From: Kostya Serebryany Date: Sat, 17 Sep 2016 05:03:05 +0000 (+0000) Subject: [sanitizer-coverage] change trace-pc to use 8-byte guards X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=028c96e26e17ac085fab03b5b02dafec8f9218cf;p=clang [sanitizer-coverage] change trace-pc to use 8-byte guards git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@281809 91177308-0d34-0410-b5e6-96231b3b80d8 --- diff --git a/docs/SanitizerCoverage.rst b/docs/SanitizerCoverage.rst index 906150014f..a4693fe2c3 100644 --- a/docs/SanitizerCoverage.rst +++ b/docs/SanitizerCoverage.rst @@ -331,24 +331,23 @@ on every edge: .. code-block:: none - if (guard_variable != 0xff) + if (guard_variable >= 0) __sanitizer_cov_trace_pc_guard(&guard_variable) -Every edge will have its own 1-byte `guard_variable`. -All such guard variables will reside in a dedicated section -(i.e. they essentially form an array). - -Similarly to `trace-pc,indirect-calls`, with `trace-pc-guards,indirect-calls` -``__sanitizer_cov_trace_pc_indirect(void *callee)`` will be inserted on every indirect call. +Every edge will have its own 8-byte `guard_variable`. The compler will also insert a module constructor that will call .. code-block:: c++ - // The guard section is the address range [start, stop). - __sanitizer_cov_trace_pc_guard_init(void *start, void *stop); + // The guards are [start, stop). + // This function may be called multiple times with the same values of start/stop. + __sanitizer_cov_trace_pc_guard_init(uint64_t *start, uint64_t *stop); + +Similarly to `trace-pc,indirect-calls`, with `trace-pc-guards,indirect-calls` +``__sanitizer_cov_trace_pc_indirect(void *callee)`` will be inserted on every indirect call. -The functions `__sanitizer_cov_trace_pc_guard[_init]` should be defined by the user. +The functions `__sanitizer_cov_trace_pc_*` should be defined by the user. Tracing data flow =================