<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/153551>153551</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            [clang] memory leak with late parsed attributes and -skip-function-bodies
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            clang:frontend
      </td>
    </tr>

    <tr>
      <th>Assignees</th>
      <td>
      </td>
    </tr>

    <tr>
      <th>Reporter</th>
      <td>
          mizvekov
      </td>
    </tr>
</table>

<pre>
    This can be observed using a clang built with Address sanitizer (LLVM_USE_SANITIZER=Address).

For this example:
```C++
void f() __attribute__((__diagnose_if__(false, "hello", "warning"))) {}
```

Running `clang -cc1 -skip-function-bodies test.cc` gives:
```
==194977==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 184 byte(s) in 1 object(s) allocated from:
    #0 0xaaaad5046c60 in operator new(unsigned long) (build/dbg/bin/clang-20+0xd3a6c60) (BuildId: 6fd25c8c9a809e25ffe2ddb309ec5769179c642e)
    #1 0xaaaadf13e234 in clang::Parser::ParseSingleGNUAttribute(clang::ParsedAttributes&, clang::SourceLocation&, clang::Parser::LateParsedAttrList*, clang::Declarator*) clang/lib/Parse/ParseDecl.cpp:206:7
    #2 0xaaaadf13f9f0 in clang::Parser::ParseGNUAttributes(clang::ParsedAttributes&, clang::Parser::LateParsedAttrList*, clang::Declarator*) clang/lib/Parse/ParseDecl.cpp:307:11
    #3 0xaaaadf078368 in clang::Parser::MaybeParseGNUAttributes(clang::Declarator&, clang::Parser::LateParsedAttrList*) clang/include/clang/Parse/Parser.h:2937:7
    #4 0xaaaadf1595ec in clang::Parser::ParseDeclGroup(clang::ParsingDeclSpec&, clang::DeclaratorContext, clang::ParsedAttributes&, clang::Parser::ParsedTemplateInfo&, clang::SourceLocation*, clang::Parser::ForRangeInit*) clang/lib/Parse/ParseDecl.cpp:2365:5
    #5 0xaaaadf068528 in clang::Parser::ParseDeclOrFunctionDefInternal(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec&, clang::AccessSpecifier) clang/lib/Parse/Parser.cpp:1244:10
    #6 0xaaaadf0674a0 in clang::Parser::ParseDeclarationOrFunctionDefinition(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec*, clang::AccessSpecifier) clang/lib/Parse/Parser.cpp:1266:12
    #7 0xaaaadf064dcc in clang::Parser::ParseExternalDeclaration(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec*) clang/lib/Parse/Parser.cpp:1069:14
    #8 0xaaaadf0610a8 in clang::Parser::ParseTopLevelDecl(clang::OpaquePtr<clang::DeclGroupRef>&, clang::Sema::ModuleImportState&) clang/lib/Parse/Parser.cpp:758:12
    #9 0xaaaadf060080 in clang::Parser::ParseFirstTopLevelDecl(clang::OpaquePtr<clang::DeclGroupRef>&, clang::Sema::ModuleImportState&) clang/lib/Parse/Parser.cpp:608:26
    #10 0xaaaadf054374 in clang::ParseAST(clang::Sema&, bool, bool) clang/lib/Parse/ParseAST.cpp:170:25
    #11 0xaaaadbe9dc98 in clang::FrontendAction::Execute() clang/lib/Frontend/FrontendAction.cpp:1077:8
