disable custom page size support when using -fPIC

libc-bottom-half/headers/public/__macro_PAGESIZE.h

@@ -14,7 +14,9 @@
  * consideration. POSIX has deprecated `getpagesize` in favor of
  * `sysconf(_SC_PAGESIZE)` which does not have this problem.
  */
-#if __clang_major__ >= 22
+// FIXME(#778): `__wasm_first_page_end` is broken for PIC as of this writing and
+// will likely require `wasm-ld` changes, at which point we can re-enable it.
+#if __clang_major__ >= 22 && !defined __pic__
 extern char __wasm_first_page_end;
 #define PAGESIZE ((unsigned long)&__wasm_first_page_end)
 #else

test/CMakeLists.txt

@@ -52,21 +52,47 @@ function(add_wasilibc_flags target)
   endif()
 endfunction()
 
-add_library(libc_test_support STATIC
+function(add_wasilibc_shared_flags target)
+  add_dependencies(${target} sysroot builtins)
+  # Using an `INTERFACE` looks to get what we want here which is to rebuild this
+  # if the library changes but not actually add any arguments to the link-line.
+  target_link_libraries(${target} INTERFACE c)
+endfunction()
+
+function(add_library_pair name)
+  add_library(${name} STATIC ${ARGN})
+
+  if (NOT TARGET_TRIPLE MATCHES "-threads")
+    add_library(${name}_shared SHARED ${ARGN})
+    set_pic(${name}_shared)
+  endif()
+endfunction()
+
+add_library_pair(libc_test_support
   "${LIBC_TEST}/src/common/path.c"
   "${LIBC_TEST}/src/common/print.c"
   "${LIBC_TEST}/src/common/rand.c"
   "${LIBC_TEST}/src/common/utf8.c"
 )
-target_include_directories(libc_test_support PUBLIC "${LIBC_TEST}/src/common")
-add_wasilibc_flags(libc_test_support)
-# Disable some warnings in this third-party code
-target_compile_options(libc_test_support PRIVATE
-  -Wno-unused-variable
-  -Wno-unused-parameter
-  -Wno-unused-function
-  -Wno-sign-compare
-)
+
+function(configure_libc_test_support suffix)
+  # Disable some warnings in this third-party code
+  target_include_directories(libc_test_support${suffix} PUBLIC "${LIBC_TEST}/src/common")
+  cmake_language(CALL add_wasilibc${suffix}_flags libc_test_support${suffix})
+  target_compile_options(libc_test_support${suffix} PRIVATE
+    -Wno-unused-variable
+    -Wno-unused-parameter
+    -Wno-unused-function
+    -Wno-sign-compare
+  )
+endfunction()
+
+configure_libc_test_support("")
+
+if (NOT TARGET_TRIPLE MATCHES "-threads")
+    configure_libc_test_support("_shared")
+    target_compile_options(libc_test_support_shared PRIVATE -fvisibility=default)
+endif()
 
 # Adds a new test executable to build
 #
@@ -83,7 +109,7 @@ function(add_test_executable executable_name src)
   set(multiValueArgs LDFLAGS CFLAGS)
   cmake_parse_arguments(PARSE_ARGV 1 arg "${options}" "${oneValueArgs}" "${multiValueArgs}")
 
-  # Build the test exeutable itself and apply all custom options as applicable.
+  # Build the test executable itself and apply all custom options as applicable.
   add_executable(${executable_name} ${src})
   clang_format_target(${executable_name})
   add_wasilibc_flags(${executable_name})
@@ -352,6 +378,38 @@ if (TARGET_TRIPLE MATCHES "-threads")
   target_compile_options(pthread_mutex_busywait.wasm PRIVATE -Wno-unused-variable)
 endif()
 
+# ========= shared library tests ================================
+
+function(add_wasilibc_shared_test test_file)
+  cmake_path(REPLACE_EXTENSION test_file so OUTPUT_VARIABLE test_library)
+  cmake_path(REPLACE_EXTENSION test_file wasm OUTPUT_VARIABLE test_name)
+  set(test_file "${CMAKE_CURRENT_SOURCE_DIR}/src/${test_file}")
+
+  add_library(${test_library} SHARED ${test_file})
+  set_pic(${test_library})
+  target_link_libraries(${test_library} PRIVATE libc_test_support_shared)
+  # Here we embed the component type custom section into `${test_library}` using
+  # `wasm-tools component embed`, then generate the `${test_name}` file by
+  # linking `${test_library}`, `liblibc_test_support_shared.so`, and `libc.so`
+  # together using `wasm-tools component link`.
+  add_custom_command(
+    TARGET ${test_library}
+    POST_BUILD
+    COMMAND ${wasm_tools} component embed --world wasi:cli/command "${CMAKE_CURRENT_SOURCE_DIR}/../wasi/p2/wit" $<TARGET_FILE:${test_library}> -o $<TARGET_FILE:${test_library}>
+    COMMAND ${wasm_tools} component link $<TARGET_FILE:${test_library}> "${SYSROOT_LIB}/libc.so" $<TARGET_FILE:libc_test_support_shared> -o ${test_name}
+    DEPENDS wasm_tools engine
+  )
+
+  add_test(
+    NAME "${test_name}"
+    COMMAND ${ENGINE} ${test_name}
+  )
+endfunction()
+
+if (WASI STREQUAL "p2")
+  add_wasilibc_shared_test(malloc-shared.c)
+endif()
+
 # ========= sockets-related tests ===============================
 
 if (NOT (WASI STREQUAL "p1"))

test/src/malloc-shared.c

@@ -0,0 +1,17 @@
+#include "test.h"
+#include <stdbool.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <__macro_PAGESIZE.h>
+
+__attribute__((__export_name__("wasi:cli/run@0.2.0#run")))
+bool exports_wasi_cli_run_run(void) {
+    void* p = malloc(7777777);
+    if (p == NULL) {
+        t_error("malloc failed\n");
+    } else {
+        free(p);
+    }
+
+    return t_status != 0;
+}