diff options
author | Robert Griesemer <gri@golang.org> | 2016-06-10 10:27:37 -0700 |
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committer | Robert Griesemer <gri@golang.org> | 2016-06-10 17:43:35 +0000 |
commit | e980a3d8856ec3b4f11daa7e5ec417ad4f5c5256 (patch) | |
tree | 31fcb71f069f09b3a818998a513c6b9d50b41b6f /src/go/parser/interface.go | |
parent | fee02d270bf850d5b390000d8545c3609718e9a5 (diff) | |
download | go-e980a3d8856ec3b4f11daa7e5ec417ad4f5c5256.tar.gz go-e980a3d8856ec3b4f11daa7e5ec417ad4f5c5256.zip |
go/parser: document that parse functions need valid token.FileSet
+ panic with explicit error if no file set it provided
(Not providing a file set is invalid use of the API; panic
is the appropriate action rather than returning an error.)
Fixes #16018.
Change-Id: I207f5b2a2e318d65826bdd9522fce46d614c24ee
Reviewed-on: https://go-review.googlesource.com/24010
Run-TryBot: Robert Griesemer <gri@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Diffstat (limited to 'src/go/parser/interface.go')
-rw-r--r-- | src/go/parser/interface.go | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/src/go/parser/interface.go b/src/go/parser/interface.go index c6fd93240a..bff79cab46 100644 --- a/src/go/parser/interface.go +++ b/src/go/parser/interface.go @@ -73,7 +73,7 @@ const ( // // The mode parameter controls the amount of source text parsed and other // optional parser functionality. Position information is recorded in the -// file set fset. +// file set fset, which must not be nil. // // If the source couldn't be read, the returned AST is nil and the error // indicates the specific failure. If the source was read but syntax @@ -82,6 +82,10 @@ const ( // are returned via a scanner.ErrorList which is sorted by file position. // func ParseFile(fset *token.FileSet, filename string, src interface{}, mode Mode) (f *ast.File, err error) { + if fset == nil { + panic("parser.ParseFile: no token.FileSet provided (fset == nil)") + } + // get source text, err := readSource(filename, src) if err != nil { @@ -125,7 +129,8 @@ func ParseFile(fset *token.FileSet, filename string, src interface{}, mode Mode) // // If filter != nil, only the files with os.FileInfo entries passing through // the filter (and ending in ".go") are considered. The mode bits are passed -// to ParseFile unchanged. Position information is recorded in fset. +// to ParseFile unchanged. Position information is recorded in fset, which +// must not be nil. // // If the directory couldn't be read, a nil map and the respective error are // returned. If a parse error occurred, a non-nil but incomplete map and the @@ -169,9 +174,14 @@ func ParseDir(fset *token.FileSet, path string, filter func(os.FileInfo) bool, m // ParseExprFrom is a convenience function for parsing an expression. // The arguments have the same meaning as for Parse, but the source must -// be a valid Go (type or value) expression. +// be a valid Go (type or value) expression. Specifically, fset must not +// be nil. // func ParseExprFrom(fset *token.FileSet, filename string, src interface{}, mode Mode) (ast.Expr, error) { + if fset == nil { + panic("parser.ParseExprFrom: no token.FileSet provided (fset == nil)") + } + // get source text, err := readSource(filename, src) if err != nil { |