add detail on C VLAs

2 files changed, 6 insertions, 2 deletions

diff --git a/.build.yml b/.build.yml
index df36fc2..e40edc3 100644
--- a/.build.yml
+++ b/.build.yml
@@ -8,7 +8,7 @@ sources:
 tasks:

     - page-count: |

         cd crowbar-spec

-        pandoc -s -o ../spec.pdf -t html -M "TITLE=Crowbar Specification" *.md

+        pandoc -s -o ../spec.pdf -t html -M "title=Crowbar Specification" *.md

         cd ..

         pdfinfo spec.pdf | grep Pages

 artifacts:

diff --git a/safety.md b/safety.md
index 6550492..271edc1 100644
--- a/safety.md
+++ b/safety.md
@@ -23,7 +23,11 @@ int main(int argc, (char[1024?])[argc] argv) {
 }

 ```

 

-Note that `malloc` as part of the Crowbar standard library has signature `(char[size])* malloc(size_t size);` and so no cast is needed above.

+Note that `malloc` as part of the Crowbar standard library has signature `(void[size])* malloc(size_t size);` and so no cast is needed above.

+In C, `buffer` in `main` would have type pointer-to-VLA-of-char, but `buffer` in `process` would have type VLA-of-char, and this conversion would emit a compiler warning.

+However, in Crowbar, a `(T[N])*` is always implicitly convertible to `T[N]`, so no warning exists.

+(This is translated into C by dereferencing `buffer` in `main`.)

+

 Note as well that the type of `argv` is complicated.

 This is because the elements of `argv` have unconstrained size.

 TODO figure out if that's the right way to handle that