Make SfxItemSet ranges correct by construction

This is a follow-up to 45a7f5b62d0b1b21763c1c94255ef2309ea4280b "Keep WID ranges
sorted, and join adjacent ones".  While SfxItemSet::MergeRange relies on the
m_pWhichRanges being sorted (and, under DBG_UTIL, asserts if they are not), the
various SfxItemSet constructors curiously only check (via assert or DBG_ASSERT)
that each individual range has an upper bound not smaller than its lower bound.
Arguably, all SfxItemSet instances should fulfill the stronger guarantees
required and checked by MergeRange.

And in many cases the ranges are statically known, so that the checking can
happen at compile time.  Therefore, replace the two SfxItemSet ctors taking
explicit ranges with two other ctors that actually do proper checking.  The
(templated) overload taking an svl::Items struct should be used in all cases
where the range values are statically known at compile time, while the overload
taking a std::initializer_list<Pair> is for the remaining cases (that can only
do runtime checking via assert).  Most of those latter cases are simple cases
with a single range covering a single item, but a few are more complex.

(At least some of the uses of the existing SfxItemSet overload taking a

  const sal_uInt16* pWhichPairTable

can probably also be strengthened, but that is left for another day.)

This commit is the first in a series of two.  Apart from the manual changes to
compilerplugins/clang/store/sfxitemsetrewrite.cxx, include/svl/itemset.hxx, and
svl/source/items/itemset.cxx, it only consists of automatic rewriting of the
relevant SfxItemSet ctor calls (plus a few required manual fixes, see next).
But it does not yet check that the individual ranges are properly sorted (see
the TODO in svl::detail::validGap).  That check will be enabled, and the ensuing
manual fixes will be made in a follow-up commit, to reduce the likelyhood of
accidents.

There were three cases of necessary manual intervention:

* sw/source/core/unocore/unostyle.cxx uses eAtr of enum type RES_FRMATR in
braced-init-list syntax now, so needs explicit narrowing conversion to
sal_uInt16.

* In sw/source/uibase/uiview/formatclipboard.cxx, the trailiing comma in the
definition of macro FORMAT_PAINTBRUSH_FRAME_IDS needed to be removed manually.

* In svx/source/svdraw/svdoashp.cxx, svx/source/svdraw/svdotext.cxx,
sw/source/uibase/app/docstyle.cxx, sw/source/uibase/shells/frmsh.cxx,
sw/source/uibase/shells/grfsh.cxx, and sw/source/uibase/shells/textsh1.cxx,
some comments had to be put back (see "TODO: the replaced range can contain
relevant comments" in compilerplugins/clang/store/sfxitemsetrewrite.cxx).

A few uses of the variadic form erroneously used nullptr instead of 0 for
termination.  But this should have been harmless even if promoted std::nullptr_t
is larger than promoted sal_uInt16, assuming that the part of the nullptr value
that was interpreted as sal_uInt16/promoted int was all-zero bits.  Similarly,
some uses made the harmless error of using 0L instead of 0.

Change-Id: I2afea97282803cb311b9321a99bb627520ef5e35
Reviewed-on: https://gerrit.libreoffice.org/38861
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>
Tested-by: Stephan Bergmann <sbergman@redhat.com>

