The attached patch adds error messages to be emitted when -mcode/data-region are used without the accompanying -mlarge option that enables the large memory model. Use of the upper/either regions without -mlarge can cause relocation overflows or stack mismanagement when incorrect call/return instructions are generated. In most cases, using the lower region without -mlarge has no effect, but it can affect code generation unexpectedly (msp430_do_not_relax_short_jumps), or add the ".lower" prefix to some section names.
Similarly, handling of the upper/lower/either attributes has been modified so the attributes will be ignored, and a warning will be emitted, when they are used without -mlarge. I have added the error messages to the driver so that uses of -mcode/data-region=none can be caught. The compiler cannot catch "none" since it is the default value that the option variable is initialized to. So only users calling cc1* directly will see the errors in msp430_option_override, but I also have updated them to be more similar to the new errors emitted by the driver. Successfully regtested on trunk for msp430-elf. Ok for trunk?
>From 0c37dc30d67229392ae8f834e462dd6336f7ccfc Mon Sep 17 00:00:00 2001 From: Jozef Lawrynowicz <joze...@mittosystems.com> Date: Mon, 22 Jul 2019 21:37:45 +0100 Subject: [PATCH] MSP430: Disallow mcode/data-region unless the large memory model is in use gcc/ChangeLog: 2019-07-23 Jozef Lawrynowicz <joze...@mittosystems.com> * config/msp430/msp430.h (DRIVER_SELF_SPECS): Define and emit errors when -m{code,data}-region are used without -mlarge. * config/msp430/msp430.c (msp430_option_override): Error when a non-default code or data region is used without -mlarge. (msp430_section_attr): Emit a warning and do not add upper/lower/either attributes when they are used without -mlarge. gcc/testsuite/ChangeLog: 2019-07-23 Jozef Lawrynowicz <joze...@mittosystems.com> * gcc.target/msp430/pr78818-data-region.c: Add -mlarge to dg-options. * gcc.target/msp430/region-misuse-code.c: New test. * gcc.target/msp430/region-misuse-data.c: Likewise. * gcc.target/msp430/region-misuse-code-data.c: Likewise. * gcc.target/msp430/region-attribute-misuse.c: Likewise. --- gcc/config/msp430/msp430.c | 35 ++++++++++++++++--- gcc/config/msp430/msp430.h | 8 +++++ .../gcc.target/msp430/pr78818-data-region.c | 3 +- .../msp430/region-attribute-misuse.c | 16 +++++++++ .../msp430/region-misuse-code-data.c | 4 +++ .../gcc.target/msp430/region-misuse-code.c | 4 +++ .../gcc.target/msp430/region-misuse-data.c | 4 +++ 7 files changed, 69 insertions(+), 5 deletions(-) create mode 100644 gcc/testsuite/gcc.target/msp430/region-attribute-misuse.c create mode 100644 gcc/testsuite/gcc.target/msp430/region-misuse-code-data.c create mode 100644 gcc/testsuite/gcc.target/msp430/region-misuse-code.c create mode 100644 gcc/testsuite/gcc.target/msp430/region-misuse-data.c diff --git a/gcc/config/msp430/msp430.c b/gcc/config/msp430/msp430.c index 265c2f642d8..c7b774e71a6 100644 --- a/gcc/config/msp430/msp430.c +++ b/gcc/config/msp430/msp430.c @@ -875,10 +875,26 @@ msp430_option_override (void) if (TARGET_LARGE && !msp430x) error ("%<-mlarge%> requires a 430X-compatible %<-mmcu=%>"); - if (msp430_code_region == MSP430_REGION_UPPER && ! msp430x) - error ("%<-mcode-region=upper%> requires 430X-compatible cpu"); - if (msp430_data_region == MSP430_REGION_UPPER && ! msp430x) - error ("%<-mdata-region=upper%> requires 430X-compatible cpu"); + if (!TARGET_LARGE && msp430_code_region == MSP430_REGION_EITHER) + error ("%<-mcode-region=either%> requires the large memory model " + "(%<-mlarge%>)"); + else if (!TARGET_LARGE && msp430_code_region == MSP430_REGION_UPPER) + error ("%<-mcode-region=upper%> requires the large memory model " + "(%<-mlarge%>)"); + else if (!TARGET_LARGE && msp430_code_region == MSP430_REGION_LOWER) + error ("%<-mcode-region=lower%> requires the large memory model " + "(%<-mlarge%>)"); + + if (!TARGET_LARGE && msp430_data_region == MSP430_REGION_EITHER) + error ("%<-mdata-region=either%> requires the large memory model " + "(%<-mlarge%>)"); + else if (!TARGET_LARGE && msp430_data_region == MSP430_REGION_UPPER) + error ("%<-mdata-region=upper%> requires the large memory model " + "(%<-mlarge%>)"); + else if (!TARGET_LARGE && msp430_data_region == MSP430_REGION_LOWER) + error ("%<-mdata-region=lower%> requires the large memory model " + "(%<-mlarge%>)"); + if (flag_exceptions || flag_non_call_exceptions || flag_unwind_tables || flag_asynchronous_unwind_tables) @@ -2038,6 +2054,17 @@ msp430_section_attr (tree * node, message = "already marked with 'upper' attribute"; } + /* It does not make sense to use upper/lower/either attributes without + -mlarge. + Without -mlarge, "lower" is the default and only region, so is redundant. + Without -mlarge, "upper" will (and "either" might) place code/data in the + upper region, which for data could result in relocation overflows, and for + code could result in stack mismanagement and incorrect call/return + instructions. */ + if (!TARGET_LARGE) + message = G_("%qE attribute ignored. large memory model (%<-mlarge%>) " + "is required"); + if (message) { warning (OPT_Wattributes, message, name); diff --git a/gcc/config/msp430/msp430.h b/gcc/config/msp430/msp430.h index 1288b1a263d..8d2354824a0 100644 --- a/gcc/config/msp430/msp430.h +++ b/gcc/config/msp430/msp430.h @@ -67,6 +67,14 @@ extern bool msp430x; #define LINK_SPEC "%{mrelax:--relax} %{mlarge:%{!r:%{!g:--gc-sections}}} " \ "%{mcode-region=*:--code-region=%*} %{mdata-region=*:--data-region=%*}" +#define DRIVER_SELF_SPECS \ + " %{!mlarge:%{mcode-region=*:%{mdata-region=*:%e-mcode-region and " \ + "-mdata-region require the large memory model (-mlarge)}}}" \ + " %{!mlarge:%{mcode-region=*:" \ + "%e-mcode-region requires the large memory model (-mlarge)}}" \ + " %{!mlarge:%{mdata-region=*:" \ + "%e-mdata-region requires the large memory model (-mlarge)}}" + extern const char * msp430_select_hwmult_lib (int, const char **); # define EXTRA_SPEC_FUNCTIONS \ { "msp430_hwmult_lib", msp430_select_hwmult_lib }, diff --git a/gcc/testsuite/gcc.target/msp430/pr78818-data-region.c b/gcc/testsuite/gcc.target/msp430/pr78818-data-region.c index 3244c0ad85d..5b0721e728a 100644 --- a/gcc/testsuite/gcc.target/msp430/pr78818-data-region.c +++ b/gcc/testsuite/gcc.target/msp430/pr78818-data-region.c @@ -1,5 +1,6 @@ /* { dg-do compile } */ -/* { dg-options "-mdata-region=either" } */ +/* { dg-skip-if "" { *-*-* } { "-mcpu=msp430" } { "" } } */ +/* { dg-options "-mlarge -mdata-region=either" } */ /* { dg-final { scan-assembler-not "\\.either\\.data" } } */ /* { dg-final { scan-assembler-not "\\.either\\.bss" } } */ diff --git a/gcc/testsuite/gcc.target/msp430/region-attribute-misuse.c b/gcc/testsuite/gcc.target/msp430/region-attribute-misuse.c new file mode 100644 index 00000000000..fe4617b917c --- /dev/null +++ b/gcc/testsuite/gcc.target/msp430/region-attribute-misuse.c @@ -0,0 +1,16 @@ +/* { dg-do compile } */ +/* { dg-skip-if "" { *-*-* } { "-mcpu=msp430" "-mlarge" "-mcode-region=*" "-mdata-region=*" } { "" } } */ +/* { dg-final { scan-assembler-not ".section.*bss" } } */ +/* { dg-final { scan-assembler ".section.*upper.data" } } */ +/* { dg-final { scan-assembler ".section.*lower.data" } } */ +/* { dg-final { scan-assembler ".section.*either.data" } } */ + +int __attribute__((upper)) upper_bss; /* { dg-warning "'upper' attribute ignored. large memory model .'-mlarge'. is required" } */ +int __attribute__((lower)) lower_bss; /* { dg-warning "'lower' attribute ignored. large memory model .'-mlarge'. is required" } */ +int __attribute__((either)) either_bss; /* { dg-warning "'either' attribute ignored. large memory model .'-mlarge'. is required" } */ + +/* Verify that even without -mlarge, objects can still be placed in + upper/lower/either regions manually. */ +int __attribute__((section(".upper.data"))) upper_data = 1; +int __attribute__((section(".lower.data"))) lower_data = 2; +int __attribute__((section(".either.data"))) either_data = 3; diff --git a/gcc/testsuite/gcc.target/msp430/region-misuse-code-data.c b/gcc/testsuite/gcc.target/msp430/region-misuse-code-data.c new file mode 100644 index 00000000000..72a160d0bda --- /dev/null +++ b/gcc/testsuite/gcc.target/msp430/region-misuse-code-data.c @@ -0,0 +1,4 @@ +/* { dg-do compile } */ +/* { dg-skip-if "" { *-*-* } { "-mlarge" } { "" } } */ +/* { dg-options "-mcode-region=either -mdata-region=none" } */ +/* { dg-error "-mcode-region and -mdata-region require the large memory model .-mlarge." "" { target *-*-* } 0 } */ diff --git a/gcc/testsuite/gcc.target/msp430/region-misuse-code.c b/gcc/testsuite/gcc.target/msp430/region-misuse-code.c new file mode 100644 index 00000000000..6441b773d6e --- /dev/null +++ b/gcc/testsuite/gcc.target/msp430/region-misuse-code.c @@ -0,0 +1,4 @@ +/* { dg-do compile } */ +/* { dg-skip-if "" { *-*-* } { "-mlarge" "-mdata-region=*" } { "" } } */ +/* { dg-options "-mcode-region=lower" } */ +/* { dg-error "-mcode-region requires the large memory model .-mlarge." "" { target *-*-* } 0 } */ diff --git a/gcc/testsuite/gcc.target/msp430/region-misuse-data.c b/gcc/testsuite/gcc.target/msp430/region-misuse-data.c new file mode 100644 index 00000000000..07523b6042d --- /dev/null +++ b/gcc/testsuite/gcc.target/msp430/region-misuse-data.c @@ -0,0 +1,4 @@ +/* { dg-do compile } */ +/* { dg-skip-if "" { *-*-* } { "-mlarge" "-mdata-region=*" } { "" } } */ +/* { dg-options "-mdata-region=upper" } */ +/* { dg-error "-mdata-region requires the large memory model .-mlarge." "" { target *-*-* } 0 } */ -- 2.17.1