From 491a9e3ab12ccb6a622df8f16912b779adc75faa Mon Sep 17 00:00:00 2001
From: Levi Morrison <levi.morrison@datadoghq.com>
Date: Fri, 30 Jan 2026 20:10:39 -0700
Subject: [PATCH 1/8] refactor(profiling): extract Backtrace type

In a future change, this may hold a refcount for another object, so
we need to encapsulate it.
---
 profiling/src/profiling/backtrace.rs     | 33 ++++++++++++++++++
 profiling/src/profiling/mod.rs           | 44 +++++++++++++-----------
 profiling/src/profiling/stack_walking.rs | 30 ++++++++--------
 3 files changed, 72 insertions(+), 35 deletions(-)
 create mode 100644 profiling/src/profiling/backtrace.rs

diff --git a/profiling/src/profiling/backtrace.rs b/profiling/src/profiling/backtrace.rs
new file mode 100644
index 00000000000..9dfcc359d96
--- /dev/null
+++ b/profiling/src/profiling/backtrace.rs
@@ -0,0 +1,33 @@
+use crate::profiling::stack_walking::ZendFrame;
+use core::ops::Deref;
+
+#[derive(Debug)]
+pub struct Backtrace {
+    frames: Vec<ZendFrame>,
+}
+
+impl Backtrace {
+    pub const fn new(frames: Vec<ZendFrame>) -> Self {
+        Self { frames }
+    }
+
+    pub fn len(&self) -> usize {
+        self.frames.len()
+    }
+
+    pub fn is_empty(&self) -> bool {
+        self.frames.is_empty()
+    }
+
+    pub fn iter(&self) -> impl Iterator<Item = &ZendFrame> {
+        self.frames.iter()
+    }
+}
+
+impl Deref for Backtrace {
+    type Target = [ZendFrame];
+
+    fn deref(&self) -> &Self::Target {
+        self.frames.as_slice()
+    }
+}
diff --git a/profiling/src/profiling/mod.rs b/profiling/src/profiling/mod.rs
index cc9cc845e60..271b192be54 100644
--- a/profiling/src/profiling/mod.rs
+++ b/profiling/src/profiling/mod.rs
@@ -1,9 +1,11 @@
+mod backtrace;
 mod interrupts;
 mod sample_type_filter;
 pub mod stack_walking;
 mod thread_utils;
 mod uploader;
 
+pub use backtrace::Backtrace;
 pub use interrupts::*;
 pub use sample_type_filter::*;
 pub use stack_walking::*;
@@ -170,7 +172,7 @@ pub struct ProfileIndex {
 
 #[derive(Debug)]
 pub struct SampleData {
-    pub frames: Vec<ZendFrame>,
+    pub frames: Backtrace,
     pub labels: Vec<Label>,
     pub sample_values: Vec<i64>,
     pub timestamp: i64,
@@ -524,7 +526,7 @@ impl TimeCollector {
         let values = message.value.sample_values;
         let labels: Vec<ApiLabel> = message.value.labels.iter().map(ApiLabel::from).collect();
 
-        for frame in &message.value.frames {
+        for frame in message.value.frames.iter() {
             let location = Location {
                 function: Function {
                     name: frame.function.as_ref(),
@@ -1065,11 +1067,11 @@ impl Profiler {
         let n_labels = labels.len();
 
         match self.prepare_and_send_message(
-            vec![ZendFrame {
+            Backtrace::new(vec![ZendFrame {
                 function: COW_EVAL,
                 file: Some(Cow::Owned(filename)),
                 line,
-            }],
+            }]),
             SampleValues {
                 timeline: duration,
                 ..Default::default()
@@ -1106,11 +1108,11 @@ impl Profiler {
         let n_labels = labels.len();
 
         match self.prepare_and_send_message(
-            vec![ZendFrame {
+            Backtrace::new(vec![ZendFrame {
                 function: format!("[{include_type}]").into(),
                 file: None,
                 line: 0,
-            }],
+            }]),
             SampleValues {
                 timeline: duration,
                 ..Default::default()
@@ -1143,11 +1145,11 @@ impl Profiler {
         let n_labels = labels.len();
 
         match self.prepare_and_send_message(
-            vec![ZendFrame {
+            Backtrace::new(vec![ZendFrame {
                 function: format!("[{event}]").into(),
                 file: None,
                 line: 0,
-            }],
+            }]),
             SampleValues {
                 timeline: 1,
                 ..Default::default()
@@ -1181,11 +1183,11 @@ impl Profiler {
         let n_labels = labels.len();
 
         match self.prepare_and_send_message(
-            vec![ZendFrame {
+            Backtrace::new(vec![ZendFrame {
                 function: "[fatal]".into(),
                 file: Some(Cow::Owned(file)),
                 line,
-            }],
+            }]),
             SampleValues {
                 timeline: 1,
                 ..Default::default()
@@ -1228,11 +1230,11 @@ impl Profiler {
         let n_labels = labels.len();
 
         match self.prepare_and_send_message(
-            vec![ZendFrame {
+            Backtrace::new(vec![ZendFrame {
                 function: "[opcache restart]".into(),
                 file: Some(Cow::Owned(file)),
                 line,
-            }],
+            }]),
             SampleValues {
                 timeline: 1,
                 ..Default::default()
@@ -1262,11 +1264,11 @@ impl Profiler {
         let n_labels = labels.len();
 
         match self.prepare_and_send_message(
-            vec![ZendFrame {
+            Backtrace::new(vec![ZendFrame {
                 function: "[idle]".into(),
                 file: None,
                 line: 0,
-            }],
+            }]),
             SampleValues {
                 timeline: duration,
                 ..Default::default()
@@ -1318,11 +1320,11 @@ impl Profiler {
         let n_labels = labels.len();
 
         match self.prepare_and_send_message(
-            vec![ZendFrame {
+            Backtrace::new(vec![ZendFrame {
                 function: "[gc]".into(),
                 file: None,
                 line: 0,
-            }],
+            }]),
             SampleValues {
                 timeline: duration,
                 ..Default::default()
@@ -1504,7 +1506,7 @@ impl Profiler {
 
     fn prepare_and_send_message(
         &self,
-        frames: Vec<ZendFrame>,
+        frames: Backtrace,
         samples: SampleValues,
         labels: Vec<Label>,
         timestamp: i64,
@@ -1517,7 +1519,7 @@ impl Profiler {
 
     fn prepare_sample_message(
         &self,
-        frames: Vec<ZendFrame>,
+        frames: Backtrace,
         samples: SampleValues,
         labels: Vec<Label>,
         timestamp: i64,
@@ -1556,12 +1558,12 @@ mod tests {
     use libdd_profiling::exporter::Uri;
     use log::LevelFilter;
 
