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dmd.expression

Compiler implementation of the D programming language.

Authors:: Walter Bright

License:: Boost License 1.0

Source: expression.d

Documentation: https://dlang.org/phobos/dmd_expression.html

Coverage: https://codecov.io/gh/dlang/dmd/src/master/src/dmd/expression.d

inout(Expression) firstComma(inout Expression e);

Find the first non-comma expression.

Parameters:

Expression e Expressions connected by commas

Returns:: left-most non-comma expression

inout(Expression) lastComma(inout Expression e);

Find the last non-comma expression.

Parameters:

Expression e Expressions connected by commas

Returns:: right-most non-comma expression

FuncDeclaration hasThis(Scope* sc);

Determine if this is available by walking up the enclosing scopes until a function is found.

Parameters:

Scope* sc where to start looking for the enclosing function

Returns:: Found function if it satisfies isThis(), otherwise null

bool isNeedThisScope(Scope* sc, Declaration d);

Determine if a this is needed to access d.

Parameters:

Scope* `sc`	context
Declaration `d`	declaration to check

Returns:: true means a this is needed

bool isDotOpDispatch(Expression e);

check e is exp.opDispatch!(tiargs) or not It's used to switch to UFCS the semantic analysis path

void expandTuples(Expressions* exps);

Expand tuples.

Input: exps aray of Expressions

Output: exps rewritten in place

TupleDeclaration isAliasThisTuple(Expression e);

Expand alias this tuples.

TemplateDeclaration getFuncTemplateDecl(Dsymbol s);

If s is a function template, i.e. the only member of a template and that member is a function, return that template.

Parameters:

Dsymbol s symbol that might be a function template

Returns:: template for that function, otherwise null

Expression valueNoDtor(Expression e);

If we want the value of this expression, but do not want to call the destructor on it.

Expression doCopyOrMove(Scope* sc, Expression e, Type t = null);

Handle the postblit call on lvalue, or the move of rvalue.

Parameters:

Scope* `sc`	the scope where the expression is encountered
Expression `e`	the expression the needs to be moved or copied (source)
Type `t`	if the struct defines a copy constructor, the type of the destination

Returns:: The expression that copy constructs or moves the value.

struct UnionExp;

int RealIdentical(real_t x1, real_t x2);

Test to see if two reals are the same. Regard NaN's as equivalent. Regard +0 and -0 as different.

Parameters:

real_t `x1`	first operand
real_t `x2`	second operand

Returns:: 1 if x1 is x2 else 0

DotIdExp typeDotIdExp(ref const Loc loc, Type type, Identifier ident);

TypeDotIdExp

VarDeclaration expToVariable(Expression e);

Given an Expression, find the variable it really is.

For example, a[index] is really a, and s.f is really s.

Parameters:

Expression e Expression to look at

Returns:: variable if there is one, null if not

abstract class Expression: dmd.ast_node.ASTNode;

http://dlang.org/spec/expression.html#expression

static void deinitialize();

Deinitializes the global state of the compiler.

This can be used to restore the state set by _init to its original state.

final Expression copy();

Does *not* do a deep copy.

static Expression combine(Expression e1, Expression e2);

Combine e1 and e2 by CommaExp if both are not NULL.

static Expression extractLast(Expression e, out Expression e0);

If 'e' is a tree of commas, returns the rightmost expression by stripping off it from the tree. The remained part of the tree is returned via e0. Otherwise 'e' is directly returned and e0 is set to NULL.

bool isLvalue();

Return !=0 if expression is an lvalue.

Expression toLvalue(Scope* sc, Expression e);

Give error if we're not an lvalue. If we can, convert expression to be an lvalue.

Expression resolveLoc(ref const Loc loc, Scope* sc);

Resolve __FILE__, __LINE__, __MODULE__, __FUNCTION__, __PRETTY_FUNCTION__, _FILE_FULL_PATH__ to loc.

bool checkType();

Check that the expression has a valid type. If not, generates an error "... has no type".

Returns:: true if the expression is not valid.

Note: When this function returns true, checkValue() should also return true.

bool checkValue();

Check that the expression has a valid value. If not, generates an error "... has no value".

