[clang] [analyzer][NFC] Document and centralize the CallEvent argument/parameter index mapping (PR #221252)

[via cfe-commits]

github-actions[bot] wrote:

<!--PREMERGE ADVISOR COMMENT: Windows-->
# :window: Windows x64 Test Results

The build failed before running any tests. Click on a failure below to see the details.

<details>
<summary>[code=1] tools/clang/lib/StaticAnalyzer/Core/CMakeFiles/obj.clangStaticAnalyzerCore.dir/MemRegion.cpp.obj</summary>

```
FAILED: [code=1] tools/clang/lib/StaticAnalyzer/Core/CMakeFiles/obj.clangStaticAnalyzerCore.dir/MemRegion.cpp.obj
sccache C:\clang\clang-msvc\bin\clang-cl.exe  /nologo -TP -DCLANG_BUILD_STATIC -DUNICODE -D_CRT_NONSTDC_NO_DEPRECATE -D_CRT_NONSTDC_NO_WARNINGS -D_CRT_SECURE_NO_DEPRECATE -D_CRT_SECURE_NO_WARNINGS -D_GLIBCXX_ASSERTIONS -D_HAS_EXCEPTIONS=0 -D_LIBCPP_HARDENING_MODE=_LIBCPP_HARDENING_MODE_EXTENSIVE -D_SCL_SECURE_NO_DEPRECATE -D_SCL_SECURE_NO_WARNINGS -D_UNICODE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -IC:\_work\llvm-project\llvm-project\build\tools\clang\lib\StaticAnalyzer\Core -IC:\_work\llvm-project\llvm-project\clang\lib\StaticAnalyzer\Core -IC:\_work\llvm-project\llvm-project\clang\include -IC:\_work\llvm-project\llvm-project\build\tools\clang\include -IC:\_work\llvm-project\llvm-project\build\include -IC:\_work\llvm-project\llvm-project\llvm\include -I"C:\BuildTools\DIA SDK\include" /DWIN32 /D_WINDOWS   /Zc:inline /Zc:__cplusplus /Oi /Brepro /bigobj /permissive- -Werror=unguarded-availability-new /W4  -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -Wimplicit-fallthrough -Wcovered-switch-default -Wno-noexcept-type -Wnon-virtual-dtor -Wdelete-non-virtual-dtor -Wsuggest-override -Wstring-conversion -Wno-pass-failed -Wmisleading-indentation -Wctad-maybe-unsupported /Gw /O2 /Ob2  -std:c++17 -MD -UNDEBUG /EHs-c- /GR- /showIncludes /Fotools\clang\lib\StaticAnalyzer\Core\CMakeFiles\obj.clangStaticAnalyzerCore.dir\MemRegion.cpp.obj /Fdtools\clang\lib\StaticAnalyzer\Core\CMakeFiles\obj.clangStaticAnalyzerCore.dir\ -c -- C:\_work\llvm-project\llvm-project\clang\lib\StaticAnalyzer\Core\MemRegion.cpp
C:\_work\llvm-project\llvm-project\clang\lib\StaticAnalyzer\Core\MemRegion.cpp(211,12): error: use of undeclared identifier 'Index'
211 |     assert(Index < FD->param_size());
|            ^~~~~
C:\_work\llvm-project\llvm-project\clang\lib\StaticAnalyzer\Core\MemRegion.cpp(212,29): error: use of undeclared identifier 'Index'
212 |     return FD->parameters()[Index];
|                             ^~~~~
C:\_work\llvm-project\llvm-project\clang\lib\StaticAnalyzer\Core\MemRegion.cpp(215,12): error: use of undeclared identifier 'Index'
215 |     assert(Index < BD->param_size());
|            ^~~~~
C:\_work\llvm-project\llvm-project\clang\lib\StaticAnalyzer\Core\MemRegion.cpp(216,29): error: use of undeclared identifier 'Index'
216 |     return BD->parameters()[Index];
|                             ^~~~~
C:\_work\llvm-project\llvm-project\clang\lib\StaticAnalyzer\Core\MemRegion.cpp(219,12): error: use of undeclared identifier 'Index'
219 |     assert(Index < MD->param_size());
|            ^~~~~
C:\_work\llvm-project\llvm-project\clang\lib\StaticAnalyzer\Core\MemRegion.cpp(220,29): error: use of undeclared identifier 'Index'
220 |     return MD->parameters()[Index];
|                             ^~~~~
C:\_work\llvm-project\llvm-project\clang\lib\StaticAnalyzer\Core\MemRegion.cpp(223,12): error: use of undeclared identifier 'Index'
223 |     assert(Index < CD->param_size());
|            ^~~~~
C:\_work\llvm-project\llvm-project\clang\lib\StaticAnalyzer\Core\MemRegion.cpp(224,29): error: use of undeclared identifier 'Index'
224 |     return CD->parameters()[Index];
|                             ^~~~~
8 errors generated.
```
</details>

If these failures are unrelated to your changes (for example tests are broken or flaky at HEAD), please open an issue at https://github.com/llvm/llvm-project/issues and add the `infrastructure` label.

https://github.com/llvm/llvm-project/pull/221252