diff options
Diffstat (limited to 'cgo')
| -rw-r--r-- | cgo/cgo.go | 53 | ||||
| -rw-r--r-- | cgo/libclang.go | 10 | ||||
| -rw-r--r-- | cgo/testdata/errors.go | 5 | ||||
| -rw-r--r-- | cgo/testdata/errors.out.go | 17 | ||||
| -rw-r--r-- | cgo/testdata/symbols.go | 5 | ||||
| -rw-r--r-- | cgo/testdata/symbols.out.go | 5 |
6 files changed, 87 insertions, 8 deletions
diff --git a/cgo/cgo.go b/cgo/cgo.go index 0ed26e3fb..cb822a38e 100644 --- a/cgo/cgo.go +++ b/cgo/cgo.go @@ -18,6 +18,7 @@ import ( "go/scanner" "go/token" "path/filepath" + "sort" "strconv" "strings" @@ -42,6 +43,7 @@ type cgoPackage struct { fset *token.FileSet tokenFiles map[string]*token.File definedGlobally map[string]ast.Node + noescapingFuncs map[string]*noescapingFunc // #cgo noescape lines anonDecls map[interface{}]string cflags []string // CFlags from #cgo lines ldflags []string // LDFlags from #cgo lines @@ -80,6 +82,13 @@ type bitfieldInfo struct { endBit int64 // may be 0 meaning "until the end of the field" } +// Information about a #cgo noescape line in the source code. +type noescapingFunc struct { + name string + pos token.Pos + used bool // true if used somewhere in the source (for proper error reporting) +} + // cgoAliases list type aliases between Go and C, for types that are equivalent // in both languages. See addTypeAliases. var cgoAliases = map[string]string{ @@ -255,6 +264,7 @@ func Process(files []*ast.File, dir, importPath string, fset *token.FileSet, cfl fset: fset, tokenFiles: map[string]*token.File{}, definedGlobally: map[string]ast.Node{}, + noescapingFuncs: map[string]*noescapingFunc{}, anonDecls: map[interface{}]string{}, visitedFiles: map[string][]byte{}, } @@ -418,6 +428,22 @@ func Process(files []*ast.File, dir, importPath string, fset *token.FileSet, cfl }) } + // Show an error when a #cgo noescape line isn't used in practice. + // This matches upstream Go. I think the goal is to avoid issues with + // misspelled function names, which seems very useful. + var unusedNoescapeLines []*noescapingFunc + for _, value := range p.noescapingFuncs { + if !value.used { + unusedNoescapeLines = append(unusedNoescapeLines, value) + } + } + sort.SliceStable(unusedNoescapeLines, func(i, j int) bool { + return unusedNoescapeLines[i].pos < unusedNoescapeLines[j].pos + }) + for _, value := range unusedNoescapeLines { + p.addError(value.pos, fmt.Sprintf("function %#v in #cgo noescape line is not used", value.name)) + } + // Print the newly generated in-memory AST, for debugging. //ast.Print(fset, p.generated) @@ -483,6 +509,33 @@ func (p *cgoPackage) parseCGoPreprocessorLines(text string, pos token.Pos) strin } text = text[:lineStart] + string(spaces) + text[lineEnd:] + allFields := strings.Fields(line[4:]) + switch allFields[0] { + case "noescape": + // The code indicates that pointer parameters will not be captured + // by the called C function. + if len(allFields) < 2 { + p.addErrorAfter(pos, text[:lineStart], "missing function name in #cgo noescape line") + continue + } + if len(allFields) > 2 { + p.addErrorAfter(pos, text[:lineStart], "multiple function names in #cgo noescape line") + continue + } + name := allFields[1] + p.noescapingFuncs[name] = &noescapingFunc{ + name: name, + pos: pos, + used: false, + } + continue + case "nocallback": + // We don't do anything special when calling a C function, so there + // appears to be no optimization that we can do here. + // Accept, but ignore the parameter for compatibility. + continue + } + // Get the text before the colon in the #cgo directive. colon := strings.IndexByte(line, ':') if colon < 0 { diff --git a/cgo/libclang.go b/cgo/libclang.go index 794d4e81f..54ff9f53f 100644 --- a/cgo/libclang.go +++ b/cgo/libclang.go @@ -256,10 +256,18 @@ func (f *cgoFile) createASTNode(name string, c clangCursor) (ast.Node, any) { }, }, } + var doc []string if C.clang_isFunctionTypeVariadic(cursorType) != 0 { + doc = append(doc, "//go:variadic") + } + if _, ok := f.noescapingFuncs[name]; ok { + doc = append(doc, "//go:noescape") + f.noescapingFuncs[name].used = true + } + if len(doc) != 0 { decl.Doc.List = append(decl.Doc.List, &ast.Comment{ Slash: pos - 1, - Text: "//go:variadic", + Text: strings.Join(doc, "\n"), }) } for i := 0; i < numArgs; i++ { diff --git a/cgo/testdata/errors.go b/cgo/testdata/errors.go index 75828ce0f..8813f83cf 100644 --- a/cgo/testdata/errors.go +++ b/cgo/testdata/errors.go @@ -10,6 +10,11 @@ typedef struct { typedef someType noType; // undefined type +// Some invalid noescape lines +#cgo noescape +#cgo noescape foo bar +#cgo noescape unusedFunction + #define SOME_CONST_1 5) // invalid const syntax #define SOME_CONST_2 6) // const not used (so no error) #define SOME_CONST_3 1234 // const too large for byte diff --git a/cgo/testdata/errors.out.go b/cgo/testdata/errors.out.go index cbac4fceb..e0f7d1f54 100644 --- a/cgo/testdata/errors.out.go +++ b/cgo/testdata/errors.out.go @@ -1,14 +1,17 @@ // CGo errors: +// testdata/errors.go:14:1: missing function name in #cgo noescape line +// testdata/errors.go:15:1: multiple function names in #cgo noescape line // testdata/errors.go:4:2: warning: some warning // testdata/errors.go:11:9: error: unknown type name 'someType' -// testdata/errors.go:26:5: warning: another warning -// testdata/errors.go:13:23: unexpected token ), expected end of expression -// testdata/errors.go:21:26: unexpected token ), expected end of expression -// testdata/errors.go:16:33: unexpected token ), expected end of expression -// testdata/errors.go:17:34: unexpected token ), expected end of expression +// testdata/errors.go:31:5: warning: another warning +// testdata/errors.go:18:23: unexpected token ), expected end of expression +// testdata/errors.go:26:26: unexpected token ), expected end of expression +// testdata/errors.go:21:33: unexpected token ), expected end of expression +// testdata/errors.go:22:34: unexpected token ), expected end of expression // -: unexpected token INT, expected end of expression -// testdata/errors.go:30:35: unexpected number of parameters: expected 2, got 3 -// testdata/errors.go:31:31: unexpected number of parameters: expected 2, got 1 +// testdata/errors.go:35:35: unexpected number of parameters: expected 2, got 3 +// testdata/errors.go:36:31: unexpected number of parameters: expected 2, got 1 +// testdata/errors.go:3:1: function "unusedFunction" in #cgo noescape line is not used // Type checking errors after CGo processing: // testdata/errors.go:102: cannot use 2 << 10 (untyped int constant 2048) as C.char value in variable declaration (overflows) diff --git a/cgo/testdata/symbols.go b/cgo/testdata/symbols.go index fb585c2f8..c8029a148 100644 --- a/cgo/testdata/symbols.go +++ b/cgo/testdata/symbols.go @@ -9,6 +9,10 @@ static void staticfunc(int x); // Global variable signatures. extern int someValue; + +void notEscapingFunction(int *a); + +#cgo noescape notEscapingFunction */ import "C" @@ -18,6 +22,7 @@ func accessFunctions() { C.variadic0() C.variadic2(3, 5) C.staticfunc(3) + C.notEscapingFunction(nil) } func accessGlobals() { diff --git a/cgo/testdata/symbols.out.go b/cgo/testdata/symbols.out.go index b49150e60..2ca80c1e6 100644 --- a/cgo/testdata/symbols.out.go +++ b/cgo/testdata/symbols.out.go @@ -75,5 +75,10 @@ func C.staticfunc!symbols.go(x C.int) var C.staticfunc!symbols.go$funcaddr unsafe.Pointer +//export notEscapingFunction +//go:noescape +func C.notEscapingFunction(a *C.int) + +var C.notEscapingFunction$funcaddr unsafe.Pointer //go:extern someValue var C.someValue C.int |