[Object][MachO] Rewrite macho-invalid-fat-arch-size into YAML

[steven_wu]

Summary

Rewrite one of the invalid macho test input file with YAML file. The
original invalid macho is breaking our internal test infrastusture
because it is too broken to be copy around.

Need to relax an assertion in the YAML/MachoEmitter to allow yaml2obj to
write an invalid object like this.

rdar://problem/56879982

[beanz]

LGTM

llvm/lib/ObjectYAML/MachOEmitter.cpp

if (ObjectFile.MachO) {
     Writer.writeMachO(OS);
     return;
   }
 
   writeFatHeader(OS);
   writeFatArchs(OS);
 
   auto &FatFile = *ObjectFile.FatMachO;
-  assert(FatFile.FatArchs.size() == FatFile.Slices.size());
+  assert(FatFile.FatArchs.size() > FatFile.Slices.size() &&
+         "Cannot write Slices if not decribed in FatArches");
   for (size_t i = 0; i < FatFile.Slices.size(); i++) {
     ZeroToOffset(OS, FatFile.FatArchs[i].offset);
     MachOWriter Writer(FatFile.Slices[i]);
     Writer.writeMachO(OS);
 
     auto SliceEnd = FatFile.FatArchs[i].offset + FatFile.FatArchs[i].size;
     ZeroToOffset(OS, SliceEnd);
   }

llvm/test/Object/Inputs/macho-invalid-fat-arch-size.yaml

+--- !fat-mach-o
+FatHeader:       
+  magic:           0xCAFEBABE
+  nfat_arch:       1
+FatArchs:        
+  - cputype:         0x00000007
+    cpusubtype:      0x00000003
+    offset:          0x000000000000020
+    size:            32
+    align:           2
+Slices:
+...

llvm/test/Object/macho-invalid.test

 INVALID-LAZY_BIND-OVERLAP: macho-invalid-lazy_bind-overlap': truncated or malformed object (dyld lazy bind info at offset 168 with a size of 32, overlaps dyld weak bind info at offset 144 with a size of 32)
 
 RUN: not llvm-objdump --macho --private-headers %p/Inputs/macho-invalid-export-overlap 2>&1 | FileCheck -check-prefix INVALID-EXPORT-OVERLAP %s
 INVALID-EXPORT-OVERLAP: macho-invalid-export-overlap': truncated or malformed object (dyld export info at offset 200 with a size of 32, overlaps dyld lazy bind info at offset 176 with a size of 32)
 
 RUN: not llvm-objdump --macho --universal-headers %p/Inputs/macho-invalid-fat-header 2>&1 | FileCheck -check-prefix INVALID-FAT-HEADER %s
 INVALID-FAT-HEADER: macho-invalid-fat-header': truncated or malformed fat file (contains zero architecture types)
 
-RUN: not llvm-objdump --macho --universal-headers %p/Inputs/macho-invalid-fat-arch-size 2>&1 | FileCheck -check-prefix INVALID-FAT-ARCH-SIZE %s
-INVALID-FAT-ARCH-SIZE: macho-invalid-fat-arch-size': truncated or malformed fat file (offset plus size of cputype (7) cpusubtype (3) extends past the end of the file)
+RUN: yaml2obj %p/Inputs/macho-invalid-fat-arch-size.yaml -o - | not llvm-objdump --macho --universal-headers - 2>&1 | FileCheck -check-prefix INVALID-FAT-ARCH-SIZE %s
+INVALID-FAT-ARCH-SIZE: '-': truncated or malformed fat file (offset plus size of cputype (7) cpusubtype (3) extends past the end of the file)
 
 RUN: not llvm-objdump --macho --universal-headers %p/Inputs/macho-invalid-fat-arch-bigalign 2>&1 | FileCheck -check-prefix INVALID-FAT-ARCH-BIGALIGN %s
 INVALID-FAT-ARCH-BIGALIGN: macho-invalid-fat-arch-bigalign': truncated or malformed fat file (align (2^212) too large for cputype (7) cpusubtype (3) (maximum 2^15))
 
 RUN: not llvm-objdump --macho --universal-headers %p/Inputs/macho-invalid-fat-arch-badalign 2>&1 | FileCheck -check-prefix INVALID-FAT-ARCH-BADALIGN %s
 INVALID-FAT-ARCH-BADALIGN: macho-invalid-fat-arch-badalign': truncated or malformed fat file (offset: 28 for cputype (7) cpusubtype (3) not aligned on it's alignment (2^4))
 
 RUN: not llvm-objdump --macho --universal-headers %p/Inputs/macho-invalid-fat-arch-twosame 2>&1 | FileCheck -check-prefix INVALID-FAT-ARCH-TWOSAME %s