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| author | Ian Lance Taylor <ian@gcc.gnu.org> | 2016-09-27 21:25:42 +0000 |
|---|---|---|
| committer | Ian Lance Taylor <ian@gcc.gnu.org> | 2016-09-27 21:25:42 +0000 |
| commit | c7ff137489343e20405473156ed589ad791149d2 (patch) | |
| tree | fd11b50b0605169cf1d4f1d098f40291ef7e6100 /gcc | |
| parent | 437018ea2b6dc966ce40cd5dd684054126ddda6b (diff) | |
| download | gcc-c7ff137489343e20405473156ed589ad791149d2.zip gcc-c7ff137489343e20405473156ed589ad791149d2.tar.gz gcc-c7ff137489343e20405473156ed589ad791149d2.tar.bz2 | |
compiler: avoid call duplication during order eval.
During the compiler's order_evaluations() pass, duplicate
call statements were being created and inserted into block
statement lists in situations where there were calls returning
multiple arguments. These duplicates were benign in that they
were ignored during backend code generation, however they
did cause duplicate calls in AST dumps. Tweak the order
evaluation code to handle this case better and avoid inserting
these duplicates.
Fixes golang/go#17237
Reviewed-on: https://go-review.googlesource.com/29857
From-SVN: r240559
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/go/gofrontend/MERGE | 2 | ||||
| -rw-r--r-- | gcc/go/gofrontend/gogo.cc | 25 |
2 files changed, 19 insertions, 8 deletions
diff --git a/gcc/go/gofrontend/MERGE b/gcc/go/gofrontend/MERGE index e80ed9f..1b53f8c 100644 --- a/gcc/go/gofrontend/MERGE +++ b/gcc/go/gofrontend/MERGE @@ -1,4 +1,4 @@ -1d8d834b5eb9f683cc06529145b353bb5b08e7ea +8aca265d317059ae6d9721a4a231895d80d0a82c The first line of this file holds the git revision number of the last merge done from the gofrontend repository. diff --git a/gcc/go/gofrontend/gogo.cc b/gcc/go/gofrontend/gogo.cc index 7617815..587ebd4 100644 --- a/gcc/go/gofrontend/gogo.cc +++ b/gcc/go/gofrontend/gogo.cc @@ -3616,11 +3616,21 @@ Order_eval::statement(Block* block, size_t* pindex, Statement* s) // be handled specially. We can't create a temporary // because there is no type to give it. Any actual uses of // the values will be done via Call_result_expressions. - s = Statement::make_statement(*pexpr, true); - } + // + // Since a given call expression can be shared by multiple + // Call_result_expressions, avoid hoisting the call the + // second time we see it here. + if (this->remember_expression(*pexpr)) + s = NULL; + else + s = Statement::make_statement(*pexpr, true); + } - block->insert_statement_before(*pindex, s); - ++*pindex; + if (s != NULL) + { + block->insert_statement_before(*pindex, s); + ++*pindex; + } } if (init != orig_init) @@ -7949,13 +7959,14 @@ Traverse::remember_type(const Type* type) } // Record that we are looking at an expression, and return true if we -// have already seen it. +// have already seen it. NB: this routine used to assert if the traverse +// mask did not include expressions/types -- this is no longer the case, +// since it can be useful to remember specific expressions during +// walks that only cover statements. bool Traverse::remember_expression(const Expression* expression) { - go_assert((this->traverse_mask() & traverse_types) != 0 - || (this->traverse_mask() & traverse_expressions) != 0); if (this->expressions_seen_ == NULL) this->expressions_seen_ = new Expressions_seen(); std::pair<Expressions_seen::iterator, bool> ins = |