C float and double not implemented

[Mossaka]

How to reproduce

package main

// #include <stdlib.h>
import "C"
import "fmt"

func FromCFloat(x C.float) float32 {
	return float32(x)
}

func main() {
	res := FromCFloat(C.float(1.0))
	fmt.Println(res)
}

(base) ➜  tinygo-float-repro go run main.go
# command-line-arguments
ld: warning: -no_pie is deprecated when targeting new OS versions
1
(base) ➜  tinygo-float-repro tinygo run main.go
# command-line-arguments
main.go:7:19: undeclared name: C.float
main.go:12:20: undeclared name: C.float

[dgryski]

Probably some missing aliases here: https://github.com/tinygo-org/tinygo/blob/release/cgo/cgo.go

[aykevl]

Indeed, those aliases are simply missing and are trivial to add.

However, you don't generally need them in TinyGo because C float is the same as Go float32 and C double is the same as Go float64.

[dgryski]

Hmm...

diff --git a/cgo/cgo.go b/cgo/cgo.go
index dfdd223e..af9fa9f7 100644
--- a/cgo/cgo.go
+++ b/cgo/cgo.go
@@ -86,6 +86,8 @@ var cgoAliases = map[string]string{
        "C.uint32_t":  "uint32",
        "C.uint64_t":  "uint64",
        "C.uintptr_t": "uintptr",
+       "C.float":     "float32",
+       "C.double":    "float64",
 }

Doesn't seem to work.

~/go/src/github.com/dgryski/bug $ tinygo run bug.go
# command-line-arguments
bug.go:7:19: undeclared name: C.float
bug.go:12:20: undeclared name: C.float

Is there something else that needs to know about them?

[aykevl]

Here is a fix: #3210. Adding them was a little bit less trivial than I expected.

[deadprogram]

0.27.0 has now been released, so closing. Thank you!