Fix build for newer solana versions (#345)

* make it build

* allow negative prices

* clean up comments

* doc

* fixme

* revert

Author: jayantk

README.md

@@ -44,6 +44,30 @@ This command runs a recent pyth-client docker image that already has the necessa
 Therefore, once the container is running, all you have to do is run `cd pyth-client && ./scripts/build.sh`.
 Note that updates to the `pyth-client` directory made inside the docker container will be persisted to the host filesystem (which is probably desirable).
 
+### Local development
+
+First, make sure you're building on the x86_64 architecture.
+On a mac, this command will switch your shell to x86_64:
+
+`env /usr/bin/arch -x86_64 /bin/bash --login`
+
+then in the `program/c` directory, run:
+
+```
+make
+make cpyth-bpf
+make cpyth-native
+```
+
+then in the `program/rust` directory, run:
+
+```
+cargo build-bpf
+cargo test
+```
+
+Note that the tests depend on the bpf build!
+
 ### Fuzzing
 
 Build a docker image for running fuzz tests:

program/c/makefile

@@ -1,6 +1,13 @@
 OUT_DIR := ./target
 SOLANA := $(shell dirname $(shell which cargo-build-bpf))
-include $(SOLANA)/sdk/bpf/c/bpf.mk
+
+ifneq ("$(wildcard $(SOLANA)/sdk/bpf/c/bpf.mk)","")
+  $(info using Solana BPF SDK)
+  include $(SOLANA)/sdk/bpf/c/bpf.mk
+else
+  $(info using Solana SBF SDK)
+  include $(SOLANA)/sdk/sbf/c/sbf.mk
+endif
 
 cpyth-bpf:
 #   Bundle C code compiled to bpf for use by rust

program/rust/build.rs

@@ -31,6 +31,14 @@ fn get_solana_inc_path() -> PathBuf {
     let mut path = PathBuf::new();
     path.push(std::str::from_utf8(&which_stdout).unwrap());
     path.pop(); //
-    path.push("sdk/bpf/c/inc/");
-    path
+    let mut bpf_path = path.clone();
+    // Older solana version have the SDK in the bpf/ folder, while newer version have
+    // it in the sbf/ folder
+    bpf_path.push("sdk/bpf/c/inc/");
+    if bpf_path.exists() {
+        bpf_path
+    } else {
+        path.push("sdk/sbf/c/inc/");
+        path
+    }
 }