Codegen error on const: ...extra brace group...

[zevv]

The following snippet causes illegal C code with nim c

type

  Opcode = enum
    iChar, iSet

  Inst = object
    case code: Opcode
      of iChar:
        c: char
      of iSet:
        cs: set[char]

  Patt* = seq[Inst]


proc `$`*(p: Patt): string =
  discard

proc P*(): Patt =
  result.add Inst(code: iSet)


const a = P()
echo a

Result:

Error: execution of an external compiler program 'gcc -c  -w  -I/home/ico/external/Nim/lib -I/tmp -o /home/ico/.cache/nim/bug_d/bug.c.o /home/ico/.cache/nim/bug_d/bug.c' failed with exit code: 1

/home/ico/.cache/nim/bug_d/bug.c:83:112: error: extra brace group at end of initializer
 } TM_rmH9bpP9b3ZIjFP4QhigizlA_2 = {{1, 1 | NIM_STRLIT_FLAG}, {{((tyEnum_Opcode_mDyAPYE0BEyHnksFSG9bR0w) 1), 0, {
                                                                                                                ^
/home/ico/.cache/nim/bug_d/bug.c:83:112: note: (near initialization for ‘TM_rmH9bpP9b3ZIjFP4QhigizlA_2.data[0]’)

Versions:

$ nim -v
Nim Compiler Version 0.19.9 [Linux: amd64]
Compiled at 2019-03-09
Copyright (c) 2006-2019 by Andreas Rumpf

git hash: b9f8528db675927aacc6443ae3a363711bb41945
active boot switches: -d:release

$ gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/8/lto-wrapper
OFFLOAD_TARGET_NAMES=nvptx-none
OFFLOAD_TARGET_DEFAULT=1
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Debian 8.3.0-2' --with-bugurl=file:///usr/share/doc/gcc-8/README.Bugs --enable-languages=c,ada,c++,go,brig,d,fortran,objc,obj-c++ --prefix=/usr --with-gcc-major-version-only --program-suffix=-8 --program-prefix=x86_64-linux-gnu- --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --libdir=/usr/lib --enable-nls --enable-bootstrap --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-gnu-unique-object --disable-vtable-verify --enable-libmpx --enable-plugin --enable-default-pie --with-system-zlib --with-target-system-zlib --enable-objc-gc=auto --enable-multiarch --disable-werror --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic --enable-offload-targets=nvptx-none --without-cuda-driver --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 8.3.0 (Debian 8.3.0-2) 

[deech]

Possibly related. #9622

[zevv]

And another example, might or might not be related:

type CharSet {.union.} = object 
  cs: set[char]
  vs: array[4, uint64]

const a = Charset(cs: {'a'..'z'})
echo a.repr

[timotheecour]

based on #15696 this is architecture specific

[timotheecour]

• test case for top example was merged in close #15696 #17518
• test case for Codegen error on const: ...extra brace group... #10815 (comment) still needs a PR (last i checked in close #10815 #15696, it worked in osx, but not linux or windows)

[ringabout]

type CharSet {.union.} = object 
  cs: set[char]
  vs: array[4, uint64]

const a = Charset(cs: {'a'..'z'})
echo a.repr

is a different issue. {.union.} pragma is actually ignored on NimVM => #13481

[ringabout]

The first case has been already added to test cases.