/*===-- BasicBlockTracing.c - Support library for basic block tracing -----===*\ |* |* The LLVM Compiler Infrastructure |* |* This file was developed by the LLVM research group and is distributed under |* the University of Illinois Open Source License. See LICENSE.TXT for details. |* |*===----------------------------------------------------------------------===*| |* |* This file implements the call back routines for the basic block tracing |* instrumentation pass. This should be used with the -trace-basic-blocks |* LLVM pass. |* \*===----------------------------------------------------------------------===*/ #include "Profiling.h" #include <stdlib.h> #include <stdio.h> static unsigned *ArrayStart, *ArrayEnd, *ArrayCursor; /* WriteAndFlushBBTraceData - write out the currently accumulated trace data * and reset the cursor to point to the beginning of the buffer. */ static void WriteAndFlushBBTraceData () { write_profiling_data(BBTraceInfo, ArrayStart, (ArrayCursor - ArrayStart)); ArrayCursor = ArrayStart; } /* BBTraceAtExitHandler - When the program exits, just write out any remaining * data and free the trace buffer. */ static void BBTraceAtExitHandler() { WriteAndFlushBBTraceData (); free (ArrayStart); } /* llvm_trace_basic_block - called upon hitting a new basic block. */ void llvm_trace_basic_block (unsigned BBNum) { *ArrayCursor++ = BBNum; if (ArrayCursor == ArrayEnd) WriteAndFlushBBTraceData (); } /* llvm_start_basic_block_tracing - This is the main entry point of the basic * block tracing library. It is responsible for setting up the atexit * handler and allocating the trace buffer. */ int llvm_start_basic_block_tracing(int argc, const char **argv, unsigned *arrayStart, unsigned numElements) { int Ret; const unsigned BufferSize = 128 * 1024; unsigned ArraySize; Ret = save_arguments(argc, argv); /* Allocate a buffer to contain BB tracing data */ ArraySize = BufferSize / sizeof (unsigned); ArrayStart = malloc (ArraySize * sizeof (unsigned)); ArrayEnd = ArrayStart + ArraySize; ArrayCursor = ArrayStart; /* Set up the atexit handler. */ atexit (BBTraceAtExitHandler); return Ret; }