Rewrite C wrapper using Clang

.gitignore

@@ -2,3 +2,5 @@ Manifest.toml
 perf/*/*.json
 perf/*/*.toml
 perf/Project.toml
+scripts/Project.toml
+scripts/*.h

Project.toml

@@ -1,26 +1,21 @@
 name = "Gurobi"
 uuid = "2e9cd046-0924-5485-92f1-d5272153d98b"
 repo = "https://github.com/jump-dev/Gurobi.jl"
-version = "0.8.1"
+version = "0.9.0"
 
 [deps]
+CEnum = "fa961155-64e5-5f13-b03f-caf6b980ea82"
 Libdl = "8f399da3-3557-5675-b5ff-fb832c97cbdb"
-LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
 MathOptInterface = "b8f27783-ece8-5eb3-8dc8-9495eed66fee"
-MathProgBase = "fdba3010-5040-5b88-9595-932c9decdf73"
-SparseArrays = "2f01184e-e22b-5df5-ae63-d93ebab69eaf"
 
 [compat]
-Compat = "2, 3"
+CEnum = "0.3, 0.4"
 MathOptInterface = "~0.9.14"
-MathProgBase = "~0.5.0, ~0.6, ~0.7"
 julia = "1"
 
 [extras]
-Compat = "34da2185-b29b-5c13-b0c7-acf172513d20"
-Pkg = "44cfe95a-1eb2-52ea-b672-e2afdf69b78f"
 Random = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 
 [targets]
-test = ["Compat", "Pkg", "Random", "Test"]
+test = ["Random", "Test"]

deps/build.jl

@@ -1,11 +1,3 @@
-if haskey(ENV, "GITHUB_ACTIONS")
-    # We're being run as part of a Github action. The most likely case is that
-    # this is the auto-merge action as part of the General registry.
-    # For now, skip the installation.
-    @info("Detected a Github action. Skipping installation.")
-    exit(0)
-end
-
 using Libdl
 
 const DEPS_FILE = joinpath(@__DIR__, "deps.jl")
@@ -15,21 +7,13 @@ if isfile(DEPS_FILE)
 end
 
 function write_depsfile(path)
-    if Sys.iswindows()
-        # When `path` gets written out to a file, it will escape any
-        # backslashes, so we need to doubly escape them. If your path uses
-        # forward slashes, this operation won't do anything.
-        path = replace(path, "\\" => "\\\\")
-    end
     open(DEPS_FILE, "w") do io
-        println(io, "const libgurobi = \"$(path)\"")
+        println(io, "const libgurobi = \"$(escape_string(path))\"")
     end
 end
 
 const ALIASES = [
     "gurobi90",
-    "gurobi81", "gurobi80",
-    "gurobi75", "gurobi70"
 ]
 
 paths_to_try = copy(ALIASES)
@@ -63,31 +47,51 @@ for l in paths_to_try
     end
 end
 
+function _print_GUROBI_HOME_help()
+    println("""
+    You should set the `GUROBI_HOME` environment variable to point to the
+    install location then try again. For example (updating the path to the
+    correct location if needed):
+    ```
+    # On Windows, this might be
+    ENV["GUROBI_HOME"] = "C:\\\\Program Files\\\\gurobi902\\\\win64\\\\"
+    import Pkg
+    Pkg.add("Gurobi")
+    Pkg.build("Gurobi")
+
+    # On OSX, this might be
+    ENV["GUROBI_HOME"] = "/Library/gurobi902/mac64/"
+    import Pkg
+    Pkg.add("Gurobi")
+    Pkg.build("Gurobi")
+
+    # On Unix, this might be
+    ENV["GUROBI_HOME"] = "/opt/gurobi902/linux64/"
+    import Pkg
+    Pkg.add("Gurobi")
+    Pkg.build("Gurobi")
+    ```
+    """)
+end
+
 function diagnose_gurobi_install()
     println("""
-    Unable to locate Gurobi installation. Running some common diagnostics.
+
+    **Unable to locate Gurobi installation. Running some common diagnostics.**
 
     Gurobi.jl only supports the following versions:
     """)
     println.(" - ", ALIASES)
     println("""
 
     Did you download and install one of these versions from gurobi.com?
-
     """)
     if haskey(ENV, "GUROBI_HOME")
         dir = joinpath(ENV["GUROBI_HOME"], Sys.isunix() ? "lib" : "bin")
         println("""
         Found GUROBI_HOME =  $(ENV["GUROBI_HOME"])
 
         Does this point to the correct install location?
-        - on Windows, this might be `C:\\Program Files\\gurobi810\\win64\\`
-        - alternatively, on Windows, this might be `C:/Program Files/gurobi810/win64/`
-        - on OSX, this might be `/Library/gurobi810/mac64/`
-        - on Unix, this might be `/home/my_user/gurobi810/linux64/`
-
-        Note: this has to be a full path, not a path relative to your current
-        directory or your home directory.
 
