From cd919e72e16012dcbb35b1dd1decf50cc670d53e Mon Sep 17 00:00:00 2001
From: Edoardo Prezioso <edward.san.dev@gmail.com>
Date: Wed, 23 Nov 2016 21:50:21 +0100
Subject: [PATCH] - Don't null-check the ZCC_TreeNode 'this' pointer.
Compilers are allowed to simplify the 'this == nullptr' code block because it makes no sense in 'well-defined C++ code'.
---
src/scripting/zscript/zcc-parse.lemon | 38 +++++++++++++--------------
src/scripting/zscript/zcc_parser.cpp | 31 ++++++++++++++++++++++
src/scripting/zscript/zcc_parser.h | 30 ++-------------------
3 files changed, 52 insertions(+), 47 deletions(-)
diff --git a/src/scripting/zscript/zcc-parse.lemon b/src/scripting/zscript/zcc-parse.lemon
index fc1803f1d..379d1516e 100644
--- a/src/scripting/zscript/zcc-parse.lemon
+++ b/src/scripting/zscript/zcc-parse.lemon
@@ -22,7 +22,7 @@ static void SetNodeLine(ZCC_TreeNode *name, int line)
// If a is non-null, appends b to a. Otherwise, sets a to b.
#define SAFE_APPEND(a,b) \
- if (a == NULL) a = b; else a->AppendSibling(b);
+ if (a == NULL) a = b; else AppendTreeNodeSibling(a, b);
#define UNARY_EXPR(X,T) NEW_AST_NODE(ExprUnary, expr1, X); expr1->Operation = T; expr1->Operand = X; expr1->Type = NULL
#define BINARY_EXPR(X,Y,T) NEW_AST_NODE(ExprBinary, expr2, X); expr2->Operation = T; expr2->Type = NULL; expr2->Left = X; expr2->Right = Y
@@ -221,14 +221,14 @@ dottable_id(X) ::= dottable_id(A) DOT IDENTIFIER(B).
{
NEW_AST_NODE(Identifier,id2,A);
id2->Id = B.Name();
- A->AppendSibling(id2);
+ AppendTreeNodeSibling(A, id2);
X = A; /*X-overwrites-A*/
}
dottable_id(X) ::= dottable_id(A) DOT DEFAULT.
{
NEW_AST_NODE(Identifier,id2,A);
id2->Id = NAME_Default;
- A->AppendSibling(id2);
+ AppendTreeNodeSibling(A, id2);
X = A; /*X-overwrites-A*/
}
@@ -239,7 +239,7 @@ dottable_id(X) ::= dottable_id(A) DOT COLOR.
{
NEW_AST_NODE(Identifier,id2,A);
id2->Id = NAME_Color;
- A->AppendSibling(id2);
+ AppendTreeNodeSibling(A, id2);
X = A; /*X-overwrites-A*/
}
@@ -299,7 +299,7 @@ opt_struct_body(X) ::= error. { X = NULL; }
struct_body(X) ::= struct_member(X).
-struct_body(X) ::= struct_member(A) struct_body(B). { X = A; /*X-overwrites-A*/ X->AppendSibling(B); }
+struct_body(X) ::= struct_member(A) struct_body(B). { X = A; /*X-overwrites-A*/ AppendTreeNodeSibling(X, B); }
struct_member(X) ::= declarator(A). { X = A; /*X-overwrites-A*/ }
struct_member(X) ::= enum_def(A). { X = A; /*X-overwrites-A*/ }
@@ -375,11 +375,11 @@ enum_def(X) ::= ENUM(T) IDENTIFIER(A) enum_type(B) LBRACE opt_enum_list(C) RBRAC
}
// Add a new terminating node, to indicate that the ConstantDefs for this enum are done.
NEW_AST_NODE(EnumTerminator,term,U);
- C->AppendSibling(term);
+ AppendTreeNodeSibling(C, term);
}
if (C != NULL)
{
- def->AppendSibling(C);
+ AppendTreeNodeSibling(def, C);
}
X = def;
}
@@ -389,7 +389,7 @@ enum_type(X) ::= COLON int_type(A). { X = A; /*X-overwrites-A*/ }
enum_list(X) ::= error. { X = NULL; }
enum_list(X) ::= enumerator(X).
-enum_list(X) ::= enum_list(A) COMMA enumerator(B). { X = A; /*X-overwrites-A*/ X->AppendSibling(B); }
+enum_list(X) ::= enum_list(A) COMMA enumerator(B). { X = A; /*X-overwrites-A*/ AppendTreeNodeSibling(X, B); }
opt_enum_list(X) ::= . { X = NULL; }
opt_enum_list(X) ::= enum_list(X) opt_comma.
