Merge pull request #1848 from Smit-create/i-1736

Support CPtr <-> u64 casting

Author: certik

integration_tests/bindc_03.py

@@ -1,6 +1,7 @@
 from lpython import (c_p_pointer, CPtr, pointer, i32,
                     Pointer, ccall, p_c_pointer, dataclass,
-                    ccallable, empty_c_void_p)
+                    ccallable, empty_c_void_p, cptr_to_u64,
+                    u64_to_cptr, u64)
 
 @dataclass
 class ArrayWrapped:
@@ -51,6 +52,11 @@ def run():
     assert a != empty_c_void_p()
     array_wrapped.array = a
     f(array_wrapped.array)
+    q: u64 = cptr_to_u64(a)
+    x: CPtr
+    x = u64_to_cptr(q)
+    array_wrapped.array = x
+    f(array_wrapped.array)
     array_wrapped1 = array_wrapped
     h(array_wrapped1.array)
 

src/libasr/ASR.asdl

@@ -414,6 +414,8 @@ cast_kind
     | LogicalToCharacter
     | UnsignedIntegerToInteger
     | IntegerToUnsignedInteger
+    | CPtrToUnsignedInteger
+    | UnsignedIntegerToCPtr
 
 dimension = (expr? start, expr? length)
 

src/libasr/codegen/asr_to_c_cpp.h

@@ -1513,6 +1513,16 @@ R"(#include <stdio.h>
                 last_expr_precedence = 2;
                 break;
             }
+            case (ASR::cast_kindType::CPtrToUnsignedInteger) : {
+                src = "(uint64_t)(" + src + ")";
+                last_expr_precedence = 2;
+                break;
+            }
+            case (ASR::cast_kindType::UnsignedIntegerToCPtr) : {
+                src = "(void*)(" + src + ")";
+                last_expr_precedence = 2;
+                break;
+            }
             default : throw CodeGenError("Cast kind " + std::to_string(x.m_kind) + " not implemented",
                 x.base.base.loc);
         }

src/libasr/codegen/asr_to_llvm.cpp

@@ -6818,6 +6818,14 @@ class ASRToLLVMVisitor : public ASR::BaseVisitor<ASRToLLVMVisitor>
                 // tmp = tmp
                 break;
             }
+            case (ASR::cast_kindType::CPtrToUnsignedInteger) : {
+                tmp = builder->CreatePtrToInt(tmp, getIntType(8, false));
+                break;
+            }
+            case (ASR::cast_kindType::UnsignedIntegerToCPtr) : {
+                tmp = builder->CreateIntToPtr(tmp, llvm::Type::getVoidTy(context)->getPointerTo());
+                break;
+            }
             case (ASR::cast_kindType::ComplexToComplex) : {
                 llvm::Type *target_type;
                 int arg_kind = -1, dest_kind = -1;

src/lpython/semantics/python_ast_to_asr.cpp

@@ -6985,7 +6985,7 @@ class BodyVisitor : public CommonVisitor<BodyVisitor> {
                 // This will all be removed once we port it to intrinsic functions
             // Intrinsic functions
             if (call_name == "size") {
-                parse_args(x, args);;
+                parse_args(x, args);
                 if( args.size() < 1 || args.size() > 2 ) {
                     throw SemanticError("array accepts only 1 (arr) or 2 (arr, axis) arguments, got " +
                                         std::to_string(args.size()) + " arguments instead.",
@@ -7018,6 +7018,43 @@ class BodyVisitor : public CommonVisitor<BodyVisitor> {
                 }
                 tmp = ASR::make_PointerNullConstant_t(al, x.base.base.loc, type);
                 return;
+            } else if (call_name == "cptr_to_u64") {
+                parse_args(x, args);
+                if (args.size() != 1) {
+                    throw SemanticError("cptr_to_u64 accpets exactly 1 argument",
+                                        x.base.base.loc);
+                }
+
+                ASR::expr_t *var = args[0].m_value;
+                ASR::ttype_t *a_type = ASRUtils::expr_type(var);
+                if (!ASR::is_a<ASR::CPtr_t>(*a_type)) {
+                    throw SemanticError("Argument of type `CPtr` is expected in cptr_to_u64",
+                                        x.base.base.loc);
+                }
+                ASR::ttype_t *u_type = ASRUtils::TYPE(ASR::make_UnsignedInteger_t(al,
+                                x.base.base.loc, 8, nullptr, 0));
+
+                tmp = ASR::make_Cast_t(al, x.base.base.loc,
+                    var, ASR::cast_kindType::CPtrToUnsignedInteger, u_type, nullptr);
+                return;
+            } else if (call_name == "u64_to_cptr") {
+                parse_args(x, args);
+                if (args.size() != 1) {
+                    throw SemanticError("u64_to_cptr accpets exactly 1 argument",
+                                        x.base.base.loc);
+                }
+
+                ASR::expr_t *var = args[0].m_value;
+                ASR::ttype_t *a_type = ASRUtils::expr_type(var);
+                if (!ASR::is_a<ASR::UnsignedInteger_t>(*a_type)) {
+                    throw SemanticError("Argument of type `u64` is expected in u64_to_cptr",
+                                        x.base.base.loc);
+                }
+                ASR::ttype_t *c_type = ASRUtils::TYPE(ASR::make_CPtr_t(al, x.base.base.loc));
+
+                tmp = ASR::make_Cast_t(al, x.base.base.loc,
+                    var, ASR::cast_kindType::UnsignedIntegerToCPtr, c_type, nullptr);
+                return;
             } else if (call_name == "TypeVar") {
                 // Ignore TypeVar for now, we handle it based on the identifier itself
                 tmp = nullptr;

src/runtime/lpython/lpython.py

@@ -591,6 +591,12 @@ def __repr__(self):
 
     return ctypes_c_void_p()
 
+def cptr_to_u64(cptr):
+    return ctypes.addressof(cptr)
+
+def u64_to_cptr(ivalue):
+    return ctypes.c_void_p(ivalue)
+
 def sizeof(arg):
     return ctypes.sizeof(convert_type_to_ctype(arg))