RISC-V: Throw compilation error for unknown extensions

This tiny patch add a check for extension starts with 'z' or 's' in `-march`
option. Currently this unknown extension will be passed to the assembler, which
then reports an error. With this patch, the compiler will throw a compilation
error if the extension starts with 'z' or 's' is not a standard sub-extension or
supervisor extension. Along with two extra changes. The first is to reduce
repeated errors, which are currently reported at least twice. The second is to
report as many mistakes as possible.

e.g.:

Run `riscv64-unknown-elf-gcc -march=rv64gvcw_zvl128_s123_x123 -mabi=lp64d a.c`
will throw these error:

riscv64-unknown-elf-gcc: error: '-march=rv64gcv_zvl128_s123': ISA string is not in canonical order. 'c'
riscv64-unknown-elf-gcc: error: '-march=rv64gcv_zvl128_s123': extension 'w' is unsupported standard single letter extension
riscv64-unknown-elf-gcc: error: '-march=rv64gcv_zvl128_s123': extension 'zvl128' start with `z` but is unsupported standard extension
riscv64-unknown-elf-gcc: error: '-march=rv64gcv_zvl128_s123': extension 's123' start with `s` but is unsupported standard supervisor extension
riscv64-unknown-elf-gcc: error: '-march=rv64gcv_zvl128_s123': extension 'x123' start with `x` but is unsupported non-standard extension

gcc/ChangeLog:

	* common/config/riscv/riscv-common.cc (riscv_supported_std_ext): Init.
	(standard_extensions_p): Add check.
	(riscv_subset_list::add): Just return NULL if it failed before.
	(riscv_subset_list::parse_std_ext): Continue parse when find a error
	(riscv_subset_list::parse): Just return NULL if it failed before.
	* config/riscv/riscv-subset.h (class riscv_subset_list): Add field.

gcc/testsuite/ChangeLog:

	* gcc.target/riscv/arch-2.c: Update -march.
	* gcc.target/riscv/arch-3.c: Ditto.
	* gcc.target/riscv/arch-5.c: Ditto.
	* gcc.target/riscv/arch-8.c: Ditto.
	* gcc.target/riscv/attribute-10.c: Ditto.
	* gcc.target/riscv/attribute-18.c: Ditto.
	* gcc.target/riscv/attribute-19.c: Ditto.
	* gcc.target/riscv/attribute-8.c: Ditto.
	* gcc.target/riscv/attribute-9.c: Ditto.
	* gcc.target/riscv/pr102957.c: Ditto.
	* gcc.target/riscv/arch-22.cc: New test.

14 files changed, 98 insertions, 25 deletions

diff --git a/gcc/common/config/riscv/riscv-common.cc b/gcc/common/config/riscv/riscv-common.cc
index 19075c0..884d81c 100644
--- a/gcc/common/config/riscv/riscv-common.cc
+++ b/gcc/common/config/riscv/riscv-common.cc
@@ -313,6 +313,8 @@ static const char *riscv_tunes[] =
 
 static const char *riscv_supported_std_ext (void);
 
+bool riscv_subset_list::parse_failed = false;
+
 static riscv_subset_list *current_subset_list = NULL;
 
 const riscv_subset_list *riscv_current_subset_list ()
@@ -520,6 +522,18 @@ subset_cmp (const std::string &a, const std::string &b)
     }
 }
 
+/* Return true if EXT is a standard extension.  */
+
+static bool
+standard_extensions_p (const char *ext)
+{
+  const riscv_ext_version *ext_ver;
+  for (ext_ver = &riscv_ext_version_table[0]; ext_ver->name != NULL; ++ext_ver)
+    if (strcmp (ext, ext_ver->name) == 0)
+      return true;
+  return false;
+}
+
 /* Add new subset to list.  */
 
 void
@@ -548,6 +562,38 @@ riscv_subset_list::add (const char *subset, int major_version,
 