-    fn get_frames() -> Vec<ZendFrame> {
-        vec![ZendFrame {
+    fn get_frames() -> Backtrace {
+        Backtrace::new(vec![ZendFrame {
             function: "foobar()".into(),
             file: Some("foobar.php".into()),
             line: 42,
-        }]
+        }])
     }
 
     pub fn get_system_settings() -> SystemSettings {
diff --git a/profiling/src/profiling/stack_walking.rs b/profiling/src/profiling/stack_walking.rs
index 6f38b74dbb1..28c22e7c489 100644
--- a/profiling/src/profiling/stack_walking.rs
+++ b/profiling/src/profiling/stack_walking.rs
@@ -1,6 +1,7 @@
 use crate::bindings::{
     zai_str_from_zstr, zend_execute_data, zend_function, zend_op, zend_op_array,
 };
+use crate::profiling::Backtrace;
 use crate::vec_ext::VecExt;
 use std::borrow::Cow;
 
@@ -289,7 +290,7 @@ mod detail {
     fn collect_stack_sample_cached(
         top_execute_data: *mut zend_execute_data,
         string_set: &mut StringSet,
-    ) -> Result<Vec<ZendFrame>, CollectStackSampleError> {
+    ) -> Result<Backtrace, CollectStackSampleError> {
         let max_depth = 512;
         let mut samples = Vec::new();
         let mut execute_data_ptr = top_execute_data;
@@ -347,13 +348,13 @@ mod detail {
 
             execute_data_ptr = execute_data.prev_execute_data;
         }
-        Ok(samples)
+        Ok(Backtrace::new(samples))
     }
 
     #[inline(never)]
     pub fn collect_stack_sample(
         execute_data: *mut zend_execute_data,
-    ) -> Result<Vec<ZendFrame>, CollectStackSampleError> {
+    ) -> Result<Backtrace, CollectStackSampleError> {
         #[cfg(feature = "tracing")]
         let _span = tracing::trace_span!("collect_stack_sample").entered();
         CACHED_STRINGS
@@ -474,7 +475,7 @@ mod detail {
     #[inline(never)]
     pub fn collect_stack_sample(
         top_execute_data: *mut zend_execute_data,
-    ) -> Result<Vec<ZendFrame>, CollectStackSampleError> {
+    ) -> Result<Backtrace, CollectStackSampleError> {
         #[cfg(feature = "tracing")]
         let _span = tracing::trace_span!("collect_stack_sample").entered();
 
@@ -503,7 +504,7 @@ mod detail {
 
             execute_data_ptr = execute_data.prev_execute_data;
         }
-        Ok(samples)
+        Ok(Backtrace::new(samples))
     }
 
     unsafe fn collect_call_frame(execute_data: &zend_execute_data) -> Option<ZendFrame> {
@@ -550,17 +551,18 @@ mod tests {
 
             assert_eq!(stack.len(), 3);
 
-            assert_eq!(stack[0].function, "function name 003");
-            assert_eq!(stack[0].file, Some("filename-003.php".into()));
-            assert_eq!(stack[0].line, 0);
+            let frames = &stack;
+            assert_eq!(frames[0].function, "function name 003");
+            assert_eq!(frames[0].file, Some("filename-003.php".into()));
+            assert_eq!(frames[0].line, 0);
 
-            assert_eq!(stack[1].function, "function name 002");
-            assert_eq!(stack[1].file, Some("filename-002.php".into()));
-            assert_eq!(stack[1].line, 0);
+            assert_eq!(frames[1].function, "function name 002");
+            assert_eq!(frames[1].file, Some("filename-002.php".into()));
+            assert_eq!(frames[1].line, 0);
 
-            assert_eq!(stack[2].function, "function name 001");
-            assert_eq!(stack[2].file, Some("filename-001.php".into()));
-            assert_eq!(stack[2].line, 0);
+            assert_eq!(frames[2].function, "function name 001");
+            assert_eq!(frames[2].file, Some("filename-001.php".into()));
+            assert_eq!(frames[2].line, 0);
 
             // Free the allocated memory
             zend::ddog_php_test_free_fake_zend_execute_data(fake_execute_data);

From 9910d2b1095c8e454ace12ba66cc77f6e7f53471 Mon Sep 17 00:00:00 2001
From: Levi Morrison <levi.morrison@datadoghq.com>
Date: Sun, 1 Feb 2026 12:50:29 -0700
Subject: [PATCH 2/8] build(profiling)!: use phpize + configure + make

