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Merged
merged 3 commits into from
Jan 22, 2020
Merged

DWARF: Update Ranges #2612

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a3bff78
DWARF: Update debug ranges [ci skip]
kripken Jan 19, 2020
f2a44b6
style
kripken Jan 22, 2020
49e793d
fix typo [ci skip]
kripken Jan 22, 2020
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57 changes: 55 additions & 2 deletions src/wasm/wasm-debug.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -368,7 +368,6 @@ struct AddrExprMap {
}
}


Expression* getStart(BinaryLocation addr) const {
auto iter = startMap.find(addr);
if (iter != startMap.end()) {
Expand Down Expand Up @@ -498,6 +497,10 @@ struct LocationUpdater {
return 0;
}

bool hasOldExprEndAddr(BinaryLocation oldAddr) const {
return oldExprAddrMap.getEnd(oldAddr);
}

BinaryLocation getNewFuncStartAddr(BinaryLocation oldAddr) const {
if (auto* func = oldFuncAddrMap.getStart(oldAddr)) {
// The function might have been optimized away, check.
Expand Down Expand Up @@ -612,7 +615,6 @@ static void updateDebugLines(llvm::DWARFYAML::Data& data,
} else if (locationUpdater.hasOldExtraAddr(oldAddr)) {
newAddr = locationUpdater.getNewExtraAddr(oldAddr);
}
// TODO: last 'end' of a function
if (newAddr) {
// LLVM sometimes emits the same address more than once. We should
// probably investigate that.
Expand Down Expand Up @@ -764,6 +766,55 @@ static void updateCompileUnits(const BinaryenDWARFInfo& info,
});
}

static void updateRanges(llvm::DWARFYAML::Data& yaml,
const LocationUpdater& locationUpdater) {
// In each range section, try to update the start and end. If we no longer
// have something to map them to, we must skip that part.
size_t skip = 0;
for (size_t i = 0; i < yaml.Ranges.size(); i++) {
auto& range = yaml.Ranges[i];
BinaryLocation oldStart = range.Start, oldEnd = range.End, newStart = 0,
newEnd = 0;
// If this was not an end marker, try to find what it should be updated to.
if (oldStart != 0 && oldEnd != 0) {
if (locationUpdater.hasOldExprAddr(oldStart)) {
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@dschuff dschuff Jan 22, 2020

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should we have some kind of combined lookup like hasOldExprOrFuncStartAddr() ? I guess when updating ranges we have no way to tell the context of the use...

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@kripken kripken Jan 22, 2020

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I could refactor a function for this, but I don't think that would be reusable anywhere else. This is the one place where we update both sides of a span (start, end) at once.

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@kripken kripken Jan 22, 2020

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For the second part, yeah, we can't tell the context atm. If the context would help I could work on getting it. However, I think it should be safe as it is, as we do have the context of whether we are at the start or end of a span, and the risky thing is just the ambiguity of the end of one thing which is equal to the start of the next, which we avoid here.

newStart = locationUpdater.getNewExprAddr(oldStart);
} else if (locationUpdater.hasOldFuncStartAddr(oldStart)) {
newStart = locationUpdater.getNewFuncStartAddr(oldStart);
}
if (locationUpdater.hasOldExprEndAddr(oldEnd)) {
newEnd = locationUpdater.getNewExprEndAddr(oldEnd);
} else if (locationUpdater.hasOldFuncEndAddr(oldEnd)) {
newEnd = locationUpdater.getNewFuncEndAddr(oldEnd);
}
if (newStart == 0 || newEnd == 0) {
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@dschuff dschuff Jan 22, 2020

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I guess in answer to my earlier question, If we have a range that represents a run of several instructions and we eliminate the last, I guess we don't have a good way to do "nearby" lookups in our current data structure.

// This part of the range no longer has a mapping, so we must skip it.
skip++;
continue;
}
// The range start and end markers have been preserved. However, TODO
// instructions in the middle may have moved around, making the range no
// longer contiguous, we should check that, and possibly split/merge
// the range. Or, we may need to have tracking in the IR for this.
} else {
// This was not a valid range in the old binary. It was either two 0's
// (an end marker) or an invalid value that should be ignored. Either way,
// write an end marker and finish the current section of ranges, filling
// it out to the original size (we must fill it out as indexes into
// the ranges section are not updated - we could update them and then
// pack the section, as an optimization TODO).
while (skip) {
auto& writtenRange = yaml.Ranges[i - skip];
writtenRange.Start = writtenRange.End = 0;
skip--;
}
}
auto& writtenRange = yaml.Ranges[i - skip];
writtenRange.Start = newStart;
writtenRange.End = newEnd;
}
}

void writeDWARFSections(Module& wasm, const BinaryLocations& newLocations) {
BinaryenDWARFInfo info(wasm);

