[Qemu-devel] [PATCH v2 1/1] include: Auto-generate the sizes lookup table

[Leonid Bloch <lbloch@janustech.com>]

The lookup table for power-of-two sizes is now auto-generated during the
build, and not hard-coded into the units.h file.

This partially reverts commit 540b8492618eb.

Signed-off-by: Leonid Bloch <lbloch@janustech.com>
---
 .gitignore           |  1 +
 Makefile             |  5 +++
 block/qcow2.h        |  2 +-
 block/vdi.c          |  1 +
 include/qemu/units.h | 73 --------------------------------------------
 scripts/gen-sizes.sh | 66 +++++++++++++++++++++++++++++++++++++++
 6 files changed, 74 insertions(+), 74 deletions(-)
 create mode 100755 scripts/gen-sizes.sh

diff --git a/.gitignore b/.gitignore
index 0430257313..721a7f4454 100644
--- a/.gitignore
+++ b/.gitignore
@@ -59,6 +59,7 @@
 /qemu-version.h
 /qemu-version.h.tmp
 /module_block.h
+/pow2_sizes.h
 /scsi/qemu-pr-helper
 /vhost-user-scsi
 /vhost-user-blk
diff --git a/Makefile b/Makefile
index dd53965f77..db72786ccb 100644
--- a/Makefile
+++ b/Makefile
@@ -122,6 +122,8 @@ endif
 
 GENERATED_FILES += module_block.h
 
+GENERATED_FILES += pow2_sizes.h
+
 TRACE_HEADERS = trace-root.h $(trace-events-subdirs:%=%/trace.h)
 TRACE_SOURCES = trace-root.c $(trace-events-subdirs:%=%/trace.c)
 TRACE_DTRACE =
@@ -499,6 +501,9 @@ ifdef CONFIG_MPATH
 scsi/qemu-pr-helper$(EXESUF): LIBS += -ludev -lmultipath -lmpathpersist
 endif
 
+pow2_sizes.h: $(SRC_PATH)/scripts/gen-sizes.sh
+	$(call quiet-command,sh $(SRC_PATH)/scripts/gen-sizes.sh $@,"GEN","$@")
+
 qemu-img-cmds.h: $(SRC_PATH)/qemu-img-cmds.hx $(SRC_PATH)/scripts/hxtool
 	$(call quiet-command,sh $(SRC_PATH)/scripts/hxtool -h < $< > $@,"GEN","$@")
 
diff --git a/block/qcow2.h b/block/qcow2.h
index a98d24500b..f5fa419ae7 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -27,7 +27,7 @@
 
 #include "crypto/block.h"
 #include "qemu/coroutine.h"
-#include "qemu/units.h"
+#include "pow2_sizes.h"
 
 //#define DEBUG_ALLOC
 //#define DEBUG_ALLOC2
diff --git a/block/vdi.c b/block/vdi.c
index 2380daa583..06d7335b3e 100644
--- a/block/vdi.c
+++ b/block/vdi.c
@@ -51,6 +51,7 @@
 
 #include "qemu/osdep.h"
 #include "qemu/units.h"
+#include "pow2_sizes.h"
 #include "qapi/error.h"
 #include "qapi/qobject-input-visitor.h"
 #include "qapi/qapi-visit-block-core.h"
diff --git a/include/qemu/units.h b/include/qemu/units.h
index 1c959d182e..692db3fbb2 100644
--- a/include/qemu/units.h
+++ b/include/qemu/units.h
@@ -17,77 +17,4 @@
 #define PiB     (INT64_C(1) << 50)
 #define EiB     (INT64_C(1) << 60)
 
