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| author | Alexandre Oliva <oliva@adacore.com> | 2019-07-04 15:00:00 +0000 |
|---|---|---|
| committer | Alexandre Oliva <aoliva@gcc.gnu.org> | 2019-07-04 15:00:00 +0000 |
| commit | ebebc928d8b0d17676e751848892f927373b1fe5 (patch) | |
| tree | 5b00c4867b3d58dc4865627ffab29da1e0baa2d0 /gcc/doc | |
| parent | e57c896e86c4257741b574d99d7cacbfda219755 (diff) | |
| download | gcc-ebebc928d8b0d17676e751848892f927373b1fe5.zip gcc-ebebc928d8b0d17676e751848892f927373b1fe5.tar.gz gcc-ebebc928d8b0d17676e751848892f927373b1fe5.tar.bz2 | |
introduce EH_ELSE_EXPR tree and gimplifier
I found GIMPLE_EH_ELSE offered exactly the semantics I needed for some
Ada changes yet to be contributed, but GIMPLE_EH_ELSE was only built
by GIMPLE passes, and I needed to build earlier something that
eventually became GIMPLE_EH_ELSE.
This patch does that, introducing an EH_ELSE_EXPR tree, and logic to
dump it and to gimplify it.
for gcc/ChangeLog
* doc/generic.texi (Cleanups): Document EH_ELSE_EXPR.
* except.c: Likewise.
* expr.c (expand_expr_real_1): Reject it.
* gimplify.c (gimplify_expr): Gimplify it, within
TRY_FINALLY_EXPR.
* tree-dump.c (dequeue_and_dump): Dump it.
* tree-pretty-print.c (dump_generic_node): Likewise.
* tree.c (block_may_fallthru): Handle it.
* tree.def (EH_ELSE_EXPR): Introduce it.
* gimple-pretty-print.c (dump_gimple_try): Dump TRY_FINALLY
with GIMPLE_EH_ELSE as try/finally/else.
From-SVN: r273084
Diffstat (limited to 'gcc/doc')
| -rw-r--r-- | gcc/doc/generic.texi | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/gcc/doc/generic.texi b/gcc/doc/generic.texi index 67f7ad5..8901d5f 100644 --- a/gcc/doc/generic.texi +++ b/gcc/doc/generic.texi @@ -2180,6 +2180,11 @@ After the second sequence is executed, if it completes normally by falling off the end, execution continues wherever the first sequence would have continued, by falling off the end, or doing a goto, etc. +If the second sequence is an @code{EH_ELSE_EXPR} selector, then the +sequence in its first operand is used when the first sequence completes +normally, and that in its second operand is used for exceptional +cleanups, i.e., when an exception propagates out of the first sequence. + @code{TRY_FINALLY_EXPR} complicates the flow graph, since the cleanup needs to appear on every edge out of the controlled block; this reduces the freedom to move code across these edges. Therefore, the |