Fixes bugs in LookupId

iftest.w

@@ -1,4 +1,15 @@
+struct MyStruct {
+    static MyFunc(): int {
+        myStructInt: int = 595959959;
+        return myStructInt;
+    }
+}
+
 struct Program {
+    static Foo(): int {
+        return 0;
+    }
+
     static Main(): int {
         myInt: int = 54;
         if (myInt < 0) {
@@ -9,7 +20,6 @@ struct Program {
             signTag: int = 1;
         }
 
-        lol: int = 420;
         myBool: bool;
         if (myBool) {
             if (myBool) {
@@ -23,6 +33,12 @@ struct Program {
             }
         }
 
+        someInt: int = 9585858;
+
+        return 0;
+    }
+
+    static Bar(): int {
         return 0;
     }
 }

src/ast.c

@@ -593,6 +593,7 @@ char* TypeTagToString(TypeTag *tag) {
             size_t innerStrLen = strlen(inner);
             char *result = malloc(sizeof(char) * (innerStrLen + 5));
             sprintf(result, "Ref<%s>", inner);
+            free(inner);
             return result;
         }
         case Custom:

src/identcheck.c

@@ -1,3 +1,4 @@
+#include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <stdint.h>
@@ -43,7 +44,7 @@ IdNode* MakeIdTree(Node *astNode, IdNode *parent) {
 
         case IfStatement: {
             Node *stmtSeq = astNode->children[1];
-            IdNode *ifNode = MakeIdNode(LexicalScope, "if", parent);
+            IdNode *ifNode = MakeIdNode(OrderedScope, "if", parent);
             for (i = 0; i < stmtSeq->childCount; i++) {
                 AddChildToNode(ifNode, MakeIdTree(stmtSeq->children[i], ifNode));
             }
@@ -53,15 +54,15 @@ IdNode* MakeIdTree(Node *astNode, IdNode *parent) {
         case IfElseStatement: {
             Node *ifNode = astNode->children[0];
             Node *elseStmts = astNode->children[1];
-            IdNode *ifElseNode = MakeIdNode(LexicalScope, "if-else", parent);
+            IdNode *ifElseNode = MakeIdNode(OrderedScope, "if-else", parent);
             IdNode *ifBranch = MakeIdTree(ifNode, ifElseNode);
-            IdNode *elseBranch = MakeIdNode(LexicalScope, "else", ifElseNode);
+            IdNode *elseBranch = MakeIdNode(OrderedScope, "else", ifElseNode);
 
             AddChildToNode(ifElseNode, ifBranch);
-            AddChildToNode(ifElseNode, elseBranch);
             for (i = 0; i < elseStmts->childCount; i++) {
                 AddChildToNode(elseBranch, MakeIdTree(elseStmts->children[i], elseBranch));
             }
+            AddChildToNode(ifElseNode, elseBranch);
 
             return ifElseNode;
         }
@@ -69,7 +70,7 @@ IdNode* MakeIdTree(Node *astNode, IdNode *parent) {
         case ForLoop: {
             Node *loopDecl = astNode->children[0];
             Node *loopBody = astNode->children[3];
-            IdNode *loopNode = MakeIdNode(LexicalScope, "for-loop", parent);
+            IdNode *loopNode = MakeIdNode(OrderedScope, "for-loop", parent);
             AddChildToNode(loopNode, MakeIdTree(loopDecl, loopNode));
             for (i = 0; i < loopBody->childCount; i++) {
                 AddChildToNode(loopNode, MakeIdTree(loopBody->children[i], loopNode));
@@ -111,7 +112,7 @@ IdNode* MakeIdTree(Node *astNode, IdNode *parent) {
         }
 
         case DeclarationSequence: {
-            IdNode *declSeqNode = MakeIdNode(LexicalScope, "", parent);
+            IdNode *declSeqNode = MakeIdNode(UnorderedScope, "", parent);
             for (i = 0; i < astNode->childCount; i++) {
                 AddChildToNode(declSeqNode, MakeIdTree(astNode->children[i], declSeqNode));
             }
@@ -130,8 +131,11 @@ void PrintIdNode(IdNode *node) {
     }
 
     switch(node->type) {
-        case LexicalScope: 
-            printf("Scope (%s)\n", node->name); 
+        case OrderedScope: 
+            printf("OrderedScope (%s)\n", node->name); 
+            break;
+        case UnorderedScope: 
+            printf("UnorderedScope (%s)\n", node->name); 
             break;
         case Struct:
             printf("%s : %s\n", node->name, TypeTagToString(node->typeTag)); 
@@ -177,9 +181,9 @@ int PrintAncestors(IdNode *node) {
     return indent;
 }
 
-IdNode* FindId(IdNode *root, NodeType targetType, char *targetName) {
+IdNode* LookdownId(IdNode *root, NodeType targetType, char *targetName) {
     if (root == NULL) {
-        fprintf(stderr, "wraith: Attempted to call FindId on a null value.\n");
+        fprintf(stderr, "wraith: Attempted to call LookdownId on a null value.\n");
         return NULL;
     }
 
