Fix error message because of macro

src/api.jl

@@ -73,7 +73,7 @@ Initializes the Optimizer library. This must be called before any other library
 
 """
 function init()
-    @checked Lib.XPRSinit(C_NULL)
+    Lib.XPRSinit(C_NULL)
 end
 
 """
@@ -83,7 +83,7 @@ Frees any allocated  memory and closes all open files.
 
 """
 function free()
-    @checked Lib.XPRSfree()
+    Lib.XPRSfree()
 end
 
 """
@@ -125,7 +125,7 @@ You can use this function to disable some of the checking and validation of func
 
 """
 function setcheckedmode(checked_mode)
-    @checked Lib.XPRSsetcheckedmode(checked_mode)
+    Lib.XPRSsetcheckedmode(checked_mode)
 end
 
 """
@@ -135,19 +135,19 @@ You can use this function to interrogate whether checking and validation of all
 
 """
 function getcheckedmode(r_checked_mode)
-    @checked Lib.XPRSgetcheckedmode(r_checked_mode)
+    Lib.XPRSgetcheckedmode(r_checked_mode)
 end
 
 function license(lic, path)
     r = Lib.XPRSlicense(lic, path)
 end
 
 function beginlicensing(r_dontAlreadyHaveLicense)
-    @checked Lib.XPRSbeginlicensing(r_dontAlreadyHaveLicense)
+    Lib.XPRSbeginlicensing(r_dontAlreadyHaveLicense)
 end
 
 function endlicensing()
-    @checked Lib.XPRSendlicensing()
+    Lib.XPRSendlicensing()
 end
 
 """
@@ -165,7 +165,7 @@ function getlicerrmsg(; len = 1024)
     msg = Cstring(pointer(Array{Cchar}(undef, len*8)))
     Lib.XPRSgetlicerrmsg(msg, len)
     # TODO - @ checked version does not work
-    # @checked Lib.XPRSgetlicerrmsg(msg, len)
+    # Lib.XPRSgetlicerrmsg(msg, len)
     return unsafe_string(msg)
 end
 
@@ -2787,7 +2787,9 @@ Returns the error message corresponding to the last error encountered by a libra
 
 """
 function getlasterror(prob::XpressProblem)
-    @invoke Lib.XPRSgetlasterror(prob, _)::String
+    out = Cstring(pointer(Array{Cchar}(undef, 512)))
+    s = Lib.XPRSgetlasterror(prob, out)
+    s == 0 ? unsafe_string(out) : "Unable to get last error"
 end
 
 """

src/helper.jl

@@ -62,6 +62,10 @@ mutable struct XpressProblem <: CWrapper
     end
 end
 
+function get_xpress_error_message(prob::XpressProblem)
+    e = lstrip(Xpress.getlasterror(prob), ['?'])
+end
+
 function XpressProblem(; logfile = "")
     ref = Ref{Lib.XPRSprob}()
     createprob(ref)

src/utils.jl

@@ -88,15 +88,20 @@ macro invoke(expr)
     return f
 end
 
+function get_xpress_error_message(xprs_ptr)
+    e = "(Unable to extract error message for $(typeof(xprs_ptr)).)"
+end
 
 macro checked(expr)
     @assert expr.head == :call "Can only use @checked on function calls"
     @assert ( expr.args[1].head == :(.) ) && ( expr.args[1].args[1] == :Lib) "Can only use @checked on Lib.\$function"
+    @assert length(expr.args) >= 2 "Lib.\$function must be contain atleast one argument and the first argument must be of type XpressProblem"
     f = replace(String(expr.args[1].args[2].value), "XPRS" => "")
     return esc(quote
         r = $(expr)
         if r != 0
-            e = lstrip(Xpress.getlasterror(prob), ['?'])
+            xprs_ptr = $(expr.args[2])
+            e = get_xpress_error_message(xprs_ptr)
             throw(XpressError(r, "Unable to call `Xpress.$($f)`:\n\n$e.\n"))
         else
             nothing

test/runtests.jl

@@ -16,4 +16,5 @@ end
     @test Xpress.getcontrol(prob, "HEURTHREADS") == 0
     @test Xpress.getcontrol(prob, :HEURTHREADS) == 0
 
+    @test_throws Xpress.XpressError Xpress.copyprob(prob, prob)
 end