code review 186263: eliminate the package global name space assumption in o...

eliminate the package global name space assumption in object files

5g/6g/8g: add import statements to export metadata, mapping package path to package name.
	recognize "" as the path of the package in export metadata.
	use "" as the path of the package in object symbol names.

5c/6c/8c, 5a/6a/8a: rewrite leading . to "". so that ·Sin means Sin in this package.

5l/6l/8l: rewrite "" in symbol names as object files are read.

gotest: handle new symbol names.

gopack: handle new import lines in export metadata.

Collectively, these changes eliminate the assumption of a global
name space in the object file formats.  Higher level pieces such as
reflect and the computation of type hashes still depend on the
assumption; we're not done yet.

[rsc, 2010-01-21 23:39:40]

Hello ken2, r (cc: golang-dev@googlegroups.com),

I'd like you to review this change.

[ken3, 2010-01-22 00:00:44]

LGTM
On 2010/01/21 23:39:40, rsc wrote:
> Hello ken2, r (cc: mailto:golang-dev@googlegroups.com),
> 
> I'd like you to review this change.

[r, 2010-01-22 00:02:26]

LGTM

http://codereview.appspot.com/186263/diff/1001/1016
File src/cmd/cc/lex.c (right):

http://codereview.appspot.com/186263/diff/1001/1016#newcode419
src/cmd/cc/lex.c:419: memmove(symb+2, symb, w-symb);
i presume there's known to be space

http://codereview.appspot.com/186263/diff/1001/1029
File src/cmd/gc/subr.c (right):

http://codereview.appspot.com/186263/diff/1001/1029#newcode3395
src/cmd/gc/subr.c:3395: if(*r < ' ' || *r == '.' || *r == '%' || *r == '"')
<= ' ' maybe?  they could appear in file names

http://codereview.appspot.com/186263/diff/1001/1029#newcode3405
src/cmd/gc/subr.c:3405: if(*r < ' ' || *r == '.' || *r == '%' || *r == '"') {
ditto

http://codereview.appspot.com/186263/diff/1001/1033
File src/cmd/gotest/gotest (right):

http://codereview.appspot.com/186263/diff/1001/1033#newcode125
src/cmd/gotest/gotest:125: pkg=$(sed -n 's/^ .* in package "\(.*\)".*/\1/p' $i |
sed 1q)
horrible question: is sed always installed?

http://codereview.appspot.com/186263/diff/1001/1035
File src/cmd/ld/lib.c (right):

http://codereview.appspot.com/186263/diff/1001/1035#newcode803
src/cmd/ld/lib.c:803: if(*r < ' ' || *r == '.' || *r == '%' || *r == '"')
again maybe <= ' ' here and below

[rsc, 2010-01-23 00:13:33]

> http://codereview.appspot.com/186263/diff/1001/1033#newcode125
> src/cmd/gotest/gotest:125: pkg=$(sed -n 's/^ .* in package
> "\(.*\)".*/\1/p' $i | sed 1q)
> horrible question: is sed always installed?

yes.  we use it in many other places too.

[rsc, 2010-01-23 01:06:24]

*** Submitted as http://code.google.com/p/go/source/detail?r=ac4d67277b86 ***

eliminate the package global name space assumption in object files

5g/6g/8g: add import statements to export metadata, mapping package path to
package name.
	recognize "" as the path of the package in export metadata.
	use "" as the path of the package in object symbol names.

5c/6c/8c, 5a/6a/8a: rewrite leading . to "". so that ·Sin means Sin in this
package.

5l/6l/8l: rewrite "" in symbol names as object files are read.

gotest: handle new symbol names.

gopack: handle new import lines in export metadata.

Collectively, these changes eliminate the assumption of a global
name space in the object file formats.  Higher level pieces such as
reflect and the computation of type hashes still depend on the
assumption; we're not done yet.

R=ken2, r, ken3
CC=golang-dev
http://codereview.appspot.com/186263

Committer: Russ Cox <rsc@golang.org>