From 74cfd869d9218e108add43083786bc248c51e86f Mon Sep 17 00:00:00 2001
From: Matt Corallo <git@bluematt.me>
Date: Mon, 1 Feb 2021 00:09:50 -0500
Subject: [PATCH] [bindings] Use global context for secp256k1

XXX: Note -lm for debug builds (unnecessary with -flto) and rand
dep we probably need to remove upstream for wasm builds
---
 c-bindings-gen/src/types.rs     |  2 +-
 genbindings.sh                  | 14 +++++++-------
 lightning-c-bindings/Cargo.toml |  1 +
 3 files changed, 9 insertions(+), 8 deletions(-)

diff --git a/c-bindings-gen/src/types.rs b/c-bindings-gen/src/types.rs
index 2b195e2dc..60ee11120 100644
--- a/c-bindings-gen/src/types.rs
+++ b/c-bindings-gen/src/types.rs
@@ -583,7 +583,7 @@ impl<'a, 'c: 'a> TypeResolver<'a, 'c> {
 	/// Returns true we if can just skip passing this to C entirely
 	fn no_arg_path_to_rust(&self, full_path: &str) -> &str {
 		if full_path == "bitcoin::secp256k1::Secp256k1" {
-			"&bitcoin::secp256k1::Secp256k1::new()"
+			"secp256k1::SECP256K1"
 		} else { unimplemented!(); }
 	}
 
diff --git a/genbindings.sh b/genbindings.sh
index 1ca2f6e8e..db870ff0d 100755
--- a/genbindings.sh
+++ b/genbindings.sh
@@ -53,11 +53,11 @@ fi
 CFLAGS="-Wall -Wno-nullability-completeness -pthread"
 
 # Naively run the C demo app:
-gcc $CFLAGS -Wall -g -pthread demo.c target/debug/libldk.a -ldl
+gcc $CFLAGS -Wall -g -pthread demo.c target/debug/libldk.a -ldl -lm
 ./a.out
 
 # And run the C++ demo app in valgrind to test memory model correctness and lack of leaks.
-g++ $CFLAGS -std=c++11 -Wall -g -pthread demo.cpp -Ltarget/debug/ -lldk -ldl
+g++ $CFLAGS -std=c++11 -Wall -g -pthread demo.cpp -Ltarget/debug/ -lldk -ldl -lm
 if [ -x "`which valgrind`" ]; then
 	LD_LIBRARY_PATH=target/debug/ valgrind --error-exitcode=4 --memcheck:leak-check=full --show-leak-kinds=all ./a.out
 	echo
@@ -67,7 +67,7 @@ fi
 
 # Test a statically-linked C++ version, tracking the resulting binary size and runtime
 # across debug, LTO, and cross-language LTO builds (using the same compiler each time).
-clang++ $CFLAGS -std=c++11 demo.cpp target/debug/libldk.a -ldl
+clang++ $CFLAGS -std=c++11 demo.cpp target/debug/libldk.a -ldl -lm
 strip ./a.out
 echo " C++ Bin size and runtime w/o optimization:"
 ls -lha a.out
@@ -88,11 +88,11 @@ if [ "$HOST_PLATFORM" = "host: x86_64-unknown-linux-gnu" ]; then
 			set +e
 
 			# First the C demo app...
-			clang-$LLVM_V $CFLAGS -fsanitize=memory -fsanitize-memory-track-origins -g demo.c target/debug/libldk.a -ldl
+			clang-$LLVM_V $CFLAGS -fsanitize=memory -fsanitize-memory-track-origins -g demo.c target/debug/libldk.a -ldl -lm
 			./a.out
 
 			# ...then the C++ demo app
-			clang++-$LLVM_V $CFLAGS -std=c++11 -fsanitize=memory -fsanitize-memory-track-origins -g demo.cpp target/debug/libldk.a -ldl
+			clang++-$LLVM_V $CFLAGS -std=c++11 -fsanitize=memory -fsanitize-memory-track-origins -g demo.cpp target/debug/libldk.a -ldl -lm
 			./a.out >/dev/null
 
 			# restore exit-on-failure
@@ -158,11 +158,11 @@ if [ "$HOST_PLATFORM" = "host: x86_64-unknown-linux-gnu" -o "$HOST_PLATFORM" = "
 		mv Cargo.toml.bk Cargo.toml
 
 		# First the C demo app...
-		$CLANG $CFLAGS -fsanitize=address -g demo.c target/debug/libldk.a -ldl
+		$CLANG $CFLAGS -fsanitize=address -g demo.c target/debug/libldk.a -ldl -lm
 		ASAN_OPTIONS='detect_leaks=1 detect_invalid_pointer_pairs=1 detect_stack_use_after_return=1' ./a.out
 
 		# ...then the C++ demo app
-		$CLANGPP $CFLAGS -std=c++11 -fsanitize=address -g demo.cpp target/debug/libldk.a -ldl
+		$CLANGPP $CFLAGS -std=c++11 -fsanitize=address -g demo.cpp target/debug/libldk.a -ldl -lm
 		ASAN_OPTIONS='detect_leaks=1 detect_invalid_pointer_pairs=1 detect_stack_use_after_return=1' ./a.out >/dev/null
 	else
 		echo "WARNING: Please install clang-$RUSTC_LLVM_V and clang++-$RUSTC_LLVM_V to build with address sanitizer"
diff --git a/lightning-c-bindings/Cargo.toml b/lightning-c-bindings/Cargo.toml
index 6bde30475..19e8031c2 100644
--- a/lightning-c-bindings/Cargo.toml
+++ b/lightning-c-bindings/Cargo.toml
@@ -16,6 +16,7 @@ crate-type = ["staticlib"
 
 [dependencies]
 bitcoin = "0.24"
+secp256k1 = { version = "0.18", features = ["global-context", "rand-std"] }
 lightning = { version = "0.0.12", path = "../lightning" }
 
 # We eventually want to join the root workspace, but for now, the bindings generation is
-- 
2.39.5