From 4acf6c38cba2a494ef038daace332281290f90be Mon Sep 17 00:00:00 2001 From: Vedant Kumar Date: Tue, 7 Jun 2016 22:25:29 +0000 Subject: [PATCH] [docs] Coverage: Explain how to avoid static initializers git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@272067 91177308-0d34-0410-b5e6-96231b3b80d8 --- docs/SourceBasedCodeCoverage.rst | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/docs/SourceBasedCodeCoverage.rst b/docs/SourceBasedCodeCoverage.rst index 75ab258e8f..22420d97cd 100644 --- a/docs/SourceBasedCodeCoverage.rst +++ b/docs/SourceBasedCodeCoverage.rst @@ -185,6 +185,22 @@ Format compatibility guarantees into instrumented binaries. Tools must retain **backwards** compatibility with these formats. These formats are not forwards-compatible. +Using the profiling runtime without static initializers +======================================================= + +By default the compiler runtime uses a static initializer to determine the +profile output path and to register a writer function. To collect profiles +without using static initializers, do this manually: + +* Export a ``int __llvm_profile_runtime`` symbol. The linker won't pull in the + object file containing the profiling runtime's static initializer if this + symbol is defined. + +* Call ``__llvm_profile_initialize_file`` once. This parses + ``LLVM_PROFILE_FILE`` and sets the output path. + +* Call ``__llvm_profile_write_file`` to write out a profile. + Drawbacks and limitations ========================= -- 2.40.0