From dc110f245d9469874b17709351ba637a5287f3eb Mon Sep 17 00:00:00 2001 From: Andy Maloney Date: Mon, 3 Aug 2015 09:25:33 -0400 Subject: [PATCH] cmd/cgo: annotate named return struct members in comments If an exported function has named return variables, then show the names as comments in the return struct we create in the header file. Example here: https://groups.google.com/forum/#!topic/golang-nuts/r393ne4zIfY Change-Id: I21fb4ca2673f6977bec35ccab0cef7d42b311f96 Reviewed-on: https://go-review.googlesource.com/13061 Reviewed-by: Ian Lance Taylor Run-TryBot: Ian Lance Taylor TryBot-Result: Gobot Gobot --- src/cmd/cgo/out.go | 56 ++++++++++++++++++++++++++-------------------- 1 file changed, 32 insertions(+), 24 deletions(-) diff --git a/src/cmd/cgo/out.go b/src/cmd/cgo/out.go index 4a371fe702..aaa105d6fd 100644 --- a/src/cmd/cgo/out.go +++ b/src/cmd/cgo/out.go @@ -693,7 +693,7 @@ func (p *Package) writeExports(fgo2, fm, fgcc, fgcch io.Writer) { } fntype := fn.Type forFieldList(fntype.Params, - func(i int, atype ast.Expr) { + func(i int, aname string, atype ast.Expr) { t := p.cgoType(atype) if off%t.Align != 0 { pad := t.Align - off%t.Align @@ -711,7 +711,7 @@ func (p *Package) writeExports(fgo2, fm, fgcc, fgcch io.Writer) { npad++ } forFieldList(fntype.Results, - func(i int, atype ast.Expr) { + func(i int, aname string, atype ast.Expr) { t := p.cgoType(atype) if off%t.Align != 0 { pad := t.Align - off%t.Align @@ -744,8 +744,12 @@ func (p *Package) writeExports(fgo2, fm, fgcc, fgcch io.Writer) { fmt.Fprintf(fgcch, "\n/* Return type for %s */\n", exp.ExpName) fmt.Fprintf(fgcch, "struct %s_return {\n", exp.ExpName) forFieldList(fntype.Results, - func(i int, atype ast.Expr) { - fmt.Fprintf(fgcch, "\t%s r%d;\n", p.cgoType(atype).C, i) + func(i int, aname string, atype ast.Expr) { + fmt.Fprintf(fgcch, "\t%s r%d;", p.cgoType(atype).C, i) + if len(aname) > 0 { + fmt.Fprintf(fgcch, " /* %s */", aname) + } + fmt.Fprint(fgcch, "\n") }) fmt.Fprintf(fgcch, "};\n") gccResult = "struct " + exp.ExpName + "_return" @@ -758,7 +762,7 @@ func (p *Package) writeExports(fgo2, fm, fgcc, fgcch io.Writer) { s += " recv" } forFieldList(fntype.Params, - func(i int, atype ast.Expr) { + func(i int, aname string, atype ast.Expr) { if i > 0 || fn.Recv != nil { s += ", " } @@ -783,7 +787,7 @@ func (p *Package) writeExports(fgo2, fm, fgcc, fgcch io.Writer) { fmt.Fprintf(fgcc, "\ta.recv = recv;\n") } forFieldList(fntype.Params, - func(i int, atype ast.Expr) { + func(i int, aname string, atype ast.Expr) { fmt.Fprintf(fgcc, "\ta.p%d = p%d;\n", i, i) }) fmt.Fprintf(fgcc, "\tcrosscall2(_cgoexp%s_%s, &a, %d);\n", cPrefix, exp.ExpName, off) @@ -792,7 +796,7 @@ func (p *Package) writeExports(fgo2, fm, fgcc, fgcch io.Writer) { fmt.Fprintf(fgcc, "\treturn a.r0;\n") } else { forFieldList(fntype.Results, - func(i int, atype ast.Expr) { + func(i int, aname string, atype ast.Expr) { fmt.Fprintf(fgcc, "\tr.r%d = a.r%d;\n", i, i) }) fmt.Fprintf(fgcc, "\treturn r;\n") @@ -824,7 +828,7 @@ func (p *Package) writeExports(fgo2, fm, fgcc, fgcch io.Writer) { fmt.Fprintf(fgo2, "func %s(recv ", goname) conf.Fprint(fgo2, fset, fn.Recv.List[0].Type) forFieldList(fntype.Params, - func(i int, atype ast.Expr) { + func(i int, aname string, atype ast.Expr) { fmt.Fprintf(fgo2, ", p%d ", i) conf.Fprint(fgo2, fset, atype) }) @@ -832,7 +836,7 @@ func (p *Package) writeExports(fgo2, fm, fgcc, fgcch io.Writer) { if gccResult != "void" { fmt.Fprint(fgo2, " (") forFieldList(fntype.Results, - func(i int, atype ast.Expr) { + func(i int, aname string, atype ast.Expr) { if i > 0 { fmt.Fprint(fgo2, ", ") } @@ -847,7 +851,7 @@ func (p *Package) writeExports(fgo2, fm, fgcc, fgcch io.Writer) { } fmt.Fprintf(fgo2, "recv.