[clang-tools-extra] r181539 - Transform for loops over pseudo-arrays only if begin/end members exist
Edwin Vane
edwin.vane at intel.com
Thu May 9 13:03:52 PDT 2013
Author: revane
Date: Thu May 9 15:03:52 2013
New Revision: 181539
URL: http://llvm.org/viewvc/llvm-project?rev=181539&view=rev
Log:
Transform for loops over pseudo-arrays only if begin/end members exist
For loops using pseudo-arrays, classes that can be used like arrays from
the Loop Convert Transform's point of view, should only get transformed
if the pseudo-array class has begin()/end() members for the
range-based for-loop to call.
Free versions of begin()/end() should also be allowed but this is an
enhancement for another revision.
Added:
clang-tools-extra/trunk/test/cpp11-migrate/LoopConvert/free_begin_end_fail.cpp
Modified:
clang-tools-extra/trunk/cpp11-migrate/LoopConvert/LoopMatchers.cpp
clang-tools-extra/trunk/test/cpp11-migrate/LoopConvert/pseudoarray.cpp
Modified: clang-tools-extra/trunk/cpp11-migrate/LoopConvert/LoopMatchers.cpp
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/cpp11-migrate/LoopConvert/LoopMatchers.cpp?rev=181539&r1=181538&r2=181539&view=diff
==============================================================================
--- clang-tools-extra/trunk/cpp11-migrate/LoopConvert/LoopMatchers.cpp (original)
+++ clang-tools-extra/trunk/cpp11-migrate/LoopConvert/LoopMatchers.cpp Thu May 9 15:03:52 2013
@@ -258,10 +258,57 @@ StatementMatcher makeIteratorLoopMatcher
/// - If the end iterator variable 'g' is defined, it is the same as 'j'
/// - The container's iterators would not be invalidated during the loop
StatementMatcher makePseudoArrayLoopMatcher() {
+ // Test that the incoming type has a record declaration that has methods
+ // called 'begin' and 'end'. If the incoming type is const, then make sure
+ // these methods are also marked const.
+ //
+ // FIXME: To be completely thorough this matcher should also ensure the
+ // return type of begin/end is an iterator that dereferences to the same as
+ // what operator[] or at() returns. Such a test isn't likely to fail except
+ // for pathological cases.
+ //
+ // FIXME: Also, a record doesn't necessarily need begin() and end(). Free
+ // functions called begin() and end() taking the container as an argument
+ // are also allowed.
+ TypeMatcher RecordWithBeginEnd =
+ qualType(anyOf(
+ qualType(
+ isConstQualified(),
+ hasDeclaration(
+ recordDecl(
+ hasMethod(
+ methodDecl(
+ hasName("begin"),
+ isConst()
+ )
+ ),
+ hasMethod(
+ methodDecl(
+ hasName("end"),
+ isConst()
+ )
+ )
+ )
+ ) // hasDeclaration
+ ), // qualType
+ qualType(
+ unless(isConstQualified()),
+ hasDeclaration(
+ recordDecl(
+ hasMethod(hasName("begin")),
+ hasMethod(hasName("end"))
+ )
+ )
+ ) // qualType
+ )
+ );
+
StatementMatcher SizeCallMatcher =
memberCallExpr(argumentCountIs(0),
callee(methodDecl(anyOf(hasName("size"),
- hasName("length")))));
+ hasName("length")))),
+ on(anyOf(hasType(pointsTo(RecordWithBeginEnd)),
+ hasType(RecordWithBeginEnd))));
StatementMatcher EndInitMatcher =
expr(anyOf(
Added: clang-tools-extra/trunk/test/cpp11-migrate/LoopConvert/free_begin_end_fail.cpp
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/test/cpp11-migrate/LoopConvert/free_begin_end_fail.cpp?rev=181539&view=auto
==============================================================================
--- clang-tools-extra/trunk/test/cpp11-migrate/LoopConvert/free_begin_end_fail.cpp (added)
+++ clang-tools-extra/trunk/test/cpp11-migrate/LoopConvert/free_begin_end_fail.cpp Thu May 9 15:03:52 2013
@@ -0,0 +1,32 @@
+// RUN: grep -Ev "// *[A-Z-]+:" %s > %t.cpp
+// RUN: cpp11-migrate -loop-convert %t.cpp -- -I %S/Inputs -std=c++11
+// RUN: FileCheck -input-file=%t.cpp %s
+// XFAIL: *
+
+struct MyArray {
+ unsigned size();
+};
+
+template <typename T>
+struct MyContainer {
+};
+
+int *begin(const MyArray &Arr);
+int *end(const MyArray &Arr);
+
+template <typename T>
+T *begin(const MyContainer<T> &C);
+template <typename T>
+T *end(const MyContainer<T> &C);
+
+// The Loop Convert Transform doesn't detect free functions begin()/end() and
+// so fails to transform these cases which it should.
