ensure the path regexes will accept all valid paths (#48686)

Previously, we might try to interpret the random bytes in a path as
UTF-8 and excluding \n, causing the regex match to fail or be incomplete
in some cases. But those are valid in a path, so we want PCRE2 to treat
them as transparent bytes. Accordingly, change r""a to specify all flags
needed to interpret the values simply as ASCII.

Note, this would be breaking if someone was previously trying to match a
Unicode character by `\u` while also disabling UCP matching of \w and
\s, but that seems an odd specific choice to need.

    julia> match(r"\u03b1"a, "α")
    ERROR: PCRE compilation error: character code point value in \u.... sequence is too large at offset 6

(this would have previously worked). Note that explicitly starting the
regex with (*UTF) or using a literal α in the regex would continue to
work as before however.

Note that `s` (DOTALL) is a more efficient matcher (if the pattern
contains `.`), as is `a`, so it is often preferable to set both when in
doubt: http://man.he.net/man3/pcre2perform

Refs: #48648

base/binaryplatforms.jl

@@ -741,10 +741,10 @@ function Base.parse(::Type{Platform}, triplet::String; validate_strict::Bool = f
         end
         os_version = nothing
         if os == "macos"
-            os_version = extract_os_version("macos", r".*darwin([\d\.]+)")
+            os_version = extract_os_version("macos", r".*darwin([\d\.]+)"sa)
         end
         if os == "freebsd"
-            os_version = extract_os_version("freebsd", r".*freebsd([\d.]+)")
+            os_version = extract_os_version("freebsd", r".*freebsd([\d.]+)"sa)
         end
         tags["os_version"] = os_version
 
@@ -798,13 +798,13 @@ function parse_dl_name_version(path::String, os::String)
     local dlregex
     if os == "windows"
         # On Windows, libraries look like `libnettle-6.dll`
-        dlregex = r"^(.*?)(?:-((?:[\.\d]+)*))?\.dll$"
+        dlregex = r"^(.*?)(?:-((?:[\.\d]+)*))?\.dll$"sa
     elseif os == "macos"
         # On OSX, libraries look like `libnettle.6.3.dylib`
-        dlregex = r"^(.*?)((?:\.[\d]+)*)\.dylib$"
+        dlregex = r"^(.*?)((?:\.[\d]+)*)\.dylib$"sa
     else
         # On Linux and FreeBSD, libraries look like `libnettle.so.6.3.0`
-        dlregex = r"^(.*?)\.so((?:\.[\d]+)*)$"
+        dlregex = r"^(.*?)\.so((?:\.[\d]+)*)$"sa
     end
 
     m = match(dlregex, basename(path))

base/compiler/ssair/show.jl

@@ -796,7 +796,7 @@ function inline_linfo_printer(code::IRCode)
     end
 end
 
-_strip_color(s::String) = replace(s, r"\e\[\d+m" => "")
+_strip_color(s::String) = replace(s, r"\e\[\d+m"a => "")
 
 function statementidx_lineinfo_printer(f, code::IRCode)
     printer = f(code.linetable)

base/deprecated.jl

@@ -48,7 +48,7 @@ arguments of type `Any`.
 
 To restrict deprecation to a specific signature, annotate the
 arguments of `old`. For example,
-```jldoctest; filter = r"@ .*"
+```jldoctest; filter = r"@ .*"a
 julia> new(x::Int) = x;
 
 julia> new(x::Float64) = 2x;

base/libc.jl

@@ -225,7 +225,7 @@ function strptime(fmt::AbstractString, timestr::AbstractString)
     @static if Sys.isapple()
         # if we didn't explicitly parse the weekday or year day, use mktime
         # to fill them in automatically.
-        if !occursin(r"([^%]|^)%(a|A|j|w|Ow)", fmt)
+        if !occursin(r"([^%]|^)%(a|A|j|w|Ow)"a, fmt)
             ccall(:mktime, Int, (Ref{TmStruct},), tm)
         end
     end