Returns:: true if the expression is not valid or has void type.

final bool checkPurity(Scope* sc, FuncDeclaration f);

Calling function f. Check the purity, i.e. if we're in a pure function we can only call other pure functions. Returns true if error occurs.

final bool checkPurity(Scope* sc, VarDeclaration v);

Accessing variable v. Check for purity and safety violations. Returns true if error occurs.

final bool checkSafety(Scope* sc, FuncDeclaration f);

Calling function f. Check the safety, i.e. if we're in a @safe function we can only call @safe or @trusted functions. Returns true if error occurs.

final bool checkNogc(Scope* sc, FuncDeclaration f);

Calling function f. Check the @nogc-ness, i.e. if we're in a @nogc function we can only call other @nogc functions. Returns true if error occurs.

final bool checkPostblit(Scope* sc, Type t);

Check that the postblit is callable if t is an array of structs. Returns true if error happens.

final bool checkReadModifyWrite(TOK rmwOp, Expression ex = null);

Check whether the expression allows RMW operations, error with rmw operator diagnostic if not. ex is the RHS expression, or NULL if ++/-- is used (for diagnostics) Returns true if error occurs.

Modifiable checkModifiable(Scope* sc, int flag = 0);

Parameters: sc: scope flag: 1: do not issue error message for invalid modification

Returns:: Whether the type is modifiable

Expression toBoolean(Scope* sc);

If expression can be tested for true or false, returns the modified expression. Otherwise returns ErrorExp.

Expression addDtorHook(Scope* sc);

Destructors are attached to VarDeclarations. Hence, if expression returns a temp that needs a destructor, make sure and create a VarDeclaration for that temp.

final Expression addressOf();

Take address of expression.

final Expression deref();

If this is a reference, dereference it.

bool isBool(bool result);

Does this expression statically evaluate to a boolean 'result' (true or false)?

class IntegerExp: dmd.expression.Expression;

IntegerExp literal(int v)();

Use this instead of creating new instances for commonly used literals such as 0 or 1.

Parameters: v = The value of the expression

Returns:: A static instance of the expression, typed as Tint32.

class ErrorExp: dmd.expression.Expression;

Use this expression for error recovery. It should behave as a 'sink' to prevent further cascaded error messages.

class VoidInitExp: dmd.expression.Expression;

An uninitialized value, generated from void initializers.

VarDeclaration var;: the variable from where the void value came from, null if not known
this(VarDeclaration var);: Useful for error messages

class RealExp: dmd.expression.Expression;

class ComplexExp: dmd.expression.Expression;

class IdentifierExp: dmd.expression.Expression;

class DollarExp: dmd.expression.IdentifierExp;

class DsymbolExp: dmd.expression.Expression;

Won't be generated by parser.

class ThisExp: dmd.expression.Expression;

http://dlang.org/spec/expression.html#this

class SuperExp: dmd.expression.ThisExp;

http://dlang.org/spec/expression.html#super

class NullExp: dmd.expression.Expression;

http://dlang.org/spec/expression.html#null

class StringExp: dmd.expression.Expression;

http://dlang.org/spec/expression.html#string_literals

const size_t numberOfCodeUnits(int tynto = 0);

Return the number of code units the string would be if it were re-encoded as tynto.

Parameters:

int tynto code unit type of the target encoding

Returns:: number of code units

const void writeTo(void* dest, bool zero, int tyto = 0);

Write the contents of the string to dest. Use numberOfCodeUnits() to determine size of result.

Parameters:

void* `dest`	destination
int `tyto`	encoding type of the result
bool `zero`	add terminating 0

const pure dchar getCodeUnit(size_t i);

Get the code unit at index i

Parameters:

size_t i index

Returns:: code unit at index i

void setCodeUnit(size_t i, dchar c);

Set the code unit at index i to c

Parameters:

size_t `i`	index
dchar `c`	code unit to set it to

char* toPtr();

If the string data is UTF-8 and can be accessed directly, return a pointer to it. Do not assume a terminating 0.

Returns:: pointer to string data if possible, null if not

StringExp toUTF8(Scope* sc);

Convert string to char[].

const const(char)[] toStringz();

Convert string contents to a 0 terminated string, allocated by mem.xmalloc().

class TupleExp: dmd.expression.Expression;

class ArrayLiteralExp: dmd.expression.Expression;

[ e1, e2, e3, ... ]

http://dlang.org/spec/expression.html#array_literals

Expression basis;: If !is null, elements[] can be sparse and basis is used for the "default" element value. In other words, non-null elements[i] overrides this 'basis' value.

class AssocArrayLiteralExp: dmd.expression.Expression;

