From 28402f534aadfee50436e0cdf62044aa924c9300 Mon Sep 17 00:00:00 2001
From: cosmonaut <evan@moonside.games>
Date: Thu, 22 Apr 2021 10:27:39 -0700
Subject: [PATCH] emitting linkable object code

---
 compiler.c | 77 ++++++++++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 69 insertions(+), 8 deletions(-)

diff --git a/compiler.c b/compiler.c
index 6c482ae..9c02612 100644
--- a/compiler.c
+++ b/compiler.c
@@ -11,6 +11,7 @@
 #include <llvm-c/Transforms/Scalar.h>
 #include <llvm-c/Transforms/Utils.h>
 #include <llvm-c/TargetMachine.h>
+#include <llvm-c/Target.h>
 
 #include "y.tab.h"
 #include "ast.h"
@@ -480,6 +481,7 @@ static uint8_t CompileStatement(LLVMBuilderRef builder, LLVMValueRef function, N
 
 static void CompileFunction(
     LLVMModuleRef module,
+    char *parentStructName,
     LLVMTypeRef wStructPointerType,
     Node **fieldDeclarations,
     uint32_t fieldDeclarationCount,
@@ -522,7 +524,12 @@ static void CompileFunction(
 
     LLVMTypeRef returnType = WraithTypeToLLVMType(functionSignature->children[1]->type);
     LLVMTypeRef functionType = LLVMFunctionType(returnType, paramTypes, paramIndex, 0);
-    LLVMValueRef function = LLVMAddFunction(module, functionSignature->children[0]->value.string, functionType);
+
+    char *functionName = strdup(parentStructName);
+    strcat(functionName, "_");
+    strcat(functionName, functionSignature->children[0]->value.string);
+    LLVMValueRef function = LLVMAddFunction(module, functionName, functionType);
+    free(functionName);
 
     LLVMBasicBlockRef entry = LLVMAppendBasicBlock(function, "entry");
     LLVMBuilderRef builder = LLVMCreateBuilder();
@@ -560,6 +567,8 @@ static void CompileFunction(
     }
 
     PopScopeFrame(scope);
+
+    LLVMDisposeBuilder(builder);
 }
 
 static void CompileStruct(LLVMModuleRef module, LLVMContextRef context, Node *node)
@@ -571,10 +580,11 @@ static void CompileStruct(LLVMModuleRef module, LLVMContextRef context, Node *no
     LLVMTypeRef types[declarationCount];
     Node *currentDeclarationNode;
     Node *fieldDeclarations[declarationCount];
+    char *structName = node->children[0]->value.string;
 
     PushScopeFrame(scope);
 
-    LLVMTypeRef wStruct = LLVMStructCreateNamed(context, node->children[0]->value.string);
+    LLVMTypeRef wStruct = LLVMStructCreateNamed(context, structName);
     LLVMTypeRef wStructPointerType = LLVMPointerType(wStruct, 0); /* FIXME: is this address space correct? */
 
     /* first, build the structure definition */
@@ -604,7 +614,7 @@ static void CompileStruct(LLVMModuleRef module, LLVMContextRef context, Node *no
         switch (currentDeclarationNode->syntaxKind)
         {
             case FunctionDeclaration:
-                CompileFunction(module, wStructPointerType, fieldDeclarations, fieldCount, currentDeclarationNode);
+                CompileFunction(module, structName, wStructPointerType, fieldDeclarations, fieldCount, currentDeclarationNode);
                 break;
         }
     }
@@ -659,13 +669,46 @@ int main(int argc, char *argv[])
 
     Compile(module, context, rootNode);
 
+    /* add main call */
+    LLVMBuilderRef builder = LLVMCreateBuilder();
+
+    LLVMTypeRef mainFunctionType = LLVMFunctionType(LLVMInt64Type(), NULL, 0, 0);
+    LLVMValueRef mainFunction = LLVMAddFunction(module, "main", mainFunctionType);
+    LLVMBasicBlockRef entry = LLVMAppendBasicBlock(mainFunction, "entry");
+    LLVMPositionBuilderAtEnd(builder, entry);
+
+    LLVMValueRef wraithMainFunction = LLVMGetNamedFunction(module, "Program_Main");
+
+    LLVMValueRef mainResult = LLVMBuildCall(builder, wraithMainFunction, NULL, 0, "result");
+    LLVMBuildRet(builder, mainResult);
+
+    LLVMDisposeBuilder(builder);
+
+    /* verify */
     char *error = NULL;
     LLVMVerifyModule(module, LLVMAbortProcessAction, &error);
 
+    /* prepare to emit assembly */
+    LLVMInitializeNativeTarget();
+    LLVMInitializeAllTargetInfos();
+    LLVMInitializeAllTargets();
+    LLVMInitializeAllTargetMCs();
+    LLVMInitializeAllAsmParsers();
+    LLVMInitializeAllAsmPrinters();
+
     LLVMSetTarget(module, LLVM_DEFAULT_TARGET_TRIPLE);
+    LLVMTargetRef target;
+    if (LLVMGetTargetFromTriple(LLVM_DEFAULT_TARGET_TRIPLE, &target, &error) != 0)
+    {
+        fprintf(stderr, "Failed to get target!\n");
+        fprintf(stderr, "%s\n", error);
+        LLVMDisposeMessage(error);
+        return 1;
+    }
 
     LLVMPassManagerRef passManager = LLVMCreatePassManager();
-    LLVMAddInstructionCombiningPass(passManager);
+
+    //LLVMAddInstructionCombiningPass(passManager);
     LLVMAddCFGSimplificationPass(passManager);
     LLVMAddReassociatePass(passManager);
     LLVMAddPromoteMemoryToRegisterPass(passManager);
@@ -680,11 +723,29 @@ int main(int argc, char *argv[])
         fprintf(stderr, "error writing bitcode to file\n");
     }
 
-    LLVMMemoryBufferRef memoryBuffer = LLVMWriteBitcodeToMemoryBuffer(module);
-    LLVMCreateBinary(memoryBuffer, context, &error);
-    LLVMDisposeMessage(error);
-    LLVMDisposeMemoryBuffer(memoryBuffer);
+    char *cpu = "generic";
+    char *features = "";
 
+    LLVMTargetMachineRef targetMachine = LLVMCreateTargetMachine(
+        target,
+        LLVM_DEFAULT_TARGET_TRIPLE,
+        cpu,
+        features,
+        LLVMCodeGenLevelDefault,
+        LLVMRelocDefault,
+        LLVMCodeModelDefault
+    );
+
+    if (LLVMTargetMachineEmitToFile(targetMachine, module, "test.o", LLVMObjectFile, &error) != 0)
+    {
+        fprintf(stderr, "Failed to emit machine code!\n");
+        fprintf(stderr, "%s\n", error);
+        LLVMDisposeMessage(error);
+        return 1;
+    }
+
+    LLVMDisposeMessage(error);
+    LLVMDisposeTargetMachine(targetMachine);
     LLVMPassManagerBuilderDispose(passManagerBuilder);
     LLVMDisposePassManager(passManager);
     LLVMDisposeModule(module);