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[wasm][cleanup] Use vector comparison instead of strncmp

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{base::Vector} comparison is easier to read (IMO), and more performant,
since {memcmp} will be used internally instead of {strncmp}.

R=ahaas@chromium.org

Bug: v8:10155
Change-Id: If92361688a85e96aa661d3e05cc9966e5ea2d04a
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2164796
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67605}
This commit is contained in:
Clemens Backes 2020-05-06 13:38:59 +02:00 committed by Commit Bot
parent 276eaea2c7
commit 8e7c6ec606
1 changed files with 14 additions and 28 deletions
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42
src/wasm/module-decoder.cc
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@ -35,11 +35,6 @@ constexpr char kCompilationHintsString[] = "compilationHints";
constexpr char kDebugInfoString[] = ".debug_info";
constexpr char kExternalDebugInfoString[] = ".external_debug_info";
template <size_t N>
constexpr size_t num_chars(const char (&)[N]) {
return N - 1; // remove null character at end.
}
const char* ExternalKindName(ImportExportKindCode kind) {
switch (kind) {
case kExternalFunction:
@ -167,30 +162,21 @@ SectionCode IdentifyUnknownSectionInternal(Decoder* decoder) {
static_cast<int>(section_name_start - decoder->start()),
string.length() < 20 ? string.length() : 20, section_name_start);
if (string.length() == num_chars(kNameString) &&
strncmp(reinterpret_cast<const char*>(section_name_start), kNameString,
num_chars(kNameString)) == 0) {
return kNameSectionCode;
} else if (string.length() == num_chars(kSourceMappingURLString) &&
strncmp(reinterpret_cast<const char*>(section_name_start),
kSourceMappingURLString,
num_chars(kSourceMappingURLString)) == 0) {
return kSourceMappingURLSectionCode;
} else if (string.length() == num_chars(kCompilationHintsString) &&
strncmp(reinterpret_cast<const char*>(section_name_start),
kCompilationHintsString,
num_chars(kCompilationHintsString)) == 0) {
return kCompilationHintsSectionCode;
} else if (string.length() == num_chars(kDebugInfoString) &&
strncmp(reinterpret_cast<const char*>(section_name_start),
kDebugInfoString, num_chars(kDebugInfoString)) == 0) {
return kDebugInfoSectionCode;
} else if (string.length() == num_chars(kExternalDebugInfoString) &&
strncmp(reinterpret_cast<const char*>(section_name_start),
kExternalDebugInfoString,
num_chars(kExternalDebugInfoString)) == 0) {
return kExternalDebugInfoSectionCode;
using SpecialSectionPair = std::pair<Vector<const char>, SectionCode>;
static constexpr SpecialSectionPair kSpecialSections[]{
{StaticCharVector(kNameString), kNameSectionCode},
{StaticCharVector(kSourceMappingURLString), kSourceMappingURLSectionCode},
{StaticCharVector(kCompilationHintsString), kCompilationHintsSectionCode},
{StaticCharVector(kDebugInfoString), kDebugInfoSectionCode},
{StaticCharVector(kExternalDebugInfoString),
kExternalDebugInfoSectionCode}};
auto name_vec =
Vector<const char>::cast(VectorOf(section_name_start, string.length()));
for (auto& special_section : kSpecialSections) {
if (name_vec == special_section.first) return special_section.second;
}
return kUnknownSectionCode;
}
} // namespace