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//===- GtestMatchers.cpp - AST Matchers for Gtest ---------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file implements several matchers for popular gtest macros. In general,
// AST matchers cannot match calls to macros. However, we can simulate such
// matches if the macro definition has identifiable elements that themselves can
// be matched. In that case, we can match on those elements and then check that
// the match occurs within an expansion of the desired macro. The more uncommon
// the identified elements, the more efficient this process will be.
//
//===----------------------------------------------------------------------===//
#include "clang/ASTMatchers/GtestMatchers.h"
#include "clang/AST/ASTConsumer.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/RecursiveASTVisitor.h"
#include "clang/ASTMatchers/ASTMatchFinder.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/StringRef.h"
namespace clang {
namespace ast_matchers {
namespace {
enum class MacroType {
Expect,
Assert,
On,
};
} // namespace
static DeclarationMatcher getComparisonDecl(GtestCmp Cmp) {
switch (Cmp) {
case GtestCmp::Eq:
return cxxMethodDecl(hasName("Compare"),
ofClass(cxxRecordDecl(isSameOrDerivedFrom(
hasName("::testing::internal::EqHelper")))));
case GtestCmp::Ne:
return functionDecl(hasName("::testing::internal::CmpHelperNE"));
case GtestCmp::Ge:
return functionDecl(hasName("::testing::internal::CmpHelperGE"));
case GtestCmp::Gt:
return functionDecl(hasName("::testing::internal::CmpHelperGT"));
case GtestCmp::Le:
return functionDecl(hasName("::testing::internal::CmpHelperLE"));
case GtestCmp::Lt:
return functionDecl(hasName("::testing::internal::CmpHelperLT"));
}
llvm_unreachable("Unhandled GtestCmp enum");
}
static llvm::StringRef getMacroTypeName(MacroType Macro) {
switch (Macro) {
case MacroType::Expect:
return "EXPECT";
case MacroType::Assert:
return "ASSERT";
case MacroType::On:
return "ON";
}
llvm_unreachable("Unhandled MacroType enum");
}
static llvm::StringRef getComparisonTypeName(GtestCmp Cmp) {
switch (Cmp) {
case GtestCmp::Eq:
return "EQ";
case GtestCmp::Ne:
return "NE";
case GtestCmp::Ge:
return "GE";
case GtestCmp::Gt:
return "GT";
case GtestCmp::Le:
return "LE";
case GtestCmp::Lt:
return "LT";
}
llvm_unreachable("Unhandled GtestCmp enum");
}
static std::string getMacroName(MacroType Macro, GtestCmp Cmp) {
return (getMacroTypeName(Macro) + "_" + getComparisonTypeName(Cmp)).str();
}
static std::string getMacroName(MacroType Macro, llvm::StringRef Operation) {
return (getMacroTypeName(Macro) + "_" + Operation).str();
}
// Under the hood, ON_CALL is expanded to a call to `InternalDefaultActionSetAt`
// to set a default action spec to the underlying function mocker, while
// EXPECT_CALL is expanded to a call to `InternalExpectedAt` to set a new
// expectation spec.
static llvm::StringRef getSpecSetterName(MacroType Macro) {
switch (Macro) {
case MacroType::On:
return "InternalDefaultActionSetAt";
case MacroType::Expect:
return "InternalExpectedAt";
default:
llvm_unreachable("Unhandled MacroType enum");
}
llvm_unreachable("Unhandled MacroType enum");
}
// In general, AST matchers cannot match calls to macros. However, we can
// simulate such matches if the macro definition has identifiable elements that
// themselves can be matched. In that case, we can match on those elements and
// then check that the match occurs within an expansion of the desired
// macro. The more uncommon the identified elements, the more efficient this
// process will be.
//
// We use this approach to implement the derived matchers gtestAssert and
// gtestExpect.