---
 profiling/.gitignore    |  18 ++++++
 profiling/Makefile.frag |  59 +++++++++++++++++++
 profiling/README.md     |  65 ++++++++++++++++++++
 profiling/build.rs      | 127 ++++++++++++++++++++--------------------
 profiling/config.m4     |  67 +++++++++++++++++++++
 5 files changed, 272 insertions(+), 64 deletions(-)
 create mode 100644 profiling/.gitignore
 create mode 100644 profiling/Makefile.frag
 create mode 100644 profiling/config.m4

diff --git a/profiling/.gitignore b/profiling/.gitignore
new file mode 100644
index 00000000000..0dabaf35589
--- /dev/null
+++ b/profiling/.gitignore
@@ -0,0 +1,18 @@
+/Makefile
+/Makefile.objects
+/Makefile.fragments
+/aclocal.m4
+/autom4te.cache/
+/build/
+/config.cache
+/config.h
+/config.h.in
+/config.log
+/config.nice
+/config.status
+/configure
+/configure.ac
+/libtool
+/ltmain.sh
+/modules/
+/target/
diff --git a/profiling/Makefile.frag b/profiling/Makefile.frag
new file mode 100644
index 00000000000..29620d1f62a
--- /dev/null
+++ b/profiling/Makefile.frag
@@ -0,0 +1,59 @@
+DD_PROFILING_NAME = datadog-profiling
+DD_PROFILING_MODULE = modules/$(DD_PROFILING_NAME).$(SHLIB_DL_SUFFIX_NAME)
+DD_PROFILING_MODULE_LA = modules/$(DD_PROFILING_NAME).la
+
+DD_PROFILING_CARGO_TARGET_DIR = $(top_builddir)/target
+
+DD_PROFILING_UNAME_S := $(shell uname -s)
+ifeq ($(DD_PROFILING_UNAME_S),Darwin)
+DD_PROFILING_RUST_EXT = dylib
+else
+DD_PROFILING_RUST_EXT = so
+endif
+
+DD_PROFILING_RUST_LIB = $(DD_PROFILING_CARGO_TARGET_DIR)/$(DD_PROFILING_CARGO_PROFILE)/libdatadog_php_profiling.$(DD_PROFILING_RUST_EXT)
+DD_PROFILING_CARGO_FEATURES_CLEAN = $(shell echo "$(DD_PROFILING_CARGO_FEATURES)" | tr ',' ' ')
+
+.PHONY: cargo-test clean distclean clean-profiling distclean-profiling
+
+PHP_MODULES += $(DD_PROFILING_MODULE_LA)
+all: $(DD_PROFILING_MODULE_LA)
+
+$(DD_PROFILING_RUST_LIB): $(top_builddir)/Makefile $(top_builddir)/config.h
+	@echo "Building Rust profiler ($(DD_PROFILING_CARGO_PROFILE))"
+	@CARGO_TARGET_DIR="$(DD_PROFILING_CARGO_TARGET_DIR)" \
+		PHP_INCLUDES="$(INCLUDES)" \
+		PHP_INCLUDE_DIR="$(phpincludedir)" \
+		PHP_PREFIX="$(prefix)" \
+		PHP_VERSION_ID="$(DATADOG_PHP_VERSION_ID)" \
+		$(DD_PROFILING_CARGO) build --manifest-path "$(top_srcdir)/Cargo.toml" $(DD_PROFILING_CARGO_ARGS) $(if $(DD_PROFILING_CARGO_FEATURES_CLEAN),--features "$(DD_PROFILING_CARGO_FEATURES_CLEAN)",)
+
+$(DD_PROFILING_MODULE): $(DD_PROFILING_RUST_LIB)
+	@mkdir -p modules
+	@cp -f "$(DD_PROFILING_RUST_LIB)" "$@"
+
+$(DD_PROFILING_MODULE_LA): $(DD_PROFILING_MODULE)
+	@printf "dlname='%s'\n" "$(DD_PROFILING_NAME).$(SHLIB_DL_SUFFIX_NAME)" > "$@"
+
+cargo-test:
+	@CARGO_TARGET_DIR="$(DD_PROFILING_CARGO_TARGET_DIR)" \
+		PHP_INCLUDES="$(INCLUDES)" \
+		PHP_INCLUDE_DIR="$(phpincludedir)" \
+		PHP_PREFIX="$(prefix)" \
+		PHP_VERSION_ID="$(DATADOG_PHP_VERSION_ID)" \
+		$(DD_PROFILING_CARGO) test --manifest-path "$(top_srcdir)/Cargo.toml" $(if $(DD_PROFILING_CARGO_FEATURES_CLEAN),--features "$(DD_PROFILING_CARGO_FEATURES_CLEAN)",)
+
+clean: clean-profiling
+
+clean-profiling:
+	@rm -f "$(DD_PROFILING_MODULE)"
+	@# Only cleans the profiler crate; dependencies remain cached.
+	@$(DD_PROFILING_CARGO) clean -p datadog-php-profiling
+
+distclean: distclean-profiling
+
+distclean-profiling:
+	@rm -rf "$(DD_PROFILING_CARGO_TARGET_DIR)"
+	@rm -rf build autom4te.cache modules
+	@rm -f configure configure.ac config.h config.h.in config.nice run-tests.php
+	@rm -f *~ *.orig
diff --git a/profiling/README.md b/profiling/README.md
index 400b89752c4..c156b0c3e56 100644
--- a/profiling/README.md
+++ b/profiling/README.md
@@ -39,6 +39,71 @@ allows us to gloss over minor differences in const-correctness in the engine
 definitions across versions, as well as provide more idiomatic types in some
 cases where they are ABI compatible.
 