@@ -213,3 +217,74 @@ IdNode* FindId(IdNode *root, NodeType targetType, char *targetName) {
     free(frontier);
     return result;
 }
+
+bool ScopeHasOrdering(IdNode *node) {
+    switch (node->type) {
+        case OrderedScope:
+        case Function:
+        case Variable: // this is only technically true
+            return true;
+        default:
+            return false;
+    }
+}
+
+IdNode* LookupId(IdNode *node, IdNode *prev, char *target) {
+    if (node == NULL) {
+        return NULL;
+    }
+
+    if (strcmp(node->name, target) == 0) {
+        return node;
+    }
+
+    // If this is the start of our search, we should not attempt to look at child nodes. Only
+    // looking up the scope tree is valid at this point.
+    //
+    // This has the notable side-effect that this function will return NULL if you attempt to look
+    // up a struct's internals starting from the node representing the struct itself. This is
+    // because an IdNode corresponds to the location *where an identifier is first declared.* Thus,
+    // an identifier has no knowledge of identifiers declared "inside" of it.
+    if (prev == NULL) {
+        return LookupId(node->parent, node, target);
+    }
+
+    uint32_t idxLimit;
+    // If the current node forms an ordered scope then we want to prevent ourselves from looking
+    // up identifiers declared after the scope we have just come from.
+    if (ScopeHasOrdering(node)) {
+        uint32_t i;
+        for (i = 0, idxLimit = 0; i < node->childCount; i++, idxLimit++) {
+            if (node->children[i] == prev) {
+                break;
+            }
+        }
+    } else {
+        idxLimit = node->childCount;
+    }
+
+    uint32_t i;
+    for (i = 0; i < idxLimit; i++) {
+        IdNode *child = node->children[i];
+        if (child == prev) {
+            // Do not inspect the node we just came from.
+            continue;
+        }
+
+        if (strcmp(child->name, target) == 0) {
+            return child;
+        } 
+
+        if (child->type == Struct) {
+            uint32_t j;
+            for (j = 0; j < child->childCount; j++) {
+                IdNode *grandchild = child->children[j];
+                if (strcmp(grandchild->name, target) == 0) {
+                    return grandchild;
+                } 
+            }
+        }
+    }
+
+    return LookupId(node->parent, node, target);
+}

src/identcheck.h

@@ -7,7 +7,8 @@
 #include "ast.h"
 
 typedef enum NodeType {
-    LexicalScope,
+    UnorderedScope,
+    OrderedScope,
     Struct,
     Function,
     Variable
@@ -30,10 +31,12 @@ typedef struct IdStatus {
 } IdStatus;
 
 
-IdNode* FindId(IdNode *root, NodeType targetType, char *targetName);
 IdNode* MakeIdTree(Node *astNode, IdNode *parent);
+void PrintIdNode(IdNode *node);
 void PrintIdTree(IdNode *tree, uint32_t tabCount);
 int PrintAncestors(IdNode *node);
+IdNode* LookdownId(IdNode *root, NodeType targetType, char *targetName);
+IdNode* LookupId(IdNode *node, IdNode *prev, char* target);
 
 //IdStatus CheckIds(Node *root);
 

src/main.c

@@ -65,9 +65,49 @@ int main(int argc, char *argv[])
                 }
                 else
                 {
-                    if (parseVerbose) {
+                    { // This shit only works if you're using iftest.w
                         IdNode *idTree = MakeIdTree(rootNode, NULL);
                         PrintIdTree(idTree, /*tabCount=*/0);
+
+                        printf("\nSeeking to struct 'Program'\n");
+                        IdNode *node = LookdownId(idTree, Struct, "Program");
+                        if (node == NULL) printf("Failed.\n");
+
+                        printf("\n[attempting to look up MyStruct]: \n");
+                        PrintIdNode(LookupId(node, /*prev=*/NULL, "MyStruct"));
+
+                            printf("\n[attempting to look up MyFunc]: \n");
+                            PrintIdNode(LookupId(node, /*prev=*/NULL, "MyFunc"));
+
+                                printf("\n[attempting to look up myStructInt]: \n");
+                                PrintIdNode(LookupId(node, /*prev=*/NULL, "myStructInt"));
+
+                        printf("\n[attempting to look up Program]: \n");
+                        PrintIdNode(LookupId(node, /*prev=*/NULL, "Program"));
+
+                            printf("\n[attempting to look up Foo]: \n");
+                            PrintIdNode(LookupId(node, /*prev=*/NULL, "Foo"));
+
+                            printf("\n[attempting to look up Main]: \n");
+                            PrintIdNode(LookupId(node, /*prev=*/NULL, "Main"));
+
+                                printf("\n[attempting to look up myInt]: \n");
+                                PrintIdNode(LookupId(node, /*prev=*/NULL, "myInt"));
+
+                                printf("\n[attempting to look up signTag]: \n");
+                                PrintIdNode(LookupId(node, /*prev=*/NULL, "signTag"));
+
+                                printf("\n[attempting to look up myBool]: \n");
+                                PrintIdNode(LookupId(node, /*prev=*/NULL, "myBool"));
+
+                                printf("\n[attempting to look up lol]: \n");
+                                PrintIdNode(LookupId(node, /*prev=*/NULL, "lol"));
+
+                                printf("\n[attempting to look up someInt]: \n");
+                                PrintIdNode(LookupId(node, /*prev=*/NULL, "someInt"));
+
+                            printf("\n[attempting to look up Bar]: \n");
+                            PrintIdNode(LookupId(node, /*prev=*/NULL, "Bar"));
                     }
                     exitCode = Codegen(rootNode, optimizationLevel);
                 }