[PATCH] D58161: Print a note to the called macro when diagnosing err_embedded_directive

[Nico Weber via Phabricator via cfe-commits]

thakis marked an inline comment as done.
thakis added inline comments.


================
Comment at: clang/lib/Lex/PPMacroExpansion.cpp:497
+
     Args = ReadMacroCallArgumentList(Identifier, MI, ExpansionEnd);
 
----------------
rnk wrote:
> Can this re-enter, something like:
>   MACRO1(MACRO2(a1), MACRO3(
>   #include "asdf"
>   )
> In this case, I think your diagnostic might do a null-deref. Maybe just add this test case and add a null test for it.
This works fine:

```
#define MACRO1(a, b, c)
#define MACRO2(a, b, c)
#define MACRO3(a, b, c)

MACRO1(MACRO2(a1), MACRO3(
#include "asdf"
)

$ out/gn/bin/clang -c test.cc
test.cc:30:2: error: embedding a #include directive within macro arguments is not supported
#include "asdf"
 ^
test.cc:29:1: note: expansion of macro 'MACRO1' requested here
MACRO1(MACRO2(a1), MACRO3(
^
test.cc:29:1: error: unterminated function-like macro invocation
MACRO1(MACRO2(a1), MACRO3(
^
test.cc:25:9: note: macro 'MACRO1' defined here
#define MACRO1(a, b, c)
        ^
2 errors generated.
```

Note that the diag is only emitted if inMacroArgs is true, and ArgMacro is always set to non-nullptr exactly when that's true.




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https://reviews.llvm.org/D58161