[clang] [clang][ASTMatcher] Add `matchesString` for `StringLiteral` which matches literals on given `RegExp` (PR #102152)

[via cfe-commits]

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@@ -2503,6 +2503,28 @@ TEST_P(ASTMatchersTest, IsDelegatingConstructor) {
       cxxConstructorDecl(isDelegatingConstructor(), parameterCountIs(1))));
 }
 
+TEST_P(ASTMatchersTest, MatchesString) {
+  StatementMatcher Literal = stringLiteral(matchesString("foo.*"));
+  EXPECT_TRUE(matches("const char* a = \"foo\";", Literal));
+  EXPECT_TRUE(matches("const char* b = \"foobar\";", Literal));
+  EXPECT_TRUE(matches("const char* b = \"fo\"\"obar\";", Literal));
+  EXPECT_TRUE(notMatches("const char* c = \"bar\";", Literal));
+  // test embedded nulls
+  StatementMatcher Literal2 = stringLiteral(matchesString("bar"));
+  EXPECT_TRUE(matches("const char* b = \"foo\\0bar\";", Literal2));
+  EXPECT_TRUE(notMatches("const char* b = \"foo\\0b\\0ar\";", Literal2));
+}
+
+TEST(MatchesString, MatchesStringPrefixed) {
+  StatementMatcher Literal = stringLiteral(matchesString("foo.*"));
+  EXPECT_TRUE(matchesConditionally("const char16_t* a = u\"foo\";", Literal,
+                                   true, {"-std=c++11"}));
+  EXPECT_TRUE(matchesConditionally("const char32_t* a = U\"foo\";", Literal,
+                                   true, {"-std=c++11"}));
+  EXPECT_TRUE(matchesConditionally("const wchar_t* a = L\"foo\";", Literal,
+                                   true, {"-std=c++11"}));
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cor3ntin wrote:

The matcher seems to be using the value produced by `StringLiteral::outputString` which will "work" - until we support non unicode encoding - but `StringLiteral::outputString` is really designed for debug, so wchar etc are going to be escaped. I think this is going to be a difficult to use interface.

We would be better off adding a way to convert back the string literal to non-escaped UTF-8 ... except numeric escape sequence would not be preserved (and might lead to replacement characters)


https://github.com/llvm/llvm-project/pull/102152