Implement string concatenation, add tests

src/lfortran/codegen/asr_to_llvm.cpp

@@ -161,6 +161,35 @@ class ASRToLLVMVisitor : public ASR::BaseVisitor<ASRToLLVMVisitor>
         return builder->CreateLoad(presult);
     }
 
+
+    llvm::Value* lfortran_strop(llvm::Value* left_arg, llvm::Value* right_arg, 
+                                         std::string runtime_func_name)
+    {
+        llvm::Function *fn = module->getFunction(runtime_func_name);
+        if (!fn) {
+            llvm::FunctionType *function_type = llvm::FunctionType::get(
+                    llvm::Type::getVoidTy(context), {
+                        character_type->getPointerTo(),
+                        character_type->getPointerTo(),
+                        character_type->getPointerTo()
+                    }, false);
+            fn = llvm::Function::Create(function_type,
+                    llvm::Function::ExternalLinkage, runtime_func_name, *module);
+        }
+        llvm::AllocaInst *pleft_arg = builder->CreateAlloca(character_type,
+            nullptr);
+        builder->CreateStore(left_arg, pleft_arg);
+        llvm::AllocaInst *pright_arg = builder->CreateAlloca(character_type,
+            nullptr);
+        builder->CreateStore(right_arg, pright_arg);
+        llvm::AllocaInst *presult = builder->CreateAlloca(character_type,
+            nullptr);
+        std::vector<llvm::Value*> args = {pleft_arg, pright_arg, presult};
+        builder->CreateCall(fn, args);
+        return builder->CreateLoad(presult);
+    }
+
+
     // This function is called as:
     // float complex_re(complex a)
     // And it extracts the real part of the complex number
@@ -792,6 +821,19 @@ class ASRToLLVMVisitor : public ASR::BaseVisitor<ASRToLLVMVisitor>
         }
     }
 
+    void visit_StrOp(const ASR::StrOp_t &x) {
+        this->visit_expr(*x.m_left);
+        llvm::Value *left_val = tmp;
+        this->visit_expr(*x.m_right);
+        llvm::Value *right_val = tmp;
+        switch (x.m_op) {
+            case ASR::stropType::Concat: {
+                tmp = lfortran_strop(left_val, right_val, "_lfortran_strcat");
+                break;
+            };
+        }
+    }
+
     void visit_BinOp(const ASR::BinOp_t &x) {
         this->visit_expr(*x.m_left);
         llvm::Value *left_val = tmp;

src/runtime/lfort_intrinsics.c

@@ -3,6 +3,7 @@
 #include <stdlib.h>
 #include <math.h>
 #include <complex.h>
+#include <string.h>
 
 struct _lfortran_complex {
     float re, im;
@@ -537,3 +538,25 @@ double_complex_t _lfortran_zatanh(double_complex_t x)
     return atanh(x);
 #endif
 }
+
+
+// strcat  --------------------------------------------------------------------
+void _lfortran_strcat(char** s1, char** s2, char** dest)
+{
+    int cntr = 0;
+    char trmn = '\0';
+    int s1_len = strlen(*s1);
+    int s2_len = strlen(*s2);
+    int trmn_size = strlen(&trmn);
+    char* dest_char = (char*)malloc(s1_len+s2_len+trmn_size);
+    for (int i = 0; i < s1_len; i++) {
+        dest_char[cntr] = (*s1)[i];
+        cntr++;
+    }
+    for (int i = 0; i < s2_len; i++) {
+        dest_char[cntr] = (*s2)[i];
+        cntr++;
+    }
+    dest_char[cntr] = trmn;
+    *dest = &(dest_char[0]);
+}

tests/reference/asr-string3-aa1dc1c.json

@@ -0,0 +1,13 @@
+{
+    "basename": "asr-string3-aa1dc1c",
+    "cmd": "lfortran --show-asr --no-color {infile} -o {outfile}",
+    "infile": "tests/../integration_tests/string3.f90",
+    "infile_hash": "90188a84217deb8d16424b3aaf49f0b2a999cad8494cdf536c6d27e1",
+    "outfile": null,
+    "outfile_hash": null,
+    "stdout": "asr-string3-aa1dc1c.stdout",
+    "stdout_hash": "ebfbc4cf253158ab88857d927cd83c32a284910515f5d521f27ffa23",
+    "stderr": null,
+    "stderr_hash": null,
+    "returncode": 0
+}