@@ -450,7 +450,7 @@ states_opt(X) ::= states_opt(A) COMMA IDENTIFIER(B).
NEW_AST_NODE(Identifier,id,B);
id->Id = B.Name();
X = A; /*X-overwrites-A*/
- X->AppendSibling(id);
+ AppendTreeNodeSibling(X, id);
}
@@ -545,7 +545,7 @@ state_opts(X) ::= state_opts(A) FAST. { A.Fast = true; X = A; /*X-overwri
state_opts(X) ::= state_opts(A) SLOW. { A.Slow = true; X = A; /*X-overwrites-A*/ }
state_opts(X) ::= state_opts(A) NODELAY. { A.NoDelay = true; X = A; /*X-overwrites-A*/ }
state_opts(X) ::= state_opts(A) CANRAISE. { A.CanRaise = true; X = A; /*X-overwrites-A*/ }
-state_opts(X) ::= state_opts(A) OFFSET LPAREN expr(B) COMMA expr(C) RPAREN. { A.Offset = B; B->AppendSibling(C); X = A; /*X-overwrites-A*/ }
+state_opts(X) ::= state_opts(A) OFFSET LPAREN expr(B) COMMA expr(C) RPAREN. { A.Offset = B; AppendTreeNodeSibling(B, C); X = A; /*X-overwrites-A*/ }
state_opts(X) ::= state_opts(A) LIGHT LPAREN light_list(B) RPAREN. { X = A; /*X-overwrites-A*/ X.Lights = B; }
%type light_list {ZCC_ExprConstant *}
@@ -565,7 +565,7 @@ light_list(X) ::= light_list(A) COMMA STRCONST(B).
strconst->Operation = PEX_ConstValue;
strconst->Type = TypeString;
strconst->StringVal = B.String;
- A->AppendSibling(strconst);
+ AppendTreeNodeSibling(A, strconst);
X = A; /*X-overwrites-A*/
}
@@ -783,7 +783,7 @@ type_or_array(X) ::= type(X).
type_or_array(X) ::= type(A) array_size(B). { X = A; /*X-overwrites-A*/ X->ArraySize = B; }
type_list(X) ::= type_or_array(X). /* A comma-separated list of types */
-type_list(X) ::= type_list(A) COMMA type_or_array(B). { X = A; /*X-overwrites-A*/ X->AppendSibling(B); }
+type_list(X) ::= type_list(A) COMMA type_or_array(B). { X = A; /*X-overwrites-A*/ AppendTreeNodeSibling(X, B); }
type_list_or_void(X) ::= VOID. { X = NULL; }
type_list_or_void(X) ::= type_list(X).
@@ -805,7 +805,7 @@ array_size_expr(X) ::= LBRACKET(L) opt_expr(A) RBRACKET.
array_size(X) ::= array_size_expr(X).
array_size(X) ::= array_size(A) array_size_expr(B).
{
- A->AppendSibling(B);
+ AppendTreeNodeSibling(A, B);
X = A; /*X-overwrites-A*/
}
@@ -911,7 +911,7 @@ variable_name(X) ::= IDENTIFIER(A) array_size(B).
variable_list(X) ::= variable_name(X).
variable_list(X) ::= variable_list(A) COMMA variable_name(B).
{
- A->AppendSibling(B);
+ AppendTreeNodeSibling(A, B);
X = A; /*X-overwrites-A*/
}
@@ -984,11 +984,11 @@ func_params(X) ::= func_param_list(A) COMMA ELLIPSIS.
parm->Flags = 0;
parm->Default = nullptr;
X = A; /*X-overwrites-A*/
- X->AppendSibling(parm);
+ AppendTreeNodeSibling(X, parm);
}
func_param_list(X) ::= func_param(X).
-func_param_list(X) ::= func_param_list(A) COMMA func_param(B). { X = A; /*X-overwrites-A*/ X->AppendSibling(B); }
+func_param_list(X) ::= func_param_list(A) COMMA func_param(B). { X = A; /*X-overwrites-A*/ AppendTreeNodeSibling(X, B); }
func_param(X) ::= func_param_flags(A) type(B) IDENTIFIER(C).
{
@@ -1422,7 +1422,7 @@ expr_list(X) ::= expr(X).
expr_list(X) ::= expr_list(A) COMMA expr(B).
