[clang] [clang][Driver] Fix libc++ include path on FreeBSD (PR #212725)
Rainer Orth via cfe-commits
cfe-commits at lists.llvm.org
Sun Aug 2 05:25:13 PDT 2026
https://github.com/rorth updated https://github.com/llvm/llvm-project/pull/212725
>From 6c1e69756696c56672c678a111fdb5b0f4bd2005 Mon Sep 17 00:00:00 2001
From: Rainer Orth <ro at gcc.gnu.org>
Date: Wed, 29 Jul 2026 11:27:31 +0200
Subject: [PATCH 1/3] [clang][Driver] Fix libc++ include path on FreeBSD
`clang++` defaults to `-stdlib=libc++` on FreeBSD. When building with both
`clang` and `libcxx` included, the freshly built `clang++` uses the system
version of the `libc++` headers. However, this is from the bundled
`libc++` 19.1.7, thus inconsistent with the `libc++` being built.
Similarly to the NetBSD case, FreeBSD has its own version of
addLibCxxIncludePaths which just includes `/usr/include/c++/v1`.
Rather than replicating the generic version in `Gnu.cpp`, this patch just
calls `Generic_GCC::addLibCxxIncludePaths`.
Tested on `amd64-pc-freebsd15.1`.
This breaks the `Driver/freebsd.cpp` and `Driver/freebsd-include-paths.c`
testcases. Once it can be confirmed the approach is sound, I'll update
them accordingly.
---
clang/lib/Driver/ToolChains/FreeBSD.cpp | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/clang/lib/Driver/ToolChains/FreeBSD.cpp b/clang/lib/Driver/ToolChains/FreeBSD.cpp
index 724ccbefd790f..519999a9a5bcf 100644
--- a/clang/lib/Driver/ToolChains/FreeBSD.cpp
+++ b/clang/lib/Driver/ToolChains/FreeBSD.cpp
@@ -10,6 +10,7 @@
#include "Arch/ARM.h"
#include "Arch/Mips.h"
#include "Arch/Sparc.h"
+#include "Gnu.h"
#include "clang/Config/config.h"
#include "clang/Driver/CommonArgs.h"
#include "clang/Driver/Compilation.h"
@@ -434,8 +435,7 @@ void FreeBSD::AddClangSystemIncludeArgs(
void FreeBSD::addLibCxxIncludePaths(const llvm::opt::ArgList &DriverArgs,
llvm::opt::ArgStringList &CC1Args) const {
- addSystemInclude(DriverArgs, CC1Args,
- concat(getDriver().SysRoot, "/usr/include/c++/v1"));
+ Generic_GCC::addLibCxxIncludePaths(DriverArgs, CC1Args);
}
void FreeBSD::AddCXXStdlibLibArgs(const ArgList &Args,
>From 3cc4ebdf09c0595114044949fef1c37b206b5cb2 Mon Sep 17 00:00:00 2001
From: Rainer Orth <ro at gcc.gnu.org>
Date: Thu, 30 Jul 2026 17:00:50 +0200
Subject: [PATCH 2/3] Remove FreeBSD::addLibCxxIncludePaths. Add testcases.
---
clang/lib/Driver/ToolChains/FreeBSD.cpp | 6 ------
clang/lib/Driver/ToolChains/FreeBSD.h | 2 --
clang/test/Driver/freebsd-include-paths.c | 3 ++-
clang/test/Driver/freebsd.cpp | 6 ++++--
4 files changed, 6 insertions(+), 11 deletions(-)
diff --git a/clang/lib/Driver/ToolChains/FreeBSD.cpp b/clang/lib/Driver/ToolChains/FreeBSD.cpp
index 519999a9a5bcf..dcf2973c364d1 100644
--- a/clang/lib/Driver/ToolChains/FreeBSD.cpp
+++ b/clang/lib/Driver/ToolChains/FreeBSD.cpp
@@ -10,7 +10,6 @@
#include "Arch/ARM.h"
#include "Arch/Mips.h"
#include "Arch/Sparc.h"
-#include "Gnu.h"
#include "clang/Config/config.h"
#include "clang/Driver/CommonArgs.h"
#include "clang/Driver/Compilation.h"
@@ -433,11 +432,6 @@ void FreeBSD::AddClangSystemIncludeArgs(
concat(D.SysRoot, "/usr/include"));
}
-void FreeBSD::addLibCxxIncludePaths(const llvm::opt::ArgList &DriverArgs,
