Small Request for review: 7005007 - Refine use of ALT_COMPILER_PATH to avoid conflict with JPRT usage

[Kelly O'Hair]

On Dec 7, 2010, at 3:26 AM, David Holmes wrote:

> Simple fix to avoid conflicting use of ALT_COMPILER_PATH.
>
> http://cr.openjdk.java.net/~dholmes/7005007/
>
> Tested with JPRT linux builds and doing an internal cross-compile  
> build.
>
> Thanks,
> David Holmes

IF nm doesn't exist, then this shell script will fail, but return exit  
code 0, and the makefile
will not stop but create a bogus mapfile, which may or may not allow  
libjvm.so to link.
I think this shell script needs to use 'set -e' or do something like  
(nm || exit 1) | awk
or maybe both.  Can we fix this shell script?

In addition. I'd like to see some makefile verifications that the  
tools actually exist, something like

# Check fullpath tool
define filecheck # fullpath
$(if $(wildcard $1),$1,$(error "ERROR: File does not exist: $1"))
endef

# Check tools
ifdef CROSS_COMPILE_ARCH
   ifdef ALT_COMPILER_PATH
     CC      := $(call filecheck,$(ALT_COMPILER_PATH)/gcc)
     CPP    := $(call filecheck,$(ALT_COMPILER_PATH)/g++)
     NM     := $(call filecheck,$(ALT_COMPILER_PATH)/nm)
     STRIP := $(call filecheck,$(ALT_COMPILER_PATH)/strip)
   endif
endif

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We also need to make sure we document this in the README-builds.html  
file, but that can be
done some other time since it is in a different repository..

-kto