static internal::BindableMatcher<Stmt>
gtestComparisonInternal(MacroType Macro, GtestCmp Cmp, StatementMatcher Left,
StatementMatcher Right) {
return callExpr(isExpandedFromMacro(getMacroName(Macro, Cmp)),
callee(getComparisonDecl(Cmp)), hasArgument(2, Left),
hasArgument(3, Right));
}
static internal::BindableMatcher<Stmt>
gtestThatInternal(MacroType Macro, StatementMatcher Actual,
StatementMatcher Matcher) {
return cxxOperatorCallExpr(
isExpandedFromMacro(getMacroName(Macro, "THAT")),
hasOverloadedOperatorName("()"), hasArgument(2, Actual),
hasArgument(
0, expr(hasType(classTemplateSpecializationDecl(hasName(
"::testing::internal::PredicateFormatterFromMatcher"))),
ignoringImplicit(
callExpr(callee(functionDecl(hasName(
"::testing::internal::"
"MakePredicateFormatterFromMatcher"))),
hasArgument(0, ignoringImplicit(Matcher)))))));
}
static internal::BindableMatcher<Stmt>
gtestCallInternal(MacroType Macro, StatementMatcher MockCall, MockArgs Args) {
// A ON_CALL or EXPECT_CALL macro expands to different AST structures
// depending on whether the mock method has arguments or not.
switch (Args) {
// For example,
// `ON_CALL(mock, TwoParamMethod)` is expanded to
// `mock.gmock_TwoArgsMethod(WithoutMatchers(),
// nullptr).InternalDefaultActionSetAt(...)`.
// EXPECT_CALL is the same except
// that it calls `InternalExpectedAt` instead of `InternalDefaultActionSetAt`
// in the end.
case MockArgs::None:
return cxxMemberCallExpr(
isExpandedFromMacro(getMacroName(Macro, "CALL")),
callee(functionDecl(hasName(getSpecSetterName(Macro)))),
onImplicitObjectArgument(ignoringImplicit(MockCall)));
// For example,
// `ON_CALL(mock, TwoParamMethod(m1, m2))` is expanded to
// `mock.gmock_TwoParamMethod(m1,m2)(WithoutMatchers(),
// nullptr).InternalDefaultActionSetAt(...)`.
// EXPECT_CALL is the same except that it calls `InternalExpectedAt` instead
// of `InternalDefaultActionSetAt` in the end.
case MockArgs::Some:
return cxxMemberCallExpr(
isExpandedFromMacro(getMacroName(Macro, "CALL")),
callee(functionDecl(hasName(getSpecSetterName(Macro)))),
onImplicitObjectArgument(ignoringImplicit(cxxOperatorCallExpr(
hasOverloadedOperatorName("()"), argumentCountIs(3),
hasArgument(0, ignoringImplicit(MockCall))))));
}
llvm_unreachable("Unhandled MockArgs enum");
}
static internal::BindableMatcher<Stmt>
gtestCallInternal(MacroType Macro, StatementMatcher MockObject,
llvm::StringRef MockMethodName, MockArgs Args) {
return gtestCallInternal(
Macro,
cxxMemberCallExpr(
onImplicitObjectArgument(MockObject),
callee(functionDecl(hasName(("gmock_" + MockMethodName).str())))),
Args);
}
internal::BindableMatcher<Stmt> gtestAssert(GtestCmp Cmp, StatementMatcher Left,
StatementMatcher Right) {
return gtestComparisonInternal(MacroType::Assert, Cmp, Left, Right);
}
internal::BindableMatcher<Stmt> gtestExpect(GtestCmp Cmp, StatementMatcher Left,
StatementMatcher Right) {
return gtestComparisonInternal(MacroType::Expect, Cmp, Left, Right);
}
internal::BindableMatcher<Stmt> gtestAssertThat(StatementMatcher Actual,
StatementMatcher Matcher) {
return gtestThatInternal(MacroType::Assert, Actual, Matcher);
}
internal::BindableMatcher<Stmt> gtestExpectThat(StatementMatcher Actual,
StatementMatcher Matcher) {
return gtestThatInternal(MacroType::Expect, Actual, Matcher);
}
internal::BindableMatcher<Stmt> gtestOnCall(StatementMatcher MockObject,
llvm::StringRef MockMethodName,
MockArgs Args) {
return gtestCallInternal(MacroType::On, MockObject, MockMethodName, Args);
}
internal::BindableMatcher<Stmt> gtestOnCall(StatementMatcher MockCall,
MockArgs Args) {
return gtestCallInternal(MacroType::On, MockCall, Args);
}
internal::BindableMatcher<Stmt> gtestExpectCall(StatementMatcher MockObject,
llvm::StringRef MockMethodName,
MockArgs Args) {
return gtestCallInternal(MacroType::Expect, MockObject, MockMethodName, Args);
}
internal::BindableMatcher<Stmt> gtestExpectCall(StatementMatcher MockCall,
MockArgs Args) {
return gtestCallInternal(MacroType::Expect, MockCall, Args);
}
} // end namespace ast_matchers
} // end namespace clang