Pass CFLAGS detected by kbuild detector to builtin clang so BPF scripts
can use kernel headers like external clang compiler.
Test:
# perf record --dry-run -e tools/perf/tests/bpf-script-test-kbuild.c ls 2>&1 |
grep built
bpf: builtin compiling successful
Signed-off-by: Wang Nan <wangn...@huawei.com>
Cc: Arnaldo Carvalho de Melo <a...@redhat.com>
Cc: Alexei Starovoitov <a...@fb.com>
Cc: He Kuang <heku...@huawei.com>
Cc: Jiri Olsa <jo...@kernel.org>
---
tools/perf/util/c++/clang.cpp | 76 +++++++++++++++++++++++++++++++++++++---
tools/perf/util/llvm-utils-cxx.h | 14 ++++++++
tools/perf/util/llvm-utils.h | 2 +-
3 files changed, 87 insertions(+), 5 deletions(-)
create mode 100644 tools/perf/util/llvm-utils-cxx.h
diff --git a/tools/perf/util/c++/clang.cpp b/tools/perf/util/c++/clang.cpp
index 812dd53..e8363b4 100644
--- a/tools/perf/util/c++/clang.cpp
+++ b/tools/perf/util/c++/clang.cpp
@@ -26,6 +26,8 @@
#include "clang.h"
#include "clang-c.h"
+#include "llvm-utils-cxx.h"
+#include "util-cxx.h"
namespace perf {
@@ -152,6 +154,72 @@ getBPFObjectFromModule(llvm::Module *Module)
return std::move(Buffer);
}
+class ClangOptions {
+ llvm::SmallString<PATH_MAX> FileName;
+ char *kbuild_dir;
+ char *kbuild_include_opts;
+ llvm::SmallString<64> kernel_ver_def;
+public:
+ ClangOptions(const char *filename) : FileName(filename),
+ kbuild_dir(NULL),
+ kbuild_include_opts(NULL),
+ kernel_ver_def("")
+ {
+ llvm::sys::fs::make_absolute(FileName);
+
+ unsigned int kernel_ver;
+ if (!fetch_kernel_version(&kernel_ver, NULL, 0))
+ kernel_ver_def = "-DLINUX_VERSION_CODE=" +
std::to_string(kernel_ver);
+
+ llvm__get_kbuild_opts(&kbuild_dir, &kbuild_include_opts);
+ if (!kbuild_dir || !kbuild_include_opts) {
+ free(kbuild_dir);
+ free(kbuild_include_opts);
+ kbuild_dir = kbuild_include_opts = NULL;
+ }
+ }
+
+ ~ClangOptions()
+ {
+ free(kbuild_dir);
+ free(kbuild_include_opts);
+ }
+
+ void getCFlags(opt::ArgStringList &CFlags)
+ {
+ CFlags.push_back(kernel_ver_def.c_str());
+
+ if (!kbuild_dir || !kbuild_include_opts)
+ return;
+ CFlags.push_back("-working-directory");
+ CFlags.push_back(kbuild_dir);
+
+ SmallVector<StringRef, 0> Terms;
+ StringRef Opts(kbuild_include_opts);
+ Opts.split(Terms, ' ');
+
+ for (auto i = Terms.begin(); i != Terms.end(); i++)
+ kbuild_include_opts[i->end() - Opts.begin()] = '\0';
+
+ for (auto i = Terms.begin(); i != Terms.end(); i++) {
+ if (i->startswith("-I"))
+ CFlags.push_back(i->begin());
+ else if (*i == "-include") {
+ CFlags.push_back((i++)->begin());
+ /* Let clang report this error */
+ if (i == Terms.end())
+ break;
+ CFlags.push_back(i->begin());
+ }
+ }
+ }
+
+ const char *getFileName(void)
+ {
+ return FileName.c_str();
+ }
+};
+
}
extern "C" {
@@ -175,11 +243,11 @@ int perf_clang__compile_bpf(const char *_filename,
if (!p_obj_buf || !p_obj_buf_sz)
return -EINVAL;
- llvm::SmallString<PATH_MAX> FileName(_filename);
- llvm::sys::fs::make_absolute(FileName);
-
+ ClangOptions Opts(_filename);
llvm::opt::ArgStringList CFlags;
- auto M = getModuleFromSource(std::move(CFlags), FileName.data());
+
+ Opts.getCFlags(CFlags);
+ auto M = getModuleFromSource(std::move(CFlags), Opts.getFileName());
if (!M)
return -EINVAL;
auto O = getBPFObjectFromModule(&*M);
diff --git a/tools/perf/util/llvm-utils-cxx.h b/tools/perf/util/llvm-utils-cxx.h
new file mode 100644
index 0000000..1202230
--- /dev/null
+++ b/tools/perf/util/llvm-utils-cxx.h
@@ -0,0 +1,14 @@
+#ifndef PERF_UTIL_LLVM_UTILS_CXX_H
+#define PERF_UTIL_LLVM_UTILS_CXX_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include "llvm-utils.h"
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/tools/perf/util/llvm-utils.h b/tools/perf/util/llvm-utils.h
index d3f410d..f9f490b 100644
--- a/tools/perf/util/llvm-utils.h
+++ b/tools/perf/util/llvm-utils.h
@@ -5,7 +5,7 @@
#ifndef __LLVM_UTILS_H
#define __LLVM_UTILS_H
-#include "debug.h"
+#include <errno.h>
struct llvm_param {
/* Path of clang executable */
--
1.8.3.4