    #12 0xaaaadbd774b0 in clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) clang/lib/Frontend/CompilerInstance.cpp:1062:33
    #13 0xaaaadc0c5e68 in clang::ExecuteCompilerInvocation(clang::CompilerInstance*) clang/lib/FrontendTool/ExecuteCompilerInvocation.cpp:296:25
    #14 0xaaaad50531d0 in cc1_main(llvm::ArrayRef<char const*>, char const*, void*) clang/tools/driver/cc1_main.cpp:286:15
    #15 0xaaaad504bb74 in ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&, llvm::ToolContext const&) clang/tools/driver/driver.cpp:218:12
    #16 0xaaaad5049fb0 in clang_main(int, char**, llvm::ToolContext const&) clang/tools/driver/driver.cpp:259:12
    #17 0xaaaad506ad30 in main build/dbg/tools/clang/tools/driver/clang-driver.cpp:17:10
    #18 0xffff9b812298  (/lib/aarch64-linux-gnu/libc.so.6+0x22298) (BuildId: b32c35038e644c70c27979cb0b90182f43f6794b)
    #19 0xffff9b812378 in __libc_start_main (/lib/aarch64-linux-gnu/libc.so.6+0x22378) (BuildId: b32c35038e644c70c27979cb0b90182f43f6794b)
    #20 0xaaaad4f6012c in _start (build/dbg/bin/clang-20+0xd2c012c) (BuildId: 6fd25c8c9a809e25ffe2ddb309ec5769179c642e)

Indirect leak of 216 byte(s) in 1 object(s) allocated from:
    #0 0xaaaad5004220 in malloc (build/dbg/bin/clang-20+0xd364220) (BuildId: 6fd25c8c9a809e25ffe2ddb309ec5769179c642e)
    #1 0xaaaada4b27c0 in llvm::safe_malloc(unsigned long) llvm/include/llvm/Support/MemAlloc.h:26:18
 #2 0xaaaada4b27c0 in llvm::SmallVectorBase<unsigned int>::grow_pod(void*, unsigned long, unsigned long) llvm/lib/Support/SmallVector.cpp:151:15
    #3 0xaaaadf25794c in llvm::SmallVectorTemplateCommon<clang::Token, void>::grow_pod(unsigned long, unsigned long) llvm/include/llvm/ADT/SmallVector.h:138:11
    #4 0xaaaadf25794c in llvm::SmallVectorTemplateBase<clang::Token, true>::grow(unsigned long) llvm/include/llvm/ADT/SmallVector.h:525:41
    #5 0xaaaadf25794c in clang::Token const* llvm::SmallVectorTemplateCommon<clang::Token, void>::reserveForParamAndGetAddressImpl<llvm::SmallVectorTemplateBase<clang::Token, true>>(llvm::SmallVectorTemplateBase<clang::Token, true>*, clang::Token const&, unsigned long) llvm/include/llvm/ADT/SmallVector.h:243:11
    #6 0xaaaadf25794c in llvm::SmallVectorTemplateBase<clang::Token, true>::reserveForParamAndGetAddress(clang::Token const&, unsigned long) llvm/include/llvm/ADT/SmallVector.h:530:12
    #7 0xaaaadf25794c in llvm::SmallVectorTemplateBase<clang::Token, true>::push_back(clang::Token const&) llvm/include/llvm/ADT/SmallVector.h:562:23
    #8 0xaaaadf25794c in clang::Parser::ConsumeAndStoreUntil(clang::tok::TokenKind, clang::tok::TokenKind, llvm::SmallVector<clang::Token, 4u>&, bool, bool) clang/lib/Parse/ParseCXXInlineMethods.cpp:958:12
    #9 0xaaaadf13e66c in clang::Parser::ConsumeAndStoreUntil(clang::tok::TokenKind, llvm::SmallVector<clang::Token, 4u>&, bool, bool) clang/include/clang/Parse/Parser.h:1678:12