- llvm::opt::ArgStringList &CC1Args) const {
- Generic_GCC::addLibCxxIncludePaths(DriverArgs, CC1Args);
-}
-
void FreeBSD::AddCXXStdlibLibArgs(const ArgList &Args,
ArgStringList &CmdArgs) const {
Generic_ELF::AddCXXStdlibLibArgs(Args, CmdArgs);
diff --git a/clang/lib/Driver/ToolChains/FreeBSD.h b/clang/lib/Driver/ToolChains/FreeBSD.h
index 55400e17b5ea4..a8f4226a88274 100644
--- a/clang/lib/Driver/ToolChains/FreeBSD.h
+++ b/clang/lib/Driver/ToolChains/FreeBSD.h
@@ -69,8 +69,6 @@ class LLVM_LIBRARY_VISIBILITY FreeBSD : public Generic_ELF {
return ToolChain::CST_Libcxx;
}
- void addLibCxxIncludePaths(const llvm::opt::ArgList &DriverArgs,
- llvm::opt::ArgStringList &CC1Args) const override;
void AddCXXStdlibLibArgs(const llvm::opt::ArgList &Args,
llvm::opt::ArgStringList &CmdArgs) const override;
void AddCudaIncludeArgs(const llvm::opt::ArgList &DriverArgs,
diff --git a/clang/test/Driver/freebsd-include-paths.c b/clang/test/Driver/freebsd-include-paths.c
index 872b2386ce9f1..be8104c9ce7ce 100644
--- a/clang/test/Driver/freebsd-include-paths.c
+++ b/clang/test/Driver/freebsd-include-paths.c
@@ -11,6 +11,7 @@
// RUN: %clang -### -xc++ %s --target=x86_64-unknown-freebsd13.1 2>&1 \
// RUN: | FileCheck %s --check-prefix=DRIVER-PASS-INCLUDES-CXX
// DRIVER-PASS-INCLUDES-CXX: "-cc1" {{.*}}"-resource-dir" "[[RESOURCE:[^"]+]]"
-// DRIVER-PASS-INCLUDES-CXX-SAME: "-internal-isystem" "/usr/include/c++/v1"
+// DRIVER-PASS-INCLUDES-CXX-SAME: "-internal-isystem" "{{.*}}bin/../include/c++/v1"
+// DRIVER-PASS-INCLUDES-CXX-NOT: "-internal-isystem" "/usr/include/c++/v1"
// DRIVER-PASS-INCLUDES-CXX-SAME: {{^}} "-internal-isystem" "[[RESOURCE]]/include"
// DRIVER-PASS-INCLUDES-CXX-SAME: {{^}} "-internal-externc-isystem" "/usr/include"
diff --git a/clang/test/Driver/freebsd.cpp b/clang/test/Driver/freebsd.cpp
index e2f76cd013f7f..6b60be0594e9a 100644
--- a/clang/test/Driver/freebsd.cpp
+++ b/clang/test/Driver/freebsd.cpp
@@ -27,7 +27,8 @@
// RUN: | FileCheck --check-prefix=CHECK-LIBCXX-SYSROOT %s
// CHECK-LIBCXX-SYSROOT: "-cc1"
// CHECK-LIBCXX-SYSROOT-SAME: "-isysroot" "[[SYSROOT:[^"]+]]"
-// CHECK-LIBCXX-SYSROOT-SAME: "-internal-isystem" "[[SYSROOT]]/usr/include/c++/v1"
+// CHECK-LIBCXX-SYSROOT-SAME: "-internal-isystem" "{{.*}}/bin/../include/c++/v1"
+// CHECK-LIBCXX-SYSROOT-NOT: "-internal-isystem" "[[SYSROOT]]/usr/include/c++/v1"
// Test include paths when the sysroot path ends with `/`.
// RUN: %clangxx %s -### -fsyntax-only 2>&1 \
@@ -37,4 +38,5 @@
// RUN: | FileCheck --check-prefix=CHECK-LIBCXX-SYSROOT-SLASH %s
// CHECK-LIBCXX-SYSROOT-SLASH: "-cc1"
// CHECK-LIBCXX-SYSROOT-SLASH-SAME: "-isysroot" "[[SYSROOT:[^"]+/]]"
-// CHECK-LIBCXX-SYSROOT-SLASH-SAME: "-internal-isystem" "[[SYSROOT]]usr/include/c++/v1"
+// CHECK-LIBCXX-SYSROOT-SLASH-SAME: "-internal-isystem" "{{.*}}/bin/../include/c++/v1"
+// CHECK-LIBCXX-SYSROOT-SLASH-NOT: "-internal-isystem" "[[SYSROOT]]usr/include/c++/v1"
>From 05af7f0de9376917c191e69d6bf49763d4138359 Mon Sep 17 00:00:00 2001
From: Rainer Orth <ro at gcc.gnu.org>
Date: Sun, 2 Aug 2026 13:18:06 +0200
Subject: [PATCH 3/3] Add install_tree_without_libcxx for reproducability. New
DRIVER-INSTALL-INCLUDES test.
