Widen integer literal to unsigned when required (#516)

* Widen integer literal to unsigned when required

* Handle large integers more robustly

* Add changelog entry

* Add test

* Realize that Clong is system-dependent

Author: serenity4

docs/src/changelog.md

@@ -18,6 +18,8 @@ Changelog](https://keepachangelog.com).
   avoid implicit imports ([#488]).
 - Added support to the auditor for detecting structs and function-like macros of
   the same name, which previously caused the generator to crash ([#500]).
+- Large L-suffixed integer literals that are greater than `typemax(Clong)` will now be wrapped
+  as unsigned integers (`Culong`) ([#516]).
 
 ## [v0.18.3] - 2024-04-23
 

src/generator/macro.jl

@@ -55,7 +55,7 @@ const LITERAL_NON_FLOAT_SUFFIXES = [
 const LITERAL_FLOAT_SUFFIXES = ["F", "f"]
 const LITERAL_SUFFIXES = vcat(LITERAL_NON_FLOAT_SUFFIXES, LITERAL_FLOAT_SUFFIXES)
 
-function c_non_float_literal_to_julia(sfx)
+function c_non_float_literal_to_julia(sfx, txt_no_sfx)
     sfx = lowercase(sfx)
     # integers following http://en.cppreference.com/w/cpp/language/integer_literal
     unsigned = occursin("u", sfx)
@@ -66,7 +66,12 @@ function c_non_float_literal_to_julia(sfx)
     elseif occursin("ul", sfx) || occursin("lu", sfx)
         return "Culong"
     elseif !unsigned && endswith(sfx, "l")
-        return "Clong"
+        value = tryparse(Clong, txt_no_sfx)
+        if isnothing(value) && !isnothing(tryparse(Culong, txt_no_sfx))
+            return "Culong"
+        else
+            return "Clong"
+        end
     else
         return unsigned ? "Cuint" : "Cint"
     end
@@ -89,7 +94,8 @@ function normalize_literal_type(text::AbstractString)
     for sfx in LITERAL_NON_FLOAT_SUFFIXES
         if endswith(txt, sfx)
             txt_no_sfx = replace(txt, Regex(sfx*"\$")=>"")
-            type = c_non_float_literal_to_julia(sfx)
+            txt_no_sfx = replace(txt_no_sfx, r"^0X" => "0x")
+            type = c_non_float_literal_to_julia(sfx, txt_no_sfx)
             return "$(type)($txt_no_sfx)"
         end
     end

test/generators.jl

@@ -249,3 +249,23 @@ end
         @test docstring_has("callback")
     end
 end
+
+@testset "Issue 515 - unsigned types for large literals" begin
+    args = get_default_args()
+    headers = joinpath(@__DIR__, "include", "large-integer-literals.h")
+    ctx = create_context(headers, args)
+    build!(ctx, BUILDSTAGE_NO_PRINTING)
+    extract_expr(ctx, i) = only(ctx.dag.nodes[i].exprs)
+    # Clong is Int32 on Windows and Int on other platforms.
+    clong_is_int32 = Sys.iswindows() || Int === Int32
+    if clong_is_int32
+        # We need an unsigned type to be able to hold the value on 4 bytes.
+        @test extract_expr(ctx, 1) == :(const TEST = Culong(0x80000001))
+        @test extract_expr(ctx, 2) == :(const TEST_2 = Culong(2147483649))
+    else
+        @test extract_expr(ctx, 1) == :(const TEST = Clong(0x80000001))
+        @test extract_expr(ctx, 2) == :(const TEST_2 = Clong(2147483649))
+    end
+    @test extract_expr(ctx, 3) == :(const TEST_SIGNED = Clong(0x00000001))
+    @test extract_expr(ctx, 4) == :(const TEST_SIGNED_2 = Clong(2147483646))
+end

test/include/large-integer-literals.h

@@ -0,0 +1,5 @@
+#define TEST 0x80000001L
+#define TEST_2 2147483649L
+
+#define TEST_SIGNED 0x00000001L
+#define TEST_SIGNED_2 2147483646L