
N3875	2026/04/12	Colomar, comparable types
N3874	2026/04/12	Thomas, April 2026 CFP teleconference agenda
N3873	2026/04/12	Thomas, March 2026 CFP teleconference minutes
N3872	2026/04/12	Douglas, Thread safe signals handling rev 3
N3867	2026/04/12	Gustedt, C semantics for contracts, v3
N3866	2026/04/12	Karl, Remove undefined behavior for non-basic source characters in source files (modified)
N3836	2026/04/12	Celeste, Ottawa ON August 2026 venue information

C semantics for contracts ｗちょっと読んでみると

Other features in our proposal that are different from C++ contracts:

We allow declarations of ghost states, similar to declarations in if-statements.

The name of the return variable in postconditions is fixed to _ReturnValue and cannot be annotated with attributes.

We use keywords _Pre, _Post and _Inv for contracts. C++’s syntax with pre and post (plus inv) is available with function-like macros. Contracts cannot be annotated with attributes.

We provide a macro (and function) stdc_contract_terminate that in general leads to the printing of a diagnostic and then to program termination.

こんなことが書かれていた

awk

gawk

MinRX regular expression failure

For example, the two lines
sub(/+[/]*-/, "")
sub("+/-[ ]*", "")
both cause a MinRX error (gawk quits parsing at the “offending” line).

細かいところでもいろいろ違いがありそう

glibc

glincのregexのバグ。 gawkはback referenceを使っていないのでセーフ(?)

Re: [PATCH] posix: fix false regex match with backrefs and $ anchor

パッチを見ると

diff --git a/lib/regexec.c b/lib/regexec.c
index c84ce1ef33..e09fc7698e 100644
--- a/lib/regexec.c
+++ b/lib/regexec.c
@@ -943,7 +943,10 @@ prune_impossible_nodes (re_match_context_t *mctx)
                  goto free_return;
                }
            } while (mctx->state_log[match_last] == NULL
-                    || !mctx->state_log[match_last]->halt);
+                    || !mctx->state_log[match_last]->halt
+                    || !check_halt_state_context (mctx,
+                                                  mctx->state_log[match_last],
+                                                  match_last));
          halt_node = check_halt_state_context (mctx,
                                                mctx->state_log[match_last],
                                                match_last);

わかるようなわからんような。 glibcのregexはわかりづらいんだよねえ

/* Check NODE match the current context.  */

static bool
check_halt_node_context (const re_dfa_t *dfa, Idx node, unsigned int context)
{
  re_token_type_t type = dfa->nodes[node].type;
  unsigned int constraint = dfa->nodes[node].constraint;
  if (type != END_OF_RE)
    return false;
  if (!constraint)
    return true;
  if (NOT_SATISFY_NEXT_CONSTRAINT (constraint, context))
    return false;
  return true;
}

/* Check the halt state STATE match the current context.
   Return 0 if not match, if the node, STATE has, is a halt node and
   match the context, return the node.  */

static Idx
check_halt_state_context (const re_match_context_t *mctx,
                          const re_dfastate_t *state, Idx idx)
{
  Idx i;
  unsigned int context;
  DEBUG_ASSERT (state->halt);
  context = re_string_context_at (&mctx->input, idx, mctx->eflags);
  for (i = 0; i < state->nodes.nelem; ++i)
    if (check_halt_node_context (mctx->dfa, state->nodes.elems[i], context))
      return state->nodes.elems[i];
  return 0;
}

glibc/posix/rxspencer/COPYRIGHT

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