    #10 0xaaaadf13e66c in clang::Parser::ParseSingleGNUAttribute(clang::ParsedAttributes&, clang::SourceLocation&, clang::Parser::LateParsedAttrList*, clang::Declarator*) clang/lib/Parse/ParseDecl.cpp:219:3
    #11 0xaaaadf13f9f0 in clang::Parser::ParseGNUAttributes(clang::ParsedAttributes&, clang::Parser::LateParsedAttrList*, clang::Declarator*) clang/lib/Parse/ParseDecl.cpp:307:11
    #12 0xaaaadf078368 in clang::Parser::MaybeParseGNUAttributes(clang::Declarator&, clang::Parser::LateParsedAttrList*) clang/include/clang/Parse/Parser.h:2937:7
    #13 0xaaaadf1595ec in clang::Parser::ParseDeclGroup(clang::ParsingDeclSpec&, clang::DeclaratorContext, clang::ParsedAttributes&, clang::Parser::ParsedTemplateInfo&, clang::SourceLocation*, clang::Parser::ForRangeInit*) clang/lib/Parse/ParseDecl.cpp:2365:5
    #14 0xaaaadf068528 in clang::Parser::ParseDeclOrFunctionDefInternal(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec&, clang::AccessSpecifier) clang/lib/Parse/Parser.cpp:1244:10
    #15 0xaaaadf0674a0 in clang::Parser::ParseDeclarationOrFunctionDefinition(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec*, clang::AccessSpecifier) clang/lib/Parse/Parser.cpp:1266:12
    #16 0xaaaadf064dcc in clang::Parser::ParseExternalDeclaration(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec*) clang/lib/Parse/Parser.cpp:1069:14
    #17 0xaaaadf0610a8 in clang::Parser::ParseTopLevelDecl(clang::OpaquePtr<clang::DeclGroupRef>&, clang::Sema::ModuleImportState&) clang/lib/Parse/Parser.cpp:758:12
    #18 0xaaaadf060080 in clang::Parser::ParseFirstTopLevelDecl(clang::OpaquePtr<clang::DeclGroupRef>&, clang::Sema::ModuleImportState&) clang/lib/Parse/Parser.cpp:608:26
    #19 0xaaaadf054374 in clang::ParseAST(clang::Sema&, bool, bool) clang/lib/Parse/ParseAST.cpp:170:25
    #20 0xaaaadbe9dc98 in clang::FrontendAction::Execute() clang/lib/Frontend/FrontendAction.cpp:1077:8
    #21 0xaaaadbd774b0 in clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) clang/lib/Frontend/CompilerInstance.cpp:1062:33
    #22 0xaaaadc0c5e68 in clang::ExecuteCompilerInvocation(clang::CompilerInstance*) clang/lib/FrontendTool/ExecuteCompilerInvocation.cpp:296:25
    #23 0xaaaad50531d0 in cc1_main(llvm::ArrayRef<char const*>, char const*, void*) clang/tools/driver/cc1_main.cpp:286:15
    #24 0xaaaad504bb74 in ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&, llvm::ToolContext const&) clang/tools/driver/driver.cpp:218:12
    #25 0xaaaad5049fb0 in clang_main(int, char**, llvm::ToolContext const&) clang/tools/driver/driver.cpp:259:12
    #26 0xaaaad506ad30 in main build/dbg/tools/clang/tools/driver/clang-driver.cpp:17:10
    #27 0xffff9b812298  (/lib/aarch64-linux-gnu/libc.so.6+0x22298) (BuildId: b32c35038e644c70c27979cb0b90182f43f6794b)
    #28 0xffff9b812378 in __libc_start_main (/lib/aarch64-linux-gnu/libc.so.6+0x22378) (BuildId: b32c35038e644c70c27979cb0b90182f43f6794b)
    #29 0xaaaad4f6012c in _start (build/dbg/bin/clang-20+0xd2c012c) (BuildId: 6fd25c8c9a809e25ffe2ddb309ec5769179c642e)

