diff --git a/src/libponyc/codegen/nix.h b/src/libponyc/codegen/nix.h new file mode 100644 index 000000000000..b1368f222b91 --- /dev/null +++ b/src/libponyc/codegen/nix.h @@ -0,0 +1,47 @@ +#ifndef CODEGEN_NIX_H +#define CODEGEN_NIX_H + +#include "../ast/stringtab.h" + +#include + +/* + Nix/NixOS toolchain path discovery for the embedded LLD linker (genexe.cc) + and the embedded clang C-shim compiler (gencshim.cc). + + On Nix there is no FHS layout: no /usr/lib, no /lib64/ld-linux-*.so, no + /usr/include. The libc, libgcc, C++ runtime, buildInputs and user FFI + libraries all live under /nix/store, and their locations reach the compiler + through baked-in defaults (the -DPONY_NIX_* macros set at configure time) and + the cc-wrapper environment (NIX_LDFLAGS, NIX_CFLAGS_COMPILE, + $NIX_CC/nix-support/*). These helpers gather those paths so the embedded + tools link and compile without a wrapper script. + + On a plain non-Nix build every source is empty, so the collectors append + nothing and behaviour is unchanged. +*/ + +// Library search directories for the linker, in priority order: +// PONY_NIX_LINK_LIBDIRS (baked default), PONY_LINK_LIBDIRS, NIX_LDFLAGS, +// NIX_LDFLAGS_BEFORE, $NIX_CC/nix-support {orig-libc, cc-ldflags}. +// Directories are interned into `strtab` and appended to `dirs`; existing +// entries are left in place. +void nix_collect_link_libdirs(strtable_t* strtab, + std::vector& dirs); + +// Header search directories for the C-shim compiler, in priority order: +// PONY_NIX_INCLUDE_DIRS (baked default), PONY_INCLUDE_DIRS, +// NIX_CFLAGS_COMPILE, $NIX_CC/nix-support/libc-cflags. +// Directories are interned into `strtab` and appended to `dirs`; existing +// entries are left in place. +void nix_collect_include_dirs(strtable_t* strtab, + std::vector& dirs); + +// The ELF dynamic linker (interpreter) path, in priority order: +// PONY_DYNAMIC_LINKER, PONY_NIX_DYNAMIC_LINKER (baked default), +// $NIX_CC/nix-support/dynamic-linker. +// Returns "" (never NULL) when none is configured, so the caller can test the +// first byte and fall back to the built-in FHS search. +const char* nix_dynamic_linker(strtable_t* strtab); + +#endif diff --git a/src/libponyc/codegen/nix.cc b/src/libponyc/codegen/nix.cc new file mode 100644 index 000000000000..eddfd7833103 --- /dev/null +++ b/src/libponyc/codegen/nix.cc @@ -0,0 +1,220 @@ +#include "nix.h" + +#include "../ast/stringtab.h" + +#include +#include +#include +#include + +#ifndef PATH_MAX +# define PATH_MAX 4096 +#endif + +/* + The baked-in Nix defaults. package.nix passes each of these through + -DPONY_NIX_*="..." in NIX_CFLAGS_COMPILE at configure time, capturing the + cc-wrapper's libc/libgcc/pcre2/openssl lib dirs, the ELF interpreter and the + libc/gcc include dirs. They are empty strings on a plain source build, which + disables every Nix-specific path below. +*/ +#ifndef PONY_NIX_LINK_LIBDIRS +# define PONY_NIX_LINK_LIBDIRS "" +#endif +#ifndef PONY_NIX_DYNAMIC_LINKER +# define PONY_NIX_DYNAMIC_LINKER "" +#endif +#ifndef PONY_NIX_INCLUDE_DIRS +# define PONY_NIX_INCLUDE_DIRS "" +#endif + +/* + Split `s` into tokens on any delimiter character in `delims`, interning each + token into `strtab` and appending it to `toks`. A token that would overflow + the buffer is dropped whole rather than truncated to a wrong path. +*/ +static void tokenize(const char* s, const char* delims, strtable_t* strtab, + std::vector& toks) +{ + if(s == NULL || s[0] == '\0') + return; + + char buf[PATH_MAX]; + size_t len = 0; + bool overflow = false; + for(const char* p = s; ; p++) + { + // The '\0' test is first so strchr is never asked to match the terminator. + if(*p == '\0' || strchr(delims, *p) != NULL) + { + if(len > 0 && !overflow) + { + buf[len] = '\0'; + toks.push_back(stringtab(strtab, buf)); + } + len = 0; + overflow = false; + if(*p == '\0') + break; + } + else if(len < sizeof(buf) - 1) + { + buf[len++] = *p; + } + else + { + overflow = true; + } + } +} + +/* + Interpret a whitespace-separated linker-flag string (NIX_LDFLAGS, + $NIX_CC/nix-support/cc-ldflags) for library directories, handling the joined + -L, the separated -L , and -rpath / -rpath-link forms. + + This is how /nix/store libraries (and directories injected by pkg-config) are + found where other distros would look in /usr/lib and the like. +*/ +static void append_ldflags_dirs(const