Move all type definitions to the ddcommon header

Cargo.toml

@@ -10,6 +10,7 @@ members = [
     "ddcommon",
     "ddcommon-ffi",
     "ddtelemetry",
+    "tools",
 ]
 # https://doc.rust-lang.org/cargo/reference/resolver.html#feature-resolver-version-2
 resolver = "2"

ddcommon-ffi/cbindgen.toml

@@ -0,0 +1,35 @@
+# Unless explicitly stated otherwise all files in this repository are licensed under the Apache License Version 2.0.
+# This product includes software developed at Datadog (https://www.datadoghq.com/). Copyright 2021-Present Datadog, Inc.
+
+language = "C"
+tab_width = 2
+header = """// Unless explicitly stated otherwise all files in this repository are licensed under the Apache License Version 2.0.
+// This product includes software developed at Datadog (https://www.datadoghq.com/). Copyright 2021-Present Datadog, Inc.
+"""
+include_guard = "DDCOMMON_FFI_H"
+style = "both"
+
+no_includes = true
+sys_includes = ["stdbool.h", "stddef.h", "stdint.h"]
+
+after_includes = """
+
+#define DDPROF_FFI_CHARSLICE_C(string) \\
+  /* NOTE: Compilation fails if you pass in a char* instead of a literal */ ((ddprof_ffi_CharSlice) {.ptr = "" string, .len = sizeof(string) - 1})"""
+
+[export]
+prefix = "ddprof_ffi_"
+
+[export.mangle]
+rename_types="SnakeCase"
+
+[enum]
+prefix_with_name = true
+rename_variants = "ScreamingSnakeCase"
+
+[fn]
+must_use = "__attribute__((warn_unused_result))"
+
+[parse]
+parse_deps = true
+include = ["ddcommon"]

ddprof-ffi/cbindgen.toml

@@ -11,11 +11,7 @@ style = "both"
 
 no_includes = true
 sys_includes = ["stdbool.h", "stddef.h", "stdint.h"]
-
-after_includes = """
-
-#define DDPROF_FFI_CHARSLICE_C(string) \\
-  /* NOTE: Compilation fails if you pass in a char* instead of a literal */ ((ddprof_ffi_CharSlice) {.ptr = "" string, .len = sizeof(string) - 1})"""
+includes = ["libdatadog/ddcommon.h"]
 
 [export]
 prefix = "ddprof_ffi_"
@@ -32,4 +28,4 @@ must_use = "__attribute__((warn_unused_result))"
 
 [parse]
 parse_deps = true
-include = ["ddcommon", "ddprof-exporter", "ddprof-profiles", "ux"]
+include = ["ddcommon", "ddcommon-ffi", "ddprof-exporter", "ddprof-profiles", "ux"]

examples/ffi/profiles.c

@@ -3,7 +3,8 @@
 // developed at Datadog (https://www.datadoghq.com/). Copyright 2021-Present
 // Datadog, Inc.
 
-#include <ddprof/ffi.h>
+#include <libdatadog/ddcommon.h>
+#include <libdatadog/ddprof.h>
 #include <stdint.h>
 
 /* Creates a profile with one sample type "wall-time" with period of "wall-time"

ffi-build.sh

@@ -118,8 +118,13 @@ if [ -n "$unexpected_native_libs" ]; then
 fi
 cd -
 
+echo "Building tools"
+cargo build --package tools --bins
+
 echo "Generating the ddprof/ffi.h header..."
-cbindgen --crate ddprof-ffi --config ddprof-ffi/cbindgen.toml --output "$destdir/include/ddprof/ffi.h"
+cbindgen --crate ddcommon-ffi --config ddcommon-ffi/cbindgen.toml --output "$destdir/include/libdatadog/ddcommon.h"
+cbindgen --crate ddprof-ffi --config ddprof-ffi/cbindgen.toml --output "$destdir/include/libdatadog/ddprof.h"
+./target/debug/dedup_headers "$destdir/include/libdatadog/ddcommon.h" "$destdir/include/libdatadog/ddprof.h"
 