SUMMARY: AddressSanitizer: 400 byte(s) leaked in 2 allocation(s).
```
</pre>
<img width="1" height="1" alt="" src="http://email.email.llvm.org/o/eJzsWktv4zgS_jXMhUjAh54HHxQ7HhibzDTi9GB2LwZFUTY3MumlqHR6fv2CkmXJshMnPenedHYAA1IoPr6vqlisqpCVpVwqIUbAvwT-5IxVdqXNaC3_fBD3-uEs1dnX0d1KlpAzBVMBdVoK8yAyWJVSLSGDvGBqCdNKFhZ-kXYFkywzoixhyZS08k9hICDR9fXvN4vP86vFPPl1djf719UtoJNtT0DiC4ASgJKpNtC6xcQjW28KAahrBQFqfmNALt0PJQ9aZjAHJAIkhosFs9bItLJisajbosUik2ypdCkWMq8bc1aUApAxBISsRFFoQMj2zy_MKKmWdUPc_CAIL0E46S_eILytlOsLQYAa4uecY3he3svNeV4pbqVW56nOpCihFaW94BwECC7lgygHbNw7nQA6wbEXh2HzfnV7-9stoAm8Fux-3krQNWTCCm5FBtdirc1XWAh2XzagJtIIbusWqHOIIw-mX60AJHKyhVJBDHX6b8Ft28SKQnPmZsuNXjfAIIQQEIogemSMscxHXsAD5IbrjTDMagOV-AJIVKnaaDJYaCe22CnYGUAGyDRLl4BMU6kAmdYSOicIkEv0mFHmptt2v3TdZ5kjFuQZ8XnEYxahWBA_zwXJspSiWHA_DGIcxjzwiHCa2aHELcocU0Go51DWyzkuNPnETFmLrX2fS7UsxC-_fk5aUwEkGg7Idh9LQAJnHb0ec10ZLq6d2KRWh9_7S14zK7oZr2VpAUkG_SeCF6yWav0t3n4j00KmgEzr4e3T9b3gmw2gCUEBoEnYSYL0JJHHOTolib4MytcK4QeRpCgENMG4Y0l3LFEY0SB6huUN-5qKU1T7wL6BZEdEKl5UmWitfUjKXKyc0mIa7mvN67Tmx77gp7Tm8P5idLU51JhUS_d1vhH8kEvHc6yVFY_2GNcXq7zpfSfWm4JZMVO5Pr1PhibRn2-qzS1TSzFTcijXE7uABj6gid8J1O8MJIh88pyB7Cb7zUy3Lnsi8pmywihWfNOWONnjWSUlnIuydN9kLoU5IQazlQEmnuceqBNC0BNC6LGTvqC1DqnVniykO3ec8r67KIbW8a2iCIL60Yki7InCy_jJDXb12Ki_J5IfQ_9lBFEQu4fXEYx6BDFiJw3-Tm-uxYOoCe4z-23D_lOJT9YAOh64jtrl3Ioc0KsjO12s2dbl6qwqxGy90cbOLXOHa_BCZqEfDTQX94ghFJ004qk0pX2n7ALk2JGgF7igjp7v0fBo5JLM7_ZJ1GAaiKnWRfd8FkUyv2vtJ0QOR89f4l0ElYo44_HQfqbGnRcqS2qf0LRdPQreRE6HC7f9e6_N0J0FuxA3iXoIdpFLmoWhlw4VPdbrjSyEmanSMsXFHoYtrD0hDSAfU1IP5XD6bqcRF4HQHtBd8MER98VB8LGF1E34sDv8ouf4HNv9LcC7WrvTJ6duz8E4GOrV6-J3n-KskSrHizVzMXlUFA_rras1hn2trX_MV8xArlUT3bjdMIb7bWQMXc41wGy1LkoX9Bv54Jz1tF2ohRfVbrkPz--lF2namH_Lcowb2j2Q8zUrit8Ft9rM1pviKNZ6W3RD3BzbYKftFzwLunlpIeOhP8JBD3Kc9-y0lalUtpVYLaDkTQH58RBQ2AEKWEZrQA4K3E_C2nmf1ladn-2thsNBSIHdOZPneR6nESYkjlxrtLNXxgxfBd55IVX1eL5UVfOFX5T6IqjzPuIGHWZ9KSWc-ohGIvA8HiJOwjiMeYrSGOGI5B7NgzD20v2sL-6DoWG9ExcLt-CitMzYWiOvBkjDtwJIdt7dywOESR12NNBeliQT7kb91SQZoGSmsv2qAMHB21QFkEfI1uRc_xcm_4Eb9dbJP_NSEvIaTLfdSpaLRYPtWK2i7tjP27YN82rjDnhApjdinbjRTepWe7D62Oon20dX7jmrS1YKQMe71Z2LoFdNt6XRXxYbnQES7XzqGA6AHjTskDd23cHtrdpuYh8P3G6XPhM_jD3-JO42txvr9dod-_2Q6U7fC7U7CY6weTGFA-Enk7sBEyd7TKNBGcB7LY-tHo6xsKYSeyxeYy3HAfvEZaUePpaWdoCHYHan2VupxIi6RjvV5hMzbJ2o7Bdht8XW7Sn6l4V29dQx_YpJDrK_PXEEb2BBxKMDCwq-lwU9J_T9QPDNWfoUPZn9vjHLTVWuFinj989TejWDOugm9Fh6e3Tj9LPAsVZltRaJyuZWG_FZWTnIAa2-7-H8h3QJwJ7hHe9wVGJPSMmrulj0FSna-I8_ZqqQStwIu9JZufXg8TNZMaYiCL6HPN6a7otKozgIDwJu9HKuH6y4j12sT49l6R-6ut-VAj5Ieb8rGfxd33-b-n5X1_h_LvBj_-8K_2Fd5qOW-HH4UWv8OPrYRf74fRT5u3LU_6rIT_BPUuQn5Ccq8hP6rov8xPvpivzEf2dFfhL8wCI_Cd9RkZ9E773IH7-XIv_8881NcvtPN3Zbadq7MughtFfyLwS7r2vRkLS1_saB7a5gtncTz7IRzWIaszMxwqHvYz8MKD1bjfIUodxjQYREnqFQeCxnwo-9zI_SMIjQmRwRRHwUYQ-FXojpBQ5pFsc5TlHGfMw48JBYM1lcuL1zoc3yTJZlJUbYp76PzwqWiqKsr6MS0jrWfOfRCfAnZ2bkxp6n1bIEHipkactuNittUV9nbQb7k_6FyeaGqktu4KYO5eDu6mgJmcqO3-Q8q0wxWlm7qa9wkikg06W0qyq94HrdlbZqUBujm3-pTGtabitumT2MyH8DAAD__2q5XFE">