%s(", exp.Func.Name) forFieldList(fntype.Params, - func(i int, atype ast.Expr) { + func(i int, aname string, atype ast.Expr) { if i > 0 { fmt.Fprint(fgo2, ", ") } @@ -879,13 +883,13 @@ func (p *Package) writeGccgoExports(fgo2, fm, fgcc, fgcch io.Writer) { cdeclBuf := new(bytes.Buffer) resultCount := 0 forFieldList(fntype.Results, - func(i int, atype ast.Expr) { resultCount++ }) + func(i int, aname string, atype ast.Expr) { resultCount++ }) switch resultCount { case 0: fmt.Fprintf(cdeclBuf, "void") case 1: forFieldList(fntype.Results, - func(i int, atype ast.Expr) { + func(i int, aname string, atype ast.Expr) { t := p.cgoType(atype) fmt.Fprintf(cdeclBuf, "%s", t.C) }) @@ -894,9 +898,13 @@ func (p *Package) writeGccgoExports(fgo2, fm, fgcc, fgcch io.Writer) { fmt.Fprintf(fgcch, "\n/* Return type for %s */\n", exp.ExpName) fmt.Fprintf(fgcch, "struct %s_result {\n", exp.ExpName) forFieldList(fntype.Results, - func(i int, atype ast.Expr) { + func(i int, aname string, atype ast.Expr) { t := p.cgoType(atype) - fmt.Fprintf(fgcch, "\t%s r%d;\n", t.C, i) + fmt.Fprintf(fgcch, "\t%s r%d;", t.C, i) + if len(aname) > 0 { + fmt.Fprintf(fgcch, " /* %s */", aname) + } + fmt.Fprint(fgcch, "\n") }) fmt.Fprintf(fgcch, "};\n") fmt.Fprintf(cdeclBuf, "struct %s_result", exp.ExpName) @@ -911,7 +919,7 @@ func (p *Package) writeGccgoExports(fgo2, fm, fgcc, fgcch io.Writer) { } // Function parameters. forFieldList(fntype.Params, - func(i int, atype ast.Expr) { + func(i int, aname string, atype ast.Expr) { if i > 0 || fn.Recv != nil { fmt.Fprintf(cdeclBuf, ", ") } @@ -956,7 +964,7 @@ func (p *Package) writeGccgoExports(fgo2, fm, fgcc, fgcch io.Writer) { fmt.Fprint(fgcc, "recv") } forFieldList(fntype.Params, - func(i int, atype ast.Expr) { + func(i int, aname string, atype ast.Expr) { if i > 0 || fn.Recv != nil { fmt.Fprintf(fgcc, ", ") } @@ -982,7 +990,7 @@ func (p *Package) writeGccgoExports(fgo2, fm, fgcc, fgcch io.Writer) { printer.Fprint(fgo2, fset, fn.Recv.List[0].Type) } forFieldList(fntype.Params, - func(i int, atype ast.Expr) { + func(i int, aname string, atype ast.Expr) { if i > 0 || fn.Recv != nil { fmt.Fprintf(fgo2, ", ") } @@ -993,7 +1001,7 @@ func (p *Package) writeGccgoExports(fgo2, fm, fgcc, fgcch io.Writer) { if resultCount > 0 { fmt.Fprintf(fgo2, " (") forFieldList(fntype.Results, - func(i int, atype ast.Expr) { + func(i int, aname string, atype ast.Expr) { if i > 0 { fmt.Fprint(fgo2, ", ") } @@ -1013,7 +1021,7 @@ func (p *Package) writeGccgoExports(fgo2, fm, fgcc, fgcch io.Writer) { } fmt.Fprintf(fgo2, "%s(", exp.Func.Name) forFieldList(fntype.Params, - func(i int, atype ast.Expr) { + func(i int, aname string, atype ast.Expr) { if i > 0 { fmt.Fprint(fgo2, ", ") } @@ -1071,19 +1079,19 @@ func (p *Package) gccgoSymbolPrefix() string { } // Call a function for each entry in an ast.FieldList, passing the -// index into the list and the type. -func forFieldList(fl *ast.FieldList, fn func(int, ast.Expr)) { +// index into the list, the name if any, and the type. +func forFieldList(fl *ast.FieldList, fn func(int, string, ast.Expr)) { if fl == nil { return } i := 0 for _, r := range fl.List { if r.Names == nil { - fn(i, r.Type) + fn(i, "", r.Type) i++ } else { - for range r.Names { - fn(i, r.Type) + for _, n := range r.Names { + fn(i, n.Name, r.Type) i++ } } -- 2.48.1