Reimplements identifier lookup to work over the AST

pull/6/head
venko 2021-05-27 16:17:25 -07:00
parent ece20a99b5
commit e3fc2826ea
4 changed files with 212 additions and 1 deletions

207
src/ast.c
View File

@ -1,5 +1,6 @@
#include "ast.h" #include "ast.h"
#include <stdbool.h>
#include <stdio.h> #include <stdio.h>
#include <stdlib.h> #include <stdlib.h>
@ -989,3 +990,209 @@ char *TypeTagToString(TypeTag *tag)
} }
} }
} }
void LinkParentPointers(Node *node)
{
static Node *parent = NULL;
if (node == NULL)
{
fprintf(stderr, "wraith: Encountered NULL node while linking parent pointers.\n");
return;
}
node->parent = parent;
parent = node;
Recurse(node, *LinkParentPointers);
}
Node *GetIdFromStruct(Node *structDecl)
{
if (structDecl->syntaxKind != StructDeclaration)
{
fprintf(stderr, "wraith: Attempted to call GetIdFromStruct on node with kind: %s.\n",
SyntaxKindString(structDecl->syntaxKind));
return NULL;
}
return structDecl->structDeclaration.identifier;
}
Node *GetIdFromFunction(Node *funcDecl)
{
if (funcDecl->syntaxKind != FunctionDeclaration)
{
fprintf(stderr, "wraith: Attempted to call GetIdFromFunction on node with kind: %s.\n",
SyntaxKindString(funcDecl->syntaxKind));
return NULL;
}
Node *sig = funcDecl->functionDeclaration.functionSignature;
return sig->functionSignature.identifier;
}
Node *GetIdFromDeclaration(Node *decl)
{
if (decl->syntaxKind != Declaration)
{
fprintf(stderr, "wraith: Attempted to call GetIdFromDeclaration on node with kind: %s.\n",
SyntaxKindString(decl->syntaxKind));
}
return decl->declaration.identifier;
}
bool AssignmentHasDeclaration(Node *assign)
{
return (assign->syntaxKind == Assignment
&& assign->assignmentStatement.left->syntaxKind == Declaration);
}
Node *GetIdFromAssignment(Node *assign)
{
if (assign->syntaxKind != Assignment)
{
fprintf(stderr, "wraith: Attempted to call GetIdFromAssignment on node with kind: %s.\n",
SyntaxKindString(assign->syntaxKind));
}
if (AssignmentHasDeclaration(assign))
{
return GetIdFromDeclaration(assign->assignmentStatement.left);
}
return NULL;
}
bool NodeMayHaveId(Node *node)
{
switch (node->syntaxKind)
{
case StructDeclaration:
case FunctionDeclaration:
case Declaration:
case Assignment:
return true;
default:
return false;
}
}
Node *TryGetId(Node *node)
{
switch (node->syntaxKind)
{
case StructDeclaration:
return GetIdFromStruct(node);
case FunctionDeclaration:
return GetIdFromFunction(node);
case Declaration:
return GetIdFromDeclaration(node);
default:
return NULL;
}
}
Node *LookupFunctionArgId(Node *funcDecl, char *target)
{
Node *args =
funcDecl->functionDeclaration.functionSignature->functionSignature.arguments;
uint32_t i;
for (i = 0; i < args->functionArgumentSequence.count; i += 1)
{
Node *arg = args->functionArgumentSequence.sequence[i];
if (arg->syntaxKind != Declaration)
{
fprintf(stderr,
"wraith: Encountered %s node in function signature args list.\n",
SyntaxKindString(arg->syntaxKind));
continue;
}
Node *argId = GetIdFromDeclaration(arg);
if (argId != NULL && strcmp(target, argId->identifier.name) == 0)
{
return argId;
}
}
return NULL;
}
Node *LookupIdNode(Node *current, Node *prev, char *target)
{
if (current == NULL) return NULL;
/* If this node may have an identifier declaration inside it, attempt to look up the identifier
* node itself, returning it if it matches the given target name. */
if (NodeMayHaveId(current))
{
Node *candidateId = TryGetId(current);
if (candidateId != NULL && strcmp(target, candidateId->identifier.name) == 0)
{
return candidateId;
}
/* If the candidate node was not the one we wanted, but the current node is a function
* declaration, it's possible that the identifier we want is one of the function's
* parameters rather than the function's name itself. */
if (current->syntaxKind == FunctionDeclaration)
{
Node *match = LookupFunctionArgId(current, target);
if (match != NULL) return match;
}
}
/* If this is the start of our search, we should not attempt to look at
* child nodes. Only looking up the AST 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. */
if (prev == NULL)
{
return LookupIdNode(current->parent, current, target);
}
uint32_t i;
uint32_t idxLimit;
switch (current->syntaxKind)
{
case DeclarationSequence:
for (i = 0; i < current->declarationSequence.count; i += 1)
{
Node *decl = current->declarationSequence.sequence[i];
Node *declId = TryGetId(decl);
if (declId != NULL) return declId;
}
break;
case StatementSequence:
idxLimit = current->statementSequence.count;
for (i = 0; i < current->statementSequence.count; i += 1)
{
if (current->statementSequence.sequence[i] == prev)
{
idxLimit = i;
break;
}
}
for (i = 0; i < idxLimit; i += 1)
{
Node *stmt = current->statementSequence.sequence[i];
if (stmt == prev) continue;
if (NodeMayHaveId(stmt))
{
Node *candidateId = TryGetId(current);
if (candidateId != NULL && strcmp(target, candidateId->identifier.name) == 0)
{
return candidateId;
}
}
}
break;
}
return LookupIdNode(current->parent, current, target);
}

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@ -373,7 +373,10 @@ const char *SyntaxKindString(SyntaxKind syntaxKind);
* function in all other cases. */ * function in all other cases. */
void Recurse(Node *node, void (*func)(Node*)); void Recurse(Node *node, void (*func)(Node*));
void LinkParentPointers(Node *node);
TypeTag *MakeTypeTag(Node *node); TypeTag *MakeTypeTag(Node *node);
char *TypeTagToString(TypeTag *tag); char *TypeTagToString(TypeTag *tag);
Node *LookupIdNode(Node *current, Node *prev, char *target);
#endif /* WRAITH_AST_H */ #endif /* WRAITH_AST_H */

View File

@ -187,7 +187,7 @@ IdNode *MakeIdTree(Node *astNode, IdNode *parent)
{ {
char *name = astNode->identifier.name; char *name = astNode->identifier.name;
mainNode = MakeIdNode(Placeholder, name, parent); mainNode = MakeIdNode(Placeholder, name, parent);
IdNode *lookupNode = LookupId(mainNode, NULL, name); Node *lookupNode = LookupIdNode(astNode, NULL, name);
if (lookupNode == NULL) if (lookupNode == NULL)
{ {
fprintf(stderr, "wraith: Could not find IdNode for id %s\n", name); fprintf(stderr, "wraith: Could not find IdNode for id %s\n", name);

View File

@ -86,6 +86,7 @@ int main(int argc, char *argv[])
} }
else else
{ {
LinkParentPointers(rootNode);
{ {
IdNode *idTree = MakeIdTree(rootNode, NULL); IdNode *idTree = MakeIdTree(rootNode, NULL);
printf("\n"); printf("\n");