1 files changed, 262 insertions, 0 deletions

diff --git a/compilerplugins/clang/store/sfxitemsetrewrite.cxx b/compilerplugins/clang/store/sfxitemsetrewrite.cxx
new file mode 100644
index 000000000000..db316f861af2
--- /dev/null
+++ b/compilerplugins/clang/store/sfxitemsetrewrite.cxx
@@ -0,0 +1,262 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4; fill-column: 100 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#include "check.hxx"
+#include "plugin.hxx"
+
+namespace {
+
+class Visitor final:
+    public RecursiveASTVisitor<Visitor>, public loplugin::RewritePlugin
+{
+public:
+    explicit Visitor(InstantiationData const & data): RewritePlugin(data) {}
+
+    bool VisitCXXConstructExpr(CXXConstructExpr const * expr) {
+        if (ignoreLocation(expr)) {
+            return true;
+        }
+        auto const ctor = expr->getConstructor();
+        if (!loplugin::DeclCheck(ctor->getParent()).Class("SfxItemSet")
+            .GlobalNamespace())
+        {
+            return true;
+        }
+        auto const numParams = ctor->getNumParams();
+        auto const variadic = ctor->isVariadic();
+        if (!(((numParams == 3 && !variadic) || (numParams == 4 && variadic))
+              && (loplugin::TypeCheck(ctor->getParamDecl(0)->getType())
+                  .LvalueReference().Class("SfxItemPool").GlobalNamespace())))
+        {
+            return true;
+        }
+        auto const numArgs = expr->getNumArgs();
+        if (numArgs < 3) {
+            report(
+                DiagnosticsEngine::Warning,
+                ("unexpected SfxItemPool constructor call with less than three"
+                 " arguments"),
+                expr->getExprLoc())
+                << expr->getSourceRange();
+            return true;
+        }
+        rewrite(expr, variadic, false, numArgs, expr->getArgs());
+        return true;
+    }
+
+    bool VisitCallExpr(CallExpr const * expr) {
+        if (ignoreLocation(expr)) {
+            return true;
+        }
+        auto const dre = dyn_cast<DeclRefExpr>(
+            expr->getCallee()->IgnoreParenImpCasts());
+        if (dre == nullptr
+            || !(loplugin::DeclCheck(dre->getDecl()).Function("make_unique")
+                 .Namespace("o3tl").GlobalNamespace()))
+        {
+            return true;
+        }
+        auto const numTArgs = dre->getNumTemplateArgs();
+        if (numTArgs == 0) {
+            report(
+                DiagnosticsEngine::Warning,
+                "unexpected o3tl::make_unique call without template arguments",
+                expr->getExprLoc())
+                << expr->getSourceRange();
+            return true;
+        }
+        auto const tArg0 = dre->getTemplateArgs()[0].getArgument();
+        if (tArg0.getKind() != TemplateArgument::Type) {
+            report(
+                DiagnosticsEngine::Warning,
+                ("unexpected o3tl::make_unique call with non-type first"
+                 " template argument"),
+                expr->getExprLoc())
+                << expr->getSourceRange();
+            return true;
+        }
+        if (!loplugin::TypeCheck(tArg0.getAsType()).Class("SfxItemSet")
+            .GlobalNamespace())
+        {
+            return true;
+        }
+        auto const numArgs = expr->getNumArgs();
+        if (numArgs < 3) {
+            return true;
+        }
+        rewrite(expr, numArgs > 3, true, numArgs, expr->getArgs());
+        return true;
+    }
+
+private:
+    void run() override {
+        if (compiler.getLangOpts().CPlusPlus) {
+            TraverseDecl(compiler.getASTContext().getTranslationUnitDecl());
+        }
+    }
+
+    SourceLocation nextToken(SourceLocation loc) {
+        return loc.getLocWithOffset(
+            Lexer::MeasureTokenLength(
+                loc, compiler.getSourceManager(), compiler.getLangOpts()));
+    }
+
+    SourceLocation atMacroExpansionStart(SourceLocation loc) {
+        while (loc.isMacroID()
+               && (compiler.getSourceManager()
+                   .isAtStartOfImmediateMacroExpansion(loc, &loc)))
+        {}
+        return loc;
+    }
+
+    SourceLocation atMacroExpansionEnd(SourceLocation loc) {
+        while (compiler.getSourceManager().isMacroBodyExpansion(loc)) {
+            loc = compiler.getSourceManager().getImmediateExpansionRange(loc)
+                .second;
+        }
+        return loc;
+    }
+
+    void rewrite(
+        Expr const * expr, bool variadic, bool forward, unsigned numArgs,
+        Expr const * const * args)
+    {
+        bool constant = true;
+        unsigned firstZero = 0;
+        for (unsigned i = 1; i != numArgs; ++i) {
+            auto const arg = args[i];
+            constant = constant
+                && arg->isCXX11ConstantExpr(compiler.getASTContext());
+            APSInt v;
+            auto const zero
+                = ((arg->EvaluateAsInt(v, compiler.getASTContext())
+                    && v == 0)
+                   || (variadic && i > 4
+                       && arg->isNullPointerConstant(
+                           compiler.getASTContext(),
