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| author | Peter Eisentraut <peter@eisentraut.org> | 2019-03-25 09:35:29 +0100 |
|---|---|---|
| committer | Peter Eisentraut <peter@eisentraut.org> | 2019-03-25 09:37:03 +0100 |
| commit | 481018f2804065cb5ed1cde75b7c0596aeef959a (patch) | |
| tree | 045013c91eb4fe8747a7b4ab0a5e36cd44d3d078 | |
| parent | 572e3e6634e55accf95e2bcfb1340019c86a21dc (diff) | |
| download | postgresql-481018f2804065cb5ed1cde75b7c0596aeef959a.tar.gz postgresql-481018f2804065cb5ed1cde75b7c0596aeef959a.zip | |
Add macro to cast away volatile without allowing changes to underlying type
This adds unvolatize(), which works just like unconstify() but for volatile.
Discussion: https://www.postgresql.org/message-id/flat/7a5cbea7-b8df-e910-0f10-04014bcad701%402ndquadrant.com
| -rw-r--r-- | src/backend/postmaster/pgstat.c | 2 | ||||
| -rw-r--r-- | src/backend/storage/ipc/pmsignal.c | 2 | ||||
| -rw-r--r-- | src/include/c.h | 8 |
3 files changed, 9 insertions, 3 deletions
diff --git a/src/backend/postmaster/pgstat.c b/src/backend/postmaster/pgstat.c index 2fbfadd9f0c..2a8472b91ae 100644 --- a/src/backend/postmaster/pgstat.c +++ b/src/backend/postmaster/pgstat.c @@ -3311,7 +3311,7 @@ pgstat_read_current_status(void) localentry->backendStatus.st_procpid = beentry->st_procpid; if (localentry->backendStatus.st_procpid > 0) { - memcpy(&localentry->backendStatus, (char *) beentry, sizeof(PgBackendStatus)); + memcpy(&localentry->backendStatus, unvolatize(PgBackendStatus *, beentry), sizeof(PgBackendStatus)); /* * strcpy is safe even if the string is modified concurrently, diff --git a/src/backend/storage/ipc/pmsignal.c b/src/backend/storage/ipc/pmsignal.c index d707993bf63..48f43114642 100644 --- a/src/backend/storage/ipc/pmsignal.c +++ b/src/backend/storage/ipc/pmsignal.c @@ -134,7 +134,7 @@ PMSignalShmemInit(void) if (!found) { - MemSet(PMSignalState, 0, PMSignalShmemSize()); + MemSet(unvolatize(PMSignalData *, PMSignalState), 0, PMSignalShmemSize()); PMSignalState->num_child_flags = MaxLivePostmasterChildren(); } } diff --git a/src/include/c.h b/src/include/c.h index 658be50e0d3..33c95181952 100644 --- a/src/include/c.h +++ b/src/include/c.h @@ -1122,7 +1122,7 @@ typedef union PGAlignedXLogBlock #endif /* - * Macro that allows to cast constness away from an expression, but doesn't + * Macro that allows to cast constness and volatile away from an expression, but doesn't * allow changing the underlying type. Enforcement of the latter * currently only works for gcc like compilers. * @@ -1141,9 +1141,15 @@ typedef union PGAlignedXLogBlock (StaticAssertExpr(__builtin_types_compatible_p(__typeof(expr), const underlying_type), \ "wrong cast"), \ (underlying_type) (expr)) +#define unvolatize(underlying_type, expr) \ + (StaticAssertExpr(__builtin_types_compatible_p(__typeof(expr), volatile underlying_type), \ + "wrong cast"), \ + (underlying_type) (expr)) #else #define unconstify(underlying_type, expr) \ ((underlying_type) (expr)) +#define unvolatize(underlying_type, expr) \ + ((underlying_type) (expr)) #endif /* ---------------------------------------------------------------- |