https://gcc.gnu.org/g:b71fd2afa8316c3a247754963d801c4b7ca0050d
commit b71fd2afa8316c3a247754963d801c4b7ca0050d
Author: Pierre-Emmanuel Patry <pierre-emmanuel.pa...@embecosm.com>
Date: Wed Oct 4 12:01:44 2023 +0200
Change proc macro entrypoint
Change proc macro entrypoint from a fixed constant declaration to a
proper generation from the stable crate id. Although the stable crate id
is not in use yet, the mechanism to handle it is.
gcc/rust/ChangeLog:
* expand/rust-proc-macro.cc
(CustomDeriveProcMacro::CustomDeriveProcMacro):
Remove constant string declaration.
(load_macros_array): Add call to the new generation function.
(generate_proc_macro_decls_symbol): Add a new function to generate
the
entrypoint symbol name from the stable crate id.
(PROC_MACRO_DECLS_FMT_ARGS):
New macro to keep formats arguments in sync between each call.
* expand/rust-proc-macro.h (generate_proc_macro_decls_symbol): Add
function prototype.
Signed-off-by: Pierre-Emmanuel Patry <pierre-emmanuel.pa...@embecosm.com>
Diff:
---
gcc/rust/expand/rust-proc-macro.cc | 21 ++++++++++++++++++---
gcc/rust/expand/rust-proc-macro.h | 3 +++
2 files changed, 21 insertions(+), 3 deletions(-)
diff --git a/gcc/rust/expand/rust-proc-macro.cc
b/gcc/rust/expand/rust-proc-macro.cc
index 2fdfcb20b19b..3865b87b75b2 100644
--- a/gcc/rust/expand/rust-proc-macro.cc
+++ b/gcc/rust/expand/rust-proc-macro.cc
@@ -45,8 +45,6 @@ CustomDeriveProcMacro::CustomDeriveProcMacro
(ProcMacro::CustomDerive macro)
macro (macro.macro)
{}
-const std::string PROC_MACRO_DECL_PREFIX = "__gccrs_proc_macro_decls_";
-
namespace {
ProcMacro::Literal
@@ -150,8 +148,10 @@ load_macros_array (std::string path)
// FIXME: Add CrateStableId handling, right now all versions may be loaded,
// even incompatible ones.
+ auto symbol_name = generate_proc_macro_decls_symbol (0 /* FIXME */);
+
return *reinterpret_cast<const ProcMacro::ProcmacroArray **> (
- dlsym (handle, PROC_MACRO_DECL_PREFIX.c_str ()));
+ dlsym (handle, symbol_name.c_str ()));
#else
rust_sorry_at (UNDEF_LOCATION,
"Procedural macros are not yet supported on windows host");
@@ -175,4 +175,19 @@ load_macros (std::string path)
array->macros + array->length);
}
+std::string
+generate_proc_macro_decls_symbol (std::uint32_t stable_crate_id)
+{
+#define PROC_MACRO_DECLS_FMT_ARGS
\
+ "__gccrs_proc_macro_decls_%08x__", stable_crate_id
+ // Size could be hardcoded since we know the input size but I elected to
+ // calculate it everytime so we won't have any desync between code and data.
+ int size = std::snprintf (nullptr, 0, PROC_MACRO_DECLS_FMT_ARGS);
+ std::vector<char> buf (size + 1);
+ std::sprintf (buf.data (), PROC_MACRO_DECLS_FMT_ARGS);
+#undef PROC_MACRO_DECLS_FMT_ARGS
+
+ return std::string (buf.cbegin (), buf.cend ());
+}
+
} // namespace Rust
diff --git a/gcc/rust/expand/rust-proc-macro.h
b/gcc/rust/expand/rust-proc-macro.h
index d994ed9bf5e0..6ffaaf6c099f 100644
--- a/gcc/rust/expand/rust-proc-macro.h
+++ b/gcc/rust/expand/rust-proc-macro.h
@@ -85,6 +85,9 @@ public:
const std::vector<ProcMacro::Procmacro>
load_macros (std::string path);
+std::string
+generate_proc_macro_decls_symbol (std::uint32_t stable_crate_id);
+
} // namespace Rust
#endif /* ! RUST_PROC_MACRO_H */
