Merge #12305: [docs] [refactor] Add help messages for datadir path mangling

5460460 Add AbsPathForConfigVal to consolidate datadir prefixing for path args (James O'Beirne)
a1e1305 Clarify help messages for path args to mention datadir prefix (James O'Beirne)

Pull request description:

  Change `-conf`'s help message to indicate that relative path values will be prefixed by the datadir path. This behavior probably merits clarification; it's kind of confusing when attempting to specify a configuration file in the current directory with `-conf=bitcoin.conf`, but instead loading the `bitcoin.conf` file in ~/.bitcoin datadir.

  ### Edit

  This PR has been modified to document all cases where relative path configurations are modified to be under datadir. A small refactoring has also been added which consolidates this normalization.

Tree-SHA512: be4fc0595fbeba33d17af08f59898af45e76a44f00719ea0282403b155ac6755584604fab765250a3aa14ed6991882c4d1ccbe601184362c5ba97c886bdda344

5 files changed, 25 insertions, 21 deletions

diff --git a/src/bitcoin-cli.cpp b/src/bitcoin-cli.cpp
index 1214b548cf..8fc708be6b 100644
--- a/src/bitcoin-cli.cpp
+++ b/src/bitcoin-cli.cpp
@@ -35,7 +35,7 @@ std::string HelpMessageCli()
     std::string strUsage;
     strUsage += HelpMessageGroup(_("Options:"));
     strUsage += HelpMessageOpt("-?", _("This help message"));
-    strUsage += HelpMessageOpt("-conf=<file>", strprintf(_("Specify configuration file (default: %s)"), BITCOIN_CONF_FILENAME));
+    strUsage += HelpMessageOpt("-conf=<file>", strprintf(_("Specify configuration file. Relative paths will be prefixed by datadir location. (default: %s)"), BITCOIN_CONF_FILENAME));
     strUsage += HelpMessageOpt("-datadir=<dir>", _("Specify data directory"));
     strUsage += HelpMessageOpt("-getinfo", _("Get general information from the remote server. Note that unlike server-side RPC calls, the results of -getinfo is the result of multiple non-atomic requests. Some entries in the result may represent results from different states (e.g. wallet balance may be as of a different block from the chain state reported)"));
     AppendParamsHelpMessages(strUsage);
diff --git a/src/init.cpp b/src/init.cpp
index 5e81e05f49..50643ff96b 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -336,7 +336,7 @@ std::string HelpMessage(HelpMessageMode mode)
     strUsage += HelpMessageOpt("-blockreconstructionextratxn=<n>", strprintf(_("Extra transactions to keep in memory for compact block reconstructions (default: %u)"), DEFAULT_BLOCK_RECONSTRUCTION_EXTRA_TXN));
     if (showDebug)
         strUsage += HelpMessageOpt("-blocksonly", strprintf(_("Whether to operate in a blocks only mode (default: %u)"), DEFAULT_BLOCKSONLY));
-    strUsage += HelpMessageOpt("-conf=<file>", strprintf(_("Specify configuration file (default: %s)"), BITCOIN_CONF_FILENAME));
+    strUsage += HelpMessageOpt("-conf=<file>", strprintf(_("Specify configuration file. Relative paths will be prefixed by datadir location. (default: %s)"), BITCOIN_CONF_FILENAME));
     if (mode == HMM_BITCOIND)
     {
 #if HAVE_DECL_DAEMON
@@ -348,7 +348,7 @@ std::string HelpMessage(HelpMessageMode mode)
         strUsage += HelpMessageOpt("-dbbatchsize", strprintf("Maximum database write batch size in bytes (default: %u)", nDefaultDbBatchSize));
     }
     strUsage += HelpMessageOpt("-dbcache=<n>", strprintf(_("Set database cache size in megabytes (%d to %d, default: %d)"), nMinDbCache, nMaxDbCache, nDefaultDbCache));
-    strUsage += HelpMessageOpt("-debuglogfile=<file>", strprintf(_("Specify location of debug log file: this can be an absolute path or a path relative to the data directory (default: %s)"), DEFAULT_DEBUGLOGFILE));
+    strUsage += HelpMessageOpt("-debuglogfile=<file>", strprintf(_("Specify location of debug log file. Relative paths will be prefixed by a net-specific datadir location. (default: %s)"), DEFAULT_DEBUGLOGFILE));
