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author | Kartik Agaram <vc@akkartik.com> | 2018-08-04 22:59:47 -0700 |
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committer | Kartik Agaram <vc@akkartik.com> | 2018-08-04 23:16:07 -0700 |
commit | 7f7d3dcca5d1974174782bc71009a808a573eae7 (patch) | |
tree | 9e587da6d40b4e22099478cc6b2630a765288f9a /subx/032check_operand_bounds.cc | |
parent | aaf24db4aeca73e985437d065b36815677716694 (diff) | |
download | mu-7f7d3dcca5d1974174782bc71009a808a573eae7.tar.gz |
4483
Reorganize layers in accordance with the plan in layer 29.
Diffstat (limited to 'subx/032check_operand_bounds.cc')
-rw-r--r-- | subx/032check_operand_bounds.cc | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/subx/032check_operand_bounds.cc b/subx/032check_operand_bounds.cc new file mode 100644 index 00000000..7ed2732b --- /dev/null +++ b/subx/032check_operand_bounds.cc @@ -0,0 +1,54 @@ +//:: Check that the different operands of an instruction aren't too large for their bitfields. + +:(scenario check_bitfield_sizes) +% Hide_errors = true; +== 0x1 +01/add 4/mod ++error: '4/mod' too large to fit in bitfield mod + +:(before "End Globals") +map<string, uint32_t> Operand_bound; +:(before "End One-time Setup") +put(Operand_bound, "subop", 1<<3); +put(Operand_bound, "mod", 1<<2); +put(Operand_bound, "rm32", 1<<3); +put(Operand_bound, "base", 1<<3); +put(Operand_bound, "index", 1<<3); +put(Operand_bound, "scale", 1<<2); +put(Operand_bound, "r32", 1<<3); +put(Operand_bound, "disp8", 1<<8); +put(Operand_bound, "disp16", 1<<16); +// no bound needed for disp32 +put(Operand_bound, "imm8", 1<<8); +// no bound needed for imm32 + +:(after "Pack Operands") +check_operand_bounds(code); +if (trace_contains_errors()) return; +:(code) +void check_operand_bounds(const segment& code) { + trace(99, "transform") << "-- check operand bounds" << end(); + for (int i = 0; i < SIZE(code.lines); ++i) { + const line& inst = code.lines.at(i); + for (int j = first_operand(inst); j < SIZE(inst.words); ++j) + check_operand_bounds(inst.words.at(j)); + if (trace_contains_errors()) return; // stop at the first mal-formed instruction + } +} + +void check_operand_bounds(const word& w) { + for (map<string, uint32_t>::iterator p = Operand_bound.begin(); p != Operand_bound.end(); ++p) { + if (!has_metadata(w, p->first)) continue; + if (!is_hex_int(w.data)) continue; // later transforms are on their own to do their own bounds checking + int32_t x = parse_int(w.data); + if (x >= 0) { + if (static_cast<uint32_t>(x) >= p->second) + raise << "'" << w.original << "' too large to fit in bitfield " << p->first << '\n' << end(); + } + else { + // hacky? assuming bound is a power of 2 + if (x < -1*static_cast<int32_t>(p->second/2)) + raise << "'" << w.original << "' too large to fit in bitfield " << p->first << '\n' << end(); + } + } +} |