<div dir="ltr"><div class="gmail_extra"><div class="gmail_quote">On 15 February 2017 at 14:43, George Burgess IV via cfe-commits <span dir="ltr"><<a href="mailto:cfe-commits@lists.llvm.org" target="_blank">cfe-commits@lists.llvm.org</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Author: gbiv<br>
Date: Wed Feb 15 16:43:27 2017<br>
New Revision: 295252<br>
<br>
URL: <a href="http://llvm.org/viewvc/llvm-project?rev=295252&view=rev" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-<wbr>project?rev=295252&view=rev</a><br>
Log:<br>
[Modules] Consider enable_if attrs in isSameEntity.<br>
<br>
Two functions that differ only in their enable_if attributes are<br>
considered overloads, so we should check for those when we're trying to<br>
figure out if two functions are mergeable.<br>
<br>
We need to do the same thing for pass_object_size, as well. Looks like<br>
that'll be a bit less trivial, since we sometimes do these merging<br>
checks before we have pass_object_size attributes available (see the<br>
merge checks in ASTDeclReader::<wbr>VisitFunctionDecl that happen before we<br>
read parameters, and merge checks in calls to ReadDeclAs<>()).<br></blockquote><div><br></div><div>Perhaps the best way to tackle this would be to track the presence of pass_object_size as part of the function type (in the ExtParameterInfo data on the function type).</div><div><br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
Added:<br>
cfe/trunk/test/Modules/Inputs/<wbr>overloadable-attrs/<br>
cfe/trunk/test/Modules/Inputs/<wbr>overloadable-attrs/a.h<br>
cfe/trunk/test/Modules/Inputs/<wbr>overloadable-attrs/module.<wbr>modulemap<br>
cfe/trunk/test/Modules/<wbr>overloadable-attrs.cpp<br>
Modified:<br>
cfe/trunk/lib/Serialization/<wbr>ASTReaderDecl.cpp<br>
<br>
Modified: cfe/trunk/lib/Serialization/<wbr>ASTReaderDecl.cpp<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Serialization/ASTReaderDecl.cpp?rev=295252&r1=295251&r2=295252&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-<wbr>project/cfe/trunk/lib/<wbr>Serialization/ASTReaderDecl.<wbr>cpp?rev=295252&r1=295251&r2=<wbr>295252&view=diff</a><br>
==============================<wbr>==============================<wbr>==================<br>
--- cfe/trunk/lib/Serialization/<wbr>ASTReaderDecl.cpp (original)<br>
+++ cfe/trunk/lib/Serialization/<wbr>ASTReaderDecl.cpp Wed Feb 15 16:43:27 2017<br>
@@ -2656,6 +2656,44 @@ static bool isSameTemplateParameterList(<br>
return true;<br>
}<br>
<br>
+/// Determine whether the attributes we can overload on are identical for A and<br>
+/// B. Expects A and B to (otherwise) have the same type.<br>
+static bool hasSameOverloadableAttrs(const FunctionDecl *A,<br>
+ const FunctionDecl *B) {<br>
+ SmallVector<const EnableIfAttr *, 4> AEnableIfs;<br>
+ // Since this is an equality check, we can ignore that enable_if attrs show up<br>
+ // in reverse order.<br>
+ for (const auto *EIA : A->specific_attrs<<wbr>EnableIfAttr>())<br>
+ AEnableIfs.push_back(EIA);<br>
+<br>
+ SmallVector<const EnableIfAttr *, 4> BEnableIfs;<br>
+ for (const auto *EIA : B->specific_attrs<<wbr>EnableIfAttr>())<br>
+ BEnableIfs.push_back(EIA);<br>
+<br>
+ // Two very common cases: either we have 0 enable_if attrs, or we have an<br>
+ // unequal number of enable_if attrs.<br>
+ if (AEnableIfs.empty() && BEnableIfs.empty())<br>
+ return true;<br>
+<br>
+ if (AEnableIfs.size() != BEnableIfs.size())<br>
+ return false;<br>
+<br>
+ llvm::FoldingSetNodeID Cand1ID, Cand2ID;<br>
+ for (unsigned I = 0, E = AEnableIfs.size(); I != E; ++I) {<br>
+ Cand1ID.clear();<br>
+ Cand2ID.clear();<br>
+<br>
+ AEnableIfs[I]->getCond()-><wbr>Profile(Cand1ID, A->getASTContext(), true);<br>
+ BEnableIfs[I]->getCond()-><wbr>Profile(Cand2ID, B->getASTContext(), true);<br>
+ if (Cand1ID != Cand2ID)<br>
+ return false;<br>
+ }<br>
+<br>
+ // FIXME: This doesn't currently consider pass_object_size attributes, since<br>
+ // we aren't guaranteed that A and B have valid parameter lists yet.<br>
+ return true;<br>
+}<br>
+<br>
/// \brief Determine whether the two declarations refer to the same entity.<br>
static bool isSameEntity(NamedDecl *X, NamedDecl *Y) {<br>
assert(X->getDeclName() == Y->getDeclName() && "Declaration name mismatch!");<br>
