[U-Boot] [PATCH v2] Enable expression support for CONFIG_BOARD_SIZE_LIMIT

[Wolfgang Denk <wd@denx.de>]

So far, the use of CONFIG_BOARD_SIZE_LIMIT would only work with
plain numeric constants.  Extend it to allow for expressions, so one
can for example use

	#define CONFIG_BOARD_SIZE_LIMIT	(768 << 10)

in the board configuration.

Signed-off-by: Wolfgang Denk <wd@denx.de>
Tested-by: Fabio Estevam <festevam@gmail.com>

Cc: Fabio Estevam <festevam@gmail.com>
Cc: Stefano Babic <sbabic@denx.de>
Cc: Vanessa Maegima <vanessa.maegima@nxp.com>
Cc: Otavio Salvador <otavio@ossystems.com.br>
Cc: John Weber <john.weber@technexion.com>
Cc: Stefan Roese <sr@denx.de>
---
v2: replace bashism for evaluating expressions in CONFIG_BOARD_SIZE_LIMIT
    by another call to awk.

Note 1: As gawk lacks an eval function and we don't want to rely on
 bash being used as shell, we use another call to awk to evaluate the
 expression. This has the disadvantage that we cannot use expressions
 like "<<" which awk does not understand. OK, one could replace awk
 by something better...

Note 2: This patch focusses on enabling this new feature.  It does
 not addres another issue that should be solved in a later
 commit: the duplication of the same code in Makefile and
 arch/arm/mach-imx/Makefile

---
 Makefile                   | 17 ++++++++---------
 arch/arm/mach-imx/Makefile | 17 ++++++++---------
 2 files changed, 16 insertions(+), 18 deletions(-)

diff --git a/Makefile b/Makefile
index 0d11ff9797..87eb0fd2b1 100644
--- a/Makefile
+++ b/Makefile
@@ -774,15 +774,14 @@ LDPPFLAGS += \
 
 ifneq ($(CONFIG_BOARD_SIZE_LIMIT),)
 BOARD_SIZE_CHECK = \
-	@actual=`wc -c $@ | awk '{print $$1}'`; \
-	limit=`printf "%d" $(CONFIG_BOARD_SIZE_LIMIT)`; \
-	if test $$actual -gt $$limit; then \
-		echo "$@ exceeds file size limit:" >&2 ; \
-		echo "  limit:  $$limit bytes" >&2 ; \
-		echo "  actual: $$actual bytes" >&2 ; \
-		echo "  excess: $$((actual - limit)) bytes" >&2; \
-		exit 1; \
-	fi
+	@(awk "END{print $$(echo $(CONFIG_BOARD_SIZE_LIMIT))}" /dev/null; wc -c $@ ) | \
+	awk 'BEGIN { getline limit } \
+	{ if ($$1 > limit) { \
+		printf "%s exceeds file size limit:\n", $$2; \
+		printf "  limit:  %d bytes\n", limit; \
+		printf "  actual: %d bytes\n", $$1; \
+		printf "  excess: %d bytes\n", $$1 - limit; \
+		exit 1; } }'
 else
 BOARD_SIZE_CHECK =
 endif
diff --git a/arch/arm/mach-imx/Makefile b/arch/arm/mach-imx/Makefile
index 53d9e5f42b..36d1ecc732 100644
--- a/arch/arm/mach-imx/Makefile
+++ b/arch/arm/mach-imx/Makefile
@@ -60,15 +60,14 @@ endif
 
 ifneq ($(CONFIG_BOARD_SIZE_LIMIT),)
 BOARD_SIZE_CHECK = \
-        @actual=`wc -c $@ | awk '{print $$1}'`; \
-        limit=`printf "%d" $(CONFIG_BOARD_SIZE_LIMIT)`; \
-        if test $$actual -gt $$limit; then \
-                echo "$@ exceeds file size limit:" >&2 ; \
-                echo "  limit:  $$limit bytes" >&2 ; \
-                echo "  actual: $$actual bytes" >&2 ; \
-                echo "  excess: $$((actual - limit)) bytes" >&2; \
-                exit 1; \
-        fi
+	@(awk "END{print $$(echo $(CONFIG_BOARD_SIZE_LIMIT))}" /dev/null; wc -c $@ ) | \
+	awk 'BEGIN { getline limit } \
+	{ if ($$1 > limit) { \
+		printf "%s exceeds file size limit:\n", $$2; \
+		printf "  limit:  %d bytes\n", limit; \
+		printf "  actual: %d bytes\n", $$1; \
+		printf "  excess: %d bytes\n", $$1 - limit; \
+		exit 1; } }'
 else
 BOARD_SIZE_CHECK =
 endif
-- 
2.19.2