| //===-- sanitizer_coverage_win_sections.cc --------------------------------===// |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file defines delimiters for Sanitizer Coverage's section. It contains |
| // Windows specific tricks to coax the linker into giving us the start and stop |
| // addresses of a section, as ELF linkers can do, to get the size of certain |
| // arrays. According to https://msdn.microsoft.com/en-us/library/7977wcck.aspx |
| // sections with the same name before "$" are sorted alphabetically by the |
| // string that comes after "$" and merged into one section. We take advantage |
| // of this by putting data we want the size of into the middle (M) of a section, |
| // by using the letter "M" after "$". We get the start of this data (ie: |
| // __start_section_name) by making the start variable come at the start of the |
| // section (using the letter A after "$"). We do the same to get the end of the |
| // data by using the letter "Z" after "$" to make the end variable come after |
| // the data. Note that because of our technique the address of the start |
| // variable is actually the address of data that comes before our middle |
| // section. We also need to prevent the linker from adding any padding. Each |
| // technique we use for this is explained in the comments below. |
| //===----------------------------------------------------------------------===// |
| |
| #include "sanitizer_platform.h" |
| #if SANITIZER_WINDOWS |
| #include <stdint.h> |
| extern "C" { |
| // The Guard array and counter array should both be merged into the .data |
| // section to reduce the number of PE sections However, because PCTable is |
| // constant it should be merged with the .rdata section. |
| #pragma section(".SCOV$GA", read, write) // NOLINT |
| // Use align(1) to avoid adding any padding that will mess up clients trying to |
| // determine the start and end of the array. |
| __declspec(allocate(".SCOV$GA")) __declspec(align(1)) uint64_t |
| __start___sancov_guards = 0; |
| #pragma section(".SCOV$GZ", read, write) // NOLINT |
| __declspec(allocate(".SCOV$GZ")) __declspec(align(1)) uint64_t |
| __stop___sancov_guards = 0; |
| |
| #pragma section(".SCOV$CA", read, write) // NOLINT |
| __declspec(allocate(".SCOV$CA")) __declspec(align(1)) uint64_t |
| __start___sancov_cntrs = 0; |
| #pragma section(".SCOV$CZ", read, write) // NOLINT |
| __declspec(allocate(".SCOV$CZ")) __declspec(align(1)) uint64_t |
| __stop___sancov_cntrs = 0; |
| |
| #pragma comment(linker, "/MERGE:.SCOV=.data") |
| |
| // Use uint64_t so there won't be any issues if the linker tries to word align |
| // the pc array. |
| #pragma section(".SCOVP$A", read) // NOLINT |
| __declspec(allocate(".SCOVP$A")) __declspec(align(1)) uint64_t |
| __start___sancov_pcs = 0; |
| #pragma section(".SCOVP$Z", read) // NOLINT |
| __declspec(allocate(".SCOVP$Z")) __declspec(align(1)) uint64_t |
| __stop___sancov_pcs = 0; |
| |
| #pragma comment(linker, "/MERGE:.SCOVP=.rdata") |
| } |
| #endif // SANITIZER_WINDOWS |