Merge pull request #10 from staticfloat/sf/do_block

Add do-block form of `readmeta()`

src/Abstract/ObjectHandle.jl

@@ -135,20 +135,31 @@ function readmeta(io::IO)
     Object file is not any of $(join(ObjTypes, ", "))!
     To force one object file format use readmeta(io, T).
     """)
-    error(replace(msg, "\n" => " "))
+    throw(MagicMismatch(replace(msg, "\n" => " ")))
 end
 
-"""
-    readmeta(path::AbstractStriong)
-
-Read an Object File out from a file `path`, guessing at the type of object
-within the stream by calling `readmeta(io, T)` for each `T` within `ObjTypes`,
-and returning the first that does not throw a `MagicMismatch`.
-"""
 function readmeta(file::AbstractString)
+    warn("`readmeta(file::AbstractString)` is deprecated, use the do-block variant instead.")
     return readmeta(open(file, "r"))
 end
 
+"""
+    readmeta(f::Function, file::AbstractString)
+
+Do-block variant of `readmeta()`.  Use via something like:
+
+    readmeta("libfoo.so") do f
+        ...
+    end
+"""
+function readmeta(f::Function, file::AbstractString)
+    io = open(file, "r")
+    try
+        return f(readmeta(io))
+    finally
+        close(io)
+    end
+end
 
 
 ## IOStream-like operations

src/MachO/MachOHandle.jl

@@ -23,6 +23,11 @@ function readmeta(io::IO,::Type{MachOHandle})
     header_type = macho_header_type(magic)
     endianness = macho_endianness(magic)
 
+    # If it's fat, just throw MagicMismatch
+    if header_type <: MachOFatHeader
+        throw(MagicMismatch("FAT header"))
+    end
+
     # Unpack the header
     header = unpack(io, header_type, endianness)
     return MachOHandle(io, start, header, path(io))

test/runtests.jl

@@ -3,8 +3,8 @@ using Compat, Compat.Test
 
 function test_libfoo_and_fooifier(fooifier_path, libfoo_path)
     # Actually read it in
-    oh_exe = readmeta(fooifier_path)
-    oh_lib = readmeta(libfoo_path)
+    oh_exe = readmeta(open(fooifier_path, "r"))
+    oh_lib = readmeta(open(libfoo_path, "r"))
 
     # Tease out some information from the containing folder name
     dir_path = basename(dirname(libfoo_path))
@@ -153,6 +153,12 @@ test_libfoo_and_fooifier("./linux64/fooifier", "./linux64/libfoo.so")
 # Run MachO tests
 test_libfoo_and_fooifier("./mac64/fooifier", "./mac64/libfoo.dylib")
 
+# Ensure that fat Mach-O files don't look like anything to us
+@testset "macfat" begin
+    @test_throws ObjectFile.MagicMismatch readmeta(open("./macfat/fooifier","r"))
+    @test_throws ObjectFile.MagicMismatch readmeta(open("./macfat/libfoo.dylib","r"))
+end
+
 # Run COFF tests
 test_libfoo_and_fooifier("./win32/fooifier.exe", "./win32/libfoo.dll")
 test_libfoo_and_fooifier("./win64/fooifier.exe", "./win64/libfoo.dll")