From 206dcfca1f5cfac344bd88e5ed4b6a095014b91f Mon Sep 17 00:00:00 2001
From: James Clark <james.clark@linaro.org>
Date: Tue, 10 Sep 2024 15:04:00 +0100
Subject: perf build: Autodetect minimum required llvm-dev version

The new LLVM addr2line feature requires a minimum version of 13 to
compile. Add a feature check for the version so that NO_LLVM=1 doesn't
need to be explicitly added. Leave the existing llvm feature check
intact because it's used by tools other than Perf.

This fixes the following compilation error when the llvm-dev version
doesn't match:

  util/llvm-c-helpers.cpp: In function 'char* llvm_name_for_code(dso*, const char*, u64)':
  util/llvm-c-helpers.cpp:178:21: error: 'std::remove_reference_t<llvm::DILineInfo>' {aka 'struct llvm::DILineInfo'} has no member named 'StartAddress'
    178 |   addr, res_or_err->StartAddress ? *res_or_err->StartAddress : 0);

Fixes: c3f8644c21df9b7d ("perf report: Support LLVM for addr2line()")
Signed-off-by: James Clark <james.clark@linaro.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Bill Wendling <morbo@google.com>
Cc: Changbin Du <changbin.du@huawei.com>
Cc: Guilherme Amadio <amadio@gentoo.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Justin Stitt <justinstitt@google.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@arm.com>
Cc: Manu Bretelle <chantr4@gmail.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Monnet <qmo@kernel.org>
Cc: Steinar H. Gunderson <sesse@google.com>
Link: https://lore.kernel.org/r/20240910140405.568791-1-james.clark@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/build/Makefile.feature           |  2 +-
 tools/build/feature/Makefile           |  9 +++++++++
 tools/build/feature/test-llvm-perf.cpp | 14 ++++++++++++++
 3 files changed, 24 insertions(+), 1 deletion(-)
 create mode 100644 tools/build/feature/test-llvm-perf.cpp

(limited to 'tools/build')

diff --git a/tools/build/Makefile.feature b/tools/build/Makefile.feature
index 0717e96d6a0e..427a9389e26c 100644
--- a/tools/build/Makefile.feature
+++ b/tools/build/Makefile.feature
@@ -136,7 +136,7 @@ FEATURE_DISPLAY ?=              \
          libunwind              \
          libdw-dwarf-unwind     \
          libcapstone            \
-         llvm                   \
+         llvm-perf              \
          zlib                   \
          lzma                   \
          get_cpuid              \
diff --git a/tools/build/feature/Makefile b/tools/build/feature/Makefile
index 12796808f07a..d6a98b3854f8 100644
--- a/tools/build/feature/Makefile
+++ b/tools/build/feature/Makefile
@@ -73,6 +73,7 @@ FILES=                                          \
          test-libopencsd.bin			\
          test-clang.bin				\
          test-llvm.bin				\
+         test-llvm-perf.bin   \
          test-llvm-version.bin			\
          test-libaio.bin			\
          test-libzstd.bin			\
@@ -388,6 +389,14 @@ $(OUTPUT)test-llvm.bin:
 		$(shell $(LLVM_CONFIG) --system-libs)		\
 		> $(@:.bin=.make.output) 2>&1
 
+$(OUTPUT)test-llvm-perf.bin:
+	$(BUILDXX) -std=gnu++17 				\
+		-I$(shell $(LLVM_CONFIG) --includedir) 		\
+		-L$(shell $(LLVM_CONFIG) --libdir)		\
+		$(shell $(LLVM_CONFIG) --libs Core BPF)		\
+		$(shell $(LLVM_CONFIG) --system-libs)		\
+		> $(@:.bin=.make.output) 2>&1
+
 $(OUTPUT)test-llvm-version.bin:
 	$(BUILDXX) -std=gnu++17					\
 		-I$(shell $(LLVM_CONFIG) --includedir)		\
diff --git a/tools/build/feature/test-llvm-perf.cpp b/tools/build/feature/test-llvm-perf.cpp
new file mode 100644
index 000000000000..a8cbb67e335e
--- /dev/null
+++ b/tools/build/feature/test-llvm-perf.cpp
@@ -0,0 +1,14 @@
+// SPDX-License-Identifier: GPL-2.0
+#include "llvm/Support/ManagedStatic.h"
+#include "llvm/Support/raw_ostream.h"
+
+#if LLVM_VERSION_MAJOR < 13
+# error "Perf requires llvm-devel/llvm-dev version 13 or greater"
+#endif
+
+int main()
+{
+	llvm::errs() << "Hello World!\n";
+	llvm::llvm_shutdown();
+	return 0;
+}
-- 
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