+void f() {
+ MyArray Arr;
+ for (unsigned i = 0, e = Arr.size(); i < e; ++i) {}
+ // CHECK: for (auto & elem : Arr) {}
+
+ MyContainer<int> C;
+ for (int *I = begin(C), *E = end(C); I != E; ++I) {}
+ // CHECK: for (auto & elem : C) {}
+}
Modified: clang-tools-extra/trunk/test/cpp11-migrate/LoopConvert/pseudoarray.cpp
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/test/cpp11-migrate/LoopConvert/pseudoarray.cpp?rev=181539&r1=181538&r2=181539&view=diff
==============================================================================
--- clang-tools-extra/trunk/test/cpp11-migrate/LoopConvert/pseudoarray.cpp (original)
+++ clang-tools-extra/trunk/test/cpp11-migrate/LoopConvert/pseudoarray.cpp Thu May 9 15:03:52 2013
@@ -1,5 +1,5 @@
// RUN: grep -Ev "// *[A-Z-]+:" %s > %t.cpp
-// RUN: cpp11-migrate -loop-convert %t.cpp -- -I %S/Inputs
+// RUN: cpp11-migrate -loop-convert %t.cpp -- -I %S/Inputs -std=c++11
// RUN: FileCheck -input-file=%t.cpp %s
#include "structures.h"
@@ -64,3 +64,42 @@ void noContainer() {
for (auto i = 0; i < v.size(); ++i) ;
// CHECK: for (auto & elem : v) ;
}
+
+struct NoBeginEnd {
+ unsigned size() const;
+};
+
+struct NoConstBeginEnd {
+ NoConstBeginEnd();
+ unsigned size() const;
+ unsigned begin();
+ unsigned end();
+};
+
+struct ConstBeginEnd {
+ ConstBeginEnd();
+ unsigned size() const;
+ unsigned begin() const;
+ unsigned end() const;
+};
+
+// Shouldn't transform pseudo-array uses if the container doesn't provide
+// begin() and end() of the right const-ness.
+void NoBeginEndTest() {
+ NoBeginEnd NBE;
+ for (unsigned i = 0, e = NBE.size(); i < e; ++i) {}
+ // CHECK: for (unsigned i = 0, e = NBE.size(); i < e; ++i) {}
+
+ const NoConstBeginEnd const_NCBE;
+ for (unsigned i = 0, e = const_NCBE.size(); i < e; ++i) {}
+ // CHECK: for (unsigned i = 0, e = const_NCBE.size(); i < e; ++i) {}
+
+ ConstBeginEnd CBE;
+ for (unsigned i = 0, e = CBE.size(); i < e; ++i) {}
+ // CHECK: for (auto & elem : CBE) {}
+
+ const ConstBeginEnd const_CBE;
+ for (unsigned i = 0, e = const_CBE.size(); i < e; ++i) {}
+ // CHECK: for (auto & elem : const_CBE) {}
+}
+
More information about the cfe-commits
mailing list