mimalloc is a compact general purpose allocator with excellent performance.
This report summarizes scanner evidence for microsoft/mimalloc, a C project with 13,445 GitHub stars. SynthScan examined 55,913 lines of code across 261 source files, recording 254 pattern matches distributed across 6 syntactic categories. The legacy adjusted pattern signal is 5.8 (Moderate pattern signal); it is not an authorship estimate.
Use the findings to ask whether maintainers can explain intent, verify dependencies, simplify unnecessary scaffolding, and focus review effort. Risk Payload v1 adds ownership, supply-chain, over-engineering, and review-effort vectors when available. These are prompts for human verification, not probabilities, security findings, or measured maintenance costs.
Use each vector to guide manual verification of the underlying findings.
Can maintainers explain intent, assumptions, and trade-offs? 220 finding(s).
Are imports declared and package/API names verified? 2 finding(s).
Are wrappers, guards, and repeated structures necessary? 32 finding(s).
Which changes need focused human review? 254 finding(s).
This chart tracks the legacy adjusted pattern score across scan runs. Changes can reflect source changes, scan coverage, or detector/scoring versions; they do not measure AI adoption or prove that a team refactored code. Compare runs only when their scoring versions are compatible. The dashed line tracks the raw pattern-hit count.
Groups findings by configured severity weight. Severity is not a confidence estimate, security rating, or proof that a package is missing. Verify imports against the project's manifests and inspect each finding in its local design context.
This horizontal bar chart shows where configured pattern scores accumulate across directories. Treat the bars as locations to inspect, not as evidence of authorship or code quality. Use the file-level findings to decide whether a directory needs a focused ownership, dependency, complexity, or review check.
The scanner identified 254 distinct pattern matches across 6 syntactic categories. Each entry below represents a discrete location in the source code where the engine recorded a detector match to inspect in context. Expand any category row to inspect the individual file paths, line numbers, code snippets, and the lexical context (CODE, COMMENT, or STRING) in which each match was detected.
Reading the findings table: The Severity column indicates the configured finding weight (CRITICAL / HIGH / MEDIUM / LOW). The Context column identifies whether the match occurred inside executable code, an inline comment, or a string literal — legacy comment-context matches receive a ×1.5 score weight. The ⚡ bolt icon marks clustered matches: three or more patterns within a 10-line window, each receiving an additional ×1.5 density multiplier under the legacy scoring model.
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW | test/main-override.cpp | 1 | #include <stdlib.h> | COMMENT |
| LOW | test/test-stress.c | 21 | #include <stdbool.h> | COMMENT |
| LOW | test/test-stress.c | 81 | COMMENT | |
| LOW | test/test-stress.c | 101 | #define custom_free(p) mi_free(p) | COMMENT |
| LOW | test/test-stress.c | 441 | COMMENT | |
| LOW | test/main-static.cpp | 1 | #include <stdlib.h> | COMMENT |
| LOW | test/main-override-static.c | 41 | mi_stats_reset(); | COMMENT |
| LOW | test/main-override-static.c | 341 | #endif | COMMENT |
| LOW | test/test-api.c | 21 | we therefore test the API over various inputs. Please add more tests :-) | COMMENT |
| LOW | test/test-api.c | 641 | // --------------------------------------------------- | COMMENT |
| LOW | include/mimalloc.h | 1 | /* ---------------------------------------------------------------------------- | COMMENT |
| LOW | include/mimalloc.h | 21 | #define mi_attr_noexcept throw() | COMMENT |
| LOW | include/mimalloc.h | 41 | #define mi_decl_export | COMMENT |
| LOW | include/mimalloc.h | 61 | #define mi_attr_alloc_align(p) | COMMENT |
| LOW | include/mimalloc.h | 81 | #define mi_attr_alloc_size2(s1,s2) __attribute__((alloc_size(s1,s2))) | COMMENT |
| LOW | include/mimalloc.h | 161 | mi_decl_nodiscard mi_decl_export void* mi_realloc_aligned_at(void* p, size_t newsize, size_t alignment, size_t offset) m | COMMENT |