+### Phpize build (recommended for installs)
+
+From the `profiling/` directory, use the normal extension build flow:
+
+```sh
+# Choose the PHP version to build against
+export PATH="/opt/php/8.4/bin:$PATH"
+
+phpize
+./configure --enable-datadog-profiling
+make
+make install
+```
+
+This builds `modules/datadog-profiling.so` and installs it into the PHP
+extension directory reported by `php-config --extension-dir`.
+
+To build with the Cargo debug profile:
+
+```sh
+./configure --enable-datadog-profiling --enable-datadog-profiling-debug
+```
+
+To enable specific Cargo features:
+
+```sh
+./configure --enable-datadog-profiling \
+  --with-datadog-profiling-cargo-features="stack_walking_tests,trigger_time_sample"
+```
+
+To run the PHPT tests with the built extension:
+
+```sh
+make test
+```
+
+To suppress the failure report prompt:
+
+```sh
+NO_INTERACTION=1 make test
+```
+
+To show diffs on failure, or to run tests in parallel, pass flags via `TESTS`:
+
+```sh
+make test TESTS="--show-diff -j8 tests/phpt"
+```
+
+To run tests in parallel on newer PHP versions (PHP 8.0+ supports `-j`):
+
+```sh
+make test TESTS="-j8 tests/phpt"
+```
+
+Note: direct `cargo build` expects you to have run `phpize` and
+`./configure` so `build.rs` can read PHP settings from the generated
+`Makefile`.
+
+If you want to run cargo commands and want to reuse artifacts from the phpize
+flow, run it with the same target directory:
+
+```sh
+CARGO_TARGET_DIR=target cargo build --release
+```
+
 ## Testing
 
 The command `cargo test` will run the tests on the profiler. To also run the
diff --git a/profiling/build.rs b/profiling/build.rs
index b8566e4a5b1..7ee2cc5feaf 100644
--- a/profiling/build.rs
+++ b/profiling/build.rs
@@ -1,25 +1,17 @@
 use bindgen::callbacks::IntKind;
+use std::collections::HashMap;
 use std::collections::HashSet;
 use std::path::Path;
 use std::path::PathBuf;
 use std::process::Command;
+use std::sync::OnceLock;
 use std::{env, fs};
 
 fn main() {
-    let php_config_includes_output = Command::new("php-config")
-        .arg("--includes")
-        .output()
-        .expect("Unable to run `php-config`. Is it in your PATH?");
-
-    if !php_config_includes_output.status.success() {
-        match String::from_utf8(php_config_includes_output.stderr) {
-            Ok(stderr) => panic!("`php-config failed: {stderr}"),
-            Err(err) => panic!(
-                "`php-config` failed, not utf8: {}",
-                String::from_utf8_lossy(err.as_bytes())
-            ),
-        }
-    }
+    let php_includes = build_var("PHP_INCLUDES");
+    let php_include_dir = build_var("PHP_INCLUDE_DIR");
+    let php_prefix = build_var("PHP_PREFIX");
+    let php_version_id = php_version_id();
 
     // Read the version from the VERSION file
     let version = fs::read_to_string("../VERSION")
@@ -29,10 +21,7 @@ fn main() {
     println!("cargo:rustc-env=PROFILER_VERSION={version}");
     println!("cargo:rerun-if-changed=../VERSION");
 
-    let php_config_includes = std::str::from_utf8(php_config_includes_output.stdout.as_slice())
-        .expect("`php-config`'s stdout to be valid utf8");
-
-    let vernum = php_config_vernum();
+    let vernum = php_version_id;
     let post_startup_cb = cfg_post_startup_cb(vernum);
     let preload = cfg_preload(vernum);
     let fibers = cfg_fibers(vernum);
@@ -40,9 +29,10 @@ fn main() {
     let trigger_time_sample = cfg_trigger_time_sample();
     let zend_error_observer = cfg_zend_error_observer(vernum);
 
-    generate_bindings(php_config_includes, fibers, zend_error_observer);
+    generate_bindings(&php_includes, fibers, zend_error_observer);
     build_zend_php_ffis(
-        php_config_includes,
+        &php_includes,
+        &php_prefix,
         post_startup_cb,
         preload,
         run_time_cache,
@@ -53,32 +43,62 @@ fn main() {
 
     cfg_php_major_version(vernum);
     cfg_php_feature_flags(vernum);
-    cfg_zts();
+    cfg_zts(&php_include_dir);
 }
 
-fn php_config_vernum() -> u64 {
-    let output = Command::new("php-config")
-        .arg("--vernum")
-        .output()
-        .expect("Unable to run `php-config`. Is it in your PATH?");
-
-    if !output.status.success() {
-        match String::from_utf8(output.stderr) {
-            Ok(stderr) => panic!("`php-config --vernum` failed: {stderr}"),
-            Err(err) => panic!(
-                "`php-config --vernum` failed, not utf8: {}",
-                String::from_utf8_lossy(err.as_bytes())
-            ),
-        }
+fn build_var(name: &str) -> String {
+    if let Some(value) = makefile_var(name) {
+        return value;
     }
 
-    let vernum = std::str::from_utf8(output.stdout.as_slice())
-        .expect("`php-config`'s stdout to be valid utf8");
+    panic!(
+        "Missing required build variable {name}. \
+Run phpize && ./configure to generate Makefile."
+    )
+}
 
-    vernum
+fn php_version_id() -> u64 {
+    build_var("PHP_VERSION_ID")
         .trim()
         .parse::<u64>()
-        .expect("output to be a number and fit in u64")
+        .expect("PHP_VERSION_ID must be a number and fit in u64")
+}
+
+fn makefile_vars() -> Option<&'static HashMap<String, String>> {
+    static MAKEFILE_VARS: OnceLock<Option<HashMap<String, String>>> = OnceLock::new();
+    MAKEFILE_VARS
+        .get_or_init(|| {
+            let path = Path::new("Makefile");
+            if !path.exists() {
+                return None;
+            }
+            println!("cargo:rerun-if-changed=Makefile");
+            let contents = fs::read_to_string(path).ok()?;
+            let mut vars = HashMap::new();
+            for line in contents.lines() {
+                if let Some((key, value)) = line.split_once('=') {
+                    let key = key.trim();
+                    let value = value.trim();
+                    if !key.is_empty() {
+                        vars.insert(key.to_string(), value.to_string());
+                    }
+                }
+            }
+            Some(vars)
+        })
+        .as_ref()
+}
+
+fn makefile_var(name: &str) -> Option<String> {
+    let vars = makefile_vars()?;
+    let key = match name {
+        "PHP_INCLUDES" => "INCLUDES",
+        "PHP_INCLUDE_DIR" => "phpincludedir",
+        "PHP_PREFIX" => "prefix",
+        "PHP_VERSION_ID" => "DATADOG_PHP_VERSION_ID",
+        _ => return None,
+    };
+    vars.get(key).cloned()
 }
 
 const ZAI_H_FILES: &[&str] = &[
@@ -98,6 +118,7 @@ const ZAI_H_FILES: &[&str] = &[
 #[allow(clippy::too_many_arguments)]
 fn build_zend_php_ffis(
     php_config_includes: &str,
+    php_prefix: &str,
     post_startup_cb: bool,
     preload: bool,
     run_time_cache: bool,
@@ -127,15 +148,9 @@ fn build_zend_php_ffis(
         println!("cargo:rerun-if-changed={file}");
     }
 