{
X = A; /*X-overwrites-A*/
- X->AppendSibling(B);
+ AppendTreeNodeSibling(X, B);
}
/*----- Function argument lists -----*/
@@ -1453,7 +1453,7 @@ func_expr_list(X) ::= func_expr_list(A) COMMA(T) func_expr_item(B).
B = nil_b;
}
X = A; /*X-overwrites-A*/
- X->AppendSibling(B);
+ AppendTreeNodeSibling(X, B);
}
func_expr_item(X) ::= .
@@ -1877,6 +1877,6 @@ var_init(X) ::= IDENTIFIER EQ LBRACE error RBRACE.
variable_list_with_init(X) ::= var_init(X).
variable_list_with_init(X) ::= variable_list_with_init(A) COMMA var_init(B).
{
- A->AppendSibling(B);
+ AppendTreeNodeSibling(A, B);
X = A; /*X-overwrites-A*/
}
diff --git a/src/scripting/zscript/zcc_parser.cpp b/src/scripting/zscript/zcc_parser.cpp
index 37fd8ff0c..401a15c25 100644
--- a/src/scripting/zscript/zcc_parser.cpp
+++ b/src/scripting/zscript/zcc_parser.cpp
@@ -466,3 +466,34 @@ ZCC_TreeNode *ZCCParseState::InitNode(size_t size, EZCCTreeNodeType type)
node->SourceLump = sc->LumpNum;
return node;
}
+
+// Appends a sibling to this node's sibling list.
+void AppendTreeNodeSibling(ZCC_TreeNode *thisnode, ZCC_TreeNode *sibling)
+{
+ if (thisnode == nullptr)
+ {
+ // Some bad syntax can actually get here, so better abort so that the user can see the error which caused this.
+ I_FatalError("Internal script compiler error. Execution aborted.");
+ }
+ if (sibling == nullptr)
+ {
+ return;
+ }
+
+ ZCC_TreeNode *&SiblingPrev = thisnode->SiblingPrev;
+ ZCC_TreeNode *&SiblingNext = thisnode->SiblingNext;
+
+ // Check integrity of our sibling list.
+ assert(SiblingPrev->SiblingNext == thisnode);
+ assert(SiblingNext->SiblingPrev == thisnode);
+
+ // Check integrity of new sibling list.
+ assert(sibling->SiblingPrev->SiblingNext == sibling);
+ assert(sibling->SiblingNext->SiblingPrev == sibling);
+
+ ZCC_TreeNode *siblingend = sibling->SiblingPrev;
+ SiblingPrev->SiblingNext = sibling;
+ sibling->SiblingPrev = SiblingPrev;
+ SiblingPrev = siblingend;
+ siblingend->SiblingNext = thisnode;
+}
diff --git a/src/scripting/zscript/zcc_parser.h b/src/scripting/zscript/zcc_parser.h
index a2fc3fb56..7a763b2c1 100644
--- a/src/scripting/zscript/zcc_parser.h
+++ b/src/scripting/zscript/zcc_parser.h
@@ -161,34 +161,6 @@ struct ZCC_TreeNode
// one of the structures below.
EZCCTreeNodeType NodeType;
- // Appends a sibling to this node's sibling list.
- void AppendSibling(ZCC_TreeNode *sibling)
- {
- if (this == nullptr)
- {
- // Some bad syntax can actually get here, so better abort so that the user can see the error which caused this.
- I_FatalError("Internal script compiler error. Execution aborted.");
- }
- if (sibling == NULL)
- {
- return;
- }
-
- // Check integrity of our sibling list.
- assert(SiblingPrev->SiblingNext == this);
- assert(SiblingNext->SiblingPrev == this);
-
- // Check integrity of new sibling list.
- assert(sibling->SiblingPrev->SiblingNext == sibling);
- assert(sibling->SiblingNext->SiblingPrev == sibling);
-
- ZCC_TreeNode *siblingend = sibling->SiblingPrev;
- SiblingPrev->SiblingNext = sibling;
- sibling->SiblingPrev = SiblingPrev;
- SiblingPrev = siblingend;
- siblingend->SiblingNext = this;
- }
-
operator FScriptPosition()
{
return FScriptPosition(*SourceName, SourceLoc);
@@ -196,6 +168,8 @@ struct ZCC_TreeNode
};
+void AppendTreeNodeSibling(ZCC_TreeNode *thisnode, ZCC_TreeNode *sibling);
+
struct ZCC_Identifier : ZCC_TreeNode
{
ENamedName Id;