feature: Add new environment variables for compiler cache

This patch add new environment variables to control compiler cache.
Works as follow: If persistent cache is set driver check if NEO_CACHE_DIR
is set. If not then driver checks XDG_CACHE_HOME - If exists
then driver create neo_compiler_cache folder, if
not then driver checks HOME directory. If each NEO_CACHE_DIR,
XDG_CACHE_HOME and HOME are not set then compiler cache is disabled.
Current support is for Linux only.

Signed-off-by: Diedrich, Kamil <kamil.diedrich@intel.com>

Related-To: NEO-4262

shared/source/compiler_interface/CMakeLists.txt

@@ -23,16 +23,19 @@ set(NEO_CORE_COMPILER_INTERFACE
     ${CMAKE_CURRENT_SOURCE_DIR}/intermediate_representations.h
     ${CMAKE_CURRENT_SOURCE_DIR}/linker.h
     ${CMAKE_CURRENT_SOURCE_DIR}/linker.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/os_compiler_cache_helper.h
     ${CMAKE_CURRENT_SOURCE_DIR}/tokenized_string.h
 )
 
 if(WIN32)
   list(APPEND NEO_CORE_COMPILER_INTERFACE
        ${CMAKE_CURRENT_SOURCE_DIR}/windows/compiler_cache_windows.cpp
+       ${CMAKE_CURRENT_SOURCE_DIR}/windows/os_compiler_cache_helper.cpp
   )
 else()
   list(APPEND NEO_CORE_COMPILER_INTERFACE
        ${CMAKE_CURRENT_SOURCE_DIR}/linux/compiler_cache_linux.cpp
+       ${CMAKE_CURRENT_SOURCE_DIR}/linux/os_compiler_cache_helper.cpp
   )
 endif()
 

shared/source/compiler_interface/linux/os_compiler_cache_helper.cpp

@@ -0,0 +1,57 @@
+/*
+ * Copyright (C) 2023 Intel Corporation
+ *
+ * SPDX-License-Identifier: MIT
+ *
+ */
+
+#include "shared/source/compiler_interface/os_compiler_cache_helper.h"
+
+#include "shared/source/os_interface/linux/sys_calls.h"
+#include "shared/source/utilities/debug_settings_reader.h"
+
+namespace NEO {
+bool createCompilerCachePath(std::string &cacheDir) {
+    if (NEO::SysCalls::pathExists(cacheDir)) {
+        if (NEO::SysCalls::pathExists(cacheDir + "neo_compiler_cache")) {
+            cacheDir = cacheDir + "neo_compiler_cache";
+            return true;
+        }
+
+        if (NEO::SysCalls::mkdir(cacheDir + "neo_compiler_cache") == 0) {
+            cacheDir = cacheDir + "neo_compiler_cache";
+            return true;
+        } else {
+            if (errno == EEXIST) {
+                cacheDir = cacheDir + "neo_compiler_cache";
+                return true;
+            }
+        }
+    }
+
+    cacheDir = "";
+    return false;
+}
+
+bool checkDefaultCacheDirSettings(std::string &cacheDir, SettingsReader *reader) {
+    std::string emptyString = "";
+    cacheDir = reader->getSetting(reader->appSpecificLocation("XDG_CACHE_HOME"), emptyString);
+
+    if (cacheDir.empty()) {
+        cacheDir = reader->getSetting(reader->appSpecificLocation("HOME"), emptyString);
+        if (cacheDir.empty()) {
+            return false;
+        }
+
+        cacheDir = cacheDir + ".cache/";
+
+        return createCompilerCachePath(cacheDir);
+    }
+
+    if (NEO::SysCalls::pathExists(cacheDir)) {
+        return createCompilerCachePath(cacheDir);
+    }
+
+    return false;
+}
+} // namespace NEO

shared/source/compiler_interface/os_compiler_cache_helper.h

@@ -0,0 +1,14 @@
+/*
+ * Copyright (C) 2023 Intel Corporation
+ *
+ * SPDX-License-Identifier: MIT
+ *
+ */
+
+#pragma once
+#include <string>
+
+namespace NEO {
+class SettingsReader;
+bool checkDefaultCacheDirSettings(std::string &cacheDir, SettingsReader *reader);
+} // namespace NEO

shared/source/compiler_interface/windows/os_compiler_cache_helper.cpp

@@ -0,0 +1,14 @@
+/*
+ * Copyright (C) 2023 Intel Corporation
+ *
+ * SPDX-License-Identifier: MIT
+ *
+ */
+
+#include "shared/source/compiler_interface/os_compiler_cache_helper.h"
+
+namespace NEO {
+bool checkDefaultCacheDirSettings(std::string &cacheDir, SettingsReader *reader) {
+    return false;
+}
+} // namespace NEO

shared/source/os_interface/linux/sys_calls.h

@@ -17,6 +17,7 @@
 namespace NEO {
 namespace SysCalls {
 int close(int fileDescriptor);
+int mkdir(const std::string &path);
 int open(const char *file, int flags);
 int openWithMode(const char *file, int flags, int mode);
 void *dlopen(const char *filename, int flag);

shared/source/os_interface/linux/sys_calls_linux.cpp

@@ -51,6 +51,10 @@ unsigned long getNumThreads() {
     return taskStat.st_nlink - 2;
 }
 
+int mkdir(const std::string &path) {
+    return ::mkdir(path.c_str(), S_IRWXU | S_IRWXG | S_IROTH | S_IXOTH);
+}
+
 int close(int fileDescriptor) {
     return ::close(fileDescriptor);
 }