tests/reference/asr-string3-aa1dc1c.stdout

@@ -0,0 +1 @@
+(TranslationUnit (SymbolTable 1 {dr_fortran: (Program (SymbolTable 2 {combined: (Variable 2 combined Local () Default (Character 4 []) Source Public), intro: (Variable 2 intro Local () Default (Character 4 []) Source Public), last_name: (Variable 2 last_name Local () Default (Character 4 []) Source Public), posit: (Variable 2 posit Local () Default (Character 4 []) Source Public), title: (Variable 2 title Local () Default (Character 4 []) Source Public), verb: (Variable 2 verb Local () Default (Character 4 []) Source Public)}) dr_fortran [(= (Var 2 intro) (Str "I've " (Character 8 []))) (= (Var 2 verb) (Str "learned " (Character 8 []))) (= (Var 2 posit) (Str "from " (Character 8 []))) (= (Var 2 title) (Str "Dr. " (Character 8 []))) (= (Var 2 last_name) (Str "Fortran" (Character 8 []))) (= (Var 2 combined) (StrOp (StrOp (StrOp (StrOp (Var 2 intro) Concat (Var 2 verb) (Character 4 [])) Concat (Var 2 posit) (Character 4 [])) Concat (Var 2 title) (Character 4 [])) Concat (Var 2 last_name) (Character 4 []))) (Print () [(Var 2 combined)])])}) [])

tests/reference/ast-string3-24139f8.json

@@ -0,0 +1,13 @@
+{
+    "basename": "ast-string3-24139f8",
+    "cmd": "lfortran --show-ast --no-color {infile} -o {outfile}",
+    "infile": "tests/../integration_tests/string3.f90",
+    "infile_hash": "90188a84217deb8d16424b3aaf49f0b2a999cad8494cdf536c6d27e1",
+    "outfile": null,
+    "outfile_hash": null,
+    "stdout": "ast-string3-24139f8.stdout",
+    "stdout_hash": "347d4112b125f40efa196d5dd603d29d7051eb7ddc0af2becad263ea",
+    "stderr": null,
+    "stderr_hash": null,
+    "returncode": 0
+}

tests/reference/ast-string3-24139f8.stdout

@@ -0,0 +1 @@
+(TranslationUnit [(Program dr_fortran [] [(Declaration [(intro "character" () [(len 5 Value)] [] [] ())]) (Declaration [(verb "character" () [(len 8 Value)] [] [] ())]) (Declaration [(posit "character" () [(len 5 Value)] [] [] ())]) (Declaration [(title "character" () [(len 4 Value)] [] [] ())]) (Declaration [(last_name "character" () [(len 7 Value)] [] [] ())]) (Declaration [(combined "character" () [(len 29 Value)] [] [] ())])] [(= intro (Str "I've ")) (= verb (Str "learned ")) (= posit (Str "from ")) (= title (Str "Dr. ")) (= last_name (Str "Fortran")) (= combined (StrOp (StrOp (StrOp (StrOp intro Concat verb) Concat posit) Concat title) Concat last_name)) (Print () [combined])] [])])

tests/reference/llvm-string3-9528793.json

@@ -0,0 +1,13 @@
+{
+    "basename": "llvm-string3-9528793",
+    "cmd": "lfortran --show-llvm {infile} -o {outfile}",
+    "infile": "tests/../integration_tests/string3.f90",
+    "infile_hash": "90188a84217deb8d16424b3aaf49f0b2a999cad8494cdf536c6d27e1",
+    "outfile": null,
+    "outfile_hash": null,
+    "stdout": "llvm-string3-9528793.stdout",
+    "stdout_hash": "5f9a0a51f4e97acfe4ecddfe4379401430df5052a9df1544f4283a21",
+    "stderr": null,
+    "stderr_hash": null,
+    "returncode": 0
+}