-    let output = Command::new("php-config")
-        .arg("--prefix")
-        .output()
-        .expect("Unable to run `php-config`. Is it in your PATH?");
-
-    let prefix = String::from_utf8(output.stdout).expect("only utf8 chars work");
     println!(
         "cargo:rustc-link-search=native={prefix}/lib",
-        prefix = prefix.trim()
+        prefix = php_prefix.trim()
     );
 
     let files = ["src/php_ffi.c", "../ext/handlers_api.c"];
@@ -392,25 +407,9 @@ fn cfg_php_feature_flags(vernum: u64) {
     }
 }
 
-fn cfg_zts() {
+fn cfg_zts(php_include_dir: &str) {
     println!("cargo::rustc-check-cfg=cfg(php_zts)");
 
-    let output = Command::new("php-config")
-        .arg("--include-dir")
-        .output()
-        .expect("Unable to run `php-config`. Is it in your PATH?");
-
-    if !output.status.success() {
-        match String::from_utf8(output.stderr) {
-            Ok(stderr) => panic!("`php-config --include-dir` failed: {stderr}"),
-            Err(err) => panic!("`php-config --include-dir` failed, not utf8: {err}"),
-        }
-    }
-
-    let include_dir = std::str::from_utf8(output.stdout.as_slice())
-        .expect("`php-config`'s stdout to be valid utf8")
-        .trim();
-
     // Create a temporary C file to probe ZTS
     let out_dir = env::var("OUT_DIR").unwrap();
     let probe_path = Path::new(&out_dir).join("zts_probe.c");
@@ -437,7 +436,7 @@ int main() {
     // Compile the probe to an executable
     let probe_exe = Path::new(&out_dir).join("zts_probe");
     let compile_status = Command::new(compiler.path())
-        .arg(format!("-I{}", include_dir))
+        .arg(format!("-I{}", php_include_dir.trim()))
         .arg(&probe_path)
         .arg("-o")
         .arg(&probe_exe)
diff --git a/profiling/config.m4 b/profiling/config.m4
new file mode 100644
index 00000000000..c244127e20b
--- /dev/null
+++ b/profiling/config.m4
@@ -0,0 +1,67 @@
+PHP_ARG_ENABLE([datadog-profiling],
+  [whether to enable Datadog profiling support],
+  [AS_HELP_STRING([--enable-datadog-profiling],
+    [Enable Datadog profiling support])],
+  [no])
+
+AC_ARG_ENABLE([datadog-profiling-debug],
+  [AS_HELP_STRING([--enable-datadog-profiling-debug],
+    [Build Datadog profiling with the Cargo debug profile])],
+  [PHP_DATADOG_PROFILING_DEBUG=$enableval],
+  [PHP_DATADOG_PROFILING_DEBUG=no])
+
+PHP_ARG_WITH([datadog-profiling-cargo],
+  [path to cargo binary],
+  [AS_HELP_STRING([--with-datadog-profiling-cargo=PATH],
+    [Path to cargo binary for Rust compilation])],
+  [cargo],
+  [no])
+
+PHP_ARG_WITH([datadog-profiling-cargo-features],
+  [cargo feature list],
+  [AS_HELP_STRING([--with-datadog-profiling-cargo-features=LIST],
+    [Comma or space-separated Cargo feature list for the profiler crate])],
+  [],
+  [no])
+
+if test "$PHP_DATADOG_PROFILING" != "no"; then
+  PHP_ALWAYS_SHARED([PHP_DATADOG_PROFILING])
+  AC_DEFINE([HAVE_DATADOG_PROFILING], [1], [Have Datadog profiling support])
+
+  if test "$PHP_DATADOG_PROFILING_CARGO" != "cargo"; then
+    if test -x "$PHP_DATADOG_PROFILING_CARGO"; then
+      DD_PROFILING_CARGO="$PHP_DATADOG_PROFILING_CARGO"
+    else
+      AC_MSG_ERROR([$PHP_DATADOG_PROFILING_CARGO is not an executable])
+    fi
+  else
+    AC_CHECK_TOOL([DD_PROFILING_CARGO], [cargo], [:])
+    AS_IF([test "$DD_PROFILING_CARGO" = ":"],
+      [AC_MSG_ERROR([Please install cargo before configuring, or specify it with --with-datadog-profiling-cargo=])])
+  fi
+  PHP_SUBST([DD_PROFILING_CARGO])
+
+  if test "$PHP_DATADOG_PROFILING_DEBUG" != "no"; then
+    DD_PROFILING_CARGO_PROFILE="debug"
+    DD_PROFILING_CARGO_ARGS=""
+  else
+    DD_PROFILING_CARGO_PROFILE="release"
+    DD_PROFILING_CARGO_ARGS="--release"
+  fi
+  PHP_SUBST([DD_PROFILING_CARGO_PROFILE])
+  PHP_SUBST([DD_PROFILING_CARGO_ARGS])
+
+  if test "$PHP_DATADOG_PROFILING_CARGO_FEATURES" = "no"; then
+    DD_PROFILING_CARGO_FEATURES=""
+  else
+    DD_PROFILING_CARGO_FEATURES="$PHP_DATADOG_PROFILING_CARGO_FEATURES"
+  fi
+  PHP_SUBST([DD_PROFILING_CARGO_FEATURES])
+
+  DATADOG_PHP_VERSION_ID="$($PHP_CONFIG --vernum 2>/dev/null)"
+  AS_VAR_IF([DATADOG_PHP_VERSION_ID],,
+    [AC_MSG_ERROR([Failed to determine PHP version id (php-config --vernum)])])
+  PHP_SUBST([DATADOG_PHP_VERSION_ID])
+
+  PHP_ADD_MAKEFILE_FRAGMENT([Makefile.frag])
+fi

