From cd919e72e16012dcbb35b1dd1decf50cc670d53e Mon Sep 17 00:00:00 2001 From: Edoardo Prezioso 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;