esp32 emulator: float output still missing (and struczero timeout) for alias/multiret/cpkgimp/struczero

[luoliwoshang]

Summary

On current main, running the same float-related cases from #1664 on esp32 (xtensa emulator) still fails.

esp32c3-basic now passes these cases, but esp32 does not.

Reproduction

Run cases one by one with ESP32 emulator target:

llgo run -a -target=esp32 -emulator ./cl/_testgo/alias
llgo run -a -target=esp32 -emulator ./cl/_testgo/multiret
llgo run -a -target=esp32 -emulator ./cl/_testgo/struczero
llgo run -a -target=esp32 -emulator ./cl/_testdata/cpkgimp

Actual behavior (esp32)

1. ./cl/_testgo/alias

   • got: blank output line
   • expect: +5.000000e+00 +8.000000e+00

2. ./cl/_testgo/multiret

   • got: 1
   • expect: 1 +2.000000e+00

3. ./cl/_testgo/struczero

   • got: no expected output; run did not finish within 240s in local check
   • expect:
     • 0x0 +0.000000e+00 notOk: true
     • 0x0 +0.000000e+00 true

4. ./cl/_testdata/cpkgimp

   • got: 3
   • expect: 3 +6.280000e+00

Comparison

With the same environment and same cases, esp32c3-basic outputs are correct and the runs finish.

Notes

A local quick test with temporary target override --undefined=_printf_float on esp32 led to link error:

undefined symbol: __fpclassifyd
referenced by nano-vfprintf_float.c ... in libc-xtensa.a

which suggests xtensa-side float printf support is still not fully wired.