---
clang/lib/Driver/ToolChains/FreeBSD.cpp | 6 ++++++
clang/lib/Driver/ToolChains/FreeBSD.h | 2 ++
.../Inputs/install_tree_without_libcxx/bin/.keep | 0
.../install_tree_without_libcxx/include/.keep | 0
.../Inputs/install_tree_without_libcxx/lib/.keep | 0
clang/test/Driver/freebsd-include-paths.c | 7 ++++---
clang/test/Driver/freebsd.cpp | 16 ++++++++++++----
7 files changed, 24 insertions(+), 7 deletions(-)
create mode 100644 clang/test/Driver/Inputs/install_tree_without_libcxx/bin/.keep
create mode 100644 clang/test/Driver/Inputs/install_tree_without_libcxx/include/.keep
create mode 100644 clang/test/Driver/Inputs/install_tree_without_libcxx/lib/.keep
diff --git a/clang/lib/Driver/ToolChains/FreeBSD.cpp b/clang/lib/Driver/ToolChains/FreeBSD.cpp
index dcf2973c364d1..724ccbefd790f 100644
--- a/clang/lib/Driver/ToolChains/FreeBSD.cpp
+++ b/clang/lib/Driver/ToolChains/FreeBSD.cpp
@@ -432,6 +432,12 @@ void FreeBSD::AddClangSystemIncludeArgs(
concat(D.SysRoot, "/usr/include"));
}
+void FreeBSD::addLibCxxIncludePaths(const llvm::opt::ArgList &DriverArgs,
+ llvm::opt::ArgStringList &CC1Args) const {
+ addSystemInclude(DriverArgs, CC1Args,
+ concat(getDriver().SysRoot, "/usr/include/c++/v1"));
+}
+
void FreeBSD::AddCXXStdlibLibArgs(const ArgList &Args,
ArgStringList &CmdArgs) const {
Generic_ELF::AddCXXStdlibLibArgs(Args, CmdArgs);
diff --git a/clang/lib/Driver/ToolChains/FreeBSD.h b/clang/lib/Driver/ToolChains/FreeBSD.h
index a8f4226a88274..55400e17b5ea4 100644
--- a/clang/lib/Driver/ToolChains/FreeBSD.h
+++ b/clang/lib/Driver/ToolChains/FreeBSD.h
@@ -69,6 +69,8 @@ class LLVM_LIBRARY_VISIBILITY FreeBSD : public Generic_ELF {
return ToolChain::CST_Libcxx;
}
+ void addLibCxxIncludePaths(const llvm::opt::ArgList &DriverArgs,
+ llvm::opt::ArgStringList &CC1Args) const override;
void AddCXXStdlibLibArgs(const llvm::opt::ArgList &Args,
llvm::opt::ArgStringList &CmdArgs) const override;
void AddCudaIncludeArgs(const llvm::opt::ArgList &DriverArgs,
diff --git a/clang/test/Driver/Inputs/install_tree_without_libcxx/bin/.keep b/clang/test/Driver/Inputs/install_tree_without_libcxx/bin/.keep
new file mode 100644
index 0000000000000..e69de29bb2d1d
diff --git a/clang/test/Driver/Inputs/install_tree_without_libcxx/include/.keep b/clang/test/Driver/Inputs/install_tree_without_libcxx/include/.keep
new file mode 100644
index 0000000000000..e69de29bb2d1d
diff --git a/clang/test/Driver/Inputs/install_tree_without_libcxx/lib/.keep b/clang/test/Driver/Inputs/install_tree_without_libcxx/lib/.keep
new file mode 100644
index 0000000000000..e69de29bb2d1d
diff --git a/clang/test/Driver/freebsd-include-paths.c b/clang/test/Driver/freebsd-include-paths.c
index be8104c9ce7ce..96c97d9ea276c 100644
--- a/clang/test/Driver/freebsd-include-paths.c
+++ b/clang/test/Driver/freebsd-include-paths.c
@@ -9,9 +9,10 @@
// Check that the driver passes include paths to cc1 on FreeBSD in C++ mode.
