From c9cc89cd8e6dbc7a1965c23eb11aa1b7e5ae569a Mon Sep 17 00:00:00 2001
From: "Christoph M. Becker" <cmbecker69@gmx.de>
Date: Sat, 30 Nov 2024 11:34:28 +0100
Subject: [PATCH] Support --enable-sanitizer for MSVC builds

While it is already possible to enable ASan for MSVC (assuming Visual
Studio 2019 16.10 or later) by passing `/fsanitizer=address` in the
`CFLAGS`, it is only usable if `ZEND_DEBUG` is also enabled; otherwise
there are `STATUS_BACK_STACK` errors all the time.

Since it makes some sense to combine ASan instrumentation with debug
assertions enabled anyway (typical for fuzzing), we support the
configure option `--enable-sanitizer`, which is already supported for
Clang builds, also for MSVC builds.  Note that MSVC supports only ASan
for now; contrary to Clang which additionally supports UBSan on Windows.

Since ASan reports can be pretty useless without debug symbol
information, we require such builds to also produce PDBs (i.e.
`--enable-debug-pack`), but forbid actual debug builds (for performance
reasons, and because the way it is implemented it would not make sense;
that was already an issue with Clang builds with sanitizers enabled).

Closes GH-16999.
---
 UPGRADING                |  3 +++
 win32/build/config.w32   | 16 ++++++++++++++--
 win32/build/confutils.js | 10 ++++++++--
 3 files changed, 25 insertions(+), 4 deletions(-)

diff --git a/UPGRADING b/UPGRADING
index c319d7299a4..4891bee45fb 100644
--- a/UPGRADING
+++ b/UPGRADING
@@ -166,6 +166,9 @@ PHP 8.5 UPGRADE NOTES
   PHP_RELEASE_VERSION are now always numbers.  Previously, they have been
   strings for buildconf builds.
 
+* --enable-sanitzer is now supported for MSVC builds.  This enables ASan and
+  debug assertions, and is supported as of MSVC 16.9 and Windows 10.
+
 * COM:
   . The extension is now build shared by default; previously it defaulted to a
     static extension, although the official Windows binaries built a shared
diff --git a/win32/build/config.w32 b/win32/build/config.w32
index 2214b7341af..70e50891964 100644
--- a/win32/build/config.w32
+++ b/win32/build/config.w32
@@ -356,8 +356,20 @@ if (PHP_SECURITY_FLAGS == "yes") {
 }
 
 ARG_WITH("uncritical-warn-choke", "Disable some uncritical warnings", "yes");
-ARG_ENABLE("sanitizer", "Enable ASan and UBSan extensions", "no");
-if (CLANG_TOOLSET) {
+ARG_ENABLE("sanitizer", "Enable ASan (and UBSan) extensions", "no");
+if (PHP_SANITIZER == "yes" && PHP_DEBUG == "yes") {
+	ERROR("Use of both --enable-sanitizer and --enable-debug not allowed.");
+}
+if (PHP_SANITIZER == "yes" && PHP_DEBUG_PACK == "no") {
+	ERROR("--enable-sanitizer requires --enable-debug-pack");
+}
+if (VS_TOOLSET) {
+	if (PHP_SANITIZER == "yes") {
+		if (COMPILER_NUMERIC_VERSION < 1929) {
+			ERROR("MSVC at least 16.10 required for sanitation plugins");
+		}
+	}
+} else if (CLANG_TOOLSET) {
 	if (PHP_UNCRITICAL_WARN_CHOKE != "no") {
 		ADD_FLAG("CFLAGS", "-Wno-ignored-attributes -Wno-deprecated-declarations -Wno-missing-braces " +
 		"-Wno-logical-op-parentheses -Wno-msvc-include -Wno-invalid-source-encoding -Wno-unknown-pragmas " +
diff --git a/win32/build/confutils.js b/win32/build/confutils.js
index e2b3f5dcb04..c44a607af1c 100644
--- a/win32/build/confutils.js
+++ b/win32/build/confutils.js
@@ -1246,6 +1246,8 @@ function SAPI(sapiname, file_list, makefiletarget, cflags, obj_dir)
 	if (PHP_SANITIZER == "yes") {
 		if (CLANG_TOOLSET) {
 			add_asan_opts("CFLAGS_" + SAPI, "LIBS_" + SAPI, (is_lib ? "ARFLAGS_" : "LDFLAGS_") + SAPI);
+		} else if (VS_TOOLSET) {
+			ADD_FLAG("CFLAGS", "/fsanitize=address");
 		}
 	}
 
@@ -3442,8 +3444,12 @@ function toolset_setup_build_mode()
 			ADD_FLAG("LDFLAGS", "/incremental:no /debug /opt:ref,icf");
 		}
 		ADD_FLAG("CFLAGS", "/LD /MD");
-		if (PHP_SANITIZER == "yes" && CLANG_TOOLSET) {
-			ADD_FLAG("CFLAGS", "/Od /D NDebug /D NDEBUG /D ZEND_WIN32_NEVER_INLINE /D ZEND_DEBUG=0");
+		if (PHP_SANITIZER == "yes") {
+			if (VS_TOOLSET) {
+				ADD_FLAG("CFLAGS", "/Ox /U NDebug /U NDEBUG /D ZEND_DEBUG=1");
+			} else if (CLANG_TOOLSET) {
+				ADD_FLAG("CFLAGS", "/Od /D NDebug /D NDEBUG /D ZEND_WIN32_NEVER_INLINE /D ZEND_DEBUG=0");
+			}
 		} else {
 			// Equivalent to Release_TSInline build -> best optimization
 			ADD_FLAG("CFLAGS", "/Ox /D NDebug /D NDEBUG /GF /D ZEND_DEBUG=0");