[compiler-rt][profile] Add initial support for WebAssembly/WASI

This patch adds initial support for WebAssembly/WASI to the profile
runtime library on the top of wasi-libc. This is a part of the ongoing
patch series to add coverage support for WebAssembly/WASI.

The patch includes the following changes:
* Add wasm32-wasi to the list of supported architectures/OSes.
* Exclude unsupported features for WASI: flock, madvise, uname.
* Enable some user-space emulation provided by wasi-libc: mmap, getpid

Author: kateinoigakukun

compiler-rt/cmake/Modules/AllSupportedArchDefs.cmake

@@ -77,7 +77,7 @@ set(ALL_HWASAN_SUPPORTED_ARCH ${X86_64} ${ARM64} ${RISCV64})
 set(ALL_MEMPROF_SUPPORTED_ARCH ${X86_64})
 set(ALL_PROFILE_SUPPORTED_ARCH ${X86} ${X86_64} ${ARM32} ${ARM64} ${PPC32} ${PPC64}
     ${MIPS32} ${MIPS64} ${S390X} ${SPARC} ${SPARCV9} ${HEXAGON}
-    ${RISCV32} ${RISCV64} ${LOONGARCH64})
+    ${RISCV32} ${RISCV64} ${LOONGARCH64} ${WASM32})
 set(ALL_CTX_PROFILE_SUPPORTED_ARCH ${X86_64})
 if (OS_NAME MATCHES "FreeBSD")
   set(ALL_TSAN_SUPPORTED_ARCH ${X86_64} ${MIPS64} ${ARM64})

compiler-rt/cmake/config-ix.cmake

@@ -822,7 +822,7 @@ else()
 endif()
 
 if (PROFILE_SUPPORTED_ARCH AND NOT LLVM_USE_SANITIZER AND
-    OS_NAME MATCHES "Darwin|Linux|FreeBSD|Windows|Android|Fuchsia|SunOS|NetBSD|AIX")
+    OS_NAME MATCHES "Darwin|Linux|FreeBSD|Windows|Android|Fuchsia|SunOS|NetBSD|AIX|WASI")
   set(COMPILER_RT_HAS_PROFILE TRUE)
 else()
   set(COMPILER_RT_HAS_PROFILE FALSE)

compiler-rt/lib/profile/CMakeLists.txt

@@ -38,6 +38,17 @@ int main() {
 
 " COMPILER_RT_TARGET_HAS_FCNTL_LCK)
 
+CHECK_CXX_SOURCE_COMPILES("
+#include <sys/file.h>
+
+int fd;
+int main() {
+  flock(fd, LOCK_EX);
+  return 0;
+}
+
+" COMPILER_RT_TARGET_HAS_FLOCK)
+
 CHECK_CXX_SOURCE_COMPILES("
 #include <sys/utsname.h>
 int main() {
@@ -93,6 +104,13 @@ if(FUCHSIA OR UNIX)
      -Wno-pedantic)
 endif()
 
+if(CMAKE_SYSTEM_NAME STREQUAL "WASI")
+  set(EXTRA_FLAGS
+      ${EXTRA_FLAGS}
+      -D_WASI_EMULATED_MMAN
+      -D_WASI_EMULATED_GETPID)
+endif()
+
 if(COMPILER_RT_TARGET_HAS_ATOMICS)
  set(EXTRA_FLAGS
      ${EXTRA_FLAGS}
@@ -105,6 +123,12 @@ if(COMPILER_RT_TARGET_HAS_FCNTL_LCK)
      -DCOMPILER_RT_HAS_FCNTL_LCK=1)
 endif()
 
+if(COMPILER_RT_TARGET_HAS_FLOCK)
+  set(EXTRA_FLAGS
+      ${EXTRA_FLAGS}
+      -DCOMPILER_RT_HAS_FLOCK=1)
+endif()
+
 if(COMPILER_RT_TARGET_HAS_UNAME)
  set(EXTRA_FLAGS
      ${EXTRA_FLAGS}

compiler-rt/lib/profile/GCDAProfiling.c

@@ -584,7 +584,7 @@ void llvm_reset_counters(void) {
   }
 }
 
-#if !defined(_WIN32)
+#if !defined(_WIN32) && !defined(__wasi__)
 COMPILER_RT_VISIBILITY
 pid_t __gcov_fork() {
   pid_t parent_pid = getpid();

compiler-rt/lib/profile/InstrProfilingPort.h

@@ -54,7 +54,7 @@
 #endif
 
 #define COMPILER_RT_MAX_HOSTLEN 128
-#ifdef __ORBIS__
+#if defined(__ORBIS__) || defined(__wasi__)
 #define COMPILER_RT_GETHOSTNAME(Name, Len) ((void)(Name), (void)(Len), (-1))
 #else
 #define COMPILER_RT_GETHOSTNAME(Name, Len) lprofGetHostName(Name, Len)

compiler-rt/lib/profile/InstrProfilingUtil.c

@@ -152,9 +152,11 @@ COMPILER_RT_VISIBILITY int lprofLockFd(int fd) {
     }
   }
   return 0;
-#else
+#elif defined(COMPILER_RT_HAS_FLOCK)
   flock(fd, LOCK_EX);
   return 0;
+#else
+  return 0;
 #endif
 }
 
@@ -177,9 +179,11 @@ COMPILER_RT_VISIBILITY int lprofUnlockFd(int fd) {
     }
   }
   return 0;
-#else
+#elif defined(COMPILER_RT_HAS_FLOCK)
   flock(fd, LOCK_UN);
   return 0;
+#else
+  return 0;
 #endif
 }
 
@@ -353,8 +357,8 @@ COMPILER_RT_VISIBILITY void lprofRestoreSigKill(void) {
 
 COMPILER_RT_VISIBILITY int lprofReleaseMemoryPagesToOS(uintptr_t Begin,
                                                        uintptr_t End) {
-#if defined(__ve__)
-  // VE doesn't support madvise.
+#if defined(__ve__) || defined(__wasi__)
+  // VE and WASI doesn't support madvise.
   return 0;
 #else
   size_t PageSize = getpagesize();