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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 09:22:09 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 09:22:09 +0000 |
commit | 43a97878ce14b72f0981164f87f2e35e14151312 (patch) | |
tree | 620249daf56c0258faa40cbdcf9cfba06de2a846 /mozglue/misc/Printf.h | |
parent | Initial commit. (diff) | |
download | firefox-upstream.tar.xz firefox-upstream.zip |
Adding upstream version 110.0.1.upstream/110.0.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | mozglue/misc/Printf.h | 266 |
1 files changed, 266 insertions, 0 deletions
diff --git a/mozglue/misc/Printf.h b/mozglue/misc/Printf.h new file mode 100644 index 0000000000..3f4fa2c1bb --- /dev/null +++ b/mozglue/misc/Printf.h @@ -0,0 +1,266 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- + * vim: set ts=8 sts=2 et sw=2 tw=80: + * This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +/* Printf-like functions, with canned variants that malloc their result. */ + +#ifndef mozilla_Printf_h +#define mozilla_Printf_h + +/* +** API for PR printf like routines. +** +** These exist partly for historical reasons -- initially they were in +** NSPR, then forked in tree and modified in js/ -- but now the prime +** motivation is both closer control over the exact formatting (with +** one exception, see below) and also the ability to control where +** exactly the generated results are sent. +** +** It might seem that this could all be dispensed with in favor of a +** wrapper around |vsnprintf| -- except that this implementation +** guarantees that the %s format will accept a NULL pointer, whereas +** with standard functions this is undefined. +** +** This supports the following formats. It implements a subset of the +** standard formats; due to the use of MOZ_FORMAT_PRINTF, it is not +** permissible to extend the standard, aside from relaxing undefined +** behavior. +** +** %d - decimal +** %u - unsigned decimal +** %x - unsigned hex +** %X - unsigned uppercase hex +** %o - unsigned octal +** %hd, %hu, %hx, %hX, %ho - "short" versions of above +** %ld, %lu, %lx, %lX, %lo - "long" versions of above +** %lld, %llu, %llx, %llX, %llo - "long long" versions of above +** %zd, %zo, %zu, %zx, %zX - size_t versions of above +** %Id, %Io, %Iu, %Ix, %IX - size_t versions of above (for Windows compat). +** Note that MSVC 2015 and newer supports the z length modifier so +** users should prefer using %z instead of %I. We are supporting %I in +** addition to %z in case third-party code that uses %I gets routed to +** use this printf implementation. +** %s - string +** %S, %ls - wide string, that is wchar_t* +** %c - character +** %p - pointer (deals with machine dependent pointer size) +** %f - float; note that this is actually formatted using the +** system's native printf, and so the results may vary +** %g - float; note that this is actually formatted using the +** system's native printf, and so the results may vary +*/ + +#include "mozilla/AllocPolicy.h" +#include "mozilla/Assertions.h" +#include "mozilla/Attributes.h" +#include "mozilla/IntegerPrintfMacros.h" +#include "mozilla/Types.h" +#include "mozilla/UniquePtr.h" + +#include <stdarg.h> +#include <string.h> + +namespace mozilla { + +/* + * This class may be subclassed to provide a way to get the output of + * a printf-like call, as the output is generated. + */ +class PrintfTarget { + public: + /* The Printf-like interface. */ + bool MFBT_API print(const char* format, ...) MOZ_FORMAT_PRINTF(2, 3); + + /* The Vprintf-like interface. */ + bool MFBT_API vprint(const char* fmt, va_list) MOZ_FORMAT_PRINTF(2, 0); + + /* Fast paths for formatting integers as though by %d, %o, %u, or %x. + Since octal and hex formatting always treat numbers as unsigned, there + are no signed overloads for AppendInt{Oct,Hex}. */ + bool MFBT_API appendIntDec(int32_t); + bool MFBT_API appendIntDec(uint32_t); + bool MFBT_API appendIntOct(uint32_t); + bool MFBT_API appendIntHex(uint32_t); + bool MFBT_API appendIntDec(int64_t); + bool MFBT_API appendIntDec(uint64_t); + bool MFBT_API appendIntOct(uint64_t); + bool MFBT_API appendIntHex(uint64_t); + + inline size_t emitted() { return mEmitted; } + + protected: + MFBT_API PrintfTarget(); + virtual ~PrintfTarget() = default; + + /* Subclasses override this. It is called when more output is + available. It may be called with len==0. This should return + true on success, or false on failure. */ + virtual bool append(const char* sp, size_t len) = 0; + + private: + /* Number of bytes emitted so far. */ + size_t mEmitted; + + /* The implementation calls this to emit