         We're going to look for the Gurobi library in this directory:
             $(dir)
@@ -101,50 +105,45 @@ function diagnose_gurobi_install()
             println("""
 
             We were looking for (but could not find) a file named like
-            `libgurobiXXX.so`, `libgurobiXXX.dylib`, or `gurobiXXX.dll`. You
-            should update your GUROBI_HOME environment variable to point to the
-            correct location.
-            """)
+            `libgurobiXXX.so`, `libgurobiXXX.dylib`, or `gurobiXXX.dll`.\n\n""")
+
+            _print_GUROBI_HOME_help()
         catch ex
             if typeof(ex) <: SystemError
                 println("""
                 Aha! We tried looking in `$(dir)`, but something went wrong. Are
                 you sure that your GUROBI_HOME environment variable is correct?
                 When combined with the appropriate suffix (e.g., `lib` or
-                `bin`, it needs to point to a valid directory.
-                """)
+                `bin`, it needs to point to a valid directory.\n\n""")
+                _print_GUROBI_HOME_help()
             else
                 rethrow(ex)
             end
         end
     else
         try
-            println("""
-            Looking for a version of Gurobi in your path:
-            """)
             # Try to call `gurobi_cl`. This should work if Gurobi is on the
             # system path. If it succeeds, it will print out the version.
-            run(`gurobi_cl --version`)
+            io = IOBuffer()
+            run(pipeline(`gurobi_cl --version`; stdout = io))
+            seekstart(io)
             println("""
-
             We couldn't find the `GUROBI_HOME` environment variable, but we
-            found this version of Gurobi on your path. Is this version one of
-            the supported versions listed above? If not, you should edit your
-            `PATH` to point to the correct version.
-            """)
+            found this version of Gurobi on your `PATH`.
+
+            $(read(io, String))
+            Is this version one of the supported versions listed above? If so,
+            we found the executable, but not the libraries we need. Follow the
+            advice below to set the `GUROBI_HOME` environment variable. If not,
+            you should edit your `PATH` to point to the correct version, or set
+            the `GUROBI_HOME` environment variable.\n""")
+            _print_GUROBI_HOME_help()
         catch
             println("""
 
-            We could not find a version of Gurobi in your path, and we could
-            not find the environment variable `GUROBI_HOME`. You should set
-            the `GUROBI_HOME` environment variable to point to the install
-            location. For example:
-            - on Windows, this might be `C:\\Program Files\\gurobi810\\win64\\`
-            - on OSX, this might be `/Library/gurobi810/mac64/`
-            - on Unix, this might be `/opt/gurobi810/linux64/`
-
-            Alternatively, you can add the Gurobi install directory to your path.
-            """)
+            We could not find a version of Gurobi in your `PATH`, and we could
+            not find the environment variable `GUROBI_HOME`.\n\n""")
+            _print_GUROBI_HOME_help()
         end
     end
 end

scripts/clang.jl

@@ -0,0 +1,39 @@
+# TODO(odow):
+#
+# This script can be used to build the C interface to Gurobi. However, it requires
+# you to manually do the following steps first:
+#
+# 1) Copy gurobi_c.h from Gurobi into this /scripts directory
+
+import Clang
+
+const LIBGRB_HEADERS = [
+    joinpath(@__DIR__, "gurobi_c.h"),
+]
+
+const GEN_DIR = joinpath(dirname(@__DIR__), "src", "gen")
+
+wc = Clang.init(
+    headers = LIBGRB_HEADERS,
+    output_file = joinpath(GEN_DIR, "libgrb_api.jl"),
+    common_file = joinpath(GEN_DIR, "libgrb_common.jl"),
+    header_wrapped = (root, current) -> root == current,
+    header_library = x -> "libgurobi",
+    clang_diagnostics = true,
+)
+
+run(wc)
+
+function manual_corrections()
+    filename = joinpath(GEN_DIR, "libgrb_api.jl")
+    lines = readlines(filename; keep = true)
+    for (i, line) in enumerate(lines)
+        lines[i] = replace(line, "Cstring" => "Ptr{Cchar}")
+    end
+    open(filename, "w") do io
+        print.(Ref(io), lines)
+    end
+end
+manual_corrections()
+
+rm(joinpath(dirname(@__DIR__), "src", "gen", "LibTemplate.jl"))

scripts/deprecate.jl

@@ -0,0 +1,54 @@
+# This file was used to create the list of deprecations when moving from v0.8.1
+# to v0.9.0.
+
+using Gurobi
+
+io = open("deprecated_functions.jl", "w")
+print(io, """
+const _DEPRECATED_ERROR_MESSAGE = \"\"\"
+The C API of Gurobi.jl has been rewritten to expose the complete C API, and
+all old functions have been removed.
+
+For example:
+
+    model = Gurobi.Optimizer()
+    stat = Gurobi.get_status_code(model.inner)
+
+is now:
+
+    model = Gurobi.Optimizer()
+    valueP = Ref{Cint}()
+    ret = GRBgetintattr(model, "Status", valueP)
+    if ret != 0
+        # Do something because the call failed
+    end
+    stat = valueP[]
+
+The new API is more verbose, but the names and function arguments are now
+identical to the C API, documentation for which is available at:
+https://www.gurobi.com/documentation/9.0/refman/c_api_details.html
+
+To revert to the old API, use:
+
+    import Pkg
+    Pkg.add(Pkg.PackageSpec(name = \"Gurobi\", version = v\"0.8.1\"))
+
+Then restart Julia for the change to take effect.
+\"\"\"
+""")
+
+exported_names = Base.names(Gurobi; all = false)
+for name in Base.names(Gurobi; all = true)
+    foo = getfield(Gurobi, name)
+    if !(foo isa Function)
+        continue
+    elseif any(startswith.(Ref(string(foo)), ["#", "@", "_"]))
+        continue
+    end
+    println(io, "$(foo)(args...; kwargs...) = error(_DEPRECATED_ERROR_MESSAGE)")
+    if name in exported_names
+        println(io, "export $(foo)")
+    end
+    println(io)
+end
+close(io)