| LOW | include/mimalloc.h | 401 | // ------------------------------------------------------ | COMMENT |
| LOW | include/mimalloc.h | 621 | assert(p!=NULL); | COMMENT |
| LOW | include/mimalloc-stats.h | 1 | /* ---------------------------------------------------------------------------- | COMMENT |
| LOW | include/mimalloc-override.h | 21 | #define malloc(n) mi_malloc(n) | COMMENT |
| LOW | include/mimalloc-override.h | 41 | COMMENT | |
| LOW | include/mimalloc-override.h | 61 | #define _aligned_recalloc(p,c,n,a) mi_aligned_recalloc(p,c,n,a) | COMMENT |
| LOW | include/mimalloc-new-delete.h | 1 | /* ---------------------------------------------------------------------------- | COMMENT |
| LOW | include/mimalloc-new-delete.h | 21 | #if defined(__cplusplus) | COMMENT |
| LOW | include/mimalloc/internal.h | 21 | // -------------------------------------------------------------------------- | COMMENT |
| LOW | include/mimalloc/internal.h | 41 | #define mi_decl_hidden | COMMENT |
| LOW | include/mimalloc/internal.h | 61 | #define mi_assume_aligned(p,sz) __builtin_assume_aligned(p,sz) | COMMENT |
| LOW | include/mimalloc/internal.h | 81 | #define mi_decl_hidden | COMMENT |
| LOW | include/mimalloc/internal.h | 101 | #else | COMMENT |
| LOW | include/mimalloc/internal.h | 361 | // use our own assertion to print without memory allocation | COMMENT |
| LOW | include/mimalloc/internal.h | 421 | #define mi_subproc_stat_decrease(subproc,stat,amount) __mi_stat_decrease_mt( &(subproc)->stats.stat, amount) | COMMENT |
| LOW | include/mimalloc/internal.h | 441 | COMMENT | |
| LOW | include/mimalloc/internal.h | 501 | ----------------------------------------------------------- */ | COMMENT |
| LOW | include/mimalloc/internal.h | 601 | COMMENT | |
| LOW | include/mimalloc/internal.h | 1201 | #define MI_SAMPLE_RATE_MAX (SIZE_MAX/4) | COMMENT |
| LOW | include/mimalloc/types.h | 1 | /* ---------------------------------------------------------------------------- | COMMENT |
| LOW | include/mimalloc/types.h | 21 | // mi_tld_t : thread local data | COMMENT |
| LOW | include/mimalloc/types.h | 41 | COMMENT | |
| LOW | include/mimalloc/types.h | 61 | // Define MI_SECURE to enable security mitigations | COMMENT |
| LOW | include/mimalloc/types.h | 81 | #endif | COMMENT |
| LOW | include/mimalloc/types.h | 101 | #endif | COMMENT |
| LOW | include/mimalloc/types.h | 121 | #endif | COMMENT |
| LOW | include/mimalloc/types.h | 141 | #if MI_SECURE>=4 || MI_PADDING || (MI_FREE_IS_CHECKED && MI_FREE_USE_PAGEMAP) | COMMENT |
| LOW | include/mimalloc/types.h | 161 | #define MI_PAGE_META_IS_SEPARATED 1 | COMMENT |
| LOW | include/mimalloc/types.h | 181 | #if !defined(MI_PAGE_META_SMALL_IS_ALIGNED) | COMMENT |
| LOW | include/mimalloc/types.h | 201 | #if MI_DEBUG && NDEBUG | COMMENT |
| LOW | include/mimalloc/types.h | 221 | #error Arena slices should be at least 8KiB | COMMENT |
| LOW | include/mimalloc/types.h | 241 | COMMENT | |
| LOW | include/mimalloc/types.h | 261 | // We never allocate more than PTRDIFF_MAX (see also <https://sourceware.org/ml/libc-announce/2019/msg00001.html>) | COMMENT |
| LOW | include/mimalloc/types.h | 281 | COMMENT | |
| LOW | include/mimalloc/types.h | 401 | COMMENT | |
| LOW | include/mimalloc/types.h | 441 | // Each page has three list of free blocks: | COMMENT |
| LOW | include/mimalloc/types.h | 501 | COMMENT | |
| LOW | include/mimalloc/types.h | 521 | #define MI_LARGE_MAX_OBJ_WSIZE (MI_LARGE_MAX_OBJ_SIZE/MI_SIZE_SIZE) | COMMENT |
| LOW | include/mimalloc/types.h | 561 | // (making them thread-local avoids atomic operations) | COMMENT |
| LOW | include/mimalloc/types.h | 841 | #endif | COMMENT |
| LOW | include/mimalloc/types.h | 861 | #define MI_DEBUG_FREED (0xDF) | COMMENT |
| LOW | include/mimalloc/track.h | 41 | #define mi_track_mem_undefined(p,size) | COMMENT |
| LOW | include/mimalloc/track.h | 61 | #define mi_track_mem_noaccess(p,size) VALGRIND_MAKE_MEM_NOACCESS(p,size) | COMMENT |
| LOW | include/mimalloc/track.h | 81 | #define MI_TRACK_ENABLED 1 | COMMENT |
| 157 more matches not shown… | ||||
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| MEDIUM | CMakeLists.txt | 165 | # ----------------------------------------------------------------------------- | COMMENT |
| MEDIUM | CMakeLists.txt | 167 | # ----------------------------------------------------------------------------- | COMMENT |