[ key0 : value0, key1 : value1, ... ]

http://dlang.org/spec/expression.html#associative_array_literals

enum int stageScrub;

scrubReturnValue is running

enum int stageSearchPointers;

hasNonConstPointers is running

enum int stageOptimize;

optimize is running

enum int stageApply;

apply is running

enum int stageInlineScan;

inlineScan is running

enum int stageToCBuffer;

toCBuffer is running

class StructLiteralExp: dmd.expression.Expression;

sd( e1, e2, e3, ... )

StructDeclaration sd;: which aggregate this is for
Expressions* elements;: parallels sd.fields[] with null entries for fields to skip
Type stype;: final type of result (can be different from sd's type)
Symbol* sym;: back end symbol to initialize with literal
StructLiteralExp origin;: pointer to the origin instance of the expression. once a new expression is created, origin is set to 'this'. anytime when an expression copy is created, 'origin' pointer is set to 'origin' pointer value of the original expression.
StructLiteralExp inlinecopy;: those fields need to prevent a infinite recursion when one field of struct initialized with 'this' pointer.
int stageflags;: anytime when recursive function is calling, 'stageflags' marks with bit flag of current stage and unmarks before return from this function. 'inlinecopy' uses similar 'stageflags' and from multiple evaluation 'doInline' (with infinite recursion) of this expression.
bool useStaticInit;: if this is true, use the StructDeclaration's init symbol
Expression getField(Type type, uint offset);: Gets expression at offset of type. Returns NULL if not found.
int getFieldIndex(Type type, uint offset);: Get index of field. Returns -1 if not found.

class TypeExp: dmd.expression.Expression;

Mainly just a placeholder

class ScopeExp: dmd.expression.Expression;

Mainly just a placeholder of Package, Module, Nspace, and TemplateInstance (including TemplateMixin)

A template instance that requires IFTI: foo!tiargs(fargs) // foo!tiargs is left until CallExp::semantic() or resolveProperties()

class TemplateExp: dmd.expression.Expression;

Mainly just a placeholder

class NewExp: dmd.expression.Expression;

thisexp.new(newargs) newtype(arguments)

class NewAnonClassExp: dmd.expression.Expression;

thisexp.new(newargs) class baseclasses { } (arguments)

class SymbolExp: dmd.expression.Expression;

class SymOffExp: dmd.expression.SymbolExp;

Offset from symbol

class VarExp: dmd.expression.SymbolExp;

Variable

class OverExp: dmd.expression.Expression;

Overload Set

class FuncExp: dmd.expression.Expression;

Function/Delegate literal

class DeclarationExp: dmd.expression.Expression;

Declaration of a symbol

D grammar allows declarations only as statements. However in AST representation it can be part of any expression. This is used, for example, during internal syntax re-writes to inject hidden symbols.

class TypeidExp: dmd.expression.Expression;

typeid(int)

class TraitsExp: dmd.expression.Expression;

_traits(identifier, args...)

class HaltExp: dmd.expression.Expression;

class IsExp: dmd.expression.Expression;

is(targ id tok tspec) is(targ id == tok2)

abstract class UnaExp: dmd.expression.Expression;

final Expression incompatibleTypes();

The type for a unary expression is incompatible. Print error message.

Returns:: ErrorExp

final void setNoderefOperand();

Mark the operand as will never be dereferenced, which is useful info for @safe checks. Do before semantic() on operands rewrites them.

abstract class BinExp: dmd.expression.Expression;

final Expression incompatibleTypes();

The types for a binary expression are incompatible. Print error message.

Returns:: ErrorExp

final void setNoderefOperands();

Mark the operands as will never be dereferenced, which is useful info for @safe checks. Do before semantic() on operands rewrites them.

class BinAssignExp: dmd.expression.BinExp;

class CompileExp: dmd.expression.Expression;

https://dlang.org/spec/expression.html#mixin_expressions

class ImportExp: dmd.expression.UnaExp;

class AssertExp: dmd.expression.UnaExp;

https://dlang.org/spec/expression.html#assert_expressions

class DotIdExp: dmd.expression.UnaExp;

class DotTemplateExp: dmd.expression.UnaExp;

Mainly just a placeholder

class DotVarExp: dmd.expression.UnaExp;

class DotTemplateInstanceExp: dmd.expression.UnaExp;

foo.bar!(args)

class DelegateExp: dmd.expression.UnaExp;

class DotTypeExp: dmd.expression.UnaExp;

class CallExp: dmd.expression.UnaExp;

this(ref const Loc loc, FuncDeclaration fd, Expression earg1);

