adding emscripten build test (#710)

* adding emscripten build test

* minor fixes

* better guarding

* lint

Author: lemire

.github/workflows/emscripten.yml

@@ -0,0 +1,19 @@
+name: emscripten
+
+on: [push, pull_request]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4.4.0
+      - uses: mymindstorm/setup-emsdk@6ab9eb1bda2574c4ddb79809fc9247783eaf9021 # v14
+      - name: Verify
+        run: emcc -v
+      - name: Checkout
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v3.6.0
+      - name: Configure
+        run: emcmake cmake -B build
+      - name: Build # We build but do not test 
+        run: cmake --build build

CMakeLists.txt

@@ -108,15 +108,15 @@ configure_file ("${CMAKE_CURRENT_SOURCE_DIR}/tests/config.h.in"
 #################################
 
 add_subdirectory(src)
-if(ENABLE_ROARING_TESTS)
+if(ENABLE_ROARING_TESTS AND NOT EMSCRIPTEN)
   if(CMAKE_SIZEOF_VOID_P EQUAL 8) # we only include the benchmarks on 64-bit systems.
     add_subdirectory(benchmarks)
   endif()
   add_subdirectory(tests)
 endif()
 find_program(BASH bash)
 
-if(ENABLE_ROARING_TESTS AND BASH)
+if(ENABLE_ROARING_TESTS AND BASH AND NOT EMSCRIPTEN)
   message(STATUS "Amalgamation tests enabled")
   set(CROARING_SINGLEHEADER_FILES
     ${CMAKE_CURRENT_BINARY_DIR}/amalgamation_demo.c

cpp/roaring64map.hh

@@ -11,6 +11,7 @@
 
 #include <algorithm>
 #include <cinttypes>  // PRIu64 macro
+#include <climits>    // for UINT64_MAX
 #include <cstdarg>    // for va_list handling in bitmapOf()
 #include <cstdio>     // for std::printf() in the printf() method
 #include <cstring>    // for std::memcpy()
@@ -781,6 +782,9 @@ class Roaring64Map {
      * Returns true if the bitmap is full (cardinality is max uint64_t + 1).
      */
     bool isFull() const {
+        // This function is somewhat absurd. A full 64-bit bitmap would surely
+        // exceed our memory limits.
+#if SIZE_MAX >= UINT64_MAX
         // only bother to check if map is fully saturated
         //
         // we put std::numeric_limits<>::max/min in parentheses
@@ -793,6 +797,11 @@ class Roaring64Map {
                                      return roaring_map_entry.second.isFull();
                                  })
                    : false;
+#else
+        // if SIZE_MAX < UINT64_MAX, then we cannot represent a full bitmap
+        // in a 64-bit integer, so we return false.
+        return false;
+#endif
     }
 
     /**

src/containers/run.c

@@ -157,7 +157,7 @@ void run_container_offset(const run_container_t *c, container_t **loc,
         lo = run_container_create_given_capacity(lo_cap);
         memcpy(lo->runs, c->runs, lo_cap * sizeof(rle16_t));
         lo->n_runs = lo_cap;
-        for (int i = 0; i < lo_cap; ++i) {
+        for (unsigned int i = 0; i < lo_cap; ++i) {
             lo->runs[i].value += offset;
         }
         *loc = (container_t *)lo;
@@ -167,7 +167,7 @@ void run_container_offset(const run_container_t *c, container_t **loc,
         hi = run_container_create_given_capacity(hi_cap);
         memcpy(hi->runs, c->runs + pivot, hi_cap * sizeof(rle16_t));
         hi->n_runs = hi_cap;
-        for (int i = 0; i < hi_cap; ++i) {
+        for (unsigned int i = 0; i < hi_cap; ++i) {
             hi->runs[i].value += offset;
         }
         *hic = (container_t *)hi;

tools/cmake/FindCTargets.cmake

@@ -1,6 +1,6 @@
 include(${PROJECT_SOURCE_DIR}/tools/cmake/Import.cmake)
 set(BUILD_STATIC_LIB ON)
-if (ENABLE_ROARING_TESTS)
+if (ENABLE_ROARING_TESTS AND NOT EMSCRIPTEN)
   if(ROARING_USE_CPM)
     CPMAddPackage(
       NAME cmocka