+                           Expr::NPC_ValueDependentIsNotNull)));
+            if (variadic) {
+                if (zero) {
+                    if (firstZero == 0) {
+                        if (i == 1) {
+                            report(
+                                DiagnosticsEngine::Warning,
+                                ("unexpected missing non-zero arguments before"
+                                 " first zero argument in SfxItemPool"
+                                 " constructor call"),
+                                arg->getExprLoc())
+                                << expr->getSourceRange();
+                            return;
+                        }
+                        if (i % 2 == 0) {
+                            report(
+                                DiagnosticsEngine::Warning,
+                                ("unexpected odd number of potentially non-zero"
+                                 " arguments before first definitely zero"
+                                 " argument in SfxItemPool constructor call"),
+                                arg->getExprLoc())
+                                << expr->getSourceRange();
+                            return;
+                        }
+                        firstZero = i;
+                    }
+                } else if (firstZero != 0) {
+                    report(
+                        DiagnosticsEngine::Warning,
+                        ("unexpected potentially non-zero argument in"
+                         " SfxItemPool constructor call, following zero"
+                         " argument"),
+                        arg->getExprLoc())
+                        << expr->getSourceRange();
+                    return;
+                }
+            } else if (zero) {
+                report(
+                    DiagnosticsEngine::Warning,
+                    "unexpected zero argument in SfxItemPool constructor call",
+                    arg->getExprLoc())
+                    << expr->getSourceRange();
+                return;
+            }
+        }
+        if (variadic && firstZero == 0) {
+            report(
+                DiagnosticsEngine::Warning,
+                ("unexpected SfxItemPool constructor call with no detectable"
+                 " zero arguments"),
+                expr->getExprLoc())
+                << expr->getSourceRange();
+            return;
+        }
+        if (rewriter != nullptr) {
+            if (!insertTextBefore(
+                    atMacroExpansionStart(args[1]->getLocStart()),
+                    (constant
+                     ? StringRef("svl::Items<")
+                     : (forward
+                        ? StringRef("std::initializer_list<SfxItemSet::Pair>{{")
+                        : StringRef("{{")))))
+            {
+                goto failed;
+            }
+            auto const postLoc = atMacroExpansionEnd(
+                args[numArgs - 1]->getLocEnd());
+            auto const postStr = constant ? StringRef(">{}") : StringRef("}}");
+            if (variadic) {
+                //TODO: the replaced range can contain relevant comments:
+                if (!replaceText(
+                        SourceRange(
+                            nextToken(
+                                atMacroExpansionEnd(
+                                    args[firstZero - 1]->getLocEnd())),
+                            postLoc),
+                        postStr))
+                {
+                    goto failed;
+                }
+            } else {
+                if (!insertTextAfterToken(postLoc, postStr)) {
+                    goto failed;
+                }
+            }
+            if (!constant && variadic) {
+                for (unsigned i = 2; i != firstZero - 1; ++i) {
+                    auto const arg = args[i];
+                    if (!(i % 2 == 0
+                          ? insertTextAfterToken(
+                              atMacroExpansionEnd(arg->getLocEnd()), "}")
+                          : insertTextBefore(
+                              atMacroExpansionStart(arg->getLocStart()), "{")))
+                    {
+                        goto failed;
+                    }
+                }
+            }
+            return;
+        }
+    failed: //TODO: undo partial changes
+        report(
+            DiagnosticsEngine::Warning,
+            ("rewrite SfxItemPool constructor call with"
+             " %select{%select{|std::initializer_list<SfxItemSet::Pair>}1"
+             "%{%{..., ...%}, ..., %{..., ...%}%}|svl::Items<...>%{%}}0 around"
+             " the %select{|leading }2%3 WID arguments%select{| and remove the"
+             " remaining %4 zero %plural{1:argument|:arguments}4}2"),
+            expr->getExprLoc())
+            << constant << forward << variadic
+            << (variadic ? firstZero - 1 : numArgs - 1) << (numArgs - firstZero)
+            << expr->getSourceRange();
+    }
+};
+
+static loplugin::Plugin::Registration<Visitor> reg("sfxitemsetrewrite",true);
+
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab cinoptions=b1,g0,N-s cinkeys+=0=break: */