PPC: Display data values on hover for pools as well (#140)

* Fix missing dependency feature for objdiff-gui

* Update .gitignore

* PPC: Display data values on hover for pools as well

* Tooltip data display: Format floats and doubles better

Floats and doubles will now always be displayed with a decimal point and one digit after it, even if they are whole numbers. Floats will also have the f suffix. This is so you can tell the data type just by glancing at the value.

* Move big functions to bottom ppc.rs

* Clear pool relocs in volatile registers on function call

This fixes some false positives.

* Revert ObjArch API changes, add fake target symbol hack

Because we no longer have access to the actual symbol name via sections, guess_data_type can no longer detect the String data type for pooled references.

* Add hack to detect strings via the addi opcode

* Move hack to resolve placeholder symbol into process_code_symbol

* Merge reloc and fake_pool_reloc fields of ObjIns

objdiff-core/src/diff/code.rs

@@ -9,7 +9,7 @@ use crate::{
         DiffObjConfig, ObjInsArgDiff, ObjInsBranchFrom, ObjInsBranchTo, ObjInsDiff, ObjInsDiffKind,
         ObjSymbolDiff,
     },
-    obj::{ObjInfo, ObjInsArg, ObjReloc, ObjSymbolFlags, SymbolRef},
+    obj::{ObjInfo, ObjInsArg, ObjReloc, ObjSection, ObjSymbol, ObjSymbolFlags, SymbolRef},
 };
 
 pub fn process_code_symbol(
@@ -21,14 +21,30 @@ pub fn process_code_symbol(
     let section = section.ok_or_else(|| anyhow!("Code symbol section not found"))?;
     let code = &section.data
         [symbol.section_address as usize..(symbol.section_address + symbol.size) as usize];
-    obj.arch.process_code(
+    let mut res = obj.arch.process_code(
         symbol.address,
         code,
         section.orig_index,
         &section.relocations,
         &section.line_info,
         config,
-    )
+    )?;
+
+    for inst in res.insts.iter_mut() {
+        if let Some(reloc) = &mut inst.reloc {
+            if reloc.target.size == 0 && reloc.target.name.is_empty() {
+                // Fake target symbol we added as a placeholder. We need to find the real one.
+                if let Some(real_target) =
+                    find_symbol_matching_fake_symbol_in_sections(&reloc.target, &obj.sections)
+                {
+                    reloc.addend = (reloc.target.address - real_target.address) as i64;
+                    reloc.target = real_target;
+                }
+            }
+        }
+    }
+
+    Ok(res)
 }
 
 pub fn no_diff_code(out: &ProcessCodeResult, symbol_ref: SymbolRef) -> Result<ObjSymbolDiff> {
@@ -369,3 +385,16 @@ fn compare_ins(
     }
     Ok(result)
 }
+
+fn find_symbol_matching_fake_symbol_in_sections(
+    fake_symbol: &ObjSymbol,
+    sections: &[ObjSection],
+) -> Option<ObjSymbol> {
+    let orig_section_index = fake_symbol.orig_section_index?;
+    let section = sections.iter().find(|s| s.orig_index == orig_section_index)?;
+    let real_symbol = section
+        .symbols
+        .iter()
+        .find(|s| s.size > 0 && (s.address..s.address + s.size).contains(&fake_symbol.address))?;
+    Some(real_symbol.clone())
+}