Expand All @@ -779,6 +830,8 @@ void writeDWARFSections(Module& wasm, const BinaryLocations& newLocations) {

updateCompileUnits(info, data, locationUpdater);

updateRanges(data, locationUpdater);

// Convert to binary sections.
auto newSections =
EmitDebugSections(data, false /* EmitFixups for debug_info */);
Expand Down
12 changes: 6 additions & 6 deletions test/passes/fannkuch0.bin.txt
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Original file line number Diff line number Diff line change
Expand Up @@ -2420,9 +2420,9 @@ Abbrev table for offset: 0x00000000
DW_AT_comp_dir [DW_FORM_strp] ( .debug_str[0x000000a8] = "/home/alon/Dev/emscripten")
DW_AT_low_pc [DW_FORM_addr] (0x0000000000000000)
DW_AT_ranges [DW_FORM_sec_offset] (0x00000000
[0x00000006, 0x0000088c)
[0x0000088e, 0x000009dc)
[0x000009de, 0x00001042))
[0x00000006, 0x00000872)
[0x00000874, 0x000009a0)
[0x000009a2, 0x00000fde))

0x00000026: DW_TAG_pointer_type [2]
DW_AT_type [DW_FORM_ref4] (cu + 0x002b => {0x0000002b} "worker_args")
Expand Down Expand Up @@ -5188,9 +5188,9 @@ file_names[ 3]:
0x00000191: "cleanup"

.debug_ranges contents:
00000000 00000006 0000088c
00000000 0000088e 000009dc
00000000 000009de 00001042
00000000 00000006 00000872
00000000 00000874 000009a0
00000000 000009a2 00000fde
00000000 <End of list>
(module
(type $i32_=>_i32 (func (param i32) (result i32)))
Expand Down
32 changes: 16 additions & 16 deletions test/passes/fannkuch3.bin.txt
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Expand Up @@ -2469,8 +2469,8 @@ Abbrev table for offset: 0x00000000
DW_AT_comp_dir [DW_FORM_strp] ( .debug_str[0x000000a9] = "/usr/local/google/home/azakai/Dev/2-binaryen")
DW_AT_low_pc [DW_FORM_addr] (0x0000000000000000)
DW_AT_ranges [DW_FORM_sec_offset] (0x00000040
[0x00000006, 0x0000039d)
[0x0000039f, 0x000006e1))
[0x00000006, 0x00000389)
[0x0000038b, 0x00000686))

0x00000026: DW_TAG_pointer_type [2]
DW_AT_type [DW_FORM_ref4] (cu + 0x002b => {0x0000002b} "worker_args")
Expand Down Expand Up @@ -2678,10 +2678,10 @@ Abbrev table for offset: 0x00000000

0x00000159: DW_TAG_lexical_block [14] *
DW_AT_ranges [DW_FORM_sec_offset] (0x00000000
[0x00000185, 0x000001c3)
[0x000001ed, 0x000001f6)
[0x0000030e, 0x0000034c)
[0x00000376, 0x0000037f))
[0x00000175, 0x000001b3)
[0x000001dd, 0x000001e6)
[0x00000302, 0x00000340)
[0x0000036a, 0x00000373))

0x0000015e: DW_TAG_variable [12]
DW_AT_name [DW_FORM_strp] ( .debug_str[0x00000163] = "p0")
Expand Down Expand Up @@ -2927,8 +2927,8 @@ Abbrev table for offset: 0x00000000

0x000002e3: DW_TAG_lexical_block [14] *
DW_AT_ranges [DW_FORM_sec_offset] (0x00000028
[0x00000517, 0x0000055e)
[0x000005de, 0x0000062b))
[0x000004d9, 0x00000520)
[0x0000059e, 0x000005eb))

0x000002e8: DW_TAG_variable [26]
DW_AT_location [DW_FORM_sec_offset] (0x000003bc:
Expand Down Expand Up @@ -4778,16 +4778,16 @@ file_names[ 4]:
0x000001ad: "char"

.debug_ranges contents:
00000000 00000185 000001c3
00000000 000001ed 000001f6
00000000 0000030e 0000034c
00000000 00000376 0000037f
00000000 00000175 000001b3
00000000 000001dd 000001e6
00000000 00000302 00000340
00000000 0000036a 00000373
00000000 <End of list>
00000028 00000517 0000055e
00000028 000005de 0000062b
00000028 000004d9 00000520
00000028 0000059e 000005eb
00000028 <End of list>
00000040 00000006 0000039d
00000040 0000039f 000006e1
00000040 00000006 00000389
00000040 0000038b 00000686
00000040 <End of list>
(module
(type $i32_=>_i32 (func (param i32) (result i32)))
Expand Down
29 changes: 12 additions & 17 deletions test/passes/fannkuch3_manyopts.bin.txt
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Expand Up @@ -2469,8 +2469,8 @@ Abbrev table for offset: 0x00000000
DW_AT_comp_dir [DW_FORM_strp] ( .debug_str[0x000000a9] = "/usr/local/google/home/azakai/Dev/2-binaryen")
DW_AT_low_pc [DW_FORM_addr] (0x0000000000000000)
DW_AT_ranges [DW_FORM_sec_offset] (0x00000040
[0x00000006, 0x0000039d)
[0x0000039f, 0x000006e1))
[0x00000007, 0x0000035a)
[0x0000035c, 0x0000062b))