tests/reference/llvm-string3-9528793.stdout

@@ -0,0 +1,66 @@
+; ModuleID = 'LFortran'
+source_filename = "LFortran"
+
+@0 = private unnamed_addr constant [6 x i8] c"I've \00", align 1
+@1 = private unnamed_addr constant [9 x i8] c"learned \00", align 1
+@2 = private unnamed_addr constant [6 x i8] c"from \00", align 1
+@3 = private unnamed_addr constant [5 x i8] c"Dr. \00", align 1
+@4 = private unnamed_addr constant [8 x i8] c"Fortran\00", align 1
+@5 = private unnamed_addr constant [4 x i8] c"%s\0A\00", align 1
+
+define i64 @main() {
+.entry:
+  %combined = alloca i8*, align 8
+  %intro = alloca i8*, align 8
+  %last_name = alloca i8*, align 8
+  %posit = alloca i8*, align 8
+  %title = alloca i8*, align 8
+  %verb = alloca i8*, align 8
+  store i8* getelementptr inbounds ([6 x i8], [6 x i8]* @0, i32 0, i32 0), i8** %intro, align 8
+  store i8* getelementptr inbounds ([9 x i8], [9 x i8]* @1, i32 0, i32 0), i8** %verb, align 8
+  store i8* getelementptr inbounds ([6 x i8], [6 x i8]* @2, i32 0, i32 0), i8** %posit, align 8
+  store i8* getelementptr inbounds ([5 x i8], [5 x i8]* @3, i32 0, i32 0), i8** %title, align 8
+  store i8* getelementptr inbounds ([8 x i8], [8 x i8]* @4, i32 0, i32 0), i8** %last_name, align 8
+  %0 = load i8*, i8** %intro, align 8
+  %1 = load i8*, i8** %verb, align 8
+  %2 = alloca i8*, align 8
+  store i8* %0, i8** %2, align 8
+  %3 = alloca i8*, align 8
+  store i8* %1, i8** %3, align 8
+  %4 = alloca i8*, align 8
+  call void @_lfortran_strcat(i8** %2, i8** %3, i8** %4)
+  %5 = load i8*, i8** %4, align 8
+  %6 = load i8*, i8** %posit, align 8
+  %7 = alloca i8*, align 8
+  store i8* %5, i8** %7, align 8
+  %8 = alloca i8*, align 8
+  store i8* %6, i8** %8, align 8
+  %9 = alloca i8*, align 8
+  call void @_lfortran_strcat(i8** %7, i8** %8, i8** %9)
+  %10 = load i8*, i8** %9, align 8
+  %11 = load i8*, i8** %title, align 8
+  %12 = alloca i8*, align 8
+  store i8* %10, i8** %12, align 8
+  %13 = alloca i8*, align 8
+  store i8* %11, i8** %13, align 8
+  %14 = alloca i8*, align 8
+  call void @_lfortran_strcat(i8** %12, i8** %13, i8** %14)
+  %15 = load i8*, i8** %14, align 8
+  %16 = load i8*, i8** %last_name, align 8
+  %17 = alloca i8*, align 8
+  store i8* %15, i8** %17, align 8
+  %18 = alloca i8*, align 8
+  store i8* %16, i8** %18, align 8
+  %19 = alloca i8*, align 8
+  call void @_lfortran_strcat(i8** %17, i8** %18, i8** %19)
+  %20 = load i8*, i8** %19, align 8
+  store i8* %20, i8** %combined, align 8
+  %21 = load i8*, i8** %combined, align 8
+  call void (i8*, ...) @_lfortran_printf(i8* getelementptr inbounds ([4 x i8], [4 x i8]* @5, i32 0, i32 0), i8* %21)
+  ret i64 0
+}
+
+declare void @_lfortran_strcat(i8**, i8**, i8**)
+
+declare void @_lfortran_printf(i8*, ...)
+

tests/tests.toml

@@ -743,3 +743,9 @@ filename = "../integration_tests/string2.f90"
 ast = true
 asr = true
 llvm = true
+
+[[test]]
+filename = "../integration_tests/string3.f90"
+ast = true
+asr = true
+llvm = true