base/methodshow.jl

@@ -7,7 +7,7 @@ function strip_gensym(sym)
     if sym === :var"#self#" || sym === :var"#unused#"
         return empty_sym
     end
-    return Symbol(replace(String(sym), r"^(.*)#(.*#)?\d+$" => s"\1"))
+    return Symbol(replace(String(sym), r"^(.*)#(.*#)?\d+$"sa => s"\1"))
 end
 
 function argtype_decl(env, n, @nospecialize(sig::DataType), i::Int, nargs, isva::Bool) # -> (argname, argtype)
@@ -364,7 +364,7 @@ function url(m::Method)
     (m.file === :null || m.file === :string) && return ""
     file = string(m.file)
     line = m.line
-    line <= 0 || occursin(r"In\[[0-9]+\]", file) && return ""
+    line <= 0 || occursin(r"In\[[0-9]+\]"a, file) && return ""
     Sys.iswindows() && (file = replace(file, '\\' => '/'))
     libgit2_id = PkgId(UUID((0x76f85450_5226_5b5a,0x8eaa_529ad045b433)), "LibGit2")
     if inbase(M)

base/path.jl

@@ -20,22 +20,22 @@ export
 
 if Sys.isunix()
     const path_separator    = "/"
-    const path_separator_re = r"/+"
-    const path_directory_re = r"(?:^|/)\.{0,2}$"
-    const path_dir_splitter = r"^(.*?)(/+)([^/]*)$"
-    const path_ext_splitter = r"^((?:.*/)?(?:\.|[^/\.])[^/]*?)(\.[^/\.]*|)$"
+    const path_separator_re = r"/+"sa
+    const path_directory_re = r"(?:^|/)\.{0,2}$"sa
+    const path_dir_splitter = r"^(.*?)(/+)([^/]*)$"sa
+    const path_ext_splitter = r"^((?:.*/)?(?:\.|[^/\.])[^/]*?)(\.[^/\.]*|)$"sa
 
     splitdrive(path::String) = ("",path)
 elseif Sys.iswindows()
     const path_separator    = "\\"
-    const path_separator_re = r"[/\\]+"
-    const path_absolute_re  = r"^(?:[A-Za-z]+:)?[/\\]"
-    const path_directory_re = r"(?:^|[/\\])\.{0,2}$"
-    const path_dir_splitter = r"^(.*?)([/\\]+)([^/\\]*)$"
-    const path_ext_splitter = r"^((?:.*[/\\])?(?:\.|[^/\\\.])[^/\\]*?)(\.[^/\\\.]*|)$"
+    const path_separator_re = r"[/\\]+"sa
+    const path_absolute_re  = r"^(?:[A-Za-z]+:)?[/\\]"sa
+    const path_directory_re = r"(?:^|[/\\])\.{0,2}$"sa
+    const path_dir_splitter = r"^(.*?)([/\\]+)([^/\\]*)$"sa
+    const path_ext_splitter = r"^((?:.*[/\\])?(?:\.|[^/\\\.])[^/\\]*?)(\.[^/\\\.]*|)$"sa
 
     function splitdrive(path::String)
-        m = match(r"^([^\\]+:|\\\\[^\\]+\\[^\\]+|\\\\\?\\UNC\\[^\\]+\\[^\\]+|\\\\\?\\[^\\]+:|)(.*)$"s, path)::AbstractMatch
+        m = match(r"^([^\\]+:|\\\\[^\\]+\\[^\\]+|\\\\\?\\UNC\\[^\\]+\\[^\\]+|\\\\\?\\[^\\]+:|)(.*)$"sa, path)::AbstractMatch
         String(something(m.captures[1])), String(something(m.captures[2]))
     end
 else