From ad0e3d2abd8f67bf30da7935f00f6130c30a71ba Mon Sep 17 00:00:00 2001
From: Levi Morrison <levi.morrison@datadoghq.com>
Date: Sun, 1 Feb 2026 13:09:24 -0700
Subject: [PATCH 3/8] ci: adjust build for phpize + configure

---
 .github/workflows/prof_asan.yml        | 2 ++
 .github/workflows/prof_correctness.yml | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/.github/workflows/prof_asan.yml b/.github/workflows/prof_asan.yml
index 218dc21e1ff..d46e68a68e2 100644
--- a/.github/workflows/prof_asan.yml
+++ b/.github/workflows/prof_asan.yml
@@ -37,6 +37,8 @@ jobs:
           set -eux
           switch-php nts-asan
           cd profiling
+          phpize
+          ./configure --with-php-config="$(command -v php-config)"
           export CARGO_TARGET_DIR=/tmp/build-cargo
           export CC=clang-17
           export CFLAGS='-fsanitize=address  -fno-omit-frame-pointer'
diff --git a/.github/workflows/prof_correctness.yml b/.github/workflows/prof_correctness.yml
index da49c2bd496..b2ce1a8bbb1 100644
--- a/.github/workflows/prof_correctness.yml
+++ b/.github/workflows/prof_correctness.yml
@@ -55,6 +55,8 @@ jobs:
           sudo apt-get update
           sudo apt install -y clang-17
           cd profiling
+          phpize
+          ./configure --with-php-config="$(command -v php-config)"
           version_number=$(awk -F' = ' '$1 == "channel" { gsub(/"/, "", $2); print $2 }' rust-toolchain.toml)
           curl https://sh.rustup.rs -sSf | sh -s -- --profile minimal -y --default-toolchain "$version_number"
           cargo rustc --features="trigger_time_sample" --profile profiler-release --crate-type=cdylib

From ff83cceb9ea3777d12dee41ce6e19b39ae2f597a Mon Sep 17 00:00:00 2001
From: Levi Morrison <levi.morrison@datadoghq.com>
Date: Sun, 1 Feb 2026 13:09:44 -0700
Subject: [PATCH 4/8] build: enable by default, fix disabled handling

---
 profiling/README.md | 7 +++----
 profiling/config.m4 | 9 ++++++---
 2 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/profiling/README.md b/profiling/README.md
index c156b0c3e56..b0a8eeb0870 100644
--- a/profiling/README.md
+++ b/profiling/README.md
@@ -48,7 +48,7 @@ From the `profiling/` directory, use the normal extension build flow:
 export PATH="/opt/php/8.4/bin:$PATH"
 
 phpize
-./configure --enable-datadog-profiling
+./configure
 make
 make install
 ```
@@ -59,14 +59,13 @@ extension directory reported by `php-config --extension-dir`.
 To build with the Cargo debug profile:
 
 ```sh
-./configure --enable-datadog-profiling --enable-datadog-profiling-debug
+./configure --enable-datadog-profiling-debug
 ```
 
 To enable specific Cargo features:
 
