| /** |
| * Contains semantic routines specific to ImportC |
| * |
| * Specification: C11 |
| * |
| * Copyright: Copyright (C) 2021-2022 by The D Language Foundation, All Rights Reserved |
| * Authors: $(LINK2 https://www.digitalmars.com, Walter Bright) |
| * License: $(LINK2 https://www.boost.org/LICENSE_1_0.txt, Boost License 1.0) |
| * Source: $(LINK2 https://github.com/dlang/dmd/blob/master/src/dmd/importc.d, _importc.d) |
| * Documentation: https://dlang.org/phobos/dmd_importc.html |
| * Coverage: https://codecov.io/gh/dlang/dmd/src/master/src/dmd/importc.d |
| */ |
| |
| module dmd.importc; |
| |
| import core.stdc.stdio; |
| |
| import dmd.astenums; |
| import dmd.dcast; |
| import dmd.declaration; |
| import dmd.dscope; |
| import dmd.dsymbol; |
| import dmd.expression; |
| import dmd.expressionsem; |
| import dmd.identifier; |
| import dmd.init; |
| import dmd.mtype; |
| import dmd.tokens; |
| import dmd.typesem; |
| |
| /************************************** |
| * C11 does not allow array or function parameters. |
| * Hence, adjust those types per C11 6.7.6.3 rules. |
| * Params: |
| * t = parameter type to adjust |
| * sc = context |
| * Returns: |
| * adjusted type |
| */ |
| Type cAdjustParamType(Type t, Scope* sc) |
| { |
| if (!(sc.flags & SCOPE.Cfile)) |
| return t; |
| |
| Type tb = t.toBasetype(); |
| |
| /* C11 6.7.6.3-7 array of T is converted to pointer to T |
| */ |
| if (auto ta = tb.isTypeDArray()) |
| { |
| t = ta.next.pointerTo(); |
| } |
| else if (auto ts = tb.isTypeSArray()) |
| { |
| t = ts.next.pointerTo(); |
| } |
| /* C11 6.7.6.3-8 function is converted to pointer to function |
| */ |
| else if (tb.isTypeFunction()) |
| { |
| t = tb.pointerTo(); |
| } |
| return t; |
| } |
| |
| /*********************************************** |
| * C11 6.3.2.1-3 Convert expression that is an array of type to a pointer to type. |
| * C11 6.3.2.1-4 Convert expression that is a function to a pointer to a function. |
| * Params: |
| * e = ImportC expression to possibly convert |
| * sc = context |
| * Returns: |
| * converted expression |
| */ |
| Expression arrayFuncConv(Expression e, Scope* sc) |
| { |
| //printf("arrayFuncConv() %s\n", e.toChars()); |
| if (!(sc.flags & SCOPE.Cfile)) |
| return e; |
| |
| auto t = e.type.toBasetype(); |
| if (auto ta = t.isTypeDArray()) |
| { |
| e = e.castTo(sc, ta.next.pointerTo()); |
| } |
| else if (auto ts = t.isTypeSArray()) |
| { |
| e = e.castTo(sc, ts.next.pointerTo()); |
| } |
| else if (t.isTypeFunction()) |
| { |
| e = new AddrExp(e.loc, e); |
| } |
| else |
| return e; |
| return e.expressionSemantic(sc); |
| } |
| |
| /**************************************** |
| * Run semantic on `e`. |
| * Expression `e` evaluates to an instance of a struct. |
| * Look up `ident` as a field of that struct. |
| * Params: |
| * e = evaluates to an instance of a struct |
| * sc = context |
| * id = identifier of a field in that struct |
| * Returns: |
| * if successful `e.ident` |
| * if not then `ErrorExp` and message is printed |
| */ |
| Expression fieldLookup(Expression e, Scope* sc, Identifier id) |
| { |
| e = e.expressionSemantic(sc); |
| if (e.isErrorExp()) |
| return e; |
| |
| Dsymbol s; |
| auto t = e.type; |
| if (t.isTypePointer()) |
| { |
