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HerrCai0907HerrCai0907
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feat: ignore unreachable branch to improve branch coverage precision
In AS test, we definitely do not want to touch unreachable branch. And since unreachable will fail the execution and result output, it does not make sure to statistic unreachable branch coverage This PR remove the basic blocks which must unreachable.
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6 files changed

+148
-19
lines changed

6 files changed

+148
-19
lines changed

‎.prettierignore

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Original file line numberDiff line numberDiff line change
@@ -5,6 +5,5 @@
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/transform/*.mjs
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/tests/ts/fixture
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/third_party
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/tests/cpp/lit/**/*.json
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/.cache
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/.github/CODEOWNERS

‎instrumentation/BasicBlockWalker.cpp

Lines changed: 65 additions & 17 deletions
Original file line numberDiff line numberDiff line change
@@ -1,5 +1,11 @@
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#include "BasicBlockWalker.hpp"
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#include <algorithm>
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#include <cfg/cfg-traversal.h>
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#include <iostream>
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#include <memory>
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#include <set>
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#include <utility>
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#include <wasm.h>
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#include "ir/branch-utils.h"
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namespace wasmInstrumentation {
@@ -27,30 +33,72 @@ void BasicBlockWalker::visitExpression(wasm::Expression *curr) noexcept {
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}
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}
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30-
void BasicBlockWalker::unlinkEmptyBlock() noexcept {
31-
const auto lambda = [](std::unique_ptr<BasicBlock> &block) {
32-
if (block->contents.exprs.empty() && block->out.size() == 1) {
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const auto outBlock = block->out[0];
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outBlock->in.erase(std::find(outBlock->in.begin(), outBlock->in.end(), block.get()));
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for (auto &inBlock : block->in) {
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inBlock->out.erase(std::find(inBlock->out.begin(), inBlock->out.end(), block.get()));
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inBlock->out.push_back(outBlock);
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outBlock->in.push_back(inBlock);
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static bool
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isBasicBlockContainUnreachable(BasicBlockWalker::BasicBlock &block,
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std::set<BasicBlockWalker::BasicBlock *> unreachableBlocks) {
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return (!block.contents.exprs.empty() &&
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std::any_of(block.contents.exprs.begin(), block.contents.exprs.end(),
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[](wasm::Expression *expr) {
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return expr->is<wasm::Unreachable>();
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})) ||
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(!block.in.empty() &&
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std::all_of(block.in.begin(), block.in.end(),
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[&unreachableBlocks](BasicBlockWalker::BasicBlock *inBlock) {
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return unreachableBlocks.find(inBlock) != unreachableBlocks.end();
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}));
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};
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static void removeDuplicates(std::vector<BasicBlockWalker::BasicBlock *> &list) {
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std::sort(list.begin(), list.end());
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list.erase(std::unique(list.begin(), list.end()), list.end());
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}
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void BasicBlockWalker::cleanBlock() noexcept {
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bool isModified = true;
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std::set<BasicBlock *> unreachableBlocks{};
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while (isModified) {
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isModified = false;
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for (auto &block : basicBlocks) {
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if (isBasicBlockContainUnreachable(*block, unreachableBlocks)) {
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isModified |= unreachableBlocks.insert(block.get()).second;
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}
40-
block->in.clear();
41-
block->out.clear();
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return true;
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}
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return false;
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};
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basicBlocks.erase(std::remove_if(basicBlocks.begin(), basicBlocks.end(), lambda),
47-
basicBlocks.end());
66+
}
67+
std::set<BasicBlock *> emptyBlocks{};
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for (auto &block : basicBlocks) {
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if (block->contents.exprs.empty() && block->out.size() == 1) {
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emptyBlocks.insert(block.get());
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}
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}
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std::set<BasicBlock *> targetCleanBlocks{};
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targetCleanBlocks.insert(unreachableBlocks.begin(), unreachableBlocks.end());
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targetCleanBlocks.insert(emptyBlocks.begin(), emptyBlocks.end());
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78+
for (auto &block : targetCleanBlocks) {
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for (auto &outBlock : block->out) {
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outBlock->in.erase(std::find(outBlock->in.begin(), outBlock->in.end(), block));
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outBlock->in.insert(outBlock->in.end(), block->in.begin(), block->in.end());
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removeDuplicates(outBlock->in);
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}
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for (auto &inBlock : block->in) {
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inBlock->out.erase(std::find(inBlock->out.begin(), inBlock->out.end(), block));
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inBlock->out.insert(inBlock->out.end(), block->out.begin(), block->out.end());
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removeDuplicates(inBlock->out);
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}
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block->in.clear();
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block->out.clear();
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basicBlocks.erase(std::find_if(basicBlocks.begin(), basicBlocks.end(),
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[&block](std::unique_ptr<BasicBlock> const &b) -> bool {
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return b.get() == block;
94+
}));
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}
4896
}
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5098
void BasicBlockWalker::doWalkFunction(wasm::Function *const func) noexcept {
5199
wasm::CFGWalker<BasicBlockWalker, wasm::UnifiedExpressionVisitor<BasicBlockWalker>,
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BasicBlockInfo>::doWalkFunction(func);
53-
unlinkEmptyBlock();
101+
cleanBlock();
54102
// LCOV_EXCL_START
55103
if (basicBlocks.size() > UINT32_MAX) {
56104
std::cerr << "Error: BasicBlocks length exceeds UINT32_MAX\n";