 ```sh
-./configure --enable-datadog-profiling \
-  --with-datadog-profiling-cargo-features="stack_walking_tests,trigger_time_sample"
+./configure --with-datadog-profiling-cargo-features="stack_walking_tests,trigger_time_sample"
 ```
 
 To run the PHPT tests with the built extension:
diff --git a/profiling/config.m4 b/profiling/config.m4
index c244127e20b..1b8f8a3199d 100644
--- a/profiling/config.m4
+++ b/profiling/config.m4
@@ -1,8 +1,11 @@
-PHP_ARG_ENABLE([datadog-profiling],
-  [whether to enable Datadog profiling support],
+AC_ARG_ENABLE([datadog-profiling],
   [AS_HELP_STRING([--enable-datadog-profiling],
     [Enable Datadog profiling support])],
-  [no])
+  [PHP_DATADOG_PROFILING=$enableval],
+  [PHP_DATADOG_PROFILING=yes])
+
+AC_MSG_CHECKING([whether to enable Datadog profiling support])
+AC_MSG_RESULT([$PHP_DATADOG_PROFILING])
 
 AC_ARG_ENABLE([datadog-profiling-debug],
   [AS_HELP_STRING([--enable-datadog-profiling-debug],

From 1afa3524022f4d58693cf68b57aee34ccee4111f Mon Sep 17 00:00:00 2001
From: Levi Morrison <levi.morrison@datadoghq.com>
Date: Sun, 1 Feb 2026 13:49:23 -0700
Subject: [PATCH 5/8] build: parse headers with libclang

---
 .gitlab/generate-profiler.php |   8 +++
 profiling/build.rs            | 123 +++++++++++++++++++---------------
 2 files changed, 77 insertions(+), 54 deletions(-)

diff --git a/.gitlab/generate-profiler.php b/.gitlab/generate-profiler.php
index a58260cb26a..775cca70b0e 100644
--- a/.gitlab/generate-profiler.php
+++ b/.gitlab/generate-profiler.php
@@ -46,6 +46,8 @@
 
     - '# NTS'
     - command -v switch-php && switch-php "${PHP_MAJOR_MINOR}"
+    - phpize
+    - ./configure --with-php-config="$(command -v php-config)"
     - cargo build --profile profiler-release --all-features
     - (cd ../; TEST_PHP_JUNIT="${CI_PROJECT_DIR}/artifacts/profiler-tests/nts-results.xml" php profiling/tests/run-tests.php -d "extension=/mnt/ramdisk/cargo/profiler-release/libdatadog_php_profiling.so" --show-diff -g "FAIL,XFAIL,BORK,WARN,LEAK,XLEAK,SKIP" "profiling/tests/phpt")
 
@@ -53,6 +55,8 @@
 
     - '# ZTS'
     - command -v switch-php && switch-php "${PHP_MAJOR_MINOR}-zts"
+    - phpize
+    - ./configure --with-php-config="$(command -v php-config)"
     - cargo build --profile profiler-release --all-features
     - (cd ../; TEST_PHP_JUNIT="${CI_PROJECT_DIR}/artifacts/profiler-tests/zts-results.xml" php profiling/tests/run-tests.php -d "extension=/mnt/ramdisk/cargo/profiler-release/libdatadog_php_profiling.so" --show-diff -g "FAIL,XFAIL,BORK,WARN,LEAK,XLEAK,SKIP" "profiling/tests/phpt")
   after_script:
@@ -85,6 +89,8 @@
   script:
     - switch-php nts # not compatible with debug
     - cd profiling
+    - phpize
+    - ./configure --with-php-config="$(command -v php-config)"
     - sed -i -e "s/crate-type.*$/crate-type = [\"rlib\"]/g" Cargo.toml
     - cargo clippy --all-targets --all-features -- -D warnings -Aunknown-lints
 
@@ -101,4 +107,6 @@
   script:
     - switch-php nts # not compatible with debug
     - cd profiling
+    - phpize
+    - ./configure --with-php-config="$(command -v php-config)"
     - cargo test --all-features
diff --git a/profiling/build.rs b/profiling/build.rs
index 7ee2cc5feaf..b306957a260 100644
--- a/profiling/build.rs
+++ b/profiling/build.rs
@@ -3,15 +3,14 @@ use std::collections::HashMap;
 use std::collections::HashSet;
 use std::path::Path;
 use std::path::PathBuf;
-use std::process::Command;
-use std::sync::OnceLock;
+use std::sync::{Arc, Mutex, OnceLock};
 use std::{env, fs};
 
 fn main() {
     let php_includes = build_var("PHP_INCLUDES");
     let php_include_dir = build_var("PHP_INCLUDE_DIR");
     let php_prefix = build_var("PHP_PREFIX");
-    let php_version_id = php_version_id();
+    let php_version_id = php_version_id(&php_includes, &php_include_dir);
 
     // Read the version from the VERSION file
     let version = fs::read_to_string("../VERSION")
@@ -43,7 +42,7 @@ fn main() {
 
     cfg_php_major_version(vernum);
     cfg_php_feature_flags(vernum);
-    cfg_zts(&php_include_dir);
+    cfg_zts_from_headers(&php_include_dir);
 }
 
 fn build_var(name: &str) -> String {
@@ -57,11 +56,17 @@ Run phpize && ./configure to generate Makefile."
     )
 }
 
-fn php_version_id() -> u64 {
-    build_var("PHP_VERSION_ID")
-        .trim()
-        .parse::<u64>()
-        .expect("PHP_VERSION_ID must be a number and fit in u64")
+fn php_version_id(php_includes: &str, php_include_dir: &str) -> u64 {
+    let macros = php_header_macros(
+        "main/php_version.h",
+        php_includes,
+        php_include_dir,
+        &["PHP_VERSION_ID"],
+    );
+    macros
+        .get("PHP_VERSION_ID")
+        .copied()
+        .unwrap_or_else(|| panic!("PHP_VERSION_ID not found in php_config.h")) as u64
 }
 
 fn makefile_vars() -> Option<&'static HashMap<String, String>> {
@@ -407,56 +412,66 @@ fn cfg_php_feature_flags(vernum: u64) {
     }
 }
 
-fn cfg_zts(php_include_dir: &str) {
+fn cfg_zts_from_headers(php_include_dir: &str) {
     println!("cargo::rustc-check-cfg=cfg(php_zts)");
-
-    // Create a temporary C file to probe ZTS
-    let out_dir = env::var("OUT_DIR").unwrap();
-    let probe_path = Path::new(&out_dir).join("zts_probe.c");
-    fs::write(
-        &probe_path,
-        r#"
-#include "main/php_config.h"
-#include <stdio.h>
-int main() {
-#ifdef ZTS
-    printf("1");
-#else
-    printf("0");
-#endif
-    return 0;
+    if php_header_macros("main/php_config.h", "", php_include_dir, &["ZTS"])
+        .get("ZTS")
+        .copied()
+        .unwrap_or(0)
+        != 0
+    {
+        println!("cargo:rustc-cfg=php_zts");
+    }