| t = t.isTypePointer().next; |
| e = new PtrExp(e.loc, e); |
| } |
| if (auto ts = t.isTypeStruct()) |
| s = ts.sym.search(e.loc, id, 0); |
| if (!s) |
| { |
| e.error("`%s` is not a member of `%s`", id.toChars(), t.toChars()); |
| return ErrorExp.get(); |
| } |
| Expression ef = new DotVarExp(e.loc, e, s.isDeclaration()); |
| return ef.expressionSemantic(sc); |
| } |
| |
| /**************************************** |
| * C11 6.5.2.1-2 |
| * Apply C semantics to `E[I]` expression. |
| * E1[E2] is lowered to *(E1 + E2) |
| * Params: |
| * ae = ArrayExp to run semantics on |
| * sc = context |
| * Returns: |
| * Expression if this was a C expression with completed semantic, null if not |
| */ |
| Expression carraySemantic(ArrayExp ae, Scope* sc) |
| { |
| if (!(sc.flags & SCOPE.Cfile)) |
| return null; |
| |
| auto e1 = ae.e1.expressionSemantic(sc); |
| |
| assert(ae.arguments.length == 1); |
| Expression e2 = (*ae.arguments)[0]; |
| |
| /* CTFE cannot do pointer arithmetic, but it can index arrays. |
| * So, rewrite as an IndexExp if we can. |
| */ |
| auto t1 = e1.type.toBasetype(); |
| if (t1.isTypeDArray() || t1.isTypeSArray()) |
| { |
| e2 = e2.expressionSemantic(sc).arrayFuncConv(sc); |
| // C doesn't do array bounds checking, so `true` turns it off |
| return new IndexExp(ae.loc, e1, e2, true).expressionSemantic(sc); |
| } |
| |
| e1 = e1.arrayFuncConv(sc); // e1 might still be a function call |
| e2 = e2.expressionSemantic(sc); |
| auto t2 = e2.type.toBasetype(); |
| if (t2.isTypeDArray() || t2.isTypeSArray()) |
| { |
| return new IndexExp(ae.loc, e2, e1, true).expressionSemantic(sc); // swap operands |
| } |
| |
| e2 = e2.arrayFuncConv(sc); |
| auto ep = new PtrExp(ae.loc, new AddExp(ae.loc, e1, e2)); |
| return ep.expressionSemantic(sc); |
| } |
| |
| /****************************************** |
| * Determine default initializer for const global symbol. |
| */ |
| void addDefaultCInitializer(VarDeclaration dsym) |
| { |
| //printf("addDefaultCInitializer() %s\n", dsym.toChars()); |
| if (!(dsym.storage_class & (STC.static_ | STC.gshared))) |
| return; |
| if (dsym.storage_class & (STC.extern_ | STC.field | STC.in_ | STC.foreach_ | STC.parameter | STC.result)) |
| return; |
| |
| Type t = dsym.type; |
| if (t.isTypeSArray() && t.isTypeSArray().isIncomplete()) |
| { |
| dsym._init = new VoidInitializer(dsym.loc); |
| return; // incomplete arrays will be diagnosed later |
| } |
| |
| if (t.isMutable()) |
| return; |
| |
| auto e = dsym.type.defaultInit(dsym.loc, true); |
| dsym._init = new ExpInitializer(dsym.loc, e); |
| } |
| |
| /******************************************** |
| * Resolve cast/call grammar ambiguity. |
| * Params: |
| * e = expression that might be a cast, might be a call |
| * sc = context |
| * Returns: |
| * null means leave as is, !=null means rewritten AST |
| */ |
| Expression castCallAmbiguity(Expression e, Scope* sc) |
| { |
| Expression* pe = &e; |
| |
| while (1) |
| { |
| // Walk down the postfix expressions till we find a CallExp or something else |
| switch ((*pe).op) |
| { |
| case EXP.dotIdentifier: |
| pe = &(*pe).isDotIdExp().e1; |
| continue; |
| |
| case EXP.plusPlus: |
| case EXP.minusMinus: |
| pe = &(*pe).isPostExp().e1; |
| continue; |
| |
| case EXP.array: |
