go/misc/cgo
Robert Griesemer 2a5cf48f91 cmd/compile: print columns (not just lines) in error messages
Compiler errors now show the exact line and line byte offset (sometimes
called "column") of where an error occured. For `go tool compile x.go`:

	package p
	const c int = false
	//line foo.go:123
	type t intg

reports

	x.go:2:7: cannot convert false to type int
	foo.go:123[x.go:4:8]: undefined: intg

(Some errors use the "wrong" position for the error message; arguably
the byte offset for the first error should be 15, the position of 'false',
rathen than 7, the position of 'c'. But that is an indepedent issue.)

The byte offset (column) values are measured in bytes; they start at 1,
matching the convention used by editors and IDEs.

Positions modified by //line directives show the line offset only for the
actual source location (in square brackets), not for the "virtual" file and
line number because that code is likely generated and the //line directive
only provides line information.

Because the new format might break existing tools or scripts, printing
of line offsets can be disabled with the new compiler flag -C. We plan
to remove this flag eventually.

Fixes #10324.

Change-Id: I493f5ee6e78457cf7b00025aba6b6e28e50bb740
Reviewed-on: https://go-review.googlesource.com/37970
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-03-09 23:29:49 +00:00
..
errors cmd/compile: print columns (not just lines) in error messages 2017-03-09 23:29:49 +00:00
fortran misc/cgo/fortran: fix gfortran compile test 2016-05-04 15:08:16 +00:00
gmp all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
life all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
nocgo cmd/ld: really import runtime/cgo for external link 2014-05-20 21:36:50 -07:00
stdio all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
test misc/cgo/test: pass current environment to syscall.Exec 2017-01-20 21:12:54 +00:00
testasan runtime: more flexible heap memory mapping on 64-bits 2013-06-12 18:47:16 +04:00
testcarchive misc/cgo/testcarchive: add missing header 2017-03-09 16:42:46 +00:00
testcshared misc/cgo/testcshared: wait up to 1 second in main2.c 2016-12-20 05:06:55 +00:00
testgodefs cmd/cgo: add -srcdir option 2016-10-30 19:14:08 +00:00
testplugin runtime: for plugins, don't add duplicate itabs 2017-01-17 22:37:19 +00:00
testsanitizers runtime/cgo: return correct sa_flags 2017-03-09 18:53:35 +00:00
testshared misc/cgo/testshared: remove unused flag.Parse() 2017-02-02 13:40:16 +00:00
testsigfwd misc/cgo/testsigfwd: add missing return statement 2016-08-30 21:44:14 +00:00
testso cmd/dist: convert testso test into Go 2015-06-12 04:33:50 +00:00
testsovar misc/cgo/testsovar: needs the `extern` keyword to export variables on non-windows platforms 2015-07-21 18:10:57 +00:00
testtls all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00