Merge #15938: refactor: Silence "control reaches end of non-void function" (-Wreturn-type) in psbt.cpp

beb42d71a0 Silence GCC 7 warning "control reaches end of non-void function" (-Wreturn-type) in psbt.cpp (practicalswift)

Pull request description:

  Silence GCC 7 warning "control reaches end of non-void function" (`-Wreturn-type`) in `psbt.cpp`.

  Context: https://github.com/bitcoin/bitcoin/commit/ef22fe8c1f331b4f13f21a54d12030b92e83fbe7#r33370109

  Before this patch:

  ```
  $ ./configure CC=gcc-7 CXX=g++-7
  $ make 2>&1 | grep -A2 "warning: "
  leveldb/util/logging.cc:58:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             (v == kMaxUint64/10 && delta > kMaxUint64%10)) {
                                    ~~~~~~^~~~~~~~~~~~~~~
  --
  leveldb/port/port_posix.cc:60:15: warning: ‘ecx’ may be used uninitialized in this function [-Wmaybe-uninitialized]
     return (ecx & (1 << 20)) != 0;
            ~~~~~^~~~~~~~~~~~
  --
  psbt.cpp:341:1: warning: control reaches end of non-void function [-Wreturn-type]
   }
   ^
  $
  ```

  After this patch:

  ```
  $ ./configure CC=gcc-7 CXX=g++-7
  $ make 2>&1 | grep -A2 "warning: "
  leveldb/util/logging.cc:58:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             (v == kMaxUint64/10 && delta > kMaxUint64%10)) {
                                    ~~~~~~^~~~~~~~~~~~~~~
  --
  leveldb/port/port_posix.cc:60:15: warning: ‘ecx’ may be used uninitialized in this function [-Wmaybe-uninitialized]
     return (ecx & (1 << 20)) != 0;
            ~~~~~^~~~~~~~~~~~
  $
  ```

ACKs for commit beb42d:

Tree-SHA512: b068b9aef565cae0bd1fa1f79c8d422ed2c3e7645edfa14a780a36dd66095a3c627f4111a6b16e706ce6c8abafe51725af8b3bf60778821de0aa8f6193bfadf8

1 files changed, 2 insertions, 0 deletions

diff --git a/src/psbt.cpp b/src/psbt.cpp
index f31f2af0d1..97bda51a63 100644
--- a/src/psbt.cpp
+++ b/src/psbt.cpp
@@ -337,7 +337,9 @@ std::string PSBTRoleName(PSBTRole role) {
     case PSBTRole::SIGNER: return "signer";
     case PSBTRole::FINALIZER: return "finalizer";
     case PSBTRole::EXTRACTOR: return "extractor";
+        // no default case, so the compiler can warn about missing cases
     }
+    assert(false);
 }
 
 bool DecodeBase64PSBT(PartiallySignedTransaction& psbt, const std::string& base64_tx, std::string& error)