@@ -2711,8 +2749,10 @@ static bool isSameEntity(NamedDecl *X, N<br>
CtorY-><wbr>getInheritedConstructor().<wbr>getConstructor()))<br>
return false;<br>
}<br>
- return (FuncX->getLinkageInternal() == FuncY->getLinkageInternal()) &&<br>
- FuncX->getASTContext().<wbr>hasSameType(FuncX->getType(), FuncY->getType());<br>
+ return FuncX->getLinkageInternal() == FuncY->getLinkageInternal() &&<br>
+ FuncX->getASTContext().<wbr>hasSameType(FuncX->getType(),<br>
+ FuncY->getType()) &&<br>
+ hasSameOverloadableAttrs(<wbr>FuncX, FuncY);<br>
}<br>
<br>
// Variables with the same type and linkage match.<br>
<br>
Added: cfe/trunk/test/Modules/Inputs/<wbr>overloadable-attrs/a.h<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Modules/Inputs/overloadable-attrs/a.h?rev=295252&view=auto" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-<wbr>project/cfe/trunk/test/<wbr>Modules/Inputs/overloadable-<wbr>attrs/a.h?rev=295252&view=auto</a><br>
==============================<wbr>==============================<wbr>==================<br>
--- cfe/trunk/test/Modules/Inputs/<wbr>overloadable-attrs/a.h (added)<br>
+++ cfe/trunk/test/Modules/Inputs/<wbr>overloadable-attrs/a.h Wed Feb 15 16:43:27 2017<br>
@@ -0,0 +1,16 @@<br>
+namespace enable_if_attrs {<br>
+constexpr int fn1() __attribute__((enable_if(0, ""))) { return 0; }<br>
+constexpr int fn1() { return 1; }<br>
+<br>
+constexpr int fn2() { return 1; }<br>
+constexpr int fn2() __attribute__((enable_if(0, ""))) { return 0; }<br>
+<br>
+constexpr int fn3(int i) __attribute__((enable_if(!i, ""))) { return 0; }<br>
+constexpr int fn3(int i) __attribute__((enable_if(i, ""))) { return 1; }<br>
+<br>
+constexpr int fn4(int i) { return 0; }<br>
+constexpr int fn4(int i) __attribute__((enable_if(i, ""))) { return 1; }<br>
+<br>
+constexpr int fn5(int i) __attribute__((enable_if(i, ""))) { return 1; }<br>
+constexpr int fn5(int i) { return 0; }<br>
+}<br>
<br>
Added: cfe/trunk/test/Modules/Inputs/<wbr>overloadable-attrs/module.<wbr>modulemap<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Modules/Inputs/overloadable-attrs/module.modulemap?rev=295252&view=auto" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-<wbr>project/cfe/trunk/test/<wbr>Modules/Inputs/overloadable-<wbr>attrs/module.modulemap?rev=<wbr>295252&view=auto</a><br>
==============================<wbr>==============================<wbr>==================<br>
--- cfe/trunk/test/Modules/Inputs/<wbr>overloadable-attrs/module.<wbr>modulemap (added)<br>
+++ cfe/trunk/test/Modules/Inputs/<wbr>overloadable-attrs/module.<wbr>modulemap Wed Feb 15 16:43:27 2017<br>
@@ -0,0 +1,3 @@<br>
+module a {<br>
+ header "a.h"<br>
+}<br>
<br>
Added: cfe/trunk/test/Modules/<wbr>overloadable-attrs.cpp<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Modules/overloadable-attrs.cpp?rev=295252&view=auto" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-<wbr>project/cfe/trunk/test/<wbr>Modules/overloadable-attrs.<wbr>cpp?rev=295252&view=auto</a><br>
==============================<wbr>==============================<wbr>==================<br>
--- cfe/trunk/test/Modules/<wbr>overloadable-attrs.cpp (added)<br>
+++ cfe/trunk/test/Modules/<wbr>overloadable-attrs.cpp Wed Feb 15 16:43:27 2017<br>
@@ -0,0 +1,19 @@<br>
+// RUN: rm -rf %t<br>
+// RUN: %clang_cc1 -I%S/Inputs/overloadable-attrs -fmodules \<br>
+// RUN: -fmodule-map-file=%S/Inputs/<wbr>overloadable-attrs/module.<wbr>modulemap \<br>
+// RUN: -fmodules-cache-path=%t -verify %s -std=c++11<br>
+//<br>
+// Ensures that we don't merge decls with attrs that we allow overloading on.<br>
+//<br>
+// expected-no-diagnostics<br>
+<br>
+#include "a.h"<br>
+<br>
+static_assert(enable_if_<wbr>attrs::fn1() == 1, "");<br>
+static_assert(enable_if_<wbr>attrs::fn2() == 1, "");<br>
+static_assert(enable_if_<wbr>attrs::fn3(0) == 0, "");<br>
+static_assert(enable_if_<wbr>attrs::fn3(1) == 1, "");<br>
+static_assert(enable_if_<wbr>attrs::fn4(0) == 0, "");<br>
+static_assert(enable_if_<wbr>attrs::fn4(1) == 1, "");<br>
+static_assert(enable_if_<wbr>attrs::fn5(0) == 0, "");<br>
+static_assert(enable_if_<wbr>attrs::fn5(1) == 1, "");<br>
<br>
<br>
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</blockquote></div><br></div></div>