‎instrumentation/BasicBlockWalker.hpp

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -167,7 +167,7 @@ class BasicBlockWalker final
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///
168168
/// @brief remove empty block that do not belong to any branch
169169
///
170-
void unlinkEmptyBlock() noexcept;
170+
void cleanBlock() noexcept;
171171
};
172172
} // namespace wasmInstrumentation
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‎tests/cpp/lit/covInstrument/unreachable.wast

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@@ -0,0 +1,49 @@
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(module
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(type $0 (func (param i32 i32 i32 i32)))
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(type $1 (func (param i32)))
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(type $2 (func))
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(import "env" "abort" (func $~lib/builtins/abort (param i32 i32 i32 i32)))
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(global $~lib/memory/__data_end i32 (i32.const 76))
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(global $~lib/memory/__stack_pointer (mut i32) (i32.const 32844))
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(global $~lib/memory/__heap_base i32 (i32.const 32844))
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(memory $0 1)
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(data $0 (i32.const 12) "<\00\00\00\00\00\00\00\00\00\00\00\02\00\00\00\"\00\00\00a\00s\00s\00e\00m\00b\00l\00y\00/\00i\00n\00d\00e\00x\00.\00t\00s\00\00\00\00\00\00\00\00\00\00\00")
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(table $0 1 1 funcref)
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(elem $0 (i32.const 1))
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(export "main" (func $assembly/index/main))
14+
(export "memory" (memory $0))
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(func $assembly/index/f (param $a i32)
16+
;;@ assembly/index.ts:5:2
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(if
18+
;;@
19+
(i32.eqz
20+
;;@ assembly/index.ts:5:9
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(i32.ge_s
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(local.get $a)
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;;@ assembly/index.ts:5:14
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(i32.const 10)
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)
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)
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(then
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;;@
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(call $~lib/builtins/abort
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(i32.const 0)
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(i32.const 32)
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(i32.const 5)
33+
(i32.const 3)
34+
)
35+
;;@
36+
(unreachable)
37+
)
38+
)
39+
)
40+
(func $assembly/index/main
41+
;;@ assembly/index.ts:2:2
42+
(call $assembly/index/f
43+
;;@ assembly/index.ts:2:4
44+
(i32.const 10)
45+
)
46+
;;@ assembly/index.ts:2:2
47+
)
48+
;; custom section "sourceMappingURL", size 17
49+
)

‎tests/cpp/lit/covInstrument/unreachable.wast.debug.json

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@@ -0,0 +1,27 @@
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{
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"debugFiles": ["assembly/index.ts"],
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"debugInfos": {
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"assembly/index/f": {
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"branchInfo": [],
6+
"index": 0,
7+
"lineInfo": [
8+
[
9+
[0, 5, 2],
10+
[0, 5, 9],
11+
[0, 5, 14]
12+
],
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[]
14+
]
15+
},
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"assembly/index/main": {
17+
"branchInfo": [],
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"index": 1,
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"lineInfo": [
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[
21+
[0, 2, 2],
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[0, 2, 4]
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]
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]
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}
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}
27+
}

‎tests/cpp/lit/covInstrument/unreachable.wast.run.log

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@@ -0,0 +1,6 @@
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make directly call to function index=1
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make directly call to function index=0
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basic block entry trace to: function=0, basic block=0
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basic block entry trace to: function=0, basic block=1
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basic block entry trace to: function=1, basic block=0
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exit from function call index=0

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