This change enables compatibility for measuring code coverage with Clang versions 14 through 20 by supporting their respective raw profile formats.
1- Add support for LLVM raw profile versions 8, 9, and 10 2- Initialized llvm_profile_header for all versions based on llvm source code in `compiler-rt/include/profile/InstrProfData.inc` for each version. 3- We tested this patch for all clang versions from 14 through 20 on both ARM and X86 platform Signed-off-by: Saman Dehghan <[email protected]> --- xen/common/coverage/llvm.c | 78 +++++++++++++++++++++++++++----------- xen/include/xen/types.h | 1 + 2 files changed, 57 insertions(+), 22 deletions(-) diff --git a/xen/common/coverage/llvm.c b/xen/common/coverage/llvm.c index 517b2aa8c2..f92f10654c 100644 --- a/xen/common/coverage/llvm.c +++ b/xen/common/coverage/llvm.c @@ -44,27 +44,55 @@ ((uint64_t)'f' << 16) | ((uint64_t)'R' << 8) | ((uint64_t)129) #endif -#define LLVM_PROFILE_VERSION 4 +#if __clang_major__ >= 19 +#define LLVM_PROFILE_VERSION 10 +#define LLVM_PROFILE_NUM_KINDS 3 +#elif __clang_major__ == 18 +#define LLVM_PROFILE_VERSION 9 #define LLVM_PROFILE_NUM_KINDS 2 +#elif __clang_major__ >= 14 +#define LLVM_PROFILE_VERSION 8 +#define LLVM_PROFILE_NUM_KINDS 2 +#else +#error "Unsupported Clang version" +#endif struct llvm_profile_data { uint64_t name_ref; uint64_t function_hash; - void *counter; - void *function; - void *values; + intptr_t *relative_counter; +#if __clang_major__ >= 18 + intptr_t *relative_bitmap; +#endif + intptr_t *function; + intptr_t *values; uint32_t nr_counters; uint16_t nr_value_sites[LLVM_PROFILE_NUM_KINDS]; +#if __clang_major__ >= 18 + uint32_t numbitmap_bytes; +#endif }; struct llvm_profile_header { uint64_t magic; uint64_t version; - uint64_t data_size; - uint64_t counters_size; + uint64_t binary_ids_size; + uint64_t num_data; + uint64_t padding_bytes_before_counters; + uint64_t num_counters; + uint64_t padding_bytes_after_counters; + uint64_t num_bitmap_bytes; + uint64_t padding_bytes_after_bitmap_bytes; uint64_t names_size; +#if __clang_major__ >= 18 uint64_t counters_delta; + uint64_t bitmap_delta; +#endif uint64_t names_delta; +#if __clang_major__ >= 19 + uint64_t num_vtables; + uint64_t vnames_size; +#endif uint64_t value_kind_last; }; @@ -76,19 +104,20 @@ struct llvm_profile_header { */ int __llvm_profile_runtime; -extern const struct llvm_profile_data __start___llvm_prf_data[]; -extern const struct llvm_profile_data __stop___llvm_prf_data[]; -extern const char __start___llvm_prf_names[]; -extern const char __stop___llvm_prf_names[]; -extern uint64_t __start___llvm_prf_cnts[]; -extern uint64_t __stop___llvm_prf_cnts[]; +extern char __start___llvm_prf_data[]; +extern char __stop___llvm_prf_data[]; +extern char __start___llvm_prf_names[]; +extern char __stop___llvm_prf_names[]; +extern char __start___llvm_prf_cnts[]; +extern char __stop___llvm_prf_cnts[]; + +#define START_DATA ((const char *)__start___llvm_prf_data) +#define END_DATA ((const char *)__stop___llvm_prf_data) +#define START_NAMES ((const char *)__start___llvm_prf_names) +#define END_NAMES ((const char *)__stop___llvm_prf_names) +#define START_COUNTERS ((char *)__start___llvm_prf_cnts) +#define END_COUNTERS ((char *)__stop___llvm_prf_cnts) -#define START_DATA ((const void *)__start___llvm_prf_data) -#define END_DATA ((const void *)__stop___llvm_prf_data) -#define START_NAMES ((const void *)__start___llvm_prf_names) -#define END_NAMES ((const void *)__stop___llvm_prf_names) -#define START_COUNTERS ((void *)__start___llvm_prf_cnts) -#define END_COUNTERS ((void *)__stop___llvm_prf_cnts) static void cf_check reset_counters(void) { @@ -107,10 +136,15 @@ static int cf_check dump( struct llvm_profile_header header = { .magic = LLVM_PROFILE_MAGIC, .version = LLVM_PROFILE_VERSION, - .data_size = (END_DATA - START_DATA) / sizeof(struct llvm_profile_data), - .counters_size = (END_COUNTERS - START_COUNTERS) / sizeof(uint64_t), - .names_size = END_NAMES - START_NAMES, - .counters_delta = (uintptr_t)START_COUNTERS, + .binary_ids_size = 0, + .num_data = (((intptr_t)END_DATA + sizeof(struct llvm_profile_data) - 1) + - (intptr_t)START_DATA) / sizeof(struct llvm_profile_data), + .padding_bytes_before_counters = 0, + .num_counters = (((intptr_t)END_COUNTERS + sizeof(uint64_t) - 1) + - (intptr_t)START_COUNTERS) / sizeof(uint64_t), + .padding_bytes_after_counters = 0, + .names_size = (END_NAMES - START_NAMES) * sizeof(char), + .counters_delta = (uintptr_t)START_COUNTERS - (uintptr_t)START_DATA, .names_delta = (uintptr_t)START_NAMES, .value_kind_last = LLVM_PROFILE_NUM_KINDS - 1, }; diff --git a/xen/include/xen/types.h b/xen/include/xen/types.h index 73ddccbbd5..799bfe0b95 100644 --- a/xen/include/xen/types.h +++ b/xen/include/xen/types.h @@ -18,6 +18,7 @@ typedef signed long ssize_t; typedef __PTRDIFF_TYPE__ ptrdiff_t; typedef __UINTPTR_TYPE__ uintptr_t; +typedef __INTPTR_TYPE__ intptr_t; /* * Users of this macro are expected to pass a positive value. -- 2.49.0 On Mon, Sep 15, 2025 at 11:56 AM Saman Dehghan <[email protected]> wrote: > This patch updates the LLVM profile raw format in > `xen/common/coverage/llvm.c` from version 4 to version 10, > enabling compatibility with LLVM versions 19 and 20. > While the patch supports only one version: > 1. It seems better to support one version than no version -- > the current profile version 4 is not compatible with > LLVM version 11 or later > 2. The patch could be extended to support multiple > LLVM profile versions, e.g., from 5 to 10 > > The llvm-cov toolchain, with its Source-based Code Coverage, > offers two substantial advantages over gcov: > - More accurate coverage reporting when compiler optimizations > are enabled, ensuring better analysis of optimized code. > - Better tracking of coverage across inlined function boundaries, > critical for complex control flows in Xen. > > Overall, this change would enhance Xen's code coverage analysis > capabilities by leveraging the latest LLVM toolchain improvements, > particularly for safety-critical hypervisor code. > > The patch modifies only `xen/common/coverage/llvm.c`, > maintaining API compatibility while enabling modern toolchain support. > Testing was performed with LLVM 19 and 20 to confirm functionality. > > --- > xen/common/coverage/llvm.c | 22 ++++++++++++++++------ > 1 file changed, 16 insertions(+), 6 deletions(-) > > diff --git a/xen/common/coverage/llvm.c b/xen/common/coverage/llvm.c > index 517b2aa8c2..3da82c6cda 100644 > --- a/xen/common/coverage/llvm.c > +++ b/xen/common/coverage/llvm.c > @@ -44,27 +44,37 @@ > ((uint64_t)'f' << 16) | ((uint64_t)'R' << 8) | ((uint64_t)129) > #endif > > -#define LLVM_PROFILE_VERSION 4 > -#define LLVM_PROFILE_NUM_KINDS 2 > +#define LLVM_PROFILE_VERSION 10 > +#define LLVM_PROFILE_NUM_KINDS 3 > > struct llvm_profile_data { > uint64_t name_ref; > uint64_t function_hash; > - void *counter; > + void *relative_counter; > + void *relative_bitmap; > void *function; > void *values; > uint32_t nr_counters; > uint16_t nr_value_sites[LLVM_PROFILE_NUM_KINDS]; > + uint32_t numbitmap_bytes; > }; > > struct llvm_profile_header { > uint64_t magic; > uint64_t version; > - uint64_t data_size; > - uint64_t counters_size; > + uint64_t binary_ids_size; > + uint64_t num_data; > + uint64_t padding_bytes_before_counters; > + uint64_t num_counters; > + uint64_t padding_bytes_after_counters; > + uint64_t num_bitmap_bytes; > + uint64_t padding_bytes_after_bitmap_bytes; > uint64_t names_size; > uint64_t counters_delta; > + uint64_t bitmap_delta; > uint64_t names_delta; > + uint64_t num_vtables; > + uint64_t vnames_size; > uint64_t value_kind_last; > }; > > @@ -110,7 +120,7 @@ static int cf_check dump( > .data_size = (END_DATA - START_DATA) / sizeof(struct > llvm_profile_data), > .counters_size = (END_COUNTERS - START_COUNTERS) / > sizeof(uint64_t), > .names_size = END_NAMES - START_NAMES, > - .counters_delta = (uintptr_t)START_COUNTERS, > + .counters_delta = (uintptr_t)(START_COUNTERS - START_DATA), > .names_delta = (uintptr_t)START_NAMES, > .value_kind_last = LLVM_PROFILE_NUM_KINDS - 1, > }; > -- > 2.49.0 > >