     if (showDebug)
         strUsage += HelpMessageOpt("-feefilter", strprintf("Tell other nodes to filter invs to us by our mempool min fee (default: %u)", DEFAULT_FEEFILTER));
     strUsage += HelpMessageOpt("-loadblock=<file>", _("Imports blocks from external blk000??.dat file on startup"));
@@ -362,7 +362,7 @@ std::string HelpMessage(HelpMessageMode mode)
         -GetNumCores(), MAX_SCRIPTCHECK_THREADS, DEFAULT_SCRIPTCHECK_THREADS));
     strUsage += HelpMessageOpt("-persistmempool", strprintf(_("Whether to save the mempool on shutdown and load on restart (default: %u)"), DEFAULT_PERSIST_MEMPOOL));
 #ifndef WIN32
-    strUsage += HelpMessageOpt("-pid=<file>", strprintf(_("Specify pid file (default: %s)"), BITCOIN_PID_FILENAME));
+    strUsage += HelpMessageOpt("-pid=<file>", strprintf(_("Specify pid file. Relative paths will be prefixed by a net-specific datadir location. (default: %s)"), BITCOIN_PID_FILENAME));
 #endif
     strUsage += HelpMessageOpt("-prune=<n>", strprintf(_("Reduce storage requirements by enabling pruning (deleting) of old blocks. This allows the pruneblockchain RPC to be called to delete specific blocks, and enables automatic pruning of old blocks if a target size in MiB is provided. This mode is incompatible with -txindex and -rescan. "
             "Warning: Reverting this setting requires re-downloading the entire blockchain. "
@@ -500,7 +500,7 @@ std::string HelpMessage(HelpMessageMode mode)
     strUsage += HelpMessageOpt("-rpcallowip=<ip>", _("Allow JSON-RPC connections from specified source. Valid for <ip> are a single IP (e.g. 1.2.3.4), a network/netmask (e.g. 1.2.3.4/255.255.255.0) or a network/CIDR (e.g. 1.2.3.4/24). This option can be specified multiple times"));
     strUsage += HelpMessageOpt("-rpcauth=<userpw>", _("Username and hashed password for JSON-RPC connections. The field <userpw> comes in the format: <USERNAME>:<SALT>$<HASH>. A canonical python script is included in share/rpcuser. The client then connects normally using the rpcuser=<USERNAME>/rpcpassword=<PASSWORD> pair of arguments. This option can be specified multiple times"));
     strUsage += HelpMessageOpt("-rpcbind=<addr>[:port]", _("Bind to given address to listen for JSON-RPC connections. This option is ignored unless -rpcallowip is also passed. Port is optional and overrides -rpcport. Use [host]:port notation for IPv6. This option can be specified multiple times (default: 127.0.0.1 and ::1 i.e., localhost, or if -rpcallowip has been specified, 0.0.0.0 and :: i.e., all addresses)"));
-    strUsage += HelpMessageOpt("-rpccookiefile=<loc>", _("Location of the auth cookie (default: data dir)"));
+    strUsage += HelpMessageOpt("-rpccookiefile=<loc>", _("Location of the auth cookie. Relative paths will be prefixed by a net-specific datadir location. (default: data dir)"));
     strUsage += HelpMessageOpt("-rpcpassword=<pw>", _("Password for JSON-RPC connections"));
     strUsage += HelpMessageOpt("-rpcport=<port>", strprintf(_("Listen for JSON-RPC connections on <port> (default: %u or testnet: %u)"), defaultBaseParams->RPCPort(), testnetBaseParams->RPCPort()));
     strUsage += HelpMessageOpt("-rpcserialversion", strprintf(_("Sets the serialization of raw transaction or block hex returned in non-verbose mode, non-segwit(0) or segwit(1) (default: %d)"), DEFAULT_RPC_SERIALIZE_VERSION));
diff --git a/src/rpc/protocol.cpp b/src/rpc/protocol.cpp
index ddc1bb6232..cdd2e67a69 100644
--- a/src/rpc/protocol.cpp
+++ b/src/rpc/protocol.cpp
@@ -72,9 +72,7 @@ static fs::path GetAuthCookieFile(bool temp=false)
     if (temp) {
         arg += ".tmp";
     }
-    fs::path path(arg);
-    if (!path.is_complete()) path = GetDataDir() / path;
-    return path;
+    return AbsPathForConfigVal(fs::path(arg));
 }
 
