6621084: ciMethodBlocks::split_block_at() is broken for methods with exception handler
Summary: After an exception handler block is split the exception information is not moved to the new block which starts in exception handler BCI.
Reviewed-by: jrose
--- a/hotspot/src/share/vm/ci/ciMethodBlocks.cpp Wed Feb 20 17:23:43 2008 -0800
+++ b/hotspot/src/share/vm/ci/ciMethodBlocks.cpp Thu Feb 21 14:03:41 2008 -0800
@@ -67,6 +67,14 @@
break;
}
}
+ // Move an exception handler information if needed.
+ if (former_block->is_handler()) {
+ int ex_start = former_block->ex_start_bci();
+ int ex_end = former_block->ex_limit_bci();
+ new_block->set_exception_range(ex_start, ex_end);
+ // Clear information in former_block.
+ former_block->clear_exception_handler();
+ }
return former_block;
}
@@ -102,7 +110,7 @@
// one and end the old one.
assert(cur_block != NULL, "must always have a current block");
ciBlock *new_block = block_containing(bci);
- if (new_block == NULL) {
+ if (new_block == NULL || new_block == cur_block) {
// We have not marked this bci as the start of a new block.
// Keep interpreting the current_range.
_bci_to_block[bci] = cur_block;
@@ -254,9 +262,33 @@
for(ciExceptionHandlerStream str(meth); !str.is_done(); str.next()) {
ciExceptionHandler* handler = str.handler();
ciBlock *eb = make_block_at(handler->handler_bci());
- eb->set_handler();
+ //
+ // Several exception handlers can have the same handler_bci:
+ //
+ // try {
+ // if (a.foo(b) < 0) {
+ // return a.error();
+ // }
+ // return CoderResult.UNDERFLOW;
+ // } finally {
+ // a.position(b);
+ // }
+ //
+ // The try block above is divided into 2 exception blocks
+ // separated by 'areturn' bci.
+ //
int ex_start = handler->start();
int ex_end = handler->limit();
+ if (eb->is_handler()) {
+ // Extend old handler exception range to cover additional range.
+ int old_ex_start = eb->ex_start_bci();
+ int old_ex_end = eb->ex_limit_bci();
+ if (ex_start > old_ex_start)
+ ex_start = old_ex_start;
+ if (ex_end < old_ex_end)
+ ex_end = old_ex_end;
+ eb->clear_exception_handler(); // Reset exception information
+ }
eb->set_exception_range(ex_start, ex_end);
// ensure a block at the start of exception range and start of following code
(void) make_block_at(ex_start);
@@ -312,9 +344,10 @@
void ciBlock::set_exception_range(int start_bci, int limit_bci) {
assert(limit_bci >= start_bci, "valid range");
- assert(is_handler(), "must be handler");
+ assert(!is_handler() && _ex_start_bci == -1 && _ex_limit_bci == -1, "must not be handler");
_ex_start_bci = start_bci;
_ex_limit_bci = limit_bci;
+ set_handler();
}
#ifndef PRODUCT
--- a/hotspot/src/share/vm/ci/ciMethodBlocks.hpp Wed Feb 20 17:23:43 2008 -0800
+++ b/hotspot/src/share/vm/ci/ciMethodBlocks.hpp Thu Feb 21 14:03:41 2008 -0800
@@ -110,9 +110,10 @@
void set_does_jsr() { _flags |= DoesJsr; }
void clear_does_jsr() { _flags &= ~DoesJsr; }
void set_does_ret() { _flags |= DoesRet; }
- void clear_does_ret() { _flags |= DoesRet; }
+ void clear_does_ret() { _flags &= ~DoesRet; }
void set_is_ret_target() { _flags |= RetTarget; }
void set_has_handler() { _flags |= HasHandler; }
+ void clear_exception_handler() { _flags &= ~Handler; _ex_start_bci = -1; _ex_limit_bci = -1; }
#ifndef PRODUCT
ciMethod *method() const { return _method; }
void dump();