       return;
     }
+  else if (strlen (subset) == 1 && !standard_extensions_p (subset))
+    {
+      error_at (m_loc,
+		"%<-march=%s%>: extension %qs is unsupported standard single "
+		"letter extension",
+		m_arch, subset);
+      return;
+    }
+  else if (subset[0] == 'z' && !standard_extensions_p (subset))
+    {
+      error_at (m_loc,
+		"%<-march=%s%>: extension %qs starts with `z` but is "
+		"unsupported standard extension",
+		m_arch, subset);
+      return;
+    }
+  else if (subset[0] == 's' && !standard_extensions_p (subset))
+    {
+      error_at (m_loc,
+		"%<-march=%s%>: extension %qs starts with `s` but is "
+		"unsupported standard supervisor extension",
+		m_arch, subset);
+      return;
+    }
+  else if (subset[0] == 'x' && !standard_extensions_p (subset))
+    {
+      error_at (m_loc,
+		"%<-march=%s%>: extension %qs starts with `x` but is "
+		"unsupported non-standard extension",
+		m_arch, subset);
+      return;
+    }
 
   riscv_subset_t *s = new riscv_subset_t ();
   riscv_subset_t *itr;
@@ -921,22 +967,16 @@ riscv_subset_list::parse_std_ext (const char *p)
       while (*std_exts && std_ext != *std_exts)
 	std_exts++;
 
-      if (std_ext != *std_exts)
-	{
-	  if (strchr (all_std_exts, std_ext) == NULL)
-	    error_at (m_loc, "%<-march=%s%>: unsupported ISA subset %<%c%>",
-		      m_arch, *p);
-	  else
-	    error_at (m_loc,
-		      "%<-march=%s%>: ISA string is not in canonical order. "
-		      "%<%c%>", m_arch, *p);
-	  return NULL;
-	}
+      subset[0] = std_ext;
+      if (std_ext != *std_exts && standard_extensions_p (subset))
+	error_at (m_loc,
+		  "%<-march=%s%>: ISA string is not in canonical order. "
+		  "%<%c%>",
+		  m_arch, *p);
 
       std_exts++;
 
       p++;
-      subset[0] = std_ext;
 
       p = parsing_subset_version (subset, p, &major_version, &minor_version,
 				  /* std_ext_p= */ true, &explicit_version_p);
@@ -1165,6 +1205,9 @@ riscv_subset_list::parse_multiletter_ext (const char *p,
 riscv_subset_list *
 riscv_subset_list::parse (const char *arch, location_t loc)
 {
+  if (riscv_subset_list::parse_failed)
+    return NULL;
+
   riscv_subset_list *subset_list = new riscv_subset_list (arch, loc);
   riscv_subset_t *itr;
   const char *p = arch;
@@ -1234,6 +1277,7 @@ riscv_subset_list::parse (const char *arch, location_t loc)
 
 fail:
   delete subset_list;
+  riscv_subset_list::parse_failed = true;
   return NULL;
 }
 
