RFC: [llvm] specialize cl::opt_storage for std::string #149172
Draft
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
You can test this locally with the following command:git-clang-format --diff HEAD~1 HEAD --extensions h -- llvm/include/llvm/Support/CommandLine.h llvm/include/llvm/TargetParser/Triple.hView the diff from clang-format here.diff --git a/llvm/include/llvm/Support/CommandLine.h b/llvm/include/llvm/Support/CommandLine.h
index 823e31a80..7c041fbff 100644
--- a/llvm/include/llvm/Support/CommandLine.h
+++ b/llvm/include/llvm/Support/CommandLine.h
@@ -1417,23 +1417,23 @@ public:
const OptionValue<std::string> &getDefault() const { return Default; }
// Support implicit conversions to std::string and LLVM string-like types.
- //operator std::string() const { return Value; }
- operator std::string&() { return Value; }
- operator const std::string&() const { return Value; }
+ // operator std::string() const { return Value; }
+ operator std::string &() { return Value; }
+ operator const std::string &() const { return Value; }
operator llvm::StringRef() const { return llvm::StringRef(Value); }
operator llvm::Twine() const { return llvm::Twine(llvm::StringRef(Value)); }
// If the datatype is a pointer, support -> on it.
std::string operator->() const { return Value; }
- Self& operator=(const Self& rhs) = default;
+ Self &operator=(const Self &rhs) = default;
- Self& operator=(const std::string& rhs) {
+ Self &operator=(const std::string &rhs) {
Value = rhs;
return *this;
}
- Self& operator=(const char* rhs) {
+ Self &operator=(const char *rhs) {
Value = rhs;
return *this;
}
@@ -1491,43 +1491,39 @@ public:
char operator[](size_t pos) const { return Value.at(pos); }
- Self& assign(const std::string& rhs) {
+ Self &assign(const std::string &rhs) {
Value.assign(rhs);
return *this;
}
- Self& assign(const char* rhs) {
+ Self &assign(const char *rhs) {
Value.assign(rhs);
return *this;
}
- Self& operator+=(const std::string& rhs) {
+ Self &operator+=(const std::string &rhs) {
Value += rhs;
return *this;
}
- Self& operator+=(const char* rhs) {
+ Self &operator+=(const char *rhs) {
Value += rhs;
return *this;
}
- friend std::string
- operator+(Self const& lhs, std::string const& rhs) {
+ friend std::string operator+(Self const &lhs, std::string const &rhs) {
return lhs.Value + rhs;
}
- friend std::string
- operator+(std::string const& lhs, Self const& rhs) {
+ friend std::string operator+(std::string const &lhs, Self const &rhs) {
return lhs + rhs.Value;
}
- friend std::string
- operator+(Self const& lhs, char const* rhs) {
+ friend std::string operator+(Self const &lhs, char const *rhs) {
return lhs.Value + rhs;
}
- friend std::string
- operator+(char const* lhs, Self const& rhs) {
+ friend std::string operator+(char const *lhs, Self const &rhs) {
return lhs + rhs.Value;
}
|
andrurogerz
force-pushed
the
clopt-string
branch
from
5748215 to
fc308a1
Compare
andrurogerz
changed the title
andrurogerz
force-pushed
the
clopt-string
branch
from
fc308a1 to
4ebd910
Compare
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Purpose
Specialize
llvm::cl::opt_storagefor data typestd::stringso that it no longer inherits fromstd::string. With this patch in place, explicitly instantiatedcl::opt<std::string>can be safely exported from an LLVM Windows DLL.Overview
cl::opt_storagefor data typestd::string. It does NOT inherit fromstd::stringas it did previously when data typestd::stringmatched the partially specified templatecl::opt_storage<DataType, false, true>std::string,llvm::StringRef, andllvm::Twineso that instances can be used in many places wherestd::stringis used.std::stringmethods so that instances of the class are mostly interoperable withstd::string.Tripleso it properly constructs fromcl::opt_storage<std::string>. This change avoids having to modify clients that constructTriples fromcl::opt<std::string>instances.Background
This patch is in support of annotating LLVM's public symbols for Windows DLL export., tracked in #109483. Additional context is provided in this discourse.
This change is needed because, without it, we cannot export
opt<std::string>from an LLVM Windows DLL. This is because MSVC exports all ancestor classes when exporting an instantiated template class. Since one ofopt's ancestor classes is its type argument (viaopt_storage), it is an ancestor ofstd::string. Therefore, if we exportopt<std::string>from the LLVM DLL, MSVC forcesstd::basic_stringto also be exported. This leads to duplicate symbol errors and generally seems like a bad idea. Compiling withclang-cldoes not exhibit this behavior.Validation
clandclang-cl.clangandgcc.