Add debugging functions for instructionAPI (#1640)

instructionAPI/CMakeLists.txt

@@ -3,6 +3,7 @@ include_guard(GLOBAL)
 include(DyninstLibrary)
 
 set(_sources
+    src/debug.C
     src/Instruction.C
     src/InstructionAST.C
     src/Operation.C
@@ -53,6 +54,7 @@ set(_public_headers
     h/Visitor.h)
 
 set(_private_headers
+    src/debug.h
     src/amdgpu_branchinsn_table.h
     src/AMDGPU/gfx940/InstructionDecoder-amdgpu-gfx940.h
     src/AMDGPU/gfx90a/InstructionDecoder-amdgpu-gfx90a.h

instructionAPI/src/debug.C

@@ -0,0 +1,36 @@
+#include "debug.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <mutex>
+
+namespace {
+  bool debug_decode = false;
+  std::once_flag init_flag{};
+
+  void init() {
+    std::call_once(init_flag,
+      []() noexcept {
+        if(getenv("INSTRUCTIONAPI_DEBUG_DECODE")) {
+            debug_decode = true;
+        }
+      }
+    );
+  }
+}
+
+namespace Dyninst { namespace InstructionAPI {
+
+  void decode_printf(const char *format, ...) {
+    if (NULL == format) return;
+
+    init();
+    if (!debug_decode) return;
+
+    va_list va;
+    va_start(va, format);
+    vfprintf(stderr, format, va);
+    va_end(va);
+  }
+
+}}

instructionAPI/src/debug.h

@@ -0,0 +1,42 @@
+/*
+ * See the dyninst/COPYRIGHT file for copyright information.
+ *
+ * We provide the Paradyn Tools (below described as "Paradyn")
+ * on an AS IS basis, and do not warrant its validity or performance.
+ * We reserve the right to update, modify, or discontinue this
+ * software at any time.  We shall have no obligation to supply such
+ * updates or modifications or any other form of support to you.
+ *
+ * By your use of Paradyn, you understand and agree that we (or any
+ * other person or entity with proprietary rights in Paradyn) are
+ * under no obligation to provide either maintenance services,
+ * update services, notices of latent defects, or correction of
+ * defects for Paradyn.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef DYNINST_INSTRUCTIONAPI_DEBUG_H
+#define DYNINST_INSTRUCTIONAPI_DEBUG_H
+
+#include "compiler_annotations.h"
+
+namespace Dyninst { namespace InstructionAPI {
+
+  void decode_printf(const char *format, ...) DYNINST_PRINTF_ANNOTATION(1, 2);
+
+}}
+
+#endif