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111 lines
3.3 KiB
C++
111 lines
3.3 KiB
C++
//===--- SemaAttr.cpp - Semantic Analysis for Attributes ------------------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This file implements semantic analysis for non-trivial attributes.
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//
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//===----------------------------------------------------------------------===//
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#include "Sema.h"
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#include "clang/AST/Expr.h"
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using namespace clang;
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void Sema::ActOnPragmaPack(PragmaPackKind Kind, IdentifierInfo *Name,
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ExprTy *alignment, SourceLocation PragmaLoc,
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SourceLocation LParenLoc, SourceLocation RParenLoc) {
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Expr *Alignment = static_cast<Expr *>(alignment);
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// If specified then alignment must be a "small" power of two.
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unsigned AlignmentVal = 0;
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if (Alignment) {
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llvm::APSInt Val;
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if (!Alignment->isIntegerConstantExpr(Val, Context) ||
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!Val.isPowerOf2() ||
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Val.getZExtValue() > 16) {
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Diag(PragmaLoc, diag::warn_pragma_pack_invalid_alignment);
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Alignment->Destroy(Context);
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return; // Ignore
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}
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AlignmentVal = (unsigned) Val.getZExtValue();
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}
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switch (Kind) {
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case Action::PPK_Default: // pack([n])
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PackContext.setAlignment(AlignmentVal);
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break;
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case Action::PPK_Show: // pack(show)
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// Show the current alignment, making sure to show the right value
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// for the default.
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AlignmentVal = PackContext.getAlignment();
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// FIXME: This should come from the target.
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if (AlignmentVal == 0)
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AlignmentVal = 8;
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Diag(PragmaLoc, diag::warn_pragma_pack_show) << AlignmentVal;
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break;
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case Action::PPK_Push: // pack(push [, id] [, [n])
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PackContext.push(Name);
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// Set the new alignment if specified.
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if (Alignment)
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PackContext.setAlignment(AlignmentVal);
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break;
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case Action::PPK_Pop: // pack(pop [, id] [, n])
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// MSDN, C/C++ Preprocessor Reference > Pragma Directives > pack:
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// "#pragma pack(pop, identifier, n) is undefined"
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if (Alignment && Name)
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Diag(PragmaLoc, diag::warn_pragma_pack_pop_identifer_and_alignment);
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// Do the pop.
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if (!PackContext.pop(Name)) {
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// If a name was specified then failure indicates the name
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// wasn't found. Otherwise failure indicates the stack was
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// empty.
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Diag(PragmaLoc, diag::warn_pragma_pack_pop_failed)
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<< (Name ? "no record matching name" : "stack empty");
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// FIXME: Warn about popping named records as MSVC does.
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} else {
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// Pop succeeded, set the new alignment if specified.
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if (Alignment)
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PackContext.setAlignment(AlignmentVal);
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}
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break;
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default:
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assert(0 && "Invalid #pragma pack kind.");
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}
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}
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bool PragmaPackStack::pop(IdentifierInfo *Name) {
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if (Stack.empty())
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return false;
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// If name is empty just pop top.
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if (!Name) {
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Alignment = Stack.back().first;
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Stack.pop_back();
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return true;
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}
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// Otherwise, find the named record.
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for (unsigned i = Stack.size(); i != 0; ) {
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--i;
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if (Stack[i].second == Name) {
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// Found it, pop up to and including this record.
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Alignment = Stack[i].first;
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Stack.erase(Stack.begin() + i, Stack.end());
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return true;
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}
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}
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return false;
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}
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