 bool GenerateAuthCookie(std::string *cookie_out)
diff --git a/src/util.cpp b/src/util.cpp
index 80eed24ffd..6738bbc6e4 100644
--- a/src/util.cpp
+++ b/src/util.cpp
@@ -4,6 +4,7 @@
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <util.h>
+#include <fs.h>
 
 #include <chainparamsbase.h>
 #include <random.h>
@@ -188,11 +189,7 @@ static void DebugPrintInit()
 fs::path GetDebugLogPath()
 {
     fs::path logfile(gArgs.GetArg("-debuglogfile", DEFAULT_DEBUGLOGFILE));
-    if (logfile.is_absolute()) {
-        return logfile;
-    } else {
-        return GetDataDir() / logfile;
-    }
+    return AbsPathForConfigVal(logfile);
 }
 
 bool OpenDebugLog()
@@ -624,11 +621,7 @@ void ClearDatadirCache()
 
 fs::path GetConfigFile(const std::string& confPath)
 {
-    fs::path pathConfigFile(confPath);
-    if (!pathConfigFile.is_complete())
-        pathConfigFile = GetDataDir(false) / pathConfigFile;
-
-    return pathConfigFile;
+    return AbsPathForConfigVal(fs::path(confPath), false);
 }
 
 void ArgsManager::ReadConfigFile(const std::string& confPath)
@@ -663,9 +656,7 @@ void ArgsManager::ReadConfigFile(const std::string& confPath)
 #ifndef WIN32
 fs::path GetPidFile()
 {
-    fs::path pathPidFile(gArgs.GetArg("-pid", BITCOIN_PID_FILENAME));
-    if (!pathPidFile.is_complete()) pathPidFile = GetDataDir() / pathPidFile;
-    return pathPidFile;
+    return AbsPathForConfigVal(fs::path(gArgs.GetArg("-pid", BITCOIN_PID_FILENAME)));
 }
 
 void CreatePidFile(const fs::path &path, pid_t pid)
@@ -936,3 +927,8 @@ int64_t GetStartupTime()
 {
     return nStartupTime;
 }
+
+fs::path AbsPathForConfigVal(const fs::path& path, bool net_specific)
+{
+    return fs::absolute(path, GetDataDir(net_specific));
+}
diff --git a/src/util.h b/src/util.h
index 277b4c66af..05138a9bfe 100644
--- a/src/util.h
+++ b/src/util.h
@@ -191,6 +191,16 @@ bool OpenDebugLog();
 void ShrinkDebugFile();
 void runCommand(const std::string& strCommand);
 
+/**
+ * Most paths passed as configuration arguments are treated as relative to
+ * the datadir if they are not absolute.
+ *
+ * @param path The path to be conditionally prefixed with datadir.
+ * @param net_specific Forwarded to GetDataDir().
+ * @return The normalized path.
+ */
+fs::path AbsPathForConfigVal(const fs::path& path, bool net_specific = true);
+
 inline bool IsSwitchChar(char c)
 {
 #ifdef WIN32