Commit b8b0618cf6fab3bd5b1da8c72f4b29847d81ac42
Committed by
Sam Ravnborg
Sam Ravnborg
1 parent
3e56f08bff
Exists in
master
and in
7 other branches
kbuild: remove extra ifdef/endif of top Makefile
The GNU make's origin function know undefined variable well,
so the outer ifdef/endif conditional checking is unneeded.
From `info make` documentation, origin will return
`undefined'
if VARIABLE was never defined.
`command line'
if VARIABLE was defined on the command line.
...
Therefore, $(origin V) will get a value anyway, killing ifdef/endif is
viable and safe.
Furthermore, I've checked the minimal requirements from
Documentation/Changes is GNU make 3.79.1, and that version of GNU make
has support of origin function well already, so now it's safe to kill
the outer conditional checking, without upgrading the minimal
requirements.
Signed-off-by: Cheng Renquan <crq@kernel.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Showing 1 changed file with 9 additions and 17 deletions Side-by-side Diff
Makefile
| ... | ... | @@ -35,10 +35,8 @@ |
| 35 | 35 | # To put more focus on warnings, be less verbose as default |
| 36 | 36 | # Use 'make V=1' to see the full commands |
| 37 | 37 | |
| 38 | -ifdef V | |
| 39 | - ifeq ("$(origin V)", "command line") | |
| 40 | - KBUILD_VERBOSE = $(V) | |
| 41 | - endif | |
| 38 | +ifeq ("$(origin V)", "command line") | |
| 39 | + KBUILD_VERBOSE = $(V) | |
| 42 | 40 | endif |
| 43 | 41 | ifndef KBUILD_VERBOSE |
| 44 | 42 | KBUILD_VERBOSE = 0 |
| ... | ... | @@ -54,10 +52,8 @@ |
| 54 | 52 | # See the file "Documentation/sparse.txt" for more details, including |
| 55 | 53 | # where to get the "sparse" utility. |
| 56 | 54 | |
| 57 | -ifdef C | |
| 58 | - ifeq ("$(origin C)", "command line") | |
| 59 | - KBUILD_CHECKSRC = $(C) | |
| 60 | - endif | |
| 55 | +ifeq ("$(origin C)", "command line") | |
| 56 | + KBUILD_CHECKSRC = $(C) | |
| 61 | 57 | endif |
| 62 | 58 | ifndef KBUILD_CHECKSRC |
| 63 | 59 | KBUILD_CHECKSRC = 0 |
| 64 | 60 | |
| ... | ... | @@ -69,13 +65,11 @@ |
| 69 | 65 | ifdef SUBDIRS |
| 70 | 66 | KBUILD_EXTMOD ?= $(SUBDIRS) |
| 71 | 67 | endif |
| 72 | -ifdef M | |
| 73 | - ifeq ("$(origin M)", "command line") | |
| 74 | - KBUILD_EXTMOD := $(M) | |
| 75 | - endif | |
| 68 | + | |
| 69 | +ifeq ("$(origin M)", "command line") | |
| 70 | + KBUILD_EXTMOD := $(M) | |
| 76 | 71 | endif |
| 77 | 72 | |
| 78 | - | |
| 79 | 73 | # kbuild supports saving output files in a separate directory. |
| 80 | 74 | # To locate output files in a separate directory two syntaxes are supported. |
| 81 | 75 | # In both cases the working directory must be the root of the kernel src. |
| ... | ... | @@ -98,10 +92,8 @@ |
| 98 | 92 | |
| 99 | 93 | # OK, Make called in directory where kernel src resides |
| 100 | 94 | # Do we want to locate output files in a separate directory? |
| 101 | -ifdef O | |
| 102 | - ifeq ("$(origin O)", "command line") | |
| 103 | - KBUILD_OUTPUT := $(O) | |
| 104 | - endif | |
| 95 | +ifeq ("$(origin O)", "command line") | |
| 96 | + KBUILD_OUTPUT := $(O) | |
| 105 | 97 | endif |
| 106 | 98 | |
| 107 | 99 | # That's our default target when none is given on the command line |