Invalid syntax when using garble to build

[coremedic]

What version of Garble and Go are you using?

$ garble version
mvdan.cc/garble v0.10.1

Build settings:
      -buildmode exe
       -compiler gc
  DefaultGODEBUG panicnil=1
     CGO_ENABLED 1
          GOARCH amd64
            GOOS linux
         GOAMD64 v1

$ go version
go version go1.21.4 linux/amd64

What environment are you running Garble on?

go env Output

$ go env
GO111MODULE=''
GOARCH='amd64'
GOBIN=''
GOCACHE='/home/ben/.cache/go-build'
GOENV='/home/ben/.config/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFLAGS=''
GOHOSTARCH='amd64'
GOHOSTOS='linux'
GOINSECURE=''
GOMODCACHE='/home/ben/.go/pkg/mod'
GONOPROXY=''
GONOSUMDB=''
GOOS='linux'
GOPATH='/home/ben/.go'
GOPRIVATE=''
GOPROXY='https://proxy.golang.org,direct'
GOROOT='/usr/local/go'
GOSUMDB='sum.golang.org'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/usr/local/go/pkg/tool/linux_amd64'
GOVCS=''
GOVERSION='go1.21.4'
GCCGO='gccgo'
GOAMD64='v1'
AR='ar'
CC='gcc'
CXX='g++'
CGO_ENABLED='1'
GOMOD='/home/ben/xShell/badger/go.mod'
GOWORK=''
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
PKG_CONFIG='pkg-config'
GOGCCFLAGS='-fPIC -m64 -pthread -Wl,--no-gc-sections -fmessage-length=0 -ffile-prefix-map=/tmp/go-build987332042=/tmp/go-build -gno-record-gcc-switches'

What did you do?

I have some go assembly code that I am trying to obfuscate, getting an "invalid syntax" error when building. When I build with "go build" my build works fine. Here are some relevant parts of the debug output:

# badger/asm
[garble] transforming asm with args: -p badger/asm -trimpath asm=>badger/asm;/tmp/go-build3214285344/b050=> -I $WORK/b050/ -I /usr/local/go/pkg/include -D GOOS_windows -D GOARCH_amd64 -D GOAMD64_v1 -gensymabis -o $WORK/b050/symabis asm/parser_asm_x64_windows.s asm/syscall_asm_x64_windows.s asm/trampoline_asm_x64_windows.s asm/util_asm_x64_windows.s
[garble] shared cache loaded in 860µs from /tmp/garble-shared2640033168/main-cache.gob
[garble] import path "badger/asm" hashed with 26a2a52d7fc9accf418cde02e0135913eac9c1e8ee188f0514e27cf7af84ec56 to "gsPjuhBO"
invalid syntax

[...]

[garble] transformed args for compile in 4.36ms: -o $WORK/b002/_pkg_.a -trimpath /tmp/garble-shared2640033168=>;/home/ben/xShell/badger/cmd/whoami=>badger/cmd/whoami;/tmp/go-build3214285344/b002=> -p vHMvj_Nzn -lang=go1.21 -complete -buildid MmSW_M4DMY_TAYsT-AKF/MmSW_M4DMY_TAYsT-AKF -goversion go1.21.4 -c=4 -nolocalimports -importcfg /tmp/garble-shared2640033168/importcfg3258481374 -pack -dwarf=false /tmp/garble-shared2640033168/vHMvj_Nzn/whoami.go /tmp/garble-shared2640033168/vHMvj_Nzn/whoami_windows.go
exit status 1

[coremedic]

Resolved my own issue. I had a comment on the same line as my #include

[lu4p]

Still if it builds with go and not garble we should fix it. Can you send in your code so we can reproduce?

[coremedic]

Sorry for the late response, I cant provide the whole context but here is how you could recreate the issue:

Assembly in go program

#include "textflag.h" // THIS COMMENT BREAKS GARBLE

// func ReadByteAtOffset(start uintptr, offset uint32) uint8
TEXT ·readByteAtOffset(SB), NOSPLIT, $0-24
    MOVQ start+0(FP), AX       // Load start into AX
    MOVL offset+8(FP), CX      // Load offset into CX
    ADDQ CX, AX                // Add offset to start
    MOVB (AX), CL              // Read byte from the address in AX
    MOVB CL, ret+16(FP)        // Store the byte in return value
    RET

Comments on the same line as #include will cause an invalid syntax error when building with garble, but is fine with go build

[mvdan]

Thanks @coremedic - that is enough for me to reproduce.