Author: jdevlieghere Date: Mon Apr 1 13:39:03 2019 New Revision: 357428 URL: http://llvm.org/viewvc/llvm-project?rev=357428&view=rev Log: [Process] Use early returns in Process::WriteMemory (NFC)
I found the code of Process::WriteMemory particularly hard to follow when reviewing Ismail's change in D60022. This simplifies the code and hopefully prevents similar oversights in the future. Differential revision: https://reviews.llvm.org/D60092 Modified: lldb/trunk/source/Target/Process.cpp Modified: lldb/trunk/source/Target/Process.cpp URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Target/Process.cpp?rev=357428&r1=357427&r2=357428&view=diff ============================================================================== --- lldb/trunk/source/Target/Process.cpp (original) +++ lldb/trunk/source/Target/Process.cpp Mon Apr 1 13:39:03 2019 @@ -2209,68 +2209,64 @@ size_t Process::WriteMemory(addr_t addr, // may have placed in our tasks memory. BreakpointSiteList bp_sites_in_range; + if (!m_breakpoint_site_list.FindInRange(addr, addr + size, bp_sites_in_range)) + return WriteMemoryPrivate(addr, buf, size, error); - if (m_breakpoint_site_list.FindInRange(addr, addr + size, - bp_sites_in_range)) { - // No breakpoint sites overlap - if (bp_sites_in_range.IsEmpty()) - return WriteMemoryPrivate(addr, buf, size, error); - else { - const uint8_t *ubuf = (const uint8_t *)buf; - uint64_t bytes_written = 0; - - bp_sites_in_range.ForEach([this, addr, size, &bytes_written, &ubuf, - &error](BreakpointSite *bp) -> void { - - if (error.Success()) { - addr_t intersect_addr; - size_t intersect_size; - size_t opcode_offset; - const bool intersects = bp->IntersectsRange( - addr, size, &intersect_addr, &intersect_size, &opcode_offset); - UNUSED_IF_ASSERT_DISABLED(intersects); - assert(intersects); - assert(addr <= intersect_addr && intersect_addr < addr + size); - assert(addr < intersect_addr + intersect_size && - intersect_addr + intersect_size <= addr + size); - assert(opcode_offset + intersect_size <= bp->GetByteSize()); - - // Check for bytes before this breakpoint - const addr_t curr_addr = addr + bytes_written; - if (intersect_addr > curr_addr) { - // There are some bytes before this breakpoint that we need to just - // write to memory - size_t curr_size = intersect_addr - curr_addr; - size_t curr_bytes_written = WriteMemoryPrivate( - curr_addr, ubuf + bytes_written, curr_size, error); - bytes_written += curr_bytes_written; - if (curr_bytes_written != curr_size) { - // We weren't able to write all of the requested bytes, we are - // done looping and will return the number of bytes that we have - // written so far. - if (error.Success()) - error.SetErrorToGenericError(); - } - } - // Now write any bytes that would cover up any software breakpoints - // directly into the breakpoint opcode buffer - ::memcpy(bp->GetSavedOpcodeBytes() + opcode_offset, - ubuf + bytes_written, intersect_size); - bytes_written += intersect_size; - } - }); - - if (bytes_written < size) - return bytes_written + WriteMemoryPrivate(addr + bytes_written, - ubuf + bytes_written, - size - bytes_written, error); - } - } else { + // No breakpoint sites overlap + if (bp_sites_in_range.IsEmpty()) return WriteMemoryPrivate(addr, buf, size, error); - } + + const uint8_t *ubuf = (const uint8_t *)buf; + uint64_t bytes_written = 0; + + bp_sites_in_range.ForEach([this, addr, size, &bytes_written, &ubuf, + &error](BreakpointSite *bp) -> void { + if (error.Fail()) + return; + + addr_t intersect_addr; + size_t intersect_size; + size_t opcode_offset; + const bool intersects = bp->IntersectsRange( + addr, size, &intersect_addr, &intersect_size, &opcode_offset); + UNUSED_IF_ASSERT_DISABLED(intersects); + assert(intersects); + assert(addr <= intersect_addr && intersect_addr < addr + size); + assert(addr < intersect_addr + intersect_size && + intersect_addr + intersect_size <= addr + size); + assert(opcode_offset + intersect_size <= bp->GetByteSize()); + + // Check for bytes before this breakpoint + const addr_t curr_addr = addr + bytes_written; + if (intersect_addr > curr_addr) { + // There are some bytes before this breakpoint that we need to just + // write to memory + size_t curr_size = intersect_addr - curr_addr; + size_t curr_bytes_written = + WriteMemoryPrivate(curr_addr, ubuf + bytes_written, curr_size, error); + bytes_written += curr_bytes_written; + if (curr_bytes_written != curr_size) { + // We weren't able to write all of the requested bytes, we are + // done looping and will return the number of bytes that we have + // written so far. + if (error.Success()) + error.SetErrorToGenericError(); + } + } + // Now write any bytes that would cover up any software breakpoints + // directly into the breakpoint opcode buffer + ::memcpy(bp->GetSavedOpcodeBytes() + opcode_offset, ubuf + bytes_written, + intersect_size); + bytes_written += intersect_size; + }); // Write any remaining bytes after the last breakpoint if we have any left - return 0; // bytes_written; + if (bytes_written < size) + bytes_written += + WriteMemoryPrivate(addr + bytes_written, ubuf + bytes_written, + size - bytes_written, error); + + return bytes_written; } size_t Process::WriteScalarToMemory(addr_t addr, const Scalar &scalar, _______________________________________________ lldb-commits mailing list lldb-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