 }
-"#,
-    )
-    .expect("Failed to write ZTS probe file");
-
-    // Get the C compiler from cc crate
-    let compiler = cc::Build::new().get_compiler();
-
-    // Compile the probe to an executable
-    let probe_exe = Path::new(&out_dir).join("zts_probe");
-    let compile_status = Command::new(compiler.path())
-        .arg(format!("-I{}", php_include_dir.trim()))
-        .arg(&probe_path)
-        .arg("-o")
-        .arg(&probe_exe)
-        .status()
-        .expect("Failed to compile ZTS probe");
-
-    if !compile_status.success() {
-        panic!("Failed to compile ZTS probe");
+
+fn php_header_macros(
+    header: &str,
+    php_includes: &str,
+    php_include_dir: &str,
+    interested: &[&str],
+) -> HashMap<String, i64> {
+    let header_path = Path::new(php_include_dir.trim()).join(header);
+    println!("cargo:rerun-if-changed={}", header_path.display());
+
+    let macros = Arc::new(Mutex::new(HashMap::<String, i64>::new()));
+    let callbacks = MacroCollector {
+        macros: Arc::clone(&macros),
+        interested: interested.iter().map(|s| s.to_string()).collect(),
+    };
+
+    let mut builder = bindgen::Builder::default()
+        .header(header_path.to_string_lossy().to_string())
+        .parse_callbacks(Box::new(callbacks));
+
+    for arg in php_includes.split_whitespace() {
+        builder = builder.clang_arg(arg);
+    }
+    if !php_include_dir.trim().is_empty() {
+        builder = builder.clang_arg(format!("-I{}", php_include_dir.trim()));
     }
 
-    // Run the probe
-    let probe_output = Command::new(&probe_exe)
-        .output()
-        .expect("Failed to run ZTS probe");
+    builder
+        .generate()
+        .expect("bindgen failed to parse PHP headers");
 
-    let zts_value = std::str::from_utf8(&probe_output.stdout)
-        .expect("ZTS probe output not UTF-8")
-        .trim();
+    let map = macros.lock().unwrap();
+    map.clone()
+}
 
-    if zts_value == "1" {
-        println!("cargo:rustc-cfg=php_zts");
+#[derive(Debug)]
+struct MacroCollector {
+    macros: Arc<Mutex<HashMap<String, i64>>>,
+    interested: HashSet<String>,
+}
+
+impl bindgen::callbacks::ParseCallbacks for MacroCollector {
+    fn int_macro(&self, name: &str, value: i64) -> Option<IntKind> {
+        if self.interested.contains(name) {
+            self.macros
+                .lock()
+                .expect("macro map lock to succeed")
+                .insert(name.to_string(), value);
+        }
+        None
     }
 }

From 05d23bc9635e0878d65f09525f32de932b5f7c67 Mon Sep 17 00:00:00 2001
From: Levi Morrison <levi.morrison@datadoghq.com>
Date: Sun, 1 Feb 2026 14:00:41 -0700
Subject: [PATCH 6/8] ci: more phpize + configure

---
 .gitlab/build-profiler.sh | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/.gitlab/build-profiler.sh b/.gitlab/build-profiler.sh
index c4182c48817..d7b18e961ca 100755
--- a/.gitlab/build-profiler.sh
+++ b/.gitlab/build-profiler.sh
@@ -38,6 +38,8 @@ else
 fi
 
 cd profiling
+phpize
+./configure --with-php-config="$(command -v php-config)"
 CARGO_TARGET_DIR="${CARGO_TARGET_DIR:-target}"
 echo "${CARGO_TARGET_DIR}"
 if [ "$thread_safety" = "zts" ]; then

From 19bca93d28a7af5418dbaff89a848ee6c922f146 Mon Sep 17 00:00:00 2001
From: Levi Morrison <levi.morrison@datadoghq.com>
Date: Sun, 1 Feb 2026 14:15:15 -0700
Subject: [PATCH 7/8] ci: try to fix benchmarks-profiler

---
 .gitlab/benchmarks.yml | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/.gitlab/benchmarks.yml b/.gitlab/benchmarks.yml
index f3bcf724fe5..08e6edd390b 100644
--- a/.gitlab/benchmarks.yml
+++ b/.gitlab/benchmarks.yml
@@ -110,6 +110,10 @@ workflow:
       fi
     - git clone --branch dd-trace-php https://gitlab-ci-token:${CI_JOB_TOKEN}@gitlab.ddbuild.io/DataDog/benchmarking-platform /platform && cd /platform
     - ./steps/capture-hardware-software-info.sh
+    - cd "${CI_PROJECT_DIR}/profiling"
+    - phpize
+    - ./configure --with-php-config="$(command -v php-config)"
+    - cd /platform
     - BP_SCENARIO=$SCENARIO bp-runner bp-runner.yml --debug -t
     - ./steps/analyze-results.sh
     - "./steps/upload-results-to-s3.sh || :"

From d2bc90ab740c02ca7ddbf3be5ac35572d933fe44 Mon Sep 17 00:00:00 2001
From: Levi Morrison <levi.morrison@datadoghq.com>
Date: Sun, 1 Feb 2026 15:07:52 -0700
Subject: [PATCH 8/8] ci: try to fix benchmarks-profiler 2

---
 .gitlab/benchmarks.yml | 4 ----
 benchmark/runall.sh    | 3 +++
 2 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/.gitlab/benchmarks.yml b/.gitlab/benchmarks.yml
index 08e6edd390b..f3bcf724fe5 100644
--- a/.gitlab/benchmarks.yml
+++ b/.gitlab/benchmarks.yml
@@ -110,10 +110,6 @@ workflow:
       fi
     - git clone --branch dd-trace-php https://gitlab-ci-token:${CI_JOB_TOKEN}@gitlab.ddbuild.io/DataDog/benchmarking-platform /platform && cd /platform
     - ./steps/capture-hardware-software-info.sh
-    - cd "${CI_PROJECT_DIR}/profiling"
-    - phpize
-    - ./configure --with-php-config="$(command -v php-config)"
-    - cd /platform
     - BP_SCENARIO=$SCENARIO bp-runner bp-runner.yml --debug -t
     - ./steps/analyze-results.sh
     - "./steps/upload-results-to-s3.sh || :"
diff --git a/benchmark/runall.sh b/benchmark/runall.sh
index 7f0a5eeafb9..58f18b84e77 100755
--- a/benchmark/runall.sh
+++ b/benchmark/runall.sh
@@ -6,6 +6,9 @@ if [ "$SCENARIO" = "profiler" ]; then
   # Run Profiling Benchmarks
   cd ../profiling/
 
+  phpize
+  ./configure --with-php-config="$(command -v php-config)"
+
   cargo build --release --features trigger_time_sample
 
   sirun benches/timeline.json > "$ARTIFACTS_DIR/sirun_timeline.ndjson"