base/regex.jl

@@ -46,19 +46,24 @@ mutable struct Regex <: AbstractPattern
 end
 
 function Regex(pattern::AbstractString, flags::AbstractString)
-    options = DEFAULT_COMPILER_OPTS
+    compile_options = DEFAULT_COMPILER_OPTS
+    match_options = DEFAULT_MATCH_OPTS
     for f in flags
         if f == 'a'
-            options &= ~PCRE.UCP
+            # instruct pcre2 to treat the strings as simple bytes (aka "ASCII"), not char encodings
+            compile_options &= ~PCRE.UCP  # user can re-enable with (*UCP)
+            compile_options &= ~PCRE.UTF # user can re-enable with (*UTF)
+            compile_options &= ~PCRE.MATCH_INVALID_UTF # this would force on UTF
+            match_options &= ~PCRE.NO_UTF_CHECK # if the user did force on UTF, we should check it for safety
         else
-            options |= f=='i' ? PCRE.CASELESS  :
-                       f=='m' ? PCRE.MULTILINE :
-                       f=='s' ? PCRE.DOTALL    :
-                       f=='x' ? PCRE.EXTENDED  :
-                       throw(ArgumentError("unknown regex flag: $f"))
+            compile_options |= f=='i' ? PCRE.CASELESS  :
+                               f=='m' ? PCRE.MULTILINE :
+                               f=='s' ? PCRE.DOTALL    :
+                               f=='x' ? PCRE.EXTENDED  :
+                               throw(ArgumentError("unknown regex flag: $f"))
         end
     end
-    Regex(pattern, options, DEFAULT_MATCH_OPTS)
+    Regex(pattern, compile_options, match_options)
 end
 Regex(pattern::AbstractString) = Regex(pattern, DEFAULT_COMPILER_OPTS, DEFAULT_MATCH_OPTS)
 
@@ -96,9 +101,15 @@ listed after the ending quote, to change its behaviour:
 - `s` allows the `.` modifier to match newlines.
 - `x` enables "comment mode": whitespace is enabled except when escaped with `\\`, and `#`
   is treated as starting a comment.
-- `a` disables `UCP` mode (enables ASCII mode). By default `\\B`, `\\b`, `\\D`, `\\d`, `\\S`,
-  `\\s`, `\\W`, `\\w`, etc. match based on Unicode character properties. With this option,
-  these sequences only match ASCII characters.
+- `a` enables ASCII mode (disables `UTF` and `UCP` modes). By default `\\B`, `\\b`, `\\D`,
+  `\\d`, `\\S`, `\\s`, `\\W`, `\\w`, etc. match based on Unicode character properties. With
+  this option, these sequences only match ASCII characters. This includes `\\u` also, which
+  will emit the specified character value directly as a single byte, and not attempt to
+  encode it into UTF-8. Importantly, this option allows matching against invalid UTF-8
+  strings, by treating both matcher and target as simple bytes (as if they were ISO/IEC
+  8859-1 / Latin-1 bytes) instead of as character encodings. In this case, this option is
+  often combined with `s`. This option can be further refined by starting the pattern with
+  (*UCP) or (*UTF).
 
 See [`Regex`](@ref) if interpolation is needed.
 
@@ -112,23 +123,38 @@ This regex has the first three flags enabled.
 macro r_str(pattern, flags...) Regex(pattern, flags...) end
 
