InputDevice: modernize IDC probe debugging logs

* Use the new-style stream syntax for readability
* Upgrade DEBUGs to INFOs (since the new-style stream syntax filters
  DEBUG logs by default, and since these are hidden behind a
  compile-time constant it's fine to promote them)
* Include the reason we didn't find a particular IDC file

Bug: 365593937
Test: set DEBUG_PROBE to true, check logcat for the InputReader tag
      while connecting an input device
Flag: EXEMPT code disabled by compile-time constant
Change-Id: I7801252b688b4869911792aa66d2dcdceed8713b

Author: HarryCutts

include/input/InputDevice.h

@@ -389,6 +389,7 @@ enum class InputDeviceConfigurationFileType : int32_t {
     CONFIGURATION = 0,     /* .idc file */
     KEY_LAYOUT = 1,        /* .kl file */
     KEY_CHARACTER_MAP = 2, /* .kcm file */
+    ftl_last = KEY_CHARACTER_MAP,
 };
 
 /*

libs/input/InputDevice.cpp

@@ -20,6 +20,7 @@
 #include <unistd.h>
 #include <ctype.h>
 
+#include <android-base/logging.h>
 #include <android-base/properties.h>
 #include <android-base/stringprintf.h>
 #include <ftl/enum.h>
@@ -31,6 +32,9 @@ using android::base::StringPrintf;
 
 namespace android {
 
+// Set to true to log detailed debugging messages about IDC file probing.
+static constexpr bool DEBUG_PROBE = false;
+
 static const char* CONFIGURATION_FILE_DIR[] = {
         "idc/",
         "keylayout/",
@@ -114,15 +118,14 @@ std::string getInputDeviceConfigurationFilePathByName(
     for (const auto& prefix : pathPrefixes) {
         path = prefix;
         appendInputDeviceConfigurationFileRelativePath(path, name, type);
-#if DEBUG_PROBE
-        ALOGD("Probing for system provided input device configuration file: path='%s'",
-              path.c_str());
-#endif
         if (!access(path.c_str(), R_OK)) {
-#if DEBUG_PROBE
-            ALOGD("Found");
-#endif
+            LOG_IF(INFO, DEBUG_PROBE)
+                    << "Found system-provided input device configuration file at " << path;
             return path;
+        } else {
+            LOG_IF(ERROR, DEBUG_PROBE)
+                    << "Didn't find system-provided input device configuration file at " << path
+                    << ": " << strerror(errno);
         }
     }
 
@@ -135,21 +138,18 @@ std::string getInputDeviceConfigurationFilePathByName(
     }
     path += "/system/devices/";
     appendInputDeviceConfigurationFileRelativePath(path, name, type);
-#if DEBUG_PROBE
-    ALOGD("Probing for system user input device configuration file: path='%s'", path.c_str());
-#endif
     if (!access(path.c_str(), R_OK)) {
-#if DEBUG_PROBE
-        ALOGD("Found");
-#endif
+        LOG_IF(INFO, DEBUG_PROBE) << "Found system user input device configuration file at "
+                                  << path;
         return path;
+    } else {
+        LOG_IF(ERROR, DEBUG_PROBE) << "Didn't find system user input device configuration file at "
+                                   << path << ": " << strerror(errno);
     }
 
     // Not found.
-#if DEBUG_PROBE
-    ALOGD("Probe failed to find input device configuration file: name='%s', type=%d",
-            name.c_str(), type);
-#endif
+    LOG_IF(INFO, DEBUG_PROBE) << "Probe failed to find input device configuration file with name '"
+                              << name << "' and type " << ftl::enum_string(type);
     return "";
 }