Merge BlockstreamResearch#280: fuzz: add regression test for value encoding

d3b240d fuzz: add regression fuzztest for value encoding (Andrew Poelstra)
ea61344 fuzz: add value construction fuzz test (Andrew Poelstra)
aa415af value: add typeskip optimization for compact decoding (Andrew Poelstra)
c06d581 value: cap maximum initial allocation (Andrew Poelstra)
fe44b28 fuzz: add lib; add target that constructs a type to demo it (Andrew Poelstra)

Pull request description:

  Despite the branch name this does *not* fix the Windows build. It adds a regression test for value encoding, which after running 250 CPU-hours locally has failed to find any regressions.  But I did find some unrelated issues, mainly around memory allocations.

  Fixes BlockstreamResearch#279

  Fixes BlockstreamResearch#278

ACKs for top commit:
  uncomputable:
    ACK d3b240d

Tree-SHA512: ee5b902a97fa57472c7ad40aebb5ab6a2275711f7c37a0eb25286cbbf7504393ac6a1dadf2fdf271cd7366501eaf41bc978346cc8f5f62997cd8a904614118a0

Author: uncomputable

.github/workflows/fuzz.yml

@@ -17,10 +17,13 @@ jobs:
       fail-fast: false
       matrix:
         fuzz_target: [
+construct_type,
+construct_value,
 c_rust_merkle,
 decode_natural,
 decode_program,
 parse_human,
+regression_value,
         ]
     steps:
       - name: Checkout Crate

Cargo-recent.lock

@@ -419,7 +419,7 @@ name = "simpcli"
 version = "0.3.0"
 dependencies = [
  "base64 0.21.7",
- "simplicity-lang",
+ "simplicity-lang 0.4.0",
 ]
 
 [[package]]
@@ -428,7 +428,23 @@ version = "0.0.1"
 dependencies = [
  "base64 0.22.1",
  "libfuzzer-sys",
- "simplicity-lang",
+ "simplicity-lang 0.3.1",
+ "simplicity-lang 0.4.0",
+]
+
+[[package]]
+name = "simplicity-lang"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d75c8fb4a18e63fbce4cf16026c36a6c38066e4f4a09ce5e81be817d0e36d8f8"
+dependencies = [
+ "bitcoin_hashes",
+ "byteorder",
+ "getrandom",
+ "hex-conservative 0.1.2",
+ "miniscript",
+ "santiago",
+ "simplicity-sys 0.3.0",
 ]
 
 [[package]]
@@ -444,7 +460,17 @@ dependencies = [
  "miniscript",
  "santiago",
  "serde",
- "simplicity-sys",
+ "simplicity-sys 0.4.0",
+]
+
+[[package]]
+name = "simplicity-sys"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4cd2cc5d458a8032d328ea85e824f54f61664ab84c3d42b3b7f8804fb9b81572"
+dependencies = [
+ "bitcoin_hashes",
+ "cc",
 ]
 
 [[package]]

fuzz/Cargo.toml

@@ -9,16 +9,36 @@ publish = false
 [package.metadata]
 cargo-fuzz = true
 
+[lib]
+path = "fuzz_lib/lib.rs"
+
 [dependencies]
 libfuzzer-sys = "0.4"
-simplicity-lang = { path = "..", features = ["test-utils"] }
+# We shouldn't need an explicit version on the next line, but Andrew's tools
+# choke on it otherwise. See https://github.com/nix-community/crate2nix/issues/373
+simplicity-lang = { path = "..", features = ["test-utils"], version = "0.4.0" }
+old_simplicity = { package = "simplicity-lang", version = "0.3.1", default-features = false }
 
 [dev-dependencies]
 base64 = "0.22.1"
 
 [lints.rust]
 unexpected_cfgs = { level = "warn", check-cfg = ['cfg(fuzzing)'] }
 
+[[bin]]
+name = "construct_type"
+path = "fuzz_targets/construct_type.rs"
+test = false
+doc = false
+bench = false
+
+[[bin]]
+name = "construct_value"
+path = "fuzz_targets/construct_value.rs"
+test = false
+doc = false
+bench = false
+
 [[bin]]
 name = "c_rust_merkle"
 path = "fuzz_targets/c_rust_merkle.rs"
@@ -46,3 +66,10 @@ path = "fuzz_targets/parse_human.rs"
 test = false
 doc = false
 bench = false
+
+[[bin]]
+name = "regression_value"
+path = "fuzz_targets/regression_value.rs"
+test = false
+doc = false
+bench = false