Fix static stack semantics for libcalls; cleanup LTO.

Author: mysterymath

mos-platform/atari8/CMakeLists.txt

@@ -11,7 +11,6 @@ merge_libraries(atari8-crt0
   common-zero-bss
   common-exit-return
 )
-target_compile_options(atari8-crt0 PRIVATE -fno-lto)
 
 add_platform_library(atari8-c
   abort.c
@@ -22,5 +21,5 @@ add_platform_library(atari8-c
 target_include_directories(atari8-c SYSTEM BEFORE PUBLIC .)
 
 # abort is preemptively included if LTO is used, which pulls in _exit support
-# unneccessarily.
-set_property(SOURCE abort.c PROPERTY COMPILE_FLAGS -fno-lto)
+# unneccessarily. It can be called in an interrupt.
+set_property(SOURCE abort.c PROPERTY COMPILE_OPTIONS -fno-lto -fno-static-stack)

mos-platform/commodore/CMakeLists.txt

@@ -12,7 +12,6 @@ merge_libraries(commodore-crt0
   common-zero-bss
   common-exit-return
 )
-target_compile_options(commodore-crt0 PRIVATE -fno-lto)
 
 add_platform_library(commodore-c
   abort.c
@@ -22,6 +21,6 @@ add_platform_library(commodore-c
   kernal.S
 )
 # abort is preemptively included if LTO is used, which pulls in _exit support
-# unneccessarily.
-set_property(SOURCE abort.c PROPERTY COMPILE_OPTIONS -fno-lto)
+# unneccessarily. It can also be called in an interrupt.
+set_property(SOURCE abort.c PROPERTY COMPILE_OPTIONS -fno-lto -fno-static-stack)
 target_include_directories(commodore-c SYSTEM BEFORE PUBLIC .)

mos-platform/common/c/stdio.c

@@ -5,7 +5,9 @@ int putchar(int c) {
   return c;
 }
 
-int puts(const char *s) {
+// This can be called by abort(), which can be called in a signal and is not
+// included in LTO.
+__attribute((interrupt, no_isr)) int puts(const char *s) {
   for (; *s; ++s)
     __putchar(*s);
   __putchar('\n');

mos-platform/common/crt/CMakeLists.txt

@@ -11,4 +11,5 @@ add_platform_library(common-crt
   shift.cc
 )
 # Don't pull in stack pointer init unnecessarily.
-set_property(SOURCE divmod-large.cc PROPERTY COMPILE_OPTIONS -fno-lto)
+# This can be called in an interrupt.
+set_property(SOURCE divmod-large.cc PROPERTY COMPILE_OPTIONS -fno-lto -fno-static-stack)

mos-platform/osi-c1p/CMakeLists.txt

@@ -13,7 +13,6 @@ merge_libraries(osi-c1p-crt0
   common-zero-bss
   common-exit-loop
 )
-target_compile_options(osi-c1p-crt0 PRIVATE -fno-lto)
 
 add_platform_library(osi-c1p-c
   abort.c

mos-platform/sim/CMakeLists.txt

@@ -13,7 +13,6 @@ merge_libraries(sim-crt0
   common-exit-custom
   common-init-stack
 )
-target_compile_options(sim-crt0 PRIVATE -fno-lto)
 
 add_platform_library(sim-c
   assert.c