-/*
- * The following lookup table is intended to be used when a literal string of
- * the number of bytes is required (for example if it needs to be stringified).
- * It can also be used for generic shortcuts of power-of-two sizes.
- * This table is generated using the AWK script below:
- *
- *  BEGIN {
- *      suffix="KMGTPE";
- *      for(i=10; i<64; i++) {
- *          val=2**i;
- *          s=substr(suffix, int(i/10), 1);
- *          n=2**(i%10);
- *          pad=21-int(log(n)/log(10));
- *          printf("#define S_%d%siB %*d\n", n, s, pad, val);
- *      }
- *  }
- */
-
-#define S_1KiB                  1024
-#define S_2KiB                  2048
-#define S_4KiB                  4096
-#define S_8KiB                  8192
-#define S_16KiB                16384
-#define S_32KiB                32768
-#define S_64KiB                65536
-#define S_128KiB              131072
-#define S_256KiB              262144
-#define S_512KiB              524288
-#define S_1MiB               1048576
-#define S_2MiB               2097152
-#define S_4MiB               4194304
-#define S_8MiB               8388608
-#define S_16MiB             16777216
-#define S_32MiB             33554432
-#define S_64MiB             67108864
-#define S_128MiB           134217728
-#define S_256MiB           268435456
-#define S_512MiB           536870912
-#define S_1GiB            1073741824
-#define S_2GiB            2147483648
-#define S_4GiB            4294967296
-#define S_8GiB            8589934592
-#define S_16GiB          17179869184
-#define S_32GiB          34359738368
-#define S_64GiB          68719476736
-#define S_128GiB        137438953472
-#define S_256GiB        274877906944
-#define S_512GiB        549755813888
-#define S_1TiB         1099511627776
-#define S_2TiB         2199023255552
-#define S_4TiB         4398046511104
-#define S_8TiB         8796093022208
-#define S_16TiB       17592186044416
-#define S_32TiB       35184372088832
-#define S_64TiB       70368744177664
-#define S_128TiB     140737488355328
-#define S_256TiB     281474976710656
-#define S_512TiB     562949953421312
-#define S_1PiB      1125899906842624
-#define S_2PiB      2251799813685248
-#define S_4PiB      4503599627370496
-#define S_8PiB      9007199254740992
-#define S_16PiB    18014398509481984
-#define S_32PiB    36028797018963968
-#define S_64PiB    72057594037927936
-#define S_128PiB  144115188075855872
-#define S_256PiB  288230376151711744
-#define S_512PiB  576460752303423488
-#define S_1EiB   1152921504606846976
-#define S_2EiB   2305843009213693952
-#define S_4EiB   4611686018427387904
-#define S_8EiB   9223372036854775808
-
 #endif
diff --git a/scripts/gen-sizes.sh b/scripts/gen-sizes.sh
new file mode 100755
index 0000000000..28fe62a4c2
--- /dev/null
+++ b/scripts/gen-sizes.sh
@@ -0,0 +1,66 @@
+#!/bin/sh
+
+size_suffix() {
+    case ${1} in
+        1)
+            printf "KiB"
+            ;;
+        2)
+            printf "MiB"
+            ;;
+        3)
+            printf "GiB"
+            ;;
+        4)
+            printf "TiB"
+            ;;
+        5)
+            printf "PiB"
+            ;;
+        6)
+            printf "EiB"
+            ;;
+    esac
+}
+
+print_sizes() {
+    local p=10
+    while [ ${p} -lt 64 ]
+    do
+        local pad=' '
+        local n=$((p % 10))
+        n=$((1 << n))
+        [ $((n / 100)) -eq 0 ] && pad='  '
+        [ $((n / 10)) -eq 0 ] && pad='   '
+        local suff=$((p / 10))
+        printf "#define S_%u%s%s%20u\n" ${n} "$(size_suffix ${suff})" \
+            "${pad}" $((1 << p))
+        p=$((p + 1))
+    done
+}
+
+print_header() {
+    cat <<EOF
+/* AUTOMATICALLY GENERATED, DO NOT MODIFY.
+ *
+ * The following lookup table is intended to be used when a literal string of
+ * the number of bytes is required (for example if it needs to be stringified).
+ * It can also be used for generic shortcuts of power-of-two sizes.
+ *
+ * Authors:
+ *   Leonid Bloch  <lbloch@janustech.com>
+ */
+
+#ifndef QEMU_SIZES_H
+#define QEMU_SIZES_H
+
+EOF
+}
+
+print_footer() {
+    printf "\n#endif  /* QEMU_SIZES_H */\n"
+}
+
+print_header  > "${1}"
+print_sizes  >> "${1}"
+print_footer >> "${1}"
-- 
2.20.1