 # CI doesn't have any clang tooling
 # clang-format -i "$destdir/include/ddprof/ffi.h"

tools/Cargo.toml

@@ -0,0 +1,16 @@
+# Unless explicitly stated otherwise all files in this repository are licensed under the Apache License Version 2.0.
+# This product includes software developed at Datadog (https://www.datadoghq.com/). Copyright 2021-Present Datadog, Inc.
+
+[package]
+name = "tools"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+regex = "1"
+lazy_static = "1.4"
+
+[[bin]]
+name = "dedup_headers"

tools/src/bin/dedup_headers.rs

@@ -0,0 +1,105 @@
+// Unless explicitly stated otherwise all files in this repository are licensed under the Apache License Version 2.0.
+// This product includes software developed at Datadog (https://www.datadoghq.com/). Copyright 2021-Present Datadog, Inc.
+
+/// Usage:
+/// ./dedup_headers <base_header> <child_headers>...
+///
+/// All type definitions will be removed from the child_headers, and moved to the base_header
+/// if they are not already defined in the parent_header
+use regex::{Match, Regex, RegexBuilder};
+use std::collections::HashSet;
+use std::fs::{File, OpenOptions};
+use std::io::{self, BufReader, BufWriter, Read, Seek, Write};
+
+fn collect_definitions(header: &str) -> Vec<regex::Match<'_>> {
+    lazy_static::lazy_static! {
+        static ref HEADER_TYPE_DECL_RE: Regex = RegexBuilder::new(r"^(/\*.*?\*/\n)?typedef (struct|enum) [a-zA-Z_0-9]+ +(\{.*?\} )?[a-zA-Z_0-9]+;\n+")
+            .multi_line(true)
+            .dot_matches_new_line(true)
+            .build()
+            .unwrap();
+    }
+    HEADER_TYPE_DECL_RE.find_iter(header).collect()
+}
+
+fn read(f: &mut BufReader<&File>, until: Option<usize>) -> String {
+    let mut s = Vec::new();
+    match until {
+        Some(until) => {
+            s.resize(until, 0);
+            f.read_exact(&mut s).unwrap()
+        }
+        None => {
+            f.read_to_end(&mut s).unwrap();
+        }
+    };
+
+    String::from_utf8(s).unwrap()
+}
+
+fn write_parts(writer: &mut BufWriter<&File>, parts: &[&str]) -> io::Result<()> {
+    writer.get_ref().set_len(0)?;
+    writer.seek(io::SeekFrom::Start(0))?;
+    for part in parts {
+        writer.write_all(part.as_bytes())?;
+    }
+    Ok(())
+}
+
+fn content_without_defs<'a>(content: &'a str, defs: &[Match]) -> Vec<&'a str> {
+    let mut new_content_parts = Vec::new();
+    let mut pos = 0;
+    for d in defs {
+        new_content_parts.push(&content[pos..d.start()]);
+        pos = d.end();
+    }
+    new_content_parts.push(&content[pos..]);
+    new_content_parts
+}
+
+fn main() {
+    let args: Vec<_> = std::env::args_os().collect();
+
+    let mut unique_child_defs: Vec<String> = Vec::new();
+    let mut present = HashSet::new();
+    for child_def in args[2..].iter().flat_map(|p| {
+        let child_header = OpenOptions::new().read(true).write(true).open(p).unwrap();
+
+        let child_header_content = read(&mut BufReader::new(&child_header), None);
+        let child_defs = collect_definitions(&child_header_content);
+        let new_content_parts = content_without_defs(&child_header_content, &child_defs);
+
+        write_parts(&mut BufWriter::new(&child_header), &new_content_parts).unwrap();
+
+        child_defs
+            .into_iter()
+            .map(|m| m.as_str().to_owned())
+            .collect::<Vec<_>>()
+    }) {
+        if present.contains(&child_def) {
+            continue;
+        }
+        unique_child_defs.push(child_def.clone());
+        present.insert(child_def);
+    }
+
+    let base_header = OpenOptions::new()
+        .read(true)
+        .write(true)
+        .open(&args[1])
+        .unwrap();
+    let base_header_content = read(&mut BufReader::new(&base_header), None);
+    let base_defs = collect_definitions(&base_header_content);
+    let base_defs_set: HashSet<_> = base_defs.iter().map(Match::as_str).collect();
+
+    let mut base_new_parts = vec![&base_header_content[..base_defs.last().unwrap().end()]];
+
+    for child_def in &unique_child_defs {
+        if base_defs_set.contains(child_def.as_str()) {
+            continue;
+        }
+        base_new_parts.push(child_def);
+    }
+    base_new_parts.push(&base_header_content[base_defs.last().unwrap().end()..]);
+    write_parts(&mut BufWriter::new(&base_header), &base_new_parts).unwrap();
+}

tools/src/lib.rs

@@ -0,0 +1,2 @@
+// Unless explicitly stated otherwise all files in this repository are licensed under the Apache License Version 2.0.
+// This product includes software developed at Datadog (https://www.datadoghq.com/). Copyright 2021-Present Datadog, Inc.