 function show(io::IO, re::Regex)
-    imsxa = PCRE.CASELESS|PCRE.MULTILINE|PCRE.DOTALL|PCRE.EXTENDED|PCRE.UCP
+    imsx = PCRE.CASELESS|PCRE.MULTILINE|PCRE.DOTALL|PCRE.EXTENDED
+    ac = PCRE.UTF|PCRE.MATCH_INVALID_UTF|PCRE.UCP
+    am = PCRE.NO_UTF_CHECK
     opts = re.compile_options
-    if (opts & ~imsxa) == (DEFAULT_COMPILER_OPTS & ~imsxa)
+    mopts = re.match_options
+    default = ((opts & ~imsx) | ac) == DEFAULT_COMPILER_OPTS
+    if default
+       if (opts & ac) == ac
+           default = mopts == DEFAULT_MATCH_OPTS
+       elseif (opts & ac) == 0
+           default = mopts == (DEFAULT_MATCH_OPTS & ~am)
+       else
+           default = false
+       end
+   end
+    if default
         print(io, "r\"")
         escape_raw_string(io, re.pattern)
         print(io, "\"")
-        if (opts & PCRE.CASELESS ) != 0; print(io, 'i'); end
-        if (opts & PCRE.MULTILINE) != 0; print(io, 'm'); end
-        if (opts & PCRE.DOTALL   ) != 0; print(io, 's'); end
-        if (opts & PCRE.EXTENDED ) != 0; print(io, 'x'); end
-        if (opts & PCRE.UCP      ) == 0; print(io, 'a'); end
+        if (opts & PCRE.CASELESS ) != 0; print(io, "i"); end
+        if (opts & PCRE.MULTILINE) != 0; print(io, "m"); end
+        if (opts & PCRE.DOTALL   ) != 0; print(io, "s"); end
+        if (opts & PCRE.EXTENDED ) != 0; print(io, "x"); end
+        if (opts & ac            ) == 0; print(io, "a"); end
     else
         print(io, "Regex(")
         show(io, re.pattern)
-        print(io, ',')
+        print(io, ", ")
         show(io, opts)
-        print(io, ')')
+        print(io, ", ")
+        show(io, mopts)
+        print(io, ")")
     end
 end
 

base/set.jl

@@ -13,7 +13,7 @@ See also: [`AbstractSet`](@ref), [`BitSet`](@ref), [`Dict`](@ref),
 [`push!`](@ref), [`empty!`](@ref), [`union!`](@ref), [`in`](@ref), [`isequal`](@ref)
 
 # Examples
-```jldoctest filter = r"^\\S.+"
+```jldoctest; filter = r"^  '.'"ma
 julia> s = Set("aaBca")
 Set{Char} with 3 elements:
   'a'
@@ -23,9 +23,9 @@ Set{Char} with 3 elements:
 julia> push!(s, 'b')
 Set{Char} with 4 elements:
   'a'
-  'c'
   'b'
   'B'
+  'c'
 
 julia> s = Set([NaN, 0.0, 1.0, 2.0]);
 

base/shell.jl

@@ -292,9 +292,9 @@ function shell_escape_csh(io::IO, args::AbstractString...)
         first = false
         i = 1
         while true
-            for (r,e) = (r"^[A-Za-z0-9/\._-]+\z" => "",
-                         r"^[^']*\z" => "'", r"^[^\$\`\"]*\z" => "\"",
-                         r"^[^']+"  => "'", r"^[^\$\`\"]+"  => "\"")
+            for (r,e) = (r"^[A-Za-z0-9/\._-]+\z"sa => "",
+                         r"^[^']*\z"sa => "'", r"^[^\$\`\"]*\z"sa => "\"",
+                         r"^[^']+"sa  => "'", r"^[^\$\`\"]+"sa  => "\"")
                 if ((m = match(r, SubString(arg, i))) !== nothing)
                     write(io, e)
                     write(io, replace(m.match, '\n' => "\\\n"))
@@ -391,7 +391,7 @@ julia> Base.shell_escape_wincmd("a^\\"^o\\"^u\\"")
 """
 function shell_escape_wincmd(io::IO, s::AbstractString)
     # https://stackoverflow.com/a/4095133/1990689
-    occursin(r"[\r\n\0]", s) &&
+    occursin(r"[\r\n\0]"sa, s) &&
         throw(ArgumentError("control character unsupported by CMD.EXE"))
     i = 1
     len = ncodeunits(s)
@@ -446,7 +446,7 @@ function escape_microsoft_c_args(io::IO, args::AbstractString...)
         else
             write(io, ' ')  # separator
         end
-        if isempty(arg) || occursin(r"[ \t\"]", arg)
+        if isempty(arg) || occursin(r"[ \t\"]"sa, arg)
             # Julia raw strings happen to use the same escaping convention
             # as the argv[] parser in Microsoft's C runtime library.
             write(io, '"')

test/path.jl

@@ -171,6 +171,9 @@
         @test string(splitdrive(S(homedir()))...) == homedir()
         @test splitdrive("a\nb") == ("", "a\nb")
 
