diff options
-rw-r--r-- | Documentation/kbuild/makefiles.txt | 14 | ||||
-rw-r--r-- | scripts/Kbuild.include | 8 |
2 files changed, 21 insertions, 1 deletions
diff --git a/Documentation/kbuild/makefiles.txt b/Documentation/kbuild/makefiles.txt index 7847fce13bd6..71c602d61680 100644 --- a/Documentation/kbuild/makefiles.txt +++ b/Documentation/kbuild/makefiles.txt | |||
@@ -18,6 +18,7 @@ This document describes the Linux kernel Makefiles. | |||
18 | --- 3.9 Dependency tracking | 18 | --- 3.9 Dependency tracking |
19 | --- 3.10 Special Rules | 19 | --- 3.10 Special Rules |
20 | --- 3.11 $(CC) support functions | 20 | --- 3.11 $(CC) support functions |
21 | --- 3.12 $(LD) support functions | ||
21 | 22 | ||
22 | === 4 Host Program support | 23 | === 4 Host Program support |
23 | --- 4.1 Simple Host Program | 24 | --- 4.1 Simple Host Program |
@@ -570,6 +571,19 @@ more details, with real examples. | |||
570 | endif | 571 | endif |
571 | endif | 572 | endif |
572 | 573 | ||
574 | --- 3.12 $(LD) support functions | ||
575 | |||
576 | ld-option | ||
577 | ld-option is used to check if $(LD) supports the supplied option. | ||
578 | ld-option takes two options as arguments. | ||
579 | The second argument is an optional option that can be used if the | ||
580 | first option is not supported by $(LD). | ||
581 | |||
582 | Example: | ||
583 | #Makefile | ||
584 | LDFLAGS_vmlinux += $(call really-ld-option, -X) | ||
585 | |||
586 | |||
573 | === 4 Host Program support | 587 | === 4 Host Program support |
574 | 588 | ||
575 | Kbuild supports building executables on the host for use during the | 589 | Kbuild supports building executables on the host for use during the |
diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include index 94a4f682f385..b3452601b0b1 100644 --- a/scripts/Kbuild.include +++ b/scripts/Kbuild.include | |||
@@ -83,11 +83,12 @@ TMPOUT := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/) | |||
83 | # is automatically cleaned up. | 83 | # is automatically cleaned up. |
84 | try-run = $(shell set -e; \ | 84 | try-run = $(shell set -e; \ |
85 | TMP="$(TMPOUT).$$$$.tmp"; \ | 85 | TMP="$(TMPOUT).$$$$.tmp"; \ |
86 | TMPO="$(TMPOUT).$$$$.o"; \ | ||
86 | if ($(1)) >/dev/null 2>&1; \ | 87 | if ($(1)) >/dev/null 2>&1; \ |
87 | then echo "$(2)"; \ | 88 | then echo "$(2)"; \ |
88 | else echo "$(3)"; \ | 89 | else echo "$(3)"; \ |
89 | fi; \ | 90 | fi; \ |
90 | rm -f "$$TMP") | 91 | rm -f "$$TMP" "$$TMPO") |
91 | 92 | ||
92 | # as-option | 93 | # as-option |
93 | # Usage: cflags-y += $(call as-option,-Wa$(comma)-isa=foo,) | 94 | # Usage: cflags-y += $(call as-option,-Wa$(comma)-isa=foo,) |
@@ -135,6 +136,11 @@ cc-ifversion = $(shell [ $(call cc-version, $(CC)) $(1) $(2) ] && echo $(3)) | |||
135 | cc-ldoption = $(call try-run,\ | 136 | cc-ldoption = $(call try-run,\ |
136 | $(CC) $(1) -nostdlib -xc /dev/null -o "$$TMP",$(1),$(2)) | 137 | $(CC) $(1) -nostdlib -xc /dev/null -o "$$TMP",$(1),$(2)) |
137 | 138 | ||
139 | # ld-option | ||
140 | # Usage: LDFLAGS += $(call ld-option, -X) | ||
141 | ld-option = $(call try-run,\ | ||
142 | $(CC) /dev/null -c -o "$$TMPO" ; $(LD) $(1) "$$TMPO" -o "$$TMP",$(1),$(2)) | ||
143 | |||
138 | ###### | 144 | ###### |
139 | 145 | ||
140 | ### | 146 | ### |