @@
 include arch/x86/Makefrag.am
 include doc/Makefrag.am
 
-EXTRA_DIST += tools/qemu.sh
+EXTRA_DIST +=                                               \
+        tools/qemu.sh                                       \
+        tools/tsort_init_ops.sh
 
 x15_SOURCES +=                                              \
         include/assert.h                                    \
diff --git a/tools/tsort_init_ops.sh b/tools/tsort_init_ops.sh
new file mode 100755
index 00000000..a367ef27
--- /dev/null
+++ b/tools/tsort_init_ops.sh
@@ -0,0 +1,51 @@
+#!/bin/sh
+
+set -e
+
+compile="$1"
+output_file="$2"
+
+shift 2
+
+tmpfile1=$(mktemp)
+tmpfile2=$(mktemp)
+
+cleanup()
+{
+    rm -f $tmpfile1 $tmpfile2
+}
+
+trap cleanup EXIT
+
+process()
+{
+    target=$1
+
+    shift
+
+    for dep in $@; do
+        echo $target $dep
+    done
+}
+
+# Define _KERN_INIT_H so that the INIT_XXX macros aren't expanded.
+$compile -E -D_KERN_INIT_H "$@" \
+     | sed -e 's/#.*$//' \
+     | tr '\n' ' ' \
+     | tr -s ' ' \
+     | sed -E -e 's/INIT_OP_DEP\(([a-zA-Z0-9_]*), 1 \)/\1/g' \
+     | grep -P -o 'INIT_OP_DEFINE\(.*?\)' \
+     | sed -e 's/^INIT_OP_DEFINE(//' \
+     | sed -e 's/).*$//' \
+     | tr -d , \
+| while read line; do
+    process $line
+done > $tmpfile1
+
+if [ -z "$(cat $tmpfile1)" ]; then
+    return 1
+fi
+
+# XXX Avoid using pipes because of the lack of a standard -o pipefail variant.
+tsort < $tmpfile1 > $tmpfile2
+tac < $tmpfile2 > "$output_file"