bytes and update + mEmitted. */ + bool emit(const char* sp, size_t len) { + mEmitted += len; + return append(sp, len); + } + + bool fill2(const char* src, int srclen, int width, int flags); + bool fill_n(const char* src, int srclen, int width, int prec, int type, + int flags); + bool cvt_l(long num, int width, int prec, int radix, int type, int flags, + const char* hexp); + bool cvt_ll(int64_t num, int width, int prec, int radix, int type, int flags, + const char* hexp); + bool cvt_f(double d, char c, int width, int prec, int flags); + bool cvt_s(const char* s, int width, int prec, int flags); +}; + +namespace detail { + +template <typename AllocPolicy = mozilla::MallocAllocPolicy> +struct AllocPolicyBasedFreePolicy { + void operator()(const void* ptr) { + AllocPolicy policy; + policy.free_(const_cast<void*>(ptr)); + } +}; + +} // namespace detail + +// The type returned by Smprintf and friends. +template <typename AllocPolicy> +using SmprintfPolicyPointer = + mozilla::UniquePtr<char, detail::AllocPolicyBasedFreePolicy<AllocPolicy>>; + +// The default type if no alloc policy is specified. +typedef SmprintfPolicyPointer<mozilla::MallocAllocPolicy> SmprintfPointer; + +// Used in the implementation of Smprintf et al. +template <typename AllocPolicy> +class MOZ_STACK_CLASS SprintfState final : private mozilla::PrintfTarget, + private AllocPolicy { + public: + explicit SprintfState(char* base) + : mMaxlen(base ? strlen(base) : 0), + mBase(base), + mCur(base ? base + mMaxlen : 0) {} + + ~SprintfState() { this->free_(mBase); } + + bool vprint(const char* format, va_list ap_list) MOZ_FORMAT_PRINTF(2, 0) { + // The "" here has a single \0 character, which is what we're + // trying to append. + return mozilla::PrintfTarget::vprint(format, ap_list) && append("", 1); + } + + SmprintfPolicyPointer<AllocPolicy> release() { + SmprintfPolicyPointer<AllocPolicy> result(mBase); + mBase = nullptr; + return result; + } + + protected: + bool append(const char* sp, size_t len) override { + ptrdiff_t off; + char* newbase; + size_t newlen; + + off = mCur - mBase; + if (off + len >= mMaxlen) { + /* Grow the buffer */ + newlen = mMaxlen + ((len > 32) ? len : 32); + newbase = this->template maybe_pod_malloc<char>(newlen); + if (!newbase) { + /* Ran out of memory */ + return false; + } + memcpy(newbase, mBase, mMaxlen); + this->free_(mBase); + mBase = newbase; + mMaxlen = newlen; + mCur = mBase + off; + } + + /* Copy data */ + memcpy(mCur, sp, len); + mCur += len; + MOZ_ASSERT(size_t(mCur - mBase) <= mMaxlen); + return true; + } + + private: + size_t mMaxlen; + char* mBase; + char* mCur; +}; + +/* +** sprintf into a malloc'd buffer. Return a pointer to the malloc'd +** buffer on success, nullptr on failure. Call AllocPolicy::free_ to release +** the memory returned. +*/ +template <typename AllocPolicy = mozilla::MallocAllocPolicy> +MOZ_FORMAT_PRINTF(1, 2) +SmprintfPolicyPointer<AllocPolicy> Smprintf(const char* fmt, ...) { + SprintfState<AllocPolicy> ss(nullptr); + va_list ap; + va_start(ap, fmt); + bool r = ss.vprint(fmt, ap); + va_end(ap); + if (!r) { + return nullptr; + } + return ss.release(); +} + +/* +** "append" sprintf into a malloc'd buffer. "last" is the last value of +** the malloc'd buffer. sprintf will append data to the end of last, +** growing it as necessary using realloc. If last is nullptr, SmprintfAppend +** will allocate the initial string. The return value is the new value of +** last for subsequent calls, or nullptr if there is a malloc failure. +*/ +template <typename AllocPolicy = mozilla::MallocAllocPolicy> +MOZ_FORMAT_PRINTF(2, 3) +SmprintfPolicyPointer<AllocPolicy> SmprintfAppend( + SmprintfPolicyPointer<AllocPolicy>&& last, const char* fmt, ...) { + SprintfState<AllocPolicy> ss(last.release()); + va_list ap; + va_start(ap, fmt); + bool r = ss.vprint(fmt, ap); + va_end(ap); + if (!r) { + return nullptr; + } + return ss.release(); +} + +/* +** va_list forms of the above. +*/ +template <typename AllocPolicy = mozilla::MallocAllocPolicy> +MOZ_FORMAT_PRINTF(1, 0) +SmprintfPolicyPointer<AllocPolicy> Vsmprintf(const char* fmt, va_list ap) { + SprintfState<AllocPolicy> ss(nullptr); + if (!ss.vprint(fmt, ap)) return nullptr; + return ss.release(); +} + +template <typename AllocPolicy = mozilla::MallocAllocPolicy> +MOZ_FORMAT_PRINTF(2, 0) +SmprintfPolicyPointer<AllocPolicy> VsmprintfAppend( + SmprintfPolicyPointer<AllocPolicy>&& last, const char* fmt, va_list ap) { + SprintfState<AllocPolicy> ss(last.release()); + if (!ss.vprint(fmt, ap)) return nullptr; + return ss.release(); +} + +} // namespace mozilla + +#endif /* mozilla_Printf_h */ |