From 10ba46874825b9d69bb8e856676bd1a4afc8062d Mon Sep 17 00:00:00 2001
From: Adriaan de Groot <groot@kde.org>
Date: Mon, 13 May 2019 12:04:31 -0400
Subject: [PATCH] [libcalamares] Avoid warnings / errors on both gcc and clang

 - Clang 8 can detect that there is no need for a return if all
   previous paths already return. GCC 8 does not. Clang warns if
   the unreachable return is there, GCC errors out if it isn't.
 - Introduce a hack NOTREACHED that comments-out on Clang, and
   marks as unreachable (but still present) on GCC.
 - This might go away with an [[unreachable]] annotation or
   similar.
---
 CMakeLists.txt                               | 3 +++
 src/libcalamares/geoip/Handler.cpp           | 1 +
 src/libcalamares/partition/PartitionSize.cpp | 4 ++++
 3 files changed, 8 insertions(+)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 843e8bc69..a4571efba 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -193,6 +193,7 @@ if( CMAKE_CXX_COMPILER_ID MATCHES "Clang" )
     )
         string( APPEND CMAKE_CXX_FLAGS " ${CLANG_WARNINGS}" )
     endforeach()
+    set( CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -DNOTREACHED='//'" )
 
     # Third-party code where we don't care so much about compiler warnings
     # (because it's uncomfortable to patch) get different flags; use
@@ -218,6 +219,8 @@ else()
 
     set( SUPPRESS_3RDPARTY_WARNINGS "" )
     set( SUPPRESS_BOOST_WARNINGS "" )
+
+    set( CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -DNOTREACHED='__builtin_unreachable();'" )
 endif()
 
 # Use mark_thirdparty_code() to reduce warnings from the compiler
diff --git a/src/libcalamares/geoip/Handler.cpp b/src/libcalamares/geoip/Handler.cpp
index 60404c2d6..192ab1a7c 100644
--- a/src/libcalamares/geoip/Handler.cpp
+++ b/src/libcalamares/geoip/Handler.cpp
@@ -113,6 +113,7 @@ create_interface( Handler::Type t, const QString& selector )
             return nullptr;
 #endif
     }
+    NOTREACHED return nullptr;
 }
 
 static RegionZonePair
diff --git a/src/libcalamares/partition/PartitionSize.cpp b/src/libcalamares/partition/PartitionSize.cpp
index 8eb399585..750f75393 100644
--- a/src/libcalamares/partition/PartitionSize.cpp
+++ b/src/libcalamares/partition/PartitionSize.cpp
@@ -166,6 +166,7 @@ PartitionSize::toBytes() const
     case SizeUnit::GiB:
         return CalamaresUtils::GiBtoBytes( static_cast<unsigned long long>( value() ) );
     }
+    NOTREACHED return -1;
 }
 
 bool
@@ -186,6 +187,7 @@ PartitionSize::operator< ( const PartitionSize& other ) const
     case SizeUnit::GiB:
         return ( toBytes() < other.toBytes () );
     }
+    NOTREACHED return false;
 }
 
 bool
@@ -206,6 +208,7 @@ PartitionSize::operator> ( const PartitionSize& other ) const
     case SizeUnit::GiB:
         return ( toBytes() > other.toBytes () );
     }
+    NOTREACHED return false;
 }
 
 bool
@@ -226,6 +229,7 @@ PartitionSize::operator== ( const PartitionSize& other ) const
     case SizeUnit::GiB:
         return ( toBytes() == other.toBytes () );
     }
+    NOTREACHED return false;
 }
 
 } // namespace Calamares