+        @test splitdir("a/\xfe/\n/b/c.ext") == ("a/\xfe/\n/b", "c.ext")
+        @test splitext("a/\xfe/\n/b/c.ext") == ("a/\xfe/\n/b/c", ".ext")
+
         if Sys.iswindows()
             @test splitdrive(S("\\\\servername\\hello.world\\filename.ext")) ==
                 ("\\\\servername\\hello.world","\\filename.ext")

test/regex.jl

@@ -59,6 +59,11 @@
     @test repr(r"\\\"") == raw"r\"\\\\\\\"\""
     @test repr(s"\\\"\\") == raw"s\"\\\\\\\"\\\\\""
 
+    @test repr(r""a) == "r\"\"a"
+    @test repr(r""imsxa) == "r\"\"imsxa"
+    @test repr(Regex("", Base.DEFAULT_COMPILER_OPTS, UInt32(0))) == """Regex("", $(repr(Base.DEFAULT_COMPILER_OPTS)), $(repr(UInt32(0))))"""
+    @test repr(Regex("", UInt32(0), Base.DEFAULT_MATCH_OPTS)) == """Regex("", $(repr(UInt32(0))), $(repr(Base.DEFAULT_MATCH_OPTS)))"""
+
     # findall
     @test findall(r"\w+", "foo bar") == [1:3, 5:7]
     @test findall(r"\w+", "foo bar", overlap=true) == [1:3, 2:3, 3:3, 5:7, 6:7, 7:7]
@@ -122,18 +127,24 @@
 
     # Backcapture reference in substitution string
     @test replace("abcde", r"(..)(?P<byname>d)" => s"\g<byname>xy\\\1") == "adxy\\bce"
-    @test_throws ErrorException replace("a", r"(?P<x>)" => s"\g<y>")
+    @test_throws(ErrorException("Bad replacement string: Group y not found in regex r\"(?P<x>)\""),
+        replace("a", r"(?P<x>)" => s"\g<y>"))
     # test replace with invalid substitution group pattern
-    @test_throws ErrorException replace("s", r"(?<g1>.)" => s"\gg1>")
+    @test_throws(ErrorException("Bad replacement string: \\gg1>"),
+        replace("s", r"(?<g1>.)" => s"\gg1>"))
     # test replace with 2-digit substitution group
     @test replace(("0" ^ 9) * "1", Regex(("(0)" ^ 9) * "(1)") => s"10th group: \10") == "10th group: 1"
 
     # Proper unicode handling
     @test  match(r"∀∀", "∀x∀∀∀").match == "∀∀"
 
-    # 'a' flag to disable UCP
+    # 'a' flag to disable UCP and UTF
     @test match(r"\w+", "Düsseldorf").match == "Düsseldorf"
     @test match(r"\w+"a, "Düsseldorf").match == "D"
+    @test match(r".+"a, "Düsseldorf").match == "Düsseldorf"
+    @test match(r".+"a, "Dü\xefsseldorf").match == "Dü\xefsseldorf"
+    @test_throws(ErrorException("PCRE.exec error: $(Base.PCRE.err_message(Base.PCRE.ERROR_UTF8_ERR6))"),
+        match(r"(*UTF).+"a, "Dü\xefsseldorf"))
 
     # Regex behaves like a scalar in broadcasting
     @test occursin.(r"Hello", ["Hello", "World"]) == [true, false]
@@ -211,8 +222,7 @@
     end
 
     # Test that PCRE throws the correct kind of error
-    # TODO: Uncomment this once the corresponding change has propagated to CI
-    #@test_throws ErrorException Base.PCRE.info(C_NULL, Base.PCRE.INFO_NAMECOUNT, UInt32)
+    @test_throws ErrorException("PCRE error: NULL regex object") Base.PCRE.info(C_NULL, Base.PCRE.INFO_NAMECOUNT, UInt32)
 
     # test that we can get the error message of negative error codes
     @test Base.PCRE.err_message(Base.PCRE.ERROR_NOMEMORY) isa String