// RUN: %clang -### -xc++ %s --target=x86_64-unknown-freebsd13.1 2>&1 \
+// RUN: -ccc-install-dir %S/Inputs/install_tree_without_libcxx/bin \
+// RUN: --sysroot=%S/Inputs/basic_freebsd_libcxx_tree \
// RUN: | FileCheck %s --check-prefix=DRIVER-PASS-INCLUDES-CXX
// DRIVER-PASS-INCLUDES-CXX: "-cc1" {{.*}}"-resource-dir" "[[RESOURCE:[^"]+]]"
-// DRIVER-PASS-INCLUDES-CXX-SAME: "-internal-isystem" "{{.*}}bin/../include/c++/v1"
-// DRIVER-PASS-INCLUDES-CXX-NOT: "-internal-isystem" "/usr/include/c++/v1"
+// DRIVER-PASS-INCLUDES-CXX-SAME: "-internal-isystem" "{{.*}}/usr/include/c++/v1"
// DRIVER-PASS-INCLUDES-CXX-SAME: {{^}} "-internal-isystem" "[[RESOURCE]]/include"
-// DRIVER-PASS-INCLUDES-CXX-SAME: {{^}} "-internal-externc-isystem" "/usr/include"
+// DRIVER-PASS-INCLUDES-CXX-SAME: {{^}} "-internal-externc-isystem" "{{.*}}/usr/include"
diff --git a/clang/test/Driver/freebsd.cpp b/clang/test/Driver/freebsd.cpp
index 6b60be0594e9a..0fe7bbd9c219c 100644
--- a/clang/test/Driver/freebsd.cpp
+++ b/clang/test/Driver/freebsd.cpp
@@ -19,24 +19,32 @@
// CHECK-PG-FOURTEEN: "-lc++" "-lm"
// CHECK-PG-TEN: "-lc++_p" "-lm_p"
+// Test that FreeBSD prefers install tree libc++ headers over system ones.
+// RUN: %clang -### %s --target=amd64-unknown-freebsd -r 2>&1 \
+// RUN: -ccc-install-dir %S/Inputs/install_tree_with_libcxx/bin \
+// RUN: --sysroot=%S/Inputs/basic_freebsd_libcxx_tree \
+// RUN: | FileCheck %s --check-prefix=DRIVER-INSTALL-INCLUDES
+// DRIVER-INSTALL-INCLUDES: "-internal-isystem" "{{.*}}bin[[SEP:/|\\\\]]..[[SEP]]include[[SEP]]c++[[SEP]]v1"
+// DRIVER-INSTALL-INCLUDES-NOT: "-internal-isystem" "{{.*}}[[SEP]]/usr[[SEP]]include[[SEP]]c++[[SEP]]v1"
+
// Test include paths with a sysroot.
// RUN: %clangxx %s -### -fsyntax-only 2>&1 \
// RUN: --target=amd64-unknown-freebsd \
+// RUN: -ccc-install-dir %S/Inputs/install_tree_without_libcxx/bin \
// RUN: --sysroot=%S/Inputs/basic_openbsd_libcxx_tree \
// RUN: -resource-dir=%S/Inputs/resource_dir \
// RUN: | FileCheck --check-prefix=CHECK-LIBCXX-SYSROOT %s
// CHECK-LIBCXX-SYSROOT: "-cc1"
// CHECK-LIBCXX-SYSROOT-SAME: "-isysroot" "[[SYSROOT:[^"]+]]"
-// CHECK-LIBCXX-SYSROOT-SAME: "-internal-isystem" "{{.*}}/bin/../include/c++/v1"
-// CHECK-LIBCXX-SYSROOT-NOT: "-internal-isystem" "[[SYSROOT]]/usr/include/c++/v1"
+// CHECK-LIBCXX-SYSROOT-SAME: "-internal-isystem" "[[SYSROOT]]/usr/include/c++/v1"
// Test include paths when the sysroot path ends with `/`.
// RUN: %clangxx %s -### -fsyntax-only 2>&1 \
// RUN: --target=amd64-unknown-freebsd \
+// RUN: -ccc-install-dir %S/Inputs/install_tree_without_libcxx/bin \
// RUN: --sysroot=%S/Inputs/basic_openbsd_libcxx_tree/ \
// RUN: -resource-dir=%S/Inputs/resource_dir \
// RUN: | FileCheck --check-prefix=CHECK-LIBCXX-SYSROOT-SLASH %s
// CHECK-LIBCXX-SYSROOT-SLASH: "-cc1"
// CHECK-LIBCXX-SYSROOT-SLASH-SAME: "-isysroot" "[[SYSROOT:[^"]+/]]"
-// CHECK-LIBCXX-SYSROOT-SLASH-SAME: "-internal-isystem" "{{.*}}/bin/../include/c++/v1"
-// CHECK-LIBCXX-SYSROOT-SLASH-NOT: "-internal-isystem" "[[SYSROOT]]usr/include/c++/v1"
+// CHECK-LIBCXX-SYSROOT-SLASH-SAME: "-internal-isystem" "[[SYSROOT]]usr/include/c++/v1"
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