| MEDIUM | CMakeLists.txt | 242 | # ----------------------------------------------------------------------------- | COMMENT |
| MEDIUM | CMakeLists.txt | 244 | # ----------------------------------------------------------------------------- | COMMENT |
| MEDIUM | CMakeLists.txt | 274 | # ----------------------------------------------------------------------------- | COMMENT |
| MEDIUM | CMakeLists.txt | 276 | # ----------------------------------------------------------------------------- | COMMENT |
| MEDIUM | CMakeLists.txt | 905 | # ----------------------------------------------------------------------------- | COMMENT |
| MEDIUM | CMakeLists.txt | 907 | # ----------------------------------------------------------------------------- | COMMENT |
| MEDIUM | CMakeLists.txt | 990 | # ----------------------------------------------------------------------------- | COMMENT |
| MEDIUM | CMakeLists.txt | 992 | # ----------------------------------------------------------------------------- | COMMENT |
| MEDIUM | CMakeLists.txt | 1140 | # ----------------------------------------------------------------------------- | COMMENT |
| MEDIUM | CMakeLists.txt | 1142 | # ----------------------------------------------------------------------------- | COMMENT |
| MEDIUM | CMakeLists.txt | 1208 | # ----------------------------------------------------------------------------- | COMMENT |
| MEDIUM | CMakeLists.txt | 1210 | # ----------------------------------------------------------------------------- | COMMENT |
| MEDIUM | azure-pipelines.yml | 196 | # ---------------------------------------------------------- | COMMENT |
| MEDIUM | azure-pipelines.yml | 198 | # ---------------------------------------------------------- | COMMENT |
| MEDIUM⚡ | bin/bundle.sh | 3 | #----------------------------------------------------------------------------- | COMMENT |
| MEDIUM⚡ | bin/bundle.sh | 5 | #----------------------------------------------------------------------------- | COMMENT |
| MEDIUM⚡ | bin/bundle.sh | 12 | #--------------------------------------------------------- | COMMENT |
| MEDIUM⚡ | bin/bundle.sh | 14 | #--------------------------------------------------------- | COMMENT |
| MEDIUM | bin/bundle.sh | 36 | #--------------------------------------------------------- | COMMENT |
| MEDIUM | bin/bundle.sh | 38 | #--------------------------------------------------------- | COMMENT |
| MEDIUM | bin/bundle.sh | 52 | #--------------------------------------------------------- | COMMENT |
| MEDIUM | bin/bundle.sh | 54 | #--------------------------------------------------------- | COMMENT |
| MEDIUM | bin/bundle.sh | 87 | #--------------------------------------------------------- | COMMENT |
| MEDIUM | bin/bundle.sh | 89 | #--------------------------------------------------------- | COMMENT |
| MEDIUM | bin/bundle.sh | 121 | #--------------------------------------------------------- | COMMENT |
| MEDIUM | bin/bundle.sh | 123 | #--------------------------------------------------------- | COMMENT |
| MEDIUM | bin/bundle.sh | 152 | #--------------------------------------------------------- | COMMENT |
| MEDIUM | bin/bundle.sh | 154 | #--------------------------------------------------------- | COMMENT |
| MEDIUM | bin/bundle.sh | 209 | #--------------------------------------------------------- | COMMENT |
| MEDIUM | bin/bundle.sh | 211 | #--------------------------------------------------------- | COMMENT |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| CRITICAL | docs/jquery.js | 2 | !function(e,t){"use strict";"object"==typeof module&&"object"==typeof module.exports?module.exports=e.document?t(e,!0):f | CODE |
| CRITICAL | docs/jquery.js | 8 | !function(t){"use strict";"function"==typeof define&&define.amd?define(["jquery"],t):t(jQuery)}(function(y){"use strict" | CODE |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| MEDIUM | .github/workflows/release.yaml | 46 | # Create a release: https://github.com/softprops/action-gh-release (MIT license) | COMMENT |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| MEDIUM | src/prim/osx/alloc-override-zone.c | 433 | // it seems less robust than using interpose. | COMMENT |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW | src/options.c | 637 | // TODO: implement ourselves to reduce dependencies on the C runtime | COMMENT |