WASM is broken

[uncomputable]

It looks like we broke WASM in c22f9de.

cargo build --target wasm32-unknown-unknown stops working after this commit.

It looks like secp256k1-zkp includes a problematic printf statement.

The following warnings were emitted during compilation:

warning: secp256k1-zkp-sys@0.10.0: In file included from depend/secp256k1/src/secp256k1.c:23:
warning: secp256k1-zkp-sys@0.10.0: In file included from depend/secp256k1/src/assumptions.h:12:
warning: secp256k1-zkp-sys@0.10.0: depend/secp256k1/src/util.h:30:5: error: call to undeclared library function 'printf' with type 'int (const char *, ...)'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
warning: secp256k1-zkp-sys@0.10.0:     printf("{");
warning: secp256k1-zkp-sys@0.10.0:     ^
warning: secp256k1-zkp-sys@0.10.0: depend/secp256k1/src/util.h:30:5: note: include the header <stdio.h> or explicitly provide a declaration for 'printf'
warning: secp256k1-zkp-sys@0.10.0: 1 error generated.

error: failed to run custom build command for `secp256k1-zkp-sys v0.10.0`

Caused by:
  process didn't exit successfully: `/home/user/Documents/blockstream/simplicity/rust/target/debug/build/secp256k1-zkp-sys-0b7c6fc4cb93b432/build-script-build` (exit status: 1)
  --- stdout
  TARGET = Some("wasm32-unknown-unknown")
  OPT_LEVEL = Some("0")
  HOST = Some("x86_64-unknown-linux-gnu")
  cargo:rerun-if-env-changed=CC_wasm32-unknown-unknown
  CC_wasm32-unknown-unknown = None
  cargo:rerun-if-env-changed=CC_wasm32_unknown_unknown
  CC_wasm32_unknown_unknown = Some("/nix/store/a5hh7zbxh9d6xchvqv9agr29yghgr7mj-clang-16.0.6/bin/clang-16")
  cargo:rerun-if-env-changed=CRATE_CC_NO_DEFAULTS
  CRATE_CC_NO_DEFAULTS = None
  DEBUG = Some("true")
  cargo:rerun-if-env-changed=CFLAGS_wasm32-unknown-unknown
  CFLAGS_wasm32-unknown-unknown = None
  cargo:rerun-if-env-changed=CFLAGS_wasm32_unknown_unknown
  CFLAGS_wasm32_unknown_unknown = Some("-I /nix/store/adsq99a3vsbw3kifg7y0qh1ph0jcabv4-clang-16.0.6-lib/lib/clang/16/include/")
  cargo:rerun-if-env-changed=CC_wasm32-unknown-unknown
  CC_wasm32-unknown-unknown = None
  cargo:rerun-if-env-changed=CC_wasm32_unknown_unknown
  CC_wasm32_unknown_unknown = Some("/nix/store/a5hh7zbxh9d6xchvqv9agr29yghgr7mj-clang-16.0.6/bin/clang-16")
  cargo:rerun-if-env-changed=CRATE_CC_NO_DEFAULTS
  CRATE_CC_NO_DEFAULTS = None
  cargo:rerun-if-env-changed=CFLAGS_wasm32-unknown-unknown
  CFLAGS_wasm32-unknown-unknown = None
  cargo:rerun-if-env-changed=CFLAGS_wasm32_unknown_unknown
  CFLAGS_wasm32_unknown_unknown = Some("-I /nix/store/adsq99a3vsbw3kifg7y0qh1ph0jcabv4-clang-16.0.6-lib/lib/clang/16/include/")
  running: "/nix/store/a5hh7zbxh9d6xchvqv9agr29yghgr7mj-clang-16.0.6/bin/clang-16" "-O0" "-ffunction-sections" "-fdata-sections" "-fPIC" "-g" "-fno-omit-frame-pointer" "--target=wasm32-unknown-unknown" "-I" "/nix/store/adsq99a3vsbw3kifg7y0qh1ph0jcabv4-clang-16.0.6-lib/lib/clang/16/include/" "-I" "depend/secp256k1/" "-I" "depend/secp256k1/include" "-I" "depend/secp256k1/src" "-I" "wasm-sysroot" "-DSECP256K1_BUILD=" "-DENABLE_MODULE_SURJECTIONPROOF=1" "-DENABLE_MODULE_GENERATOR=1" "-DENABLE_MODULE_RANGEPROOF=1" "-DENABLE_MODULE_ECDSA_ADAPTOR=1" "-DENABLE_MODULE_WHITELIST=1" "-DECMULT_GEN_PREC_BITS=4" "-DUSE_NUM_NONE=1" "-DUSE_FIELD_INV_BUILTIN=1" "-DUSE_SCALAR_INV_BUILTIN=1" "-DECMULT_WINDOW_SIZE=15" "-DUSE_EXTERNAL_DEFAULT_CALLBACKS=1" "-o" "/home/user/Documents/blockstream/simplicity/rust/target/wasm32-unknown-unknown/debug/build/secp256k1-zkp-sys-b3c85c87fe7a5c8f/out/depend/secp256k1/contrib/lax_der_parsing.o" "-c" "depend/secp256k1/contrib/lax_der_parsing.c"
  exit status: 0
  running: "/nix/store/a5hh7zbxh9d6xchvqv9agr29yghgr7mj-clang-16.0.6/bin/clang-16" "-O0" "-ffunction-sections" "-fdata-sections" "-fPIC" "-g" "-fno-omit-frame-pointer" "--target=wasm32-unknown-unknown" "-I" "/nix/store/adsq99a3vsbw3kifg7y0qh1ph0jcabv4-clang-16.0.6-lib/lib/clang/16/include/" "-I" "depend/secp256k1/" "-I" "depend/secp256k1/include" "-I" "depend/secp256k1/src" "-I" "wasm-sysroot" "-DSECP256K1_BUILD=" "-DENABLE_MODULE_SURJECTIONPROOF=1" "-DENABLE_MODULE_GENERATOR=1" "-DENABLE_MODULE_RANGEPROOF=1" "-DENABLE_MODULE_ECDSA_ADAPTOR=1" "-DENABLE_MODULE_WHITELIST=1" "-DECMULT_GEN_PREC_BITS=4" "-DUSE_NUM_NONE=1" "-DUSE_FIELD_INV_BUILTIN=1" "-DUSE_SCALAR_INV_BUILTIN=1" "-DECMULT_WINDOW_SIZE=15" "-DUSE_EXTERNAL_DEFAULT_CALLBACKS=1" "-o" "/home/user/Documents/blockstream/simplicity/rust/target/wasm32-unknown-unknown/debug/build/secp256k1-zkp-sys-b3c85c87fe7a5c8f/out/depend/secp256k1/src/secp256k1.o" "-c" "depend/secp256k1/src/secp256k1.c"
  cargo:warning=In file included from depend/secp256k1/src/secp256k1.c:23:

  cargo:warning=In file included from depend/secp256k1/src/assumptions.h:12:

  cargo:warning=depend/secp256k1/src/util.h:30:5: error: call to undeclared library function 'printf' with type 'int (const char *, ...)'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]

  cargo:warning=    printf("{");

  cargo:warning=    ^

  cargo:warning=depend/secp256k1/src/util.h:30:5: note: include the header <stdio.h> or explicitly provide a declaration for 'printf'

  cargo:warning=1 error generated.

  exit status: 1

  --- stderr


  error occurred: Command "/nix/store/a5hh7zbxh9d6xchvqv9agr29yghgr7mj-clang-16.0.6/bin/clang-16" "-O0" "-ffunction-sections" "-fdata-sections" "-fPIC" "-g" "-fno-omit-frame-pointer" "--target=wasm32-unknown-unknown" "-I" "/nix/store/adsq99a3vsbw3kifg7y0qh1ph0jcabv4-clang-16.0.6-lib/lib/clang/16/include/" "-I" "depend/secp256k1/" "-I" "depend/secp256k1/include" "-I" "depend/secp256k1/src" "-I" "wasm-sysroot" "-DSECP256K1_BUILD=" "-DENABLE_MODULE_SURJECTIONPROOF=1" "-DENABLE_MODULE_GENERATOR=1" "-DENABLE_MODULE_RANGEPROOF=1" "-DENABLE_MODULE_ECDSA_ADAPTOR=1" "-DENABLE_MODULE_WHITELIST=1" "-DECMULT_GEN_PREC_BITS=4" "-DUSE_NUM_NONE=1" "-DUSE_FIELD_INV_BUILTIN=1" "-DUSE_SCALAR_INV_BUILTIN=1" "-DECMULT_WINDOW_SIZE=15" "-DUSE_EXTERNAL_DEFAULT_CALLBACKS=1" "-o" "/home/user/Documents/blockstream/simplicity/rust/target/wasm32-unknown-unknown/debug/build/secp256k1-zkp-sys-b3c85c87fe7a5c8f/out/depend/secp256k1/src/secp256k1.o" "-c" "depend/secp256k1/src/secp256k1.c" with args "clang-16" did not execute successfully (status code exit status: 1).


warning: build failed, waiting for other jobs to finish...

[apoelstra]

We can port rust-bitcoin/rust-secp256k1#735 to rust-secp256k1-zkp.

But WASM is broken everywhere this morning.

[uncomputable]

See BlockstreamResearch/rust-secp256k1-zkp#86

[uncomputable]

Fixed in BlockstreamResearch/rust-secp256k1-zkp#88