Fix reading IMAGE_REL_PPC_REFHI/REFLO without PAIR

Author: encounter

objdiff-core/src/arch/mod.rs

@@ -462,13 +462,15 @@ impl Arch for ArchDummy {
     fn data_reloc_size(&self, _flags: RelocationFlags) -> usize { 0 }
 }
 
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub enum RelocationOverrideTarget {
     Keep,
     Skip,
     Symbol(object::SymbolIndex),
     Section(object::SectionIndex),
 }
 
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub struct RelocationOverride {
     pub target: RelocationOverrideTarget,
     pub addend: i64,

objdiff-core/src/arch/ppc/mod.rs

@@ -229,13 +229,19 @@ impl Arch for ArchPpc {
                         typ: pe::IMAGE_REL_PPC_PAIR
                     })
                 })
-                .map_or(Ok(None), |(_, reloc)| match reloc.target() {
-                    object::RelocationTarget::Symbol(index) => Ok(Some(RelocationOverride {
+                .map_or(
+                    Ok(Some(RelocationOverride {
                         target: RelocationOverrideTarget::Keep,
-                        addend: index.0 as u16 as i16 as i64,
+                        addend: 0,
                     })),
-                    target => Err(anyhow!("Unsupported IMAGE_REL_PPC_PAIR target {target:?}")),
-                }),
+                    |(_, reloc)| match reloc.target() {
+                        object::RelocationTarget::Symbol(index) => Ok(Some(RelocationOverride {
+                            target: RelocationOverrideTarget::Keep,
+                            addend: index.0 as u16 as i16 as i64,
+                        })),
+                        target => Err(anyhow!("Unsupported IMAGE_REL_PPC_PAIR target {target:?}")),
+                    },
+                ),
             // Skip PAIR relocations as they are handled by the previous case
             object::RelocationFlags::Coff { typ: pe::IMAGE_REL_PPC_PAIR } => {
                 Ok(Some(RelocationOverride { target: RelocationOverrideTarget::Skip, addend: 0 }))

objdiff-core/src/obj/read.rs

@@ -361,7 +361,8 @@ fn map_section_relocations(
             None => {
                 ensure!(
                     !reloc.has_implicit_addend(),
-                    "Unsupported implicit relocation {:?}",
+                    "Unsupported {:?} implicit relocation {:?}",
+                    obj_file.architecture(),
                     reloc.flags()
                 );
             }