Instatiates a new function call expression

Parameters:

Loc `loc`	location
FuncDeclaration `fd`	the declaration of the function to call
Expression `earg1`	the function argument

static CallExp create(Loc loc, FuncDeclaration fd, Expression earg1);

Creates a new function call expression

Parameters:

Loc `loc`	location
FuncDeclaration `fd`	the declaration of the function to call
Expression `earg1`	the function argument

class AddrExp: dmd.expression.UnaExp;

class PtrExp: dmd.expression.UnaExp;

class NegExp: dmd.expression.UnaExp;

class UAddExp: dmd.expression.UnaExp;

class ComExp: dmd.expression.UnaExp;

class NotExp: dmd.expression.UnaExp;

class DeleteExp: dmd.expression.UnaExp;

class CastExp: dmd.expression.UnaExp;

Possible to cast to one type while painting to another type

class VectorExp: dmd.expression.UnaExp;

class VectorArrayExp: dmd.expression.UnaExp;

e1.array property for vectors.

https://dlang.org/spec/simd.html#properties

class SliceExp: dmd.expression.UnaExp;

e1 [lwr .. upr]

http://dlang.org/spec/expression.html#slice_expressions

this(ref const Loc loc, Expression e1, IntervalExp ie);

class ArrayLengthExp: dmd.expression.UnaExp;

class ArrayExp: dmd.expression.UnaExp;

e1 [ a0, a1, a2, a3 ,... ]

http://dlang.org/spec/expression.html#index_expressions

class DotExp: dmd.expression.BinExp;

class CommaExp: dmd.expression.BinExp;

const bool isGenerated;

This is needed because AssignExp rewrites CommaExp, hence it needs to trigger the deprecation.

bool allowCommaExp;

Temporary variable to enable / disable deprecation of comma expression depending on the context. Since most constructor calls are rewritting, the only place where false will be passed will be from the parser.

static void allow(Expression exp);

If the argument is a CommaExp, set a flag to prevent deprecation messages

It's impossible to know from CommaExp.semantic if the result will be used, hence when there is a result (type != void), a deprecation message is always emitted. However, some construct can produce a result but won't use it (ExpStatement and for loop increment). Those should call this function to prevent unwanted deprecations to be emitted.

Parameters:

Expression exp An expression that discards its result. If the argument is null or not a CommaExp, nothing happens.

class IntervalExp: dmd.expression.Expression;

Mainly just a placeholder

class DelegateFuncptrExp: dmd.expression.UnaExp;

class IndexExp: dmd.expression.BinExp;

e1 [ e2 ]

class PostExp: dmd.expression.BinExp;

For both i++ and i--

class PreExp: dmd.expression.UnaExp;

For both ++i and --i

class AssignExp: dmd.expression.BinExp;

this(ref const Loc loc, Expression e1, Expression e2);

class ConstructExp: dmd.expression.AssignExp;

class BlitExp: dmd.expression.AssignExp;

class AddAssignExp: dmd.expression.BinAssignExp;

class MinAssignExp: dmd.expression.BinAssignExp;

class MulAssignExp: dmd.expression.BinAssignExp;

class DivAssignExp: dmd.expression.BinAssignExp;

class ModAssignExp: dmd.expression.BinAssignExp;

class AndAssignExp: dmd.expression.BinAssignExp;

class OrAssignExp: dmd.expression.BinAssignExp;

class XorAssignExp: dmd.expression.BinAssignExp;

class PowAssignExp: dmd.expression.BinAssignExp;

class ShlAssignExp: dmd.expression.BinAssignExp;

class ShrAssignExp: dmd.expression.BinAssignExp;

class UshrAssignExp: dmd.expression.BinAssignExp;

class CatAssignExp: dmd.expression.BinAssignExp;

The ~= operator. It can have one of the following operators:

TOK.concatenateAssign - appending T[] to T[] TOK.concatenateElemAssign - appending T to T[] TOK.concatenateDcharAssign - appending dchar to T[]

The parser initially sets it to TOK.concatenateAssign, and semantic() later decides which of the three it will be set to.

class CatElemAssignExp: dmd.expression.CatAssignExp;

class CatDcharAssignExp: dmd.expression.CatAssignExp;

class AddExp: dmd.expression.BinExp;