| pe = &(*pe).isArrayExp().e1; |
| continue; |
| |
| case EXP.call: |
| auto ce = (*pe).isCallExp(); |
| if (ce.e1.parens) |
| { |
| ce.e1 = expressionSemantic(ce.e1, sc); |
| if (ce.e1.op == EXP.type) |
| { |
| const numArgs = ce.arguments ? ce.arguments.length : 0; |
| if (numArgs >= 1) |
| { |
| ce.e1.parens = false; |
| Expression arg; |
| foreach (a; (*ce.arguments)[]) |
| { |
| arg = arg ? new CommaExp(a.loc, arg, a) : a; |
| } |
| auto t = ce.e1.isTypeExp().type; |
| *pe = arg; |
| return new CastExp(ce.loc, e, t); |
| } |
| } |
| } |
| return null; |
| |
| default: |
| return null; |
| } |
| } |
| } |
| |
| /******************************************** |
| * Implement the C11 notion of function equivalence, |
| * which allows prototyped functions to match K+R functions, |
| * even though they are different. |
| * Params: |
| * tf1 = type of first function |
| * tf2 = type of second function |
| * Returns: |
| * true if C11 considers them equivalent |
| */ |
| |
| bool cFuncEquivalence(TypeFunction tf1, TypeFunction tf2) |
| { |
| //printf("cFuncEquivalence()\n %s\n %s\n", tf1.toChars(), tf2.toChars()); |
| if (tf1.equals(tf2)) |
| return true; |
| |
| if (tf1.linkage != tf2.linkage) |
| return false; |
| |
| // Allow func(void) to match func() |
| if (tf1.parameterList.length == 0 && tf2.parameterList.length == 0) |
| return true; |
| |
| if (!cTypeEquivalence(tf1.next, tf2.next)) |
| return false; // function return types don't match |
| |
| if (tf1.parameterList.length != tf2.parameterList.length) |
| return false; |
| |
| if (!tf1.parameterList.hasIdentifierList && !tf2.parameterList.hasIdentifierList) // if both are prototyped |
| { |
| if (tf1.parameterList.varargs != tf2.parameterList.varargs) |
| return false; |
| } |
| |
| foreach (i, fparam ; tf1.parameterList) |
| { |
| Type t1 = fparam.type; |
| Type t2 = tf2.parameterList[i].type; |
| |
| /* Strip off head const. |
| * Not sure if this is C11, but other compilers treat |
| * `void fn(int)` and `fn(const int x)` |
| * as equivalent. |
| */ |
| t1 = t1.mutableOf(); |
| t2 = t2.mutableOf(); |
| |
| if (!t1.equals(t2)) |
| return false; |
| } |
| |
| //printf("t1: %s\n", tf1.toChars()); |
| //printf("t2: %s\n", tf2.toChars()); |
| return true; |
| } |
| |
| /******************************* |
| * Types haven't been merged yet, because we haven't done |
| * semantic() yet. |
| * But we still need to see if t1 and t2 are the same type. |
| * Params: |
| * t1 = first type |
| * t2 = second type |
| * Returns: |
| * true if they are equivalent types |
| */ |
| bool cTypeEquivalence(Type t1, Type t2) |
| { |
| if (t1.equals(t2)) |
| return true; // that was easy |
| |
| if (t1.ty != t2.ty || t1.mod != t2.mod) |
| return false; |
| |
| if (auto tp = t1.isTypePointer()) |
| return cTypeEquivalence(tp.next, t2.nextOf()); |
| |
| if (auto ta = t1.isTypeSArray()) |
| // Bug: should check array dimension |
| return cTypeEquivalence(ta.next, t2.nextOf()); |
| |
| if (auto ts = t1.isTypeStruct()) |
| return ts.sym is t2.isTypeStruct().sym; |
| |
| if (auto te = t1.isTypeEnum()) |
| return te.sym is t2.isTypeEnum().sym; |
| |
| if (auto tf = t1.isTypeFunction()) |
| return cFuncEquivalence(tf, tf.isTypeFunction()); |
| |
| return false; |
| } |