char* flags, strtable_t* strtab, + std::vector& dirs) +{ + std::vector toks; + tokenize(flags, " \t\n\r", strtab, toks); + + for(size_t i = 0; i < toks.size(); i++) + { + const char* t = toks[i]; + if(strncmp(t, "-L", 2) == 0) + { + if(t[2] != '\0') + dirs.push_back(stringtab(strtab, t + 2)); + else if(i + 1 < toks.size()) + dirs.push_back(toks[++i]); + } + else if(strcmp(t, "-rpath") == 0 || strcmp(t, "-rpath-link") == 0) + { + if(i + 1 < toks.size()) + dirs.push_back(toks[++i]); + } + } +} + +/* + Interpret a whitespace-separated compiler-flag string (NIX_CFLAGS_COMPILE, + $NIX_CC/nix-support/libc-cflags) for header search directories, handling the + joined -I, the separated -I , and -isystem / -idirafter / -iquote + forms. This covers directories injected by pkg-config too. +*/ +static void append_cflags_include_dirs(const char* flags, strtable_t* strtab, + std::vector& dirs) +{ + std::vector toks; + tokenize(flags, " \t\n\r", strtab, toks); + + for(size_t i = 0; i < toks.size(); i++) + { + const char* t = toks[i]; + if(strcmp(t, "-isystem") == 0 || strcmp(t, "-idirafter") == 0 || + strcmp(t, "-iquote") == 0 || strcmp(t, "-I") == 0) + { + if(i + 1 < toks.size()) + dirs.push_back(toks[++i]); + } + else if(strncmp(t, "-I", 2) == 0 && t[2] != '\0') + { + dirs.push_back(stringtab(strtab, t + 2)); + } + } +} + +/* + Read $NIX_CC/nix-support/ into `out`, trimming trailing whitespace. + Returns false if the file is missing, empty, or so long it would be + truncated -- acting on a partial flag string would be worse than ignoring it. +*/ +static bool read_nix_support_file(const char* nix_cc, const char* name, + char* out, size_t outsz) +{ + char path[PATH_MAX]; + snprintf(path, sizeof(path), "%s/nix-support/%s", nix_cc, name); + + FILE* f = fopen(path, "rb"); + if(f == NULL) + return false; + + size_t n = fread(out, 1, outsz - 1, f); + // If the buffer filled and the file still has bytes, the content was + // truncated; reject it rather than acting on a partial flag string. + bool truncated = (n == outsz - 1) && (fgetc(f) != EOF); + fclose(f); + if(truncated) + return false; + out[n] = '\0'; + + while(n > 0 && (out[n - 1] == '\n' || out[n - 1] == '\r' || + out[n - 1] == ' ' || out[n - 1] == '\t')) + out[--n] = '\0'; + + return n > 0; +} + +void nix_collect_link_libdirs(strtable_t* strtab, + std::vector& dirs) +{ + tokenize(PONY_NIX_LINK_LIBDIRS, ":", strtab, dirs); + tokenize(getenv("PONY_LINK_LIBDIRS"), ":", strtab, dirs); + append_ldflags_dirs(getenv("NIX_LDFLAGS"), strtab, dirs); + append_ldflags_dirs(getenv("NIX_LDFLAGS_BEFORE"), strtab, dirs); + + const char* nix_cc = getenv("NIX_CC"); + if(nix_cc == NULL || nix_cc[0] == '\0') + return; + + char buf[PATH_MAX]; + if(read_nix_support_file(nix_cc, "orig-libc", buf, sizeof(buf))) + { + char libdir[PATH_MAX]; + snprintf(libdir, sizeof(libdir), "%s/lib", buf); + dirs.push_back(stringtab(strtab, libdir)); + } + + if(read_nix_support_file(nix_cc, "cc-ldflags", buf, sizeof(buf))) + append_ldflags_dirs(buf, strtab, dirs); +} + +void nix_collect_include_dirs(strtable_t* strtab, + std::vector& dirs) +{ + tokenize(PONY_NIX_INCLUDE_DIRS, ":", strtab, dirs); + tokenize(getenv("PONY_INCLUDE_DIRS"), ":", strtab, dirs); + append_cflags_include_dirs(getenv("NIX_CFLAGS_COMPILE"), strtab, dirs); + + const char* nix_cc = getenv("NIX_CC"); + if(nix_cc != NULL && nix_cc[0] != '\0') + { + char cflags[PATH_MAX * 4]; + if(read_nix_support_file(nix_cc, "libc-cflags", cflags, sizeof(cflags))) + append_cflags_include_dirs(cflags, strtab, dirs); + } +} + +const char* nix_dynamic_linker(strtable_t* strtab) +{ + const char* dl = getenv("PONY_DYNAMIC_LINKER"); + if(dl != NULL && dl[0] != '\0') + return stringtab(strtab, dl); + + if(PONY_NIX_DYNAMIC_LINKER[0] != '\0') + return stringtab(strtab, PONY_NIX_DYNAMIC_LINKER); + + const char* nix_cc = getenv("NIX_CC"); + if(nix_cc != NULL && nix_cc[0] != '\0') + { + char buf[PATH_MAX]; + if(read_nix_support_file(nix_cc, "dynamic-linker", buf, sizeof(buf))) + return stringtab(strtab, buf); + } + + return ""; +} diff --git a/src/libponyc/CMakeLists.txt b/src/libponyc/CMakeLists.txt index f4e3e42ef48f..4a477e306ac1 100644 --- a/src/libponyc/CMakeLists.txt +++ b/src/libponyc/CMakeLists.txt @@ -27,6 +27,7 @@ add_library(libponyc STATIC codegen/gendesc.c codegen/gencshim.cc codegen/genexe.cc + codegen/nix.cc codegen/genexpr.c codegen/genfun.c codegen/genheader.c