1
0
mirror of https://github.com/golang/go synced 2024-11-19 06:14:39 -07:00
go/include
Russ Cox e97b3ab1f9 build: remove tmp dir names from objects, support GOROOT_FINAL again
If we compile a generated file stored in a temporary
directory - let's say /tmp/12345/work/x.c - then by default
6c stores the full path and then the pcln table in the
final binary includes the full path. This makes repeated builds
(using different temporary directories) produce different
binaries, even if the inputs are the same.

In the old 'go tool pack', the P flag specified a prefix to remove
from all stored paths (if present), and cmd/go invoked
'go tool pack grcP $WORK' to remove references to the
temporary work directory.

We've changed the build to avoid pack as much as possible,
under the theory that instead of making pack convert from
.6 to .a, the tools should just write the .a directly and save a
round of I/O.

Instead of going back to invoking pack always, define a common
flag -trimpath in the assemblers, C compilers, and Go compilers,
implemented in liblink, and arrange for cmd/go to use the flag.
Then the object files being written out have the shortened paths
from the start.

While we are here, reimplement pcln support for GOROOT_FINAL.
A build in /tmp/go uses GOROOT=/tmp/go, but if GOROOT_FINAL=/usr/local/go
is set, then a source file named /tmp/go/x.go is recorded instead as
/usr/local/go/x.go. We use this so that we can prepare distributions
to be installed in /usr/local/go without actually working in that
directory. The conversion to liblink deleted all the old file name
handling code, including the GOROOT_FINAL translation.
Bring the GOROOT_FINAL translation back.

Before this CL, using GOROOT_FINAL=/goroot make.bash:

        g% strings $(which go) | grep -c $TMPDIR
        6
        g% strings $(which go) | grep -c $GOROOT
        793
        g%

After this CL:

        g% strings $(which go) | grep -c $TMPDIR
        0
        g% strings $(which go) | grep -c $GOROOT
        0
        g%

(The references to $TMPDIR tend to be cgo-generated source files.)

Adding the -trimpath flag to the assemblers required converting
them to the new Go-semantics flag parser. The text in go1.3.html
is copied and adjusted from go1.1.html, which is when we applied
that conversion to the compilers and linkers.

Fixes #6989.

LGTM=iant
R=r, iant
CC=golang-codereviews
https://golang.org/cl/88300045
2014-04-15 20:46:46 -04:00
..
plan9 cmd/prof, libmach: delete 2014-04-14 11:09:25 -04:00
ar.h gopack: change archive file name length back to 16 2011-11-01 00:29:16 -04:00
bio.h libbio, libmach: warnings from the Plan 9 tool chain 2014-04-07 08:40:13 -07:00
fmt.h convert C runtime to 32-bit runes; 2009-08-31 16:38:50 -07:00
libc.h cmd/dist, cmd/ld: GO_EXTLINK_ENABLED=0 defaults to -linkmode=internal 2013-03-29 16:33:35 -07:00
link.h build: remove tmp dir names from objects, support GOROOT_FINAL again 2014-04-15 20:46:46 -04:00
README include: add a README file 2013-05-22 18:51:15 +08:00
u.h liblink: create new library based on linker code 2013-12-08 22:49:37 -05:00
utf.h add missing include file 2008-06-12 13:31:17 -07:00

The header files under this directory are strictly internal to the gc
toolchain, so please don't copy them to the system include file
directory (/usr/include, /usr/local/include, etc.)

Also note that they must be kept as is in $GOROOT/include, or cmd/dist
will malfunction.