maybe using valgrind gives another output that could help ?

the latest code has fixes for big-endian arch. Try to pull and check again, please

LD is not used anymore by meson. It's now CC_LD and CXX_LD.

in machines.c, host_machine and build_machine are the same. So for example, on my Windows 10 64 bits, even if i run the 32 bits Visual Studio prompt (where cl.exe is the 32 bits one), host_machine.address_bits is 64

strlen() is declared in string.h :

../include/lang/string.h:18:38: warning: implicit declaration of function 'strlen' [-Wimplicit-function-declaration]

this would avoid including <string.h> in files including include/lang/string.h

since the latest big change in code, this document is out of date

in compilers.c, guess_version() returns a char* which is always defined, so the test line 249 is useless

currently, I pass the standard to /std: whatever the standard is. Meson is passing it only if it is c11 or c17 (see https://github.com/mesonbuild/meson/blob/master/mesonbuild/compilers/c.py#L477). Should I do the same for muon ?

here are the warnings that I get with cl.exe when using bootstrap.bat

C:\Documents\msys2\home\vincent.torri\gitroot_64\muon_github>bootstrap.bat build
amalgam.c
C:\Documents\msys2\home\vincent.torri\gitroot_64\muon_github\src\backend/common_args.c(441): warning C4113: 'iteration_result (__cdecl *)(workspace *,void *,compiler_language,obj)' est différent de 'obj_dict_iterator' dans les listes de paramètres
C:\Documents\msys2\home\vincent.torri\gitroot_64\muon_github\src\backend/ninja/rules.c(191): warning C4113: 'iteration_result (__cdecl *)(workspace *,void *,compiler_language,obj)' est différent de 'obj_dict_iterator' dans les listes de paramètres
C:\Documents\msys2\home\vincent.torri\gitroot_64\muon_github\src\backend/ninja/rules.c(274): warning C4113: 'iteration_result (__cdecl *)(workspace *,void *,compiler_language,uint32_t)' est différent de 'obj_dict_iterator' dans les listes de paramètres
C:\Documents\msys2\home\vincent.torri\gitroot_64\muon_github\src\backend/ninja/rules.c(393): warning C4113: 'iteration_result (__cdecl *)(workspace *,void *,compiler_language,obj)' est différent de 'obj_dict_iterator' dans les listes de paramètres
C:\Documents\msys2\home\vincent.torri\gitroot_64\muon_github\src\backend/ninja/rules.c(397): warning C4113: 'iteration_result (__cdecl *)(workspace *,void *,compiler_language,obj)' est différent de 'obj_dict_iterator' dans les listes de paramètres
C:\Documents\msys2\home\vincent.torri\gitroot_64\muon_github\src\lang/lexer.c(245): warning C4133: 'fonction' : types incompatibles - de 'token_type *' à 'uint32_t *'
C:\Documents\msys2\home\vincent.torri\gitroot_64\muon_github\src\lang/lexer.c(257): warning C4133: 'fonction' : types incompatibles - de 'token_type *' à 'uint32_t *'
C:\Documents\msys2\home\vincent.torri\gitroot_64\muon_github\src\machine_file.c(65): warning C4133: 'fonction' : types incompatibles - de 'machine_file_section *' à 'uint32_t *'
C:\Documents\msys2\home\vincent.torri\gitroot_64\muon_github\src\wrap.c(173): warning C4133: 'fonction' : types incompatibles - de 'wrap_type *' à 'uint32_t *'
C:\Program Files (x86)\Windows Kits\10\include\10.0.19041.0\ucrt\corecrt_io.h(509): warning C4142: 'lseek' : redéfinition bénigne du type

oups, analyze of course