Merge pull request lcompilers#754 from namannimmo10/stringtoint

Make `int()` work for non-constant strings
krshrimali · Jul 19, 2022 · 0cb0f83 · 0cb0f83
2 parents b76b9db + f12c03b
commit 0cb0f83
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Showing 6 changed files with 50 additions and 6 deletions.
diff --git a/integration_tests/test_str_to_int.py b/integration_tests/test_str_to_int.py
@@ -6,5 +6,18 @@ def f():
     assert i == 314
     i = int("-314")
     assert i == -314
+    s: str
+    s = "123"
+    i = int(s)
+    assert i == 123
+    s = "-123"
+    i = int(s)
+    assert i == -123
+    s = "    1234"
+    i = int(s)
+    assert i == 1234
+    s = "    -1234   "
+    i = int(s)
+    assert i == -1234
 
-f()
+f()
diff --git a/src/libasr/ASR.asdl b/src/libasr/ASR.asdl
@@ -345,6 +345,7 @@ cast_kind
     | IntegerToLogical
     | RealToLogical
     | CharacterToLogical
+    | CharacterToInteger
     | ComplexToLogical
     | ComplexToComplex
     | ComplexToReal

diff --git a/src/libasr/codegen/asr_to_llvm.cpp b/src/libasr/codegen/asr_to_llvm.cpp
@@ -800,6 +800,21 @@ class ASRToLLVMVisitor : public ASR::BaseVisitor<ASRToLLVMVisitor>
         return builder->CreateCall(fn, {str});
     }
 
+    llvm::Value* lfortran_str_to_int(llvm::Value* str)
+    {
+        std::string runtime_func_name = "_lfortran_str_to_int";
+        llvm::Function *fn = module->getFunction(runtime_func_name);
+        if (!fn) {
+            llvm::FunctionType *function_type = llvm::FunctionType::get(
+                    llvm::Type::getInt32Ty(context), {
+                        character_type->getPointerTo()
+                    }, false);
+            fn = llvm::Function::Create(function_type,
+                    llvm::Function::ExternalLinkage, runtime_func_name, *module);
+        }
+        return builder->CreateCall(fn, {str});
+    }
+
     llvm::Value* lfortran_str_copy(llvm::Value* str, llvm::Value* idx1, llvm::Value* idx2)
     {
         std::string runtime_func_name = "_lfortran_str_copy";
@@ -4103,6 +4118,12 @@ class ASRToLLVMVisitor : public ASR::BaseVisitor<ASRToLLVMVisitor>
                 tmp = builder->CreateICmpNE(lfortran_str_len(parg), builder->getInt32(0));
                 break;
             }
+            case (ASR::cast_kindType::CharacterToInteger) : {
+                llvm::AllocaInst *parg = builder->CreateAlloca(character_type, nullptr);
+                builder->CreateStore(tmp, parg);
+                tmp = lfortran_str_to_int(parg);
+                break;
+            }
             case (ASR::cast_kindType::ComplexToLogical) : {
                 // !(c.real == 0.0 && c.imag == 0.0)
                 llvm::Value *zero;

diff --git a/src/lpython/semantics/python_ast_to_asr.cpp b/src/lpython/semantics/python_ast_to_asr.cpp
@@ -3423,8 +3423,8 @@ class BodyVisitor : public CommonVisitor<BodyVisitor> {
                                 loc, ival, to_type));
             }
             return (ASR::asr_t *)ASR::down_cast<ASR::expr_t>(ASR::make_Cast_t(
-            al, loc, arg, ASR::cast_kindType::RealToInteger,
-            to_type, value));
+                al, loc, arg, ASR::cast_kindType::RealToInteger,
+                to_type, value));
         } else if (ASRUtils::is_character(*type)) {
             if (ASRUtils::expr_value(arg) != nullptr) {
                 char *c = ASR::down_cast<ASR::StringConstant_t>(
@@ -3447,7 +3447,9 @@ class BodyVisitor : public CommonVisitor<BodyVisitor> {
                 return (ASR::asr_t *)ASR::down_cast<ASR::expr_t>(ASR::make_IntegerConstant_t(al,
                                 loc, ival, to_type));
             }
-            // TODO: make int() work for non-constant strings
+            return (ASR::asr_t *)ASR::down_cast<ASR::expr_t>(ASR::make_Cast_t(
+                al, loc, arg, ASR::cast_kindType::CharacterToInteger,
+                to_type, value));
         } else if (ASRUtils::is_logical(*type)) {
             if (ASRUtils::expr_value(arg) != nullptr) {
                 int32_t ival = ASR::down_cast<ASR::LogicalConstant_t>(
@@ -3456,8 +3458,8 @@ class BodyVisitor : public CommonVisitor<BodyVisitor> {
                                 loc, ival, to_type));
             }
             return (ASR::asr_t *)ASR::down_cast<ASR::expr_t>(ASR::make_Cast_t(
-            al, loc, arg, ASR::cast_kindType::LogicalToInteger,
-            to_type, value));
+                al, loc, arg, ASR::cast_kindType::LogicalToInteger,
+                to_type, value));
         } else if (!ASRUtils::is_integer(*type)) {
             std::string stype = ASRUtils::type_to_str_python(type);
             throw SemanticError(

diff --git a/src/runtime/impure/lfortran_intrinsics.c b/src/runtime/impure/lfortran_intrinsics.c
@@ -710,6 +710,12 @@ LFORTRAN_API int _lfortran_str_len(char** s)
     return strlen(*s);
 }
 
+LFORTRAN_API int _lfortran_str_to_int(char** s)
+{
+    char *ptr;
+    return strtol(*s, &ptr, 10);
+}
+
 LFORTRAN_API char* _lfortran_malloc(int size) {
     return (char*)malloc(size);
 }

diff --git a/src/runtime/impure/lfortran_intrinsics.h b/src/runtime/impure/lfortran_intrinsics.h
@@ -146,6 +146,7 @@ LFORTRAN_API bool _lpython_str_compare_gte(char** s1, char** s2);
 LFORTRAN_API void _lfortran_strrepeat(char** s, int32_t n, char** dest);
 LFORTRAN_API void _lfortran_strcat(char** s1, char** s2, char** dest);
 LFORTRAN_API int _lfortran_str_len(char** s);
+LFORTRAN_API int _lfortran_str_to_int(char** s);
 LFORTRAN_API char* _lfortran_malloc(int size);
 LFORTRAN_API void _lfortran_free(char* ptr);
 LFORTRAN_API void _lfortran_string_init(int size_plus_one, char *s);