diff --git a/gcc/config/riscv/riscv-subset.h b/gcc/config/riscv/riscv-subset.h
index 84a7a82..dca0728 100644
--- a/gcc/config/riscv/riscv-subset.h
+++ b/gcc/config/riscv/riscv-subset.h
@@ -41,6 +41,11 @@ struct riscv_subset_t
 /* Subset list.  */
 class riscv_subset_list
 {
+public:
+  /* Because the parse method is called in several places, to prevent repeated
+     errors, use this flag to prevent it from repeating parse. */
+  static bool parse_failed;
+
 private:
   /* Original arch string.  */
   const char *m_arch;
diff --git a/gcc/testsuite/gcc.target/riscv/arch-2.c b/gcc/testsuite/gcc.target/riscv/arch-2.c
index 8908b4b..e308bf7 100644
--- a/gcc/testsuite/gcc.target/riscv/arch-2.c
+++ b/gcc/testsuite/gcc.target/riscv/arch-2.c
@@ -1,5 +1,5 @@
 /* { dg-do compile } */
-/* { dg-options "-march=rv32ixabc_xfoo -mabi=ilp32" } */
+/* { dg-options "-march=rv32ixtheadba_xtheadsync -mabi=ilp32" } */
 int foo()
 {
 }
diff --git a/gcc/testsuite/gcc.target/riscv/arch-22.cc b/gcc/testsuite/gcc.target/riscv/arch-22.cc
new file mode 100644
index 0000000..1cb5588
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/arch-22.cc
@@ -0,0 +1,11 @@
+/* { dg-do compile } */
+/* { dg-options "-march=rv64gvcw_zvl128_s123_x123 -mabi=lp64d" } */
+int foo()
+{
+}
+
+/* { dg-error "ISA string is not in canonical order. 'c'" "" { target *-*-* } 0 } */
+/* { dg-error "extension 'w' is unsupported standard single letter extension" "" { target *-*-* } 0 } */
+/* { dg-error "extension 'zvl' starts with `z` but is unsupported standard extension" "" { target *-*-* } 0 } */
+/* { dg-error "extension 's123' starts with `s` but is unsupported standard supervisor extension" "" { target *-*-* } 0 } */
+/* { dg-error "extension 'x123' starts with `x` but is unsupported non-standard extension" "" { target *-*-* } 0 } */
diff --git a/gcc/testsuite/gcc.target/riscv/arch-23.c b/gcc/testsuite/gcc.target/riscv/arch-23.c
new file mode 100644
index 0000000..1cb5588
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/arch-23.c
@@ -0,0 +1,11 @@
+/* { dg-do compile } */
+/* { dg-options "-march=rv64gvcw_zvl128_s123_x123 -mabi=lp64d" } */
+int foo()
+{
+}
+
+/* { dg-error "ISA string is not in canonical order. 'c'" "" { target *-*-* } 0 } */
+/* { dg-error "extension 'w' is unsupported standard single letter extension" "" { target *-*-* } 0 } */
+/* { dg-error "extension 'zvl' starts with `z` but is unsupported standard extension" "" { target *-*-* } 0 } */
+/* { dg-error "extension 's123' starts with `s` but is unsupported standard supervisor extension" "" { target *-*-* } 0 } */
+/* { dg-error "extension 'x123' starts with `x` but is unsupported non-standard extension" "" { target *-*-* } 0 } */
diff --git a/gcc/testsuite/gcc.target/riscv/arch-3.c b/gcc/testsuite/gcc.target/riscv/arch-3.c
index 7aa945e..ac73374 100644
--- a/gcc/testsuite/gcc.target/riscv/arch-3.c
+++ b/gcc/testsuite/gcc.target/riscv/arch-3.c
@@ -1,5 +1,5 @@
 /* { dg-do compile } */
-/* { dg-options "-march=rv32isabc_xbar -mabi=ilp32" } */
+/* { dg-options "-march=rv32isvinval_xtheadba -mabi=ilp32" } */
 int foo()
 {
 }
diff --git a/gcc/testsuite/gcc.target/riscv/arch-5.c b/gcc/testsuite/gcc.target/riscv/arch-5.c
index 8258552..b8b6cd0 100644
--- a/gcc/testsuite/gcc.target/riscv/arch-5.c
+++ b/gcc/testsuite/gcc.target/riscv/arch-5.c
@@ -1,5 +1,5 @@
 /* { dg-do compile } */
-/* { dg-options "-march=rv32i_zfoo_sabc_xbar -mabi=ilp32" } */
+/* { dg-options "-march=rv32i_zmmul_svnapot_xtheadba -mabi=ilp32" } */
 int foo()
 {
 }
diff --git a/gcc/testsuite/gcc.target/riscv/arch-8.c b/gcc/testsuite/gcc.target/riscv/arch-8.c
index 1b9e51b..ef557ae 100644
--- a/gcc/testsuite/gcc.target/riscv/arch-8.c
+++ b/gcc/testsuite/gcc.target/riscv/arch-8.c
@@ -1,5 +1,5 @@
 /* { dg-do compile } */
-/* { dg-options "-march=rv32id_zicsr_zifence -mabi=ilp32" } */
+/* { dg-options "-march=rv32id_zicsr_zifencei -mabi=ilp32" } */
 int foo()
 {
 }
diff --git a/gcc/testsuite/gcc.target/riscv/attribute-10.c b/gcc/testsuite/gcc.target/riscv/attribute-10.c
index 1e121a1..868adef 100644
--- a/gcc/testsuite/gcc.target/riscv/attribute-10.c
+++ b/gcc/testsuite/gcc.target/riscv/attribute-10.c
@@ -1,5 +1,5 @@
 /* { dg-do compile } */
-/* { dg-options "-march=rv32i -march=rv32im_sx_unexpectedstring -mabi=ilp32" } */
+/* { dg-options "-march=rv32i -march=rv32im_svnapot_unexpectedstring -mabi=ilp32" } */
 int foo()
 {
 }
diff --git a/gcc/testsuite/gcc.target/riscv/attribute-18.c b/gcc/testsuite/gcc.target/riscv/attribute-18.c
index 492360c..fddbf15 100644
--- a/gcc/testsuite/gcc.target/riscv/attribute-18.c
+++ b/gcc/testsuite/gcc.target/riscv/attribute-18.c
@@ -1,4 +1,4 @@
 /* { dg-do compile } */
-/* { dg-options "-mriscv-attribute -march=rv64imafdcp -mabi=lp64d -misa-spec=2.2" } */
+/* { dg-options "-mriscv-attribute -march=rv64imafdc -mabi=lp64d -misa-spec=2.2" } */
 int foo() {}
-/* { dg-final { scan-assembler ".attribute arch, \"rv64i2p0_m2p0_a2p0_f2p0_d2p0_c2p0_p\"" } } */
+/* { dg-final { scan-assembler ".attribute arch, \"rv64i2p0_m2p0_a2p0_f2p0_d2p0_c2p0\"" } } */
diff --git a/gcc/testsuite/gcc.target/riscv/attribute-19.c b/gcc/testsuite/gcc.target/riscv/attribute-19.c
index 562f808..8150452 100644
--- a/gcc/testsuite/gcc.target/riscv/attribute-19.c
+++ b/gcc/testsuite/gcc.target/riscv/attribute-19.c
@@ -1,4 +1,4 @@
 /* { dg-do compile } */
-/* { dg-options "-mriscv-attribute -march=rv64imp0p9 -mabi=lp64 -misa-spec=2.2" } */
+/* { dg-options "-mriscv-attribute -march=rv64im -mabi=lp64 -misa-spec=2.2" } */
 int foo() {}
-/* { dg-final { scan-assembler ".attribute arch, \"rv64i2p0_m2p0_p0p9\"" } } */
+/* { dg-final { scan-assembler ".attribute arch, \"rv64i2p0_m2p0\"" } } */
diff --git a/gcc/testsuite/gcc.target/riscv/attribute-8.c b/gcc/testsuite/gcc.target/riscv/attribute-8.c
index 4c91b9e..2065f74 100644
--- a/gcc/testsuite/gcc.target/riscv/attribute-8.c
+++ b/gcc/testsuite/gcc.target/riscv/attribute-8.c
@@ -1,6 +1,6 @@
 /* { dg-do compile } */
-/* { dg-options "-mriscv-attribute -march=rv32i2p0xabc_xv5 -mabi=ilp32" } */
+/* { dg-options "-mriscv-attribute -march=rv32i2p0xtheadba_xtheadbb -mabi=ilp32" } */
 int foo()
 {
 }
-/* { dg-final { scan-assembler ".attribute arch, \"rv32i2p0_xabc_xv5p0\"" } } */
+/* { dg-final { scan-assembler ".attribute arch, \"rv32i2p0_xtheadba1p0_xtheadbb1p0\"" } } */
diff --git a/gcc/testsuite/gcc.target/riscv/attribute-9.c b/gcc/testsuite/gcc.target/riscv/attribute-9.c
index 7e3741a..3c31848 100644
--- a/gcc/testsuite/gcc.target/riscv/attribute-9.c
+++ b/gcc/testsuite/gcc.target/riscv/attribute-9.c
@@ -1,6 +1,6 @@
 /* { dg-do compile } */
-/* { dg-options "-mriscv-attribute -march=rv32i2p0sabc_xbar -mabi=ilp32e" } */
+/* { dg-options "-mriscv-attribute -march=rv32i2p0svinval_xtheadba -mabi=ilp32e" } */
 int foo()
 {
 }
-/* { dg-final { scan-assembler ".attribute arch, \"rv32i2p0_sabc_xbar\"" } } */
+/* { dg-final { scan-assembler ".attribute arch, \"rv32i2p0_svinval1p0_xtheadba1p0\"" } } */
diff --git a/gcc/testsuite/gcc.target/riscv/pr102957.c b/gcc/testsuite/gcc.target/riscv/pr102957.c
index 9747dde..322d49c 100644
--- a/gcc/testsuite/gcc.target/riscv/pr102957.c
+++ b/gcc/testsuite/gcc.target/riscv/pr102957.c
@@ -3,3 +3,5 @@
 int foo()
 {
 }
+
+/* { dg-error "extension 'zb' starts with `z` but is unsupported standard extension" "" { target *-*-* } 0 } */