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fold/third_party/ghidra-decompiler/specs/x86/x86.opinion
trvon c08081a016
 feat: vendor x86-64 + 32-bit SLEIGH; precise SSA def-use; write-loop FP guard 
Unlocks the x86 family end-to-end and makes the write-loop detector precise
enough for statically-linked binaries.

x86 SLEIGH:
- Vendor Ghidra's x86 language specs (specs/x86, x86:LE:64:default + :32:default);
  add x86-64/x86 .sla build targets. archSpecFor maps x86/64 + x86/32.
- ghidra_lifter: set the x86-64 decode context (longMode/addrsize/opsize) in the
  raw path, and bound decompiler flow at the function end (0xC3 tail fill) so
  variable-length x86 does not run away into zero padding.

Precise SSA def-use (benefits all arches):
- ir::pcode::PcodeOp gains in_def (defining-op index per input); the SSA lifter
  records real def-use. summarizePointerWrites now resolves the store-address
  base via def-use instead of a last-write heuristic — essential on x86 where
  arg registers are reused as scratch (RAX) and sub-registers are written (SIL).
- paramIndexOf is arch-aware (AArch64 x0–x7; SysV x86-64 RDI/RSI/RDX/RCX/R8/R9).

Precision (the key fix at scale):
- A copy bounded by a size *parameter* (memcpy-like `for i<n`) is suppressed:
  if the loop index is `<`-compared against a pure parameter input, the function
  is size-bounded and not flagged. baby_bof's decode_base64 bounds on
  strlen(input) (a computed value, not a param) so it still fires. This cut a
  statically-linked x86-64 binary from 101 findings (≈100 glibc/libstdc++ FPs)
  to 1 — the real decode_base64 → 264-byte overflow.

Perf + reach:
- Cache the pre-pass SSA lift and reuse it in the main pass (re-lifting only the
  few callers of a write-loop callee that need the injected prototype).
- Give whole-binary r2 analysis a generous timeout (FOLD_R2_ANALYSIS_TIMEOUT_MS,
  default 120s) so large static binaries actually analyze (the 3s per-command
  watchdog left them with an empty function list).

Validated: decode_base64 overflow fires on x86-64 (index_amd64.cgi) and AArch64
(index_nocanary.cgi); AArch64 corpus BOF counts unchanged (3/1/1); x86-64 static
FP 101→1. Unit: test_pcode_summary +x86-64 case (9 assertions). meson test 77/77.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
2026-06-01 10:34:28 -04:00

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<opinions>
<!-- NOTE: variant="default" is specified for 64-bit to give preference to the default variant -->
<constraint loader="Portable Executable (PE)">
<constraint compilerSpecID="windows">
<constraint primary="332" processor="x86" endian="little" size="32" />
<constraint primary="333" processor="x86" endian="little" size="32" />
<constraint primary="334" processor="x86" endian="little" size="32" />
<constraint primary="34404" processor="x86" endian="little" size="64" variant="default" />
</constraint>
<constraint compilerSpecID="clangwindows">
<constraint primary="332" secondary="clang" processor="x86" endian="little" size="32" />
<constraint primary="333" secondary="clang" processor="x86" endian="little" size="32" />
<constraint primary="334" secondary="clang" processor="x86" endian="little" size="32" />
<constraint primary="34404" secondary="clang" processor="x86" endian="little" size="64" variant="default" />
</constraint>
<constraint compilerSpecID="borlandcpp">
<constraint primary="332" secondary="borlandcpp" processor="x86" endian="little" size="32" />
<constraint primary="333" secondary="borlandcpp" processor="x86" endian="little" size="32" />
<constraint primary="334" secondary="borlandcpp" processor="x86" endian="little" size="32" />
</constraint>
<constraint compilerSpecID="borlanddelphi">
<constraint primary="332" secondary="borlanddelphi" processor="x86" endian="little" size="32" />
<constraint primary="333" secondary="borlanddelphi" processor="x86" endian="little" size="32" />
<constraint primary="334" secondary="borlanddelphi" processor="x86" endian="little" size="32" />
</constraint>
<constraint compilerSpecID="golang">
<constraint primary="332" secondary="golang" processor="x86" endian="little" size="32" />
<constraint primary="34404" secondary="golang" processor="x86" endian="little" size="64" variant="default" />
</constraint>
<constraint compilerSpecID="swift">
<constraint primary="34404" secondary="swift" processor="x86" endian="little" size="64" variant="default" />
</constraint>
</constraint>
<constraint loader="Debug Symbols (DBG)" compilerSpecID="windows">
<constraint primary="332" processor="x86" endian="little" size="32" />
<constraint primary="333" processor="x86" endian="little" size="32" />
<constraint primary="334" processor="x86" endian="little" size="32" />
<constraint primary="34404" processor="x86" endian="little" size="64" variant="default" />
</constraint>
<constraint loader="Executable and Linking Format (ELF)">
<constraint compilerSpecID="gcc">
<constraint primary="3" processor="x86" endian="little" size="32" />
<constraint primary="62" processor="x86" endian="little" size="64" variant="default" />
</constraint>
<constraint compilerSpecID="swift">
<constraint primary="62" secondary="swift" processor="x86" endian="little" size="64" variant="default" />
</constraint>
<constraint compilerSpecID="golang">
<constraint primary="62" secondary="golang" processor="x86" endian="little" size="64" variant="default" />
</constraint>
</constraint>
<constraint loader="Module Definition (DEF)" compilerSpecID="windows">
<constraint primary="0" processor="x86" endian="little" size="32" />
</constraint>
<constraint loader="Program Mapfile (MAP)" compilerSpecID="windows">
<constraint primary="0" processor="x86" endian="little" size="32" />
</constraint>
<constraint loader="Old-style DOS Executable (MZ)" compilerSpecID="default">
<constraint primary="23117" processor="x86" endian="little" size="16" variant="Real Mode"/>
</constraint>
<constraint loader="New Executable (NE)" compilerSpecID="default">
<constraint primary="17742" processor="x86" endian="little" size="16" variant="Protected Mode"/>
</constraint>
<constraint loader="Mac OS X Mach-O" compilerSpecID="gcc">
<constraint primary="7" processor="x86" endian="little" size="32" />
<constraint primary="16777223" processor="x86" endian="little" size="64" variant="default" />
</constraint>
<constraint loader="Mac OS X Mach-O" compilerSpecID="swift">
<constraint primary="16777223" secondary="swift" processor="x86" endian="little" size="64" variant="default" />
</constraint>
<constraint loader="DYLD Cache" compilerSpecID="gcc">
<constraint primary="x86_64" processor="x86" endian="little" size="64" variant="default" />
</constraint>
<constraint loader="Common Object File Format (COFF)" compilerSpecID="gcc">
<constraint primary="332" processor="x86" endian="little" size="32" />
<constraint primary="-31132" processor="x86" endian="little" size="64" variant="default" />
</constraint>
<constraint loader="MS Common Object File Format (COFF)" compilerSpecID="windows">
<constraint primary="332" processor="x86" endian="little" size="32" />
<constraint primary="-31132" processor="x86" endian="little" size="64" variant="default" />
</constraint>
<constraint loader="Assembler Output (AOUT)" compilerSpecID="gcc">
<constraint primary="134" processor="x86" endian="little" size="32" />
</constraint>
<constraint loader="Relocatable Object Module Format (OMF)">
<constraint compilerSpecID="windows">
<constraint primary="32bit" processor="x86" endian="little" size="32" />
</constraint>
<constraint compilerSpecID="default">
<constraint primary="16bit" processor="x86" endian="little" size="16" />
</constraint>
<constraint compilerSpecID="borlandcpp">
<constraint primary="32bit" secondary="borlandcpp" processor="x86" endian="little" size="32" />
<constraint primary="32bit" secondary="codegearcpp" processor="x86" endian="little" size="32" />
</constraint>
<constraint compilerSpecID="borlanddelphi">
<constraint primary="32bit" secondary="borlanddelphi" processor="x86" endian="little" size="32" />
</constraint>
</constraint>
</opinions>
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