0x00000026: DW_TAG_pointer_type [2]
DW_AT_type [DW_FORM_ref4] (cu + 0x002b => {0x0000002b} "worker_args")
Expand Down Expand Up @@ -2677,11 +2677,7 @@ Abbrev table for offset: 0x00000000
DW_AT_type [DW_FORM_ref4] (cu + 0x0059 => {0x00000059} "int")

0x00000159: DW_TAG_lexical_block [14] *
DW_AT_ranges [DW_FORM_sec_offset] (0x00000000
[0x00000185, 0x000001c3)
[0x000001ed, 0x000001f6)
[0x0000030e, 0x0000034c)
[0x00000376, 0x0000037f))
DW_AT_ranges [DW_FORM_sec_offset] (0x00000000)

0x0000015e: DW_TAG_variable [12]
DW_AT_name [DW_FORM_strp] ( .debug_str[0x00000163] = "p0")
Expand Down Expand Up @@ -2927,8 +2923,7 @@ Abbrev table for offset: 0x00000000

0x000002e3: DW_TAG_lexical_block [14] *
DW_AT_ranges [DW_FORM_sec_offset] (0x00000028
[0x00000517, 0x0000055e)
[0x000005de, 0x0000062b))
[0x00000553, 0x0000059d))

0x000002e8: DW_TAG_variable [26]
DW_AT_location [DW_FORM_sec_offset] (0x000003bc:
Expand Down Expand Up @@ -3712,16 +3707,16 @@ file_names[ 4]:
0x000001ad: "char"

.debug_ranges contents:
00000000 00000185 000001c3
00000000 000001ed 000001f6
00000000 0000030e 0000034c
00000000 00000376 0000037f
00000000 <End of list>
00000028 00000517 0000055e
00000028 000005de 0000062b
00000008 <End of list>
00000010 <End of list>
00000018 <End of list>
00000020 <End of list>
00000028 00000553 0000059d
00000028 <End of list>
00000040 00000006 0000039d
00000040 0000039f 000006e1
00000038 <End of list>
00000040 00000007 0000035a
00000040 0000035c 0000062b
00000040 <End of list>
(module
(type $i32_=>_i32 (func (param i32) (result i32)))
Expand Down
4 changes: 2 additions & 2 deletions test/passes/fib2.bin.txt
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Expand Up @@ -382,7 +382,7 @@ Abbrev table for offset: 0x00000000
DW_AT_low_pc [DW_FORM_addr] (0x0000000000000000)
DW_AT_ranges [DW_FORM_sec_offset] (0x00000000
[0x00000005, 0x0000003d)
[0x0000003e, 0x00000048))
[0x0000003e, 0x00000044))

0x00000026: DW_TAG_subprogram [2] *
DW_AT_low_pc [DW_FORM_addr] (0x0000000000000005)
Expand Down Expand Up @@ -610,7 +610,7 @@ file_names[ 1]:

.debug_ranges contents:
00000000 00000005 0000003d
00000000 0000003e 00000048
00000000 0000003e 00000044
00000000 <End of list>
(module
(type $none_=>_none (func))
Expand Down
6 changes: 3 additions & 3 deletions test/passes/ignore_missing_func.bin.txt
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Expand Up @@ -622,7 +622,7 @@ Abbrev table for offset: 0x00000000
DW_AT_comp_dir [DW_FORM_strp] ( .debug_str[0x0000009b] = "/home/alon/Dev/emscripten")
DW_AT_low_pc [DW_FORM_addr] (0x0000000000000000)
DW_AT_ranges [DW_FORM_sec_offset] (0x00000000
[0x00000005, 0x0000005f))
[0x00000005, 0x0000005b))

0x00000026: DW_TAG_variable [2]
DW_AT_name [DW_FORM_strp] ( .debug_str[0x000000b5] = "quine")
Expand Down Expand Up @@ -817,9 +817,9 @@ file_names[ 1]:
0x000000e9: "x"

.debug_ranges contents:
00000000 00000005 0000005f
00000000 00000005 0000005b
00000000 <End of list>
00000010 00000060 000000c4
00000010 0000005c 000000ad
00000010